F-35A maximum G rating lower than 5?!

Unread postPosted: 18 Mar 2014, 05:03
by ryokenmk
http://www.flightglobal.com/news/articl ... al-381683/

Just read this. Somebody please tell me that's bull.

Re: F35A Maximum G rating lower than 5?!

Unread postPosted: 18 Mar 2014, 05:16
by mk82
Its definitely bullshit :D. These figures are useless if you do not know the specific circumstances (e.g. airspeed, altitude,aircraft weight etc) involved in obtaining these G "readings". The F35A is definitely a 9G capable aircraft.

Re: F35A Maximum G rating lower than 5?!

Unread postPosted: 18 Mar 2014, 05:42
by ryokenmk
mk82 wrote:Its definitely bullshit :D. These figures are useless if you do not know the specific circumstances (e.g. airspeed, altitude,aircraft weight etc) involved in obtaining these G "readings". The F35A is definitely a 9G capable aircraft.



I believe you, but I'd like some sources to use as ammunition if you don't mind :)

Re: F35A Maximum G rating lower than 5?!

Unread postPosted: 18 Mar 2014, 06:13
by exosphere
mk82 wrote:Its definitely bullshit :D. These figures are useless if you do not know the specific circumstances (e.g. airspeed, altitude,aircraft weight etc) involved in obtaining these G "readings". The F35A is definitely a 9G capable aircraft.


I believe they're talking about sustained gee maneuvering. The F-35A is a nine-gee capable aircraft, though -- it is nine-gee capable in an instantaneous turn. The C is limited to seven and a half gees, and the B is limited to seven gees, just like the Hornet and Harrier they are replacing.

Like you said, though, those limits are meaningless unless you know the exact parameters under which they are applicable. I believe smsgtmac has an excellent piece about that on his site (Elements of Power).

Although the F-35A/B/C instantaneous gee limits are identical to the aircraft they are replacing, the JSF has one major advantage -- the F-35 variants can pull their maximum gee loadings with combat loads. The F-16 might be able to pull nine gees at an airshow or with a light load, but I seriously doubt it could do so with two 2k bombs, two AMRAAMs, a Sniper pod, and a full tank of gas. I seriously doubt it could accelerate to more than mach 1.6 or fly at its absolute ceiling with that load either, which tackles two other complaints people have about the F-35A vs the plane it is replacing.

I think much of the argument that the F-35 is in maneuverable comes from a failure to understand the difference between an airshow loadout and a combat loadout. Without knowing the difference, people invariably make apples to oranges comparisons.

Regarding transonic acceleration -- I might be wrong, but I don't think most dogfights involve accelerating to supersonic speeds. I believe they're mostly subsonic. Gums would probably know more about that, though.

Re: F35A Maximum G rating lower than 5?!

Unread postPosted: 18 Mar 2014, 09:13
by zero-one
Here's my take on the reduced spec fiasco.

Regarding Turning, We know that in Air-air configuration the F-35 can turn better than the Vipper.
As seen here: viewtopic.php?t=24472

We know that at subsonic speeds, it can accelerate just as well as a Viper to which really good for air-air combat.

So just by those two alone, the fear that the F-35 might be outmaneuvered by a horde of Flankers and Fulcrums should go all out the window.

The F-35 can hold its own in a gun fight if it ever came to that.

But on the other hand the reduced spec also tells me that for a certain particular airspeed, altitude and loadout where the
F-35A was suposed to hit 5.3Gs,
it didn't quite make it.
dont know if it was close or way off,
but it tells me that for that particular configuration the F-35 did not make it.

How much will this affect the F-35, well I don't know, Sustaining 4.6Gs is about the same for an F-15 with a combat load, and new more powerful engines will eventually be feilded on the F-35 increasing sustained G rates, so I wouldn't be too worried.

Re: F35A Maximum G rating lower than 5?!

Unread postPosted: 18 Mar 2014, 12:20
by cantaz
Everything you want to know, I'm surprised it was not the first response: http://elementsofpower.blogspot.ca/2013 ... -spec.html

Re: F35A Maximum G rating lower than 5?!

Unread postPosted: 18 Mar 2014, 23:59
by cola
exosphere wrote:Although the F-35A/B/C instantaneous gee limits are identical to the aircraft they are replacing, the JSF has one major advantage -- the F-35 variants can pull their maximum gee loadings with combat loads.

Of course it can't...it can't even pull 9g with its fuel tanks full and AIMs only, let alone in 'combat load' (assuming non-AA weaponry, like bombs and such).

Re: F35A Maximum G rating lower than 5?!

Unread postPosted: 19 Mar 2014, 00:29
by archeman
cola wrote:
exosphere wrote:Although the F-35A/B/C instantaneous gee limits are identical to the aircraft they are replacing, the JSF has one major advantage -- the F-35 variants can pull their maximum gee loadings with combat loads.

Of course it can't...it can't even pull 9g with its fuel tanks full and AIMs only, let alone in 'combat load' (assuming non-AA weaponry, like bombs and such).


But keep in mind, the F-35 has a crazy-high fuel % when just topped off. Far greater than most other combat aircraft w/out external tanks.

Re: F35A Maximum G rating lower than 5?!

Unread postPosted: 19 Mar 2014, 00:35
by spazsinbad
Somebody might know more than 'cola' ["...it can't even pull 9g with its fuel tanks full and AIMs only..."] here:
The F-35’s Race Against Time Nov 2012 John A. Tirpak Executive Editor
"...Lockheed Martin Vice President Stephen O’Bryan, the company’s point man for F-35 affairs, declared that the fighter meets requirements. A former Navy F/A-18 Hornet pilot, O’Bryan said...

...Stealth also permits (and requires) internal fuel and weapons carriage. The Air Force F-35 variant, fully loaded for combat, can pull nine-G turns with a full load of fuel and missiles. This cannot be done by fighters lugging along external weapons and fuel tanks..."

SOURCE: http://www.airforcemag.com/magazinearch ... ghter.aspx

Re: F35A Maximum G rating lower than 5?!

Unread postPosted: 19 Mar 2014, 00:51
by basher54321
spazsinbad wrote:The Air Force F-35 variant, fully loaded for combat, can pull nine-G turns with a full load of fuel and missiles. This cannot be done by fighters lugging along external weapons and fuel tanks..."



To be fair - Pulling it with missiles (A-A) you would expect - but certain A-G stores could still have a G limit on them could they not - if slightly higher than external carriage.

Also that quote could suggest it can handle 9G at More than 60% fuel.

Re: F35A Maximum G rating lower than 5?!

Unread postPosted: 19 Mar 2014, 00:56
by cola
spazsinbad wrote:Somebody might know more than 'cola'

Well, I'm quoting Bowman, who certainly is the only one that gave any figures unlike dimensionless and therefore meaningless 'tea leaves oracle readings' from O'Bryan.

Re: F35A Maximum G rating lower than 5?!

Unread postPosted: 19 Mar 2014, 01:33
by spazsinbad
No quotes from 'Bowman' then? Do you refer to 5 yr old quotes or more recent ones? Enquiring mind wants to know.

Scorecard - A Case study of the Joint Strike Fighter Program April 2008 LCDR Bowman USN

"...The most notable differences are related to the USAF requirements for the CTOL JSF. The USAF includes a threshold requirement for a 9.0 G capability at 60% fuel and no air-to ground ordnance remaining. In addition to the high-end requirement, the USAF also provides for a more realistic scenario of high altitude, large payload performance. The CTOL must have the capability of performing a 30 degree bank turn while still maintaining a 1000 foot per minute climb at 30,000 feet with a combat loadout of two external fuel tanks, two external JDAM, two internal JDAM, two internal AIM-120 missiles, and a fully loaded gun...."

SOURCE: http://www.f-16.net/f-16_forum_download-id-14791.html (PDF 0.25Mb)

Re: F35A Maximum G rating lower than 5?!

Unread postPosted: 19 Mar 2014, 02:13
by cola
There you go...I thought Bowman's doc is so well known, there's no need to spam it here, again.
Anyway, unlike O'Bryan, Bowman is unequivocal and therefore relevant.
Also, there's a JPO statement released through Aviation Weekly where 240-3's performance is put in the Bowman's class, so why would a JSF be able to pull 9g with full fuel and bombs all of a sudden, when that was never KPPed nor claimed by anyone and the plane is even heavier now than it was before?
Just because O'Bryan's vague statement can be interpreted that way?
I mean seriously, the entire JSF PR campaign is based on misleading hints, like the one when g and accel. KPPs extensions raised concerns, to which LM replayed (paraphrasing here) "What did you expect, it's a strike fighter?".

Fans will believe anything and it's fine, but hardly relevant.

Re: F35A Maximum G rating lower than 5?!

Unread postPosted: 19 Mar 2014, 03:34
by Corsair1963
cola wrote:There you go...I thought Bowman's doc is so well known, there's no need to spam it here, again.
Anyway, unlike O'Bryan, Bowman is unequivocal and therefore relevant.
Also, there's a JPO statement released through Aviation Weekly where 240-3's performance is put in the Bowman's class, so why would a JSF be able to pull 9g with full fuel and bombs all of a sudden, when that was never KPPed nor claimed by anyone and the plane is even heavier now than it was before?
Just because O'Bryan's vague statement can be interpreted that way?
I mean seriously, the entire JSF PR campaign is based on misleading hints, like the one when g and accel. KPPs extensions raised concerns, to which LM replayed (paraphrasing here) "What did you expect, it's a strike fighter?"
Fans will believe anything and it's fine, but hardly relevant.



You mean Critics will believe anything...........Especially, critics that have no access to the JSF Program and haven't even flown the F-35. :doh:

Re: F35A Maximum G rating lower than 5?!

Unread postPosted: 19 Mar 2014, 03:38
by smsgtmac
Wow. you guys are covering a lot of ground...again. :D

I would take (and have taken) Bowman's figures with a grain of salt, and caution others against leaning too hard on them either in support of the F-35 or in opposition to it.

First, they were old data points when he used them, and over time it is TYPICAL (uninformed whimpering to the contrary) for requirements to morph over time, or at the very least be recognized as either more important or less important as a program progresses.

Second, in some cases, such as the transsonic acceleration objectives/thresholds, they can be improperly specified in the first place: a 'clean' unloaded spec for a legacy fighter ignoring the internal stores-driven cross-section and wetted area. Gums has dropped hints about 'unloading' often enough, I'm surprised more people haven't picked up on the significance of that one little operational technique: it kind of trivializes the transsonic performance complaint all on its own. We've read LM bringing the 'clean spec' point up in interviews and public official testimony. The JSFPO, DOT&E, nor anyone else in the know has made a big deal of it. that should be the first clue. Most of all, I understand the math involved (working a similar tradeoff on a lesser scale right now) so I'm inclined to accept the acceleration spec as being no big thang. It is up to others outside the program to 'prove' otherwise...and they can't.

Third, Bowman is a NoGreatBrain F-18 Meat Servo, who wrote a mandatory paper to get through Air Command and Golf. It is hard to be any 'less' authoritative. I still hope he gets an F-35 billet before he's done [He's a 'Captain' now]: That would be truly Cosmic Justice!

This selective attention to individual specifications, while fun to some is irksome to those of us who look at total systems. What will be acceptable or unacceptable in F-35 performance for any particular KPP is how does it support the overall top-level program objectives? In cases of the Sustained G turn and Transonic Acceleration, those KPPS support the Survivability end Lethality objectives. As there are performance metrics no one has ever seen the 'measure' of (should we assume that DOT&E would only report it if they weren't being met?) for all we know those parameters obviate the utility of the ones the h8rs squawk endlessly about.

Think 'total package' when you think 'value' and no one outside program/user channels has a clue as to the 'total value'. Which I must admit makes it that much more pleasurable to watch the naysayers writhe in their lack of knowledge. They feel entitled to 'certainty' they have no right to have. And when they don't get it, things apparently look like 'smoke and mirrors' ,or perhaps 'misleading hints', to them. :wink:

Re: F35A Maximum G rating lower than 5?!

Unread postPosted: 19 Mar 2014, 03:48
by spazsinbad
So no thanks for finding the SPAM for you 'cola'. Nice.

Re: F35A Maximum G rating lower than 5?!

Unread postPosted: 19 Mar 2014, 03:57
by Corsair1963
Many of these so called sources that are critical of the F-35. Seem to be vastly different than the ones provided by people with access to the JSF Program and/or that have actually flown it!

Re: F35A Maximum G rating lower than 5?!

Unread postPosted: 19 Mar 2014, 04:21
by cola
Corsair1963 wrote:You mean Critics will believe anything...........Especially, critics that have no access to the JSF Program and haven't even flown the F-35. :doh:

JSF isn't a religion to 'belive' in...or not. Lack of understanding and knowledge certainly can make one if it, though.
There's simply no reason why a plane that has been KPPed and designed accordingly as JSF did, would overperform by such an outstanding margin in instantaneous g (~140%, which is nowhere near any fighter in the world), particularly with all the structural problems we often listen about.
If anything, the team that overdesigned a design by 140% in ANY aspect, should get fired immediately.

Spaz, c'mon...didn't mean like that. :)
But surely everyone here and his dog already heard of Bowman's doc and what does it read.
Thx for posting it, though.

Re: F35A Maximum G rating lower than 5?!

Unread postPosted: 19 Mar 2014, 09:45
by zero-one
Well I guess its safe to say that the title of this thread is inaccurate.

F-35A's maximum G rating is 9Gs and has been tested to 9.9Gs (but none of the critics seem to care)

About the Sustained G, I guess we will need to get more info on that, everything we have right now, even SgtMac's impressive 3 part article is largely bassed on assumptions as (like he said), We don't have enough info to draw an accurate conclusion.

At a worst case scenario, 4.6Gs may be taken from an F-35 with 40% fuel and internal A-A load. At corner speed and optimum altitude.

At best, (and more realistically IMHO) it could have been taken with an A-G load (with external stores), more than 60% fuel, not at corner speed, and not optimum altitudes.

And the A model may have only sustained 4.95G as stated here
http://www.military.com/features/0,15240,186349,00.html
military.com wrote:(240-3) was credited with a maximum speed of Mach 1.67; acceleration from Mach 0.8 to Mach 1.2 at 30,000 ft. in 61 sec.; a top turning speed of 370 kt. at 9g and 15,000 ft.; and a sustained turn capability of 4.95g at Mach 0.8 and 15,000 ft. Moreover, an aircraft with those performance figures would carry two beyond-visual-range AIM-120 Advanced Medium-Range Air-to-Air Missiles (Amraams) in the internal weapons bay


Now this was from the older 240-3 configuration, this may or may not have been improved upon. But like I said, Right now, its too early to tell.

Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 11 Feb 2020, 21:26
by steve2267
The McLaren race and the pilot's comments about 7g limiter pulls at 400mph (350kts) etc has had me poking around at Viper E-M diagrams ("overlay the E-M plots on 4th gen and will be as good as or better..." -- Flynn) and what not. Something reminded me about the infamous reduced g-spec. I dug out the article and read it. Another fine, fine article by McJumbles (NOT). Then I started doing some searching on the forum for past discussion. This thread seems most apropos. (I'm not sure I want to spend the time wading through the 27 pages of F-35 is the bar lowering?.)

Given all that has transpired in the seven years since McJumbles threw that journalistic excuse for sh*t against the wall to see what would stick... it seems clear that the F-35 has delivered on the requirements of F-16-like and F/A-18-like performance: rates like a Viper, with nose pointing authority like a Hornet. Numerous comments, statements by and quotes of pilots bear this out, e.g. "It's like a Hornet with four engines!". Statements about E-M diagrams being very similar to F/A-18 Hornet but with better acceleration at certain points also point to this conclusion that the F-35 met the goals set for it.

So, not really trying to resurrect an old thread for days additional yakking, but trying to keep pertinent discussion in the same place, my question is simple:

Was it ever determined or revealed at what point in the envelope the g-spec was relaxed from 5.3g to 4.6g (for the Aye)? Altitude? Aircraft weight? Speed?

Using a Blk50 Viper E-M diagram (i.e. the Greek one), suggests the spec may have been at 15,000 corresponding to a Viper with 4xAIM-120s and full internal fuel, OR at 20,000 corresponding to a Viper with maybe 50% fuel and 4 slammers.

As an aside, I find a disconnect in the reasoning skills of those who have for so long been slinging mud and casting aspersions upon the Lighting, "it can't turn, it can't climb" etc. Those same people seem to love to ding the Lightning over T/W ratio, wing loading etc. But an A-A loaded Lightning with 50% internal fuel and four AIM-120's has a wing loading of ~86lb/ft^2, and a T/W ratio of ~1.08. An A-A loaded Blk 50 Viper with four AIM-120's, and no external tanks or pods, has a wing loading varying from ~79 psf (no gas) to ~91 psf (full internal gas), and a T/W ratio of ~1.24 (50% internal gas) down to ~1.08 (full internal gas). IMO, full internal gas makes more sense, as if a Viper had just punched tanks, and 7000lb gas remaining seems to be about the same amount of flying time remaining (roughly) for a Viper as a Lightning with 9125lb of gas remaining. So, with very similar T/W and wing loadings, why wouldn't someone expect the Lighting to have performance comparable to the Viper?

Anyways, am curious if the location in the envelope (altitude / weight / speed) where this spec was specified was ever revealed. TIA.

Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 11 Feb 2020, 21:48
by sprstdlyscottsmn
steve2267 wrote:Anyways, am curious if the location in the envelope (altitude / weight / speed) where this spec was specified was ever revealed. TIA.

15,000ft and 0.8M. An arbitrary standard location. 4.6G was the requirement based on end of life engines and such, 4.95G was demonstrated. This with two AIM-120s, but no mention of fuel which is the biggest variable. assuming 60% would not be unreasonable.

From my stash of F-35 quotes.

"The aircraft can also reach a 55-deg. angle of attack in trimmed flight, while most fighters, excluding the F/A-18, are limited to 30 deg. The exact performance of the current F-35A configuration -- also known as the 240-4 -- are classified. But a similar earlier standard (240-3) was credited with a maximum speed of Mach 1.67; acceleration from Mach 0.8 to Mach 1.2 at 30,000 ft. in 61 sec.; a top turning speed of 370 kt. at 9g and 15,000 ft.; and a sustained turn capability of 4.95g at Mach 0.8 and 15,000 ft. Moreover, an aircraft with those performance figures would carry two beyond-visual-range AIM-120 Advanced Medium-Range Air-to-Air Missiles (Amraams) in the internal weapons bay."

Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 11 Feb 2020, 22:15
by marsavian
Steve, if the only E-M graph they released is indicative of current 3F performance then the sustained turn performance of F-35A has improved. At ~19kft ~5.5g is sustained at Mach 0.8 giving about 12º/s turn rate.

Image

Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 11 Feb 2020, 22:15
by steve2267
Thanks Spurts.

Looks like a Blk50 @26000lb GW (two slammers + full internal fuel -- just punched tanks?) is right around 5.3-5.5g @ 0.8 Mach at 15,000. The Lightning demonstrated 4.95g, huh? Ok. From what I have gleaned from glimpses into numbers, the Lightning seems to like to turn at an airspeed a bit slower than a Viper. That's just a hunch I have, and it could well be wrong. This seems in line with pilot quotes, that an airshow-clean Viper may outrate a Lightning slightly.

Thanks for the clarification.

Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 11 Feb 2020, 22:18
by steve2267
marsavian wrote:Steve, if the only E-M graph they released is indicative of current 3F performance then the sustained turn performance of F-35A has improved. At ~19kft ~5.5g is sustained at Mach 0.8.

Image


Sh*t, good point Mars. Thanks. Tickling 6g there.

Gums told me... "we couldn't believe an aircraft that could sustain 5-6g's for minutes at a time..." back when he and his buds were first flying Vipers. So yet another re-affirming / impressive datapoint about the least impressive nature of the F-35 (it's kinematics).

Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 11 Feb 2020, 23:52
by Gums
Salute!

Steve and I and Blind have gone thru this before on my deck and at a local brewery, after a toast of Jeremiah Week.

I'll still feel the old Block 10 Vipers could hold the 5 or 6 gee turn without bleeding as much speed or energy compared to this latest F-35 diagram.

No doubt the Stubbie can accelerate better than anything out there except an X-wing in zero atmosphere. The big thing has to do is when you need the accel and when you need the turn rate or nose-pointing.

With the Stubbie sensors, new weapons and such, I have a hard time thinking I might need cosmic nose pointing ability except as a last ditch maneuver. I would relish great acceleration capability, and the low RCS is also a great help, folks.

Gums sends..

Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 11 Feb 2020, 23:58
by quicksilver
The apparent improvement in sustained turn performance is a consequence of demonstrated engine performance as flight test progressed. You may recall that the analytically assumed performance at the beginning of flight test was spec min engine; as flight test progressed, the analytic engine performance model was adjusted to reflect actual engine performance as demonstrated in instrumented flight test. AIUI, the sustained G perf was derived from the updated model.

Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 12 Feb 2020, 01:11
by marsavian
Gums wrote:Salute!

Steve and I and Blind have gone thru this before on my deck and at a local brewery, after a toast of Jeremiah Week.

I'll still feel the old Block 10 Vipers could hold the 5 or 6 gee turn without bleeding as much speed or energy compared to this latest F-35 diagram.

No doubt the Stubbie can accelerate better than anything out there except an X-wing in zero atmosphere. The big thing has to do is when you need the accel and when you need the turn rate or nose-pointing.

With the Stubbie sensors, new weapons and such, I have a hard time thinking I might need cosmic nose pointing ability except as a last ditch maneuver. I would relish great acceleration capability, and the low RCS is also a great help, folks.

Gums sends..


F-16 E-M diagrams are in agreement with your recollections Gums. The Block 15 at 15 kft could sustain 6g from Mach 0.75 to Mach 1.3 and 7g from Mach 0.85 to Mach 0.95.

F-16Blk15 at 15k.jpg


The Block 50 at 20 kft could sustain 6g from Mach 0.85 to Mach 1.5. F-16 undoubtedly sustains higher g than F-35, well at least the F-35A variant, F-35C might be closer ;).

Image

Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 12 Feb 2020, 01:18
by fbw
Part may be the demonstrated engine performance, part is due to the misinterpretation at the time by journalists and the like of the difference between the stated objective sustained g and threshold sustained g performance. When the news broke, many misconstrued the lowering of the threshold to 4.6g as the demonstrated performance of the air vehicle in testing.

The heavier, non-production 240-3 aircraft were already demonstrating a sustained g performance above the threshold (as noted above) so it shouldn’t have been a surprise that the weight optimized production F-35A would outperform that threshold. They probably lowered the threshold due to uncertainty at that time of weight growth over the course of the program.

Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 12 Feb 2020, 01:33
by quicksilver
fbw wrote:Part may be the demonstrated engine performance, part is due to the misinterpretation at the time by journalists and the like of the difference between the stated objective sustained g and threshold sustained g performance. When the news broke, many misconstrued the lowering of the threshold to 4.6g as the demonstrated performance of the air vehicle in testing.

The heavier, non-production 240-3 aircraft were already demonstrating a sustained g performance above the threshold (as noted above) so it shouldn’t have been a surprise that the weight optimized production F-35A would outperform that threshold. They probably lowered the threshold due to uncertainty at that time of weight growth over the course of the program.


:thumb:

Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 12 Feb 2020, 02:12
by steve2267
marsavian wrote:
F-16 E-M diagrams are in agreement with your recollections Gums. The Block 15 at 15 kft could sustain 6g from Mach 0.75 to Mach 1.3 and 7g from Mach 0.85 to Mach 0.95.

<...snip...>

The Block 50 at 20 kft could sustain 6g from Mach 0.85 to Mach 1.5. F-16 undoubtedly sustains higher g than F-35, well at least the F-35A variant, F-35C might be closer ;).

<...snip...>


Are you comparing apples, or apples and oranges?

While comparing an F-16 with 50% fuel may seem like a fair comparison to an F-35 with 50% fuel, IMO it is not. With only 3500lb of internal gas left, an F-16 has about 1hr cruise time. An F-35 with 9125lb of go juice left has about 2hrs. I think you need to compare an F-16 with full internal tanks (figure the pilot punched his externals) to an F-35 with 50%. So I figured an F-16 @ 26000lb was a better comparison to an F-35 with 50% gas. Both had 4 slammers. With that configuration, you need to knock 2°/sec off the Viper turn rate. The Viper wing loading and T/W ratio were also almost identical to the F-35. As best I can tell, the Viper and Lightning were real darn close to each other turn rate-wise and g-wise, though, because of the shapes of it's Ps curves, the Viper may very well be able to sustain some of those g-loadings over a much wider speed range.

'Pologies if I don't recall all of those conversations with you and Blind, Gums... I blame it on the weed... :D

Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 12 Feb 2020, 02:22
by wrightwing
marsavian wrote:


The Block 50 at 20 kft could sustain 6g from Mach 0.85 to Mach 1.5. F-16 undoubtedly sustains higher g than F-35, well at least the F-35A variant, F-35C might be closer ;).

Image

That's for a clean F-16. Once you put it into a combat configuration, the F-35 will have better sustained/instantaneous turn rates.

Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 12 Feb 2020, 03:12
by marsavian
F-16 wingtip Amraams have no drag index and CFTs have none barely (1-2). That is an air to air combat configuration that those E-M diagrams are still valid for.

Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 12 Feb 2020, 03:18
by steve2267
:bang:

It's a weight thing

Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 12 Feb 2020, 03:43
by steve2267
F-16C Blk50 (18238 lb) with full internal fuel (7000lb) + 4 x AIM-120 (@ 335lb each): 26578 lb
F110-GE-110: 29500lb full AB
figure the Viper driver punched tanks; DI=0
Cruise fuel flow (DI=0) @ 26K: 3042 pph @ 450 kts (0.8 Mach): ~2hrs 20min cruise time

T/W= 29500 / 26578 = 1.11
WL = 26578 / 300 = 89 psf

F-35A (29300) with 50% internal fuel (9000lb) + 4 x AIM-120 (@ 335lb each): 39765 lb
F135-PW-100: 43000lb full AB

T/W = 43000 / 39765 = 1.08
WL = 39765 / 460 = 86 psf
Cruise fuel flow (clean)... best guess (Reference: Spurts): 4500pph (ish): ~2hrs cruise time

Why am I not surprised that the F-35 E-M numbers are not sitting right on top of the Viper?

F-16Blk50 E-M 20K DI=0 MaxAB.PNG


Note: the T/W ratios are invariably off, as that is based on spec, uninstalled thrust, but it is as close to an apples-to-apples comparison as I can think.

Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 12 Feb 2020, 03:44
by optimist
marsavian wrote:F-16 wingtip Amraams have no drag index and CFTs have none barely (1-2). That is an air to air combat configuration that those E-M diagrams are still valid for.

How strange for you to have apples and oranges. A f-16 with no fuel and 2 aim-xx
All F-16 drag index numbers are subsonic and the 2 wingtip missiles are included in base drag numbers of 0

GW)
C The GW of the aircraft including pilot, oil, two tip
AIM120 missiles, and a full load of 20 mm
ammunition is approximately 21,000 pounds and
with full internal JP8 fuel 28,200 pounds

Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 12 Feb 2020, 05:04
by quicksilver
What exactly is this ‘comparison‘ trying to achieve?

Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 12 Feb 2020, 05:51
by marsavian
Steve, don't forget that F-16C at 20 kft does its best turning at Mach 0.9 not Mach 0.8 and there it can sustain 5.5g and 10.5 deg/s with 7klb full internal fuel. In your adjusted example two 370 gal fuel tanks is about 5 klb fuel so 50% mission fuel weight in that case is 25+ klb which brings the sustained performances even closer to parity (11 deg/s to 12 deg/s) although still slightly favoring F-35 bearing in mind also that the F-35 figure is at a slightly lower height (19 kft). Instantaneously turning though its no contest at altitude, F-35 wins whatever the 50% mission fuel weight. Lighter fighters with less thrust (2/3 in this case) would be more sensitive to extra fuel weight.

Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 12 Feb 2020, 05:58
by optimist
quicksilver wrote:What exactly is this ‘comparison‘ trying to achieve?

A below bingo f-16 with 2 missiles turns pretty good?

Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 12 Feb 2020, 06:24
by steve2267
quicksilver wrote:What exactly is this ‘comparison‘ trying to achieve?


Good question. I dunno? I am not really trying to achieve anything, I suppose. However, I did note the other day, that an F-35 at 50% gas has about 2 hours of cruise time left. An F-16 with full internal fuel and 2-4 AIM-120s appears to have about 2 hours cruise time left. So I went, "Huh... I wonder how their T/W ratios and wing loads compare?" and I discovered they are damn near identical. In the past (some) people were going ballistic claiming how poor the F-35 "turns" compared to the F-16 (and other 4th gen jets). This "infamous g-spec" change was something many (lesser informed) people got in a tizzy over. But the more I poked around, and pulled out bits here and there (e.g. the turn rate of the Bee as the RN/RAF pilot raced the McLaren for beer (or ale) bragging rights)... the more the data supported that the F-35 really is quite comparable to the F-16. We've been told that by LM & pilots. And I for one believe them (why would they lie), but being an engineer... seeing the numbers pop out and support that is quiet satisfying.

As far as I can tell, these same "critics", who for years have lambasted the "poor" performance of the F-35 ("can't turn, can't climb" etc), used to "claim" the F-35 had a very poor T/W ratio and poor "wing loading". (H*ll, didn't Pierre "I designed the F-16!" Sprey even claim the wing loading on the F-16 was too high at one point?) F-35 supporters would respond that they were comparing apples to oranges and argue fuel fraction etc. Well, I never really ran the numbers for msyelf.... well, I think I did... but it wasn't until yesterday that I saw the F-35 @ 50% fuel really sit right on top of an F-16 that had just punched tanks and still had full fuel. FWIW (probably not much.)

I think I posted my question in this thread today with the following question in mind: "If the F-35 after dropping bombs and on its way back (i.e. @ 50% fuel), really does have the same T/W ratio and wing loading as a Viper, how in the h*ll could that infamous reduced g-spec have caused such a brouhaha? What was the fussing all about?" So I went and re-read it, and noted that it appeared that n o one specified at what speed (or Mach), or altitude, or weight this 'spec reduction' took place. So I asked... and Spurts had the answer for me: 15k and 0.8Mach. At first glance, the F-35 does appear to be deficient compared to the Viper at 15k. But the purported F-35 E-M diagram (it's probably from a Bee -- cuz it almost appears to be of crayon quality :D ) at 19K MSL appears to overlay very closely the F-16 Blk50 E-M plot @ 20K for a 26000 lb Viper (.e.g ~2hrs flying time remaining). So without an F-35 E-M plot @ 15K to compare to a Viper (because the 'spec change' apparently occurred there), even though "the numbers seemed close", the fact that F-35 @ 19K ft and F-16C Blk50 @ 20K ft are on top of each other (taking Gum's admonition to not sweat tenths of degrees), it is case closed for me.

I guess this is a long drawn out way of my describing a personal, intellectual journey of discovery that the numbers I'm seeing from different places are coalescing around the F-35 kinematic performance is truly as LM has been describing for the past 10+ years, and I find that satisfying.

QS, still with me? still reading? No? Good for you! Go have another beer! Or, next time you're in Denver, give me a shout. First rounds on me.

Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 12 Feb 2020, 06:36
by spazsinbad
The other day I found the insignia for the OLD NAS Denver. IF I ever get back there I'll have to re-instate said NAS (Buckley).

https://www.history.navy.mil/research/h ... /june.html

Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 12 Feb 2020, 06:48
by steve2267
marsavian wrote:Steve, don't forget that F-16C at 20 kft does its best turning at Mach 0.9 not Mach 0.8 and there it can sustain 5.5g and 10.5 deg/s with 7klb full internal fuel. In your adjusted example two 370 gal fuel tanks is about 5 klb fuel so 50% mission fuel weight in that case is 25+ klb which brings the sustained performances even closer to parity (11 deg/s to 12 deg/s) although still slightly favoring F-35 bearing in mind also that the F-35 figure is at a slightly lower height (19 kft). Instantaneously turning though its no contest at altitude, F-35 wins whatever the 50% mission fuel weight. Lighter fighters with less thrust (2/3 in this case) would be more sensitive to extra fuel weight.


I am seeing a rate band for the Viper @ 26K lb weight (full internal fuel, I figured the pilot punched the EFTs) from ~ 0.70 Mach to 0.96 Mach with a turn rate of 9.5°/sec (which, if I'm reading the chart correctly, varies from about 3.8g @ 0.7 Mach to 5.2g @ ~0.96 Mach.)

From the one (and only) F-35 E-M plot we have, the Lightning seems to rate around 11.5°/sec from 0.65 Mach to 0.9 Mach. The Lighting does seem to like it ~0.1 Mach slower than a Viper. Dunno why, just an observation. But that is also kind of in keeping with descriptions of the Lighting being "between the Hornet and Viper," and I believe, hopefully those that have flown them will correct me if they are still reading this :drool:, the Hornet tends to like speeds a bit slower than the Viper.

Now if Gums says he thinks the Viper will bleed a bit less than the Lightning, who am I to say otherwise? I didn't design (or analyze either), I don't have wind tunnel, CFD numbers, nor flight test data to look at. I'm just a snot nosed brat compared to Gums. I'm just happy he puts up with me, and lets me re-supply him with Jeremiah when I find it in stock... :mrgreen:

Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 12 Feb 2020, 06:51
by steve2267
Well, damn, Spaz... first round's on me if you should find your way up here...

Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 12 Feb 2020, 07:57
by marsavian
Steve, that chart came from this supplemental manual and it has turn charts for F-16C at 22, 26 and 28 klb of weight for both GE/PW engines (+CFT) at all heights and drag index starting at page 668

https://info.publicintelligence.net/HAF ... lement.pdf

Main manual

https://info.publicintelligence.net/HAF-F16.pdf

p.s. also remember that Gums F-16A had a 50% fuel combat weight of only 21 klb, see earlier chart on page 2 of this thread.

Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 12 Feb 2020, 08:00
by wrightwing
marsavian wrote:F-16 wingtip Amraams have no drag index and CFTs have none barely (1-2). That is an air to air combat configuration that those E-M diagrams are still valid for.

When is an F-16 ever going into combat with 2 wingtip AAMs? Try adding EFTs, pods, and other ordnance.

Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 12 Feb 2020, 08:03
by marsavian
Get real, it's not going into turning combat with EFTs which are partially superfluous anyway with CFTs. But for a real life example with wingtip AAMs how about Israeli F-16 in the Bekaa Valley conflict with Syria.

https://www.google.com/amp/s/theaviatio ... valley/amp

Image

Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 12 Feb 2020, 10:54
by wrightwing
marsavian wrote:Get real, it's not going into turning combat with EFTs which are partially superfluous anyway with CFTs. But for a real life example with wingtip AAMs how about Israeli F-16 in the Bekaa Valley conflict with Syria.

https://www.google.com/amp/s/theaviatio ... valley/amp

Image

The point is that a combat configured 4th generation jet is at a huge disadvantage vs an F-35 in either STR or ITR. Only an airshow configuration has competitive agility and acceleration. F-35s with GBU-12s have outmaneuvered clean F-16s in exercises, and then gone on to bombing ranges afterwards. As for not going into combat with EFTs, how many threads do we need to have discussing that it's rare for fighters to jettison their EFTs. We've also spent countless pages discussing how 4th generation jets have G/AoA/speed limits with external stores/pods, while F-35As are 9G/50° AoA/M1.6+, with full internal payload and fuel.

Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 12 Feb 2020, 10:59
by weasel1962
I beg to differ. Any 4G fighter carrying EFTs that's going to go up against an F-35 WILL drop their tanks in actual combat. That is if they actually know its an F-35 that they're going up against in the first instance. Not doing so will not be recommended (trying my best understatement impression).

Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 12 Feb 2020, 11:21
by marsavian
As for not going into combat with EFTs, how many threads do we need to have discussing that it's rare for fighters to jettison their EFTs.


It's not rare in real fighting wars.

https://theaviationist.com/2013/09/18/f ... s-se-asia/
https://aviationhumor.net/fuel-tanks-je ... to-canoes/

Several thousand drop tanks were jettisoned over Southeast Asia during the Vietnam War.

Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 12 Feb 2020, 11:33
by weasel1962
wrightwing is right because that's the SOP today, not in the Vietnam war and reflects the air superiority of USAF (not other forces) today.

However, if there is a USAF F-16 carrying EFTs that suddenly in a combat situation with a J-20, that SOP is not going to hold any water....or tanks for that matter.

Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 12 Feb 2020, 11:35
by optimist
weasel1962 wrote:I beg to differ. Any 4G fighter carrying EFTs that's going to go up against an F-35 WILL drop their tanks in actual combat. That is if they actually know its an F-35 that they're going up against in the first instance. Not doing so will not be recommended (trying my best understatement impression).

I don't think anyone would disagree, if the aircraft knew it was targeted. So they had tanks for the ingress and egress bombing mission. Dropped them and had a 2hr full internal fuel load, equivalent to the 2hr 50% fuel load of the F-35. Enough for both to get home.
Now it seems given this. The f-35 looks good.

Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 12 Feb 2020, 11:39
by spazsinbad
The second link [ https://aviationhumor.net/fuel-tanks-je ... to-canoes/ ] I think I have successfully DEBUNKED but hey wot do I know, nothing like wot you know obviously. Here:

viewtopic.php?f=55&t=11311&p=433767&hilit=jagged#p433767

First link [ https://theaviationist.com/2013/09/18/f ... s-se-asia/ ] is more or less the same as the 'aviationHUMOR' link wot I debunked.

Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 12 Feb 2020, 11:56
by marsavian
There were no US bases at or near Tha Bek in Laos. OTOH Laos was the most bombed country in history. Who knows, maybe it did rain fuel tanks on them too ...

https://www.atlasobscura.com/places/tha-bak-bomb-boats
https://www.bbc.co.uk/news/world-asia-37286520

Image

Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 12 Feb 2020, 12:03
by spazsinbad
I'm not certain why you persist with the nonsense you do. As explained: A full fuel tank will explode into a zillion small jagged pieces of metal if dropped in flight (NAPALM) whilst any significant amount of fuel will damage it entirely. IF you follow the previous link I posted you will see the damage to an empty fuel tank dripped during an armament release.

The PRISTINE fuel tanks seen in those articles have come from a warehouse full of pristine tanks after the war ended.

Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 12 Feb 2020, 12:19
by quicksilver
Saw your answer Steve, thx.

Wrt to the ‘spec’ change, I think fbw captured the essence of the matter earlier — alotta ignorance and lack of curiosity in modern media (and some/many websites). The ‘devil’s (often) in the details’ and many are too lazy to pursue same in spite of the fact that they're getting pay and a by-line to do so.

For marsavian, I tend to agree w/ ww about dropping EFTs these days; it’s very unusual, and citing examples from a war 50ish years ago doesn’t bolster the case. However, there’s also not a whole lotta recent experience in western air forces dodging SAMs and thwarting enemy fighters either. Until those circumstances again occur, that leaves the discussion wrestling with hypotheticals. I will say however that defenders of their own real estate will be more likely to fly without tanks or clean them off the jet (if they’re so-configured) because they are operating closer to their home plate. Changes the risk matrix...

The other relevant factor is about weapons. Somewhere in one of my recent posts I commented about the differences between the Viper, the Hornet and their predecessors when they first showed up in the early 80s. Nothing could sustain energy like a Viper; nothing could ‘point’ like a Hornet (although a well-flown Eagle was/is no slouch). But...the kind of (training) fights they fought against each other changed when all-aspect heaters showed up. It shifted the advantage to ‘pointing’ except where — for training purposes — the set-up specified G/H/P/J missile parameters or ‘guns only’ for weapons/kill criteria. Similarly, new HOBS weapons and HMDs have shifted the advantage once again. The consequence of that is that it allows, to some degree, avoidance of extended hard turning, energy-bleeding fights except where we allow engagements to continue for training purposes. In short, it’s a bit easier to keep ones knots up, particularly when the HMD is fed the kind of SA-building info that one sees in an F-35.

Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 12 Feb 2020, 12:20
by marsavian
Spazsinbad, Laos is full of thick green forests which obviously dampened the impact of the fall. In your theory poor peasants somehow transported pristine fuel tanks all the way from South Vietnam hundreds of miles North West into another country ! Why didn't the South Vietnamese keep them instead ? Obviously we are only seeing the ones that survived the impact in Laos being made into boats. Occam's Razor !!

Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 12 Feb 2020, 15:26
by spazsinbad
You can invent stories all you like however I am relating facts as they are known to me. You have only theories - sadly. Ask why would empty drop tanks be dropped & what happens to a full drop tank (NAPALM). Theory your way around that.

Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 12 Feb 2020, 15:29
by basher54321
marsavian wrote:Get real, it's not going into turning combat with EFTs which are partially superfluous anyway with CFTs. But for a real life example with wingtip AAMs how about Israeli F-16 in the Bekaa Valley conflict with Syria.





A drawing with a representation of air war from 1982 - which has very little to do with modern F-16s. From photos and Israeli sources typical loadout A-A back then was 4 x AIM-9 and a centreline tank - 4 AIM-9s because they were apparently short of them. You will also probably find they had little need to jettison the tank considering the crap they were up against.

Also so you know there should be big differences in the EM charts of the Block 5/10 they used to the modern blocks and again with the F-2.

Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 12 Feb 2020, 16:17
by steve2267
basher54321 wrote:Also so you know there should be big differences in the EM charts of the Block 5/10 they used to the modern blocks and again with the F-2.


The EM chart of a Blk 5/10 oughta be close to a Blk 15, correct? The Blk 15 chart from page 2 of this thread (20875 lb weight @ 15k ft) shows that a light F-16 can turn like nobodies business. It's turn rate band is around 14°/sec, and it can pull 7.3g @ 0.9 Mach (Ps=0). Could you imagine SLEPping a Blk15/20 MLU and dropping a F100-PW-229EEP in it? That sucker would rip everything up with a TW ratio around 1.38.

basher54321 wrote:A drawing with a representation of air war from 1982 - which has very little to do with modern F-16s. From photos and Israeli sources typical loadout A-A back then was 4 x AIM-9 and a centreline tank - 4 AIM-9s because they were apparently short of them. You will also probably find they had little need to jettison the tank considering the crap they were up against.

As an aside, wasn't the Viper still a 9g machine with a single centerline tank?

WRT the argument raging about dropping tanks vs not dropping tanks, I will note that in a number of Eagle vs Mig combat accounts from the '91 Gulf War and Kosovo, the Eagles punched tanks. Dunno if they still had gas or not.

I just kinda had an "Aha!" moment when I noted the close numerical similarities of TW ratio and wing loading between an F-16 @ 26K weight, which one would get with a Blk 50/52 + full internal gas + 4 AIM-120's (or 2 AIM-120's and 2 AIM-9's) and an F-35 with 4 AIM-120's and 50% gas. It made sense to me that perhaps this was one of the design points for the JSF program cum F-35 contract. Dunno. But that's my story.

Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 12 Feb 2020, 16:26
by steve2267
quicksilver wrote:Saw your answer Steve, thx.

I apologize for the excessive verbosity. I tend to be particular when it comes to numbers. It seems to take me too many words to nail down corner conditions and get the context correct. Still working on that fighter pilot brevity. Not there yet. :oops:

quicksilver wrote:Wrt to the ‘spec’ change, I think fbw captured the essence of the matter earlier — alotta ignorance and lack of curiosity in modern media (and some/many websites). The ‘devil’s (often) in the details’ and many are too lazy to pursue same in spite of the fact that they're getting pay and a by-line to do so.

The apparent lack of giving twosh*ts by these journo types is rather astounding. I guess it would make them late to lunch with somebody.

quicksilver wrote:The other relevant factor is about weapons. Somewhere in one of my recent posts I commented about the differences between the Viper, the Hornet and their predecessors when they first showed up in the early 80s. Nothing could sustain energy like a Viper; nothing could ‘point’ like a Hornet (although a well-flown Eagle was/is no slouch). But...the kind of (training) fights they fought against each other changed when all-aspect heaters showed up. It shifted the advantage to ‘pointing’ except where — for training purposes — the set-up specified G/H/P/J missile parameters or ‘guns only’ for weapons/kill criteria. Similarly, new HOBS weapons and HMDs have shifted the advantage once again. The consequence of that is that it allows, to some degree, avoidance of extended hard turning, energy-bleeding fights except where we allow engagements to continue for training purposes. In short, it’s a bit easier to keep ones knots up, particularly when the HMD is fed the kind of SA-building info that one sees in an F-35.


I don't think this can be overstated. Seems to zip past most people, esp the journos.

Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 12 Feb 2020, 16:45
by f-16adf
Steve,
For more info (as pertaining to a jet with full internal fuel) on the Block 15, consult the Block 15 SAC (standard aircraft characteristics) charts. Also, the USAF WEM (weapons employment manual) has a chart of the Block 15 with 50% gas no AAMS at 15Kft, in comparison with a Block 42 (with -220 motor). I posted that one a while back.

The Block 10 was around 600lbs (if not a bit more) lighter than the 15. So it would have better numbers. I have the Block 30 at 30,000ft chart ---and would post it, but I don't think the mods would approve. But even at 30Kft, it is still better than the Block 50 (generally at subsonic speeds and still slower). Also have words from the CO of Wisconsin ANG about his Block 30 in comparison to F-35 and their upcoming conversion to it.

Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 12 Feb 2020, 16:48
by steve2267
f-16adf wrote:Steve,
Also have words from the CO of Wisconsin ANG about his Block 30 in comparison to F-35 and their upcoming conversion to it.


Have you posted these anywhere? If not, are you at liberty to share? If not, I shirley understand.

Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 12 Feb 2020, 16:57
by marsavian
Steve, there's something else that Optimist brought to my attention here viewtopic.php?p=434884#p434884 and which comes straight from the manuals, the empty weight of Block 50 is not 18,238 lb as we both thought and as stated here

http://www.f-16.net/f-16_versions_article9.html

That's most likely Block 30,

http://www.f-16.net/f-16_versions_article6.html

Block 50 appears to be around 20 klb empty, 21 klb with pilot, gun ammo and 2 amraams.

https://info.publicintelligence.net/HAF-F16.pdf

So you need to use the 28 klb weight charts in link below if you want fully fueled and armed Block 50/52 performance.

https://info.publicintelligence.net/HAF ... lement.pdf

Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 12 Feb 2020, 17:02
by f-16adf
Steve, here are a few:

F-16A Block 15 turn charts.jpg






F-16 Block 15 and Block 42  P&W F100-220.jpg






As far as Block 50 weight. Technically you are suppose to do a Weight and Balance load with the numbers from each particular jet's licensed AFM. Same as a Cessna 172RG, you do it with copyrighted manual to that serialed plane. You just cannot use any C-172RG POH/AFM. However, since we do not have that for the F-16 B50, I would reference the 19,261lbs empty number that is even used in a sample load out problem on pg B1-3 of the HAF Supplement. For example:

F-16C  HAF empty weight pg.jpg




I'll try and find the other stuff, may take a bit...

Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 12 Feb 2020, 18:01
by basher54321
steve2267 wrote:The EM chart of a Blk 5/10 oughta be close to a Blk 15, correct?

As an aside, wasn't the Viper still a 9g machine with a single centerline tank?

WRT the argument raging about dropping tanks vs not dropping tanks, I will note that in a number of Eagle vs Mig combat accounts from the '91 Gulf War and Kosovo, the Eagles punched tanks. Dunno if they still had gas or not.





If you are referring to the original Block 15 and not later ones maybe - it also had a bigger tail over the Israeli block 5/10 of 82.

Yes by the time they got there the tank was probably empty so even if turning fights happened there would have been next to no difference in relative performance to the potential foes.

Vietnam and before (long story short) - tanks were dropped a lot for various reasons - e.g. the tanks were not stressed for combat in a lot of cases also F-4s had to drop tanks to fire AIM-7s etc blah. With 4 gen the tanks were combat stressed so less need to jettison them but they do in an emergency situation (SAM / A-A) like DS shows. But these aircraft still spend most of their lives with tanks - e.g. taking off and going to a combat area.

Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 12 Feb 2020, 18:27
by f-16adf
Badger Militia article:

Badger Militia 1.jpeg

Badger Militia 2.jpeg

Badger Militia 3.jpeg

Badger Militia 4.jpeg

Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 12 Feb 2020, 18:51
by quicksilver
OK. Are we through ‘boiling the ocean‘ (again) yet? :wink:

See smsgtmac’s post on page one of this thread. That was 6ish years ago...and he had three detailed discussions on ‘spec’ changes on his blog that you can find with a simple search.

Obtw, great podcast find above. Kinda says it all.

Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 12 Feb 2020, 18:59
by steve2267
quicksilver wrote:OK. Are we through ‘boiling the ocean‘ (again) yet? :wink:


I don't know... Maybe. It's a nice respite from Canaduh and Gripenitis, me thinks. :o

Only other thing I'll offer is this... in a conversation with Gums, I was surprised to learn that "most air combat" (take this with a grain of salt, this is me (an aero engineer) regurgitating what I heard) takes place at 5-6g. I had this mistaken notion that Viper dudes tore around the sky with their hair on fire at 9g and 400kt for the entire fight. At the merge you might put on 9g for something like 3-9 seconds (sounded like 2-4 sec was more "typical") in a break turn as you sought to gain an angles advantage, by then you have either pissed away some energy, or you are tracking your bandit and seeing what he is doing. The statement that Gums made that really caught my attention was something like "if you can sustain 5-6g for 2-3 minutes... your golden..." And the fact that the early Vipers anyway, could sit out there at 5-6g until they ran out of gas from like 10-20k feet was hugely eye opening to pilots in the 1980's, and still a YUGE advantage 'til today.

After that conversation, I'm looking at Lightning numbers and I'm seeing 5-6g sustained up to, it seems, at least 20k feet... so, yeah, the F-35 can bring it, if it needs to. And, yet again, this is the least important aspect of the jet so many of us like to yak about.

Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 12 Feb 2020, 19:09
by quicksilver
‘Sustained turn performance’ is what turned lotsa guys into gym rats — weight training, healthy eating and all kinds of counter-fighter culture stuff.

Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 12 Feb 2020, 19:18
by steve2267
quicksilver wrote:See smsgtmac’s post on page one of this thread. That was 6ish years ago...and he had three detailed discussions on ‘spec’ changes on his blog that you can find with a simple search.


I was reading through smsgtmac's blog posts before I posted on this thread. As I recall, he hadn't noted or specified at what weight / altitude the spec change had occurred (or I missed it). He may have just guessed it was at 15k feet, dunno. That's also kinda what prompted me to ask in here.

Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 12 Feb 2020, 19:21
by quicksilver
steve2267 wrote:
quicksilver wrote:See smsgtmac’s post on page one of this thread. That was 6ish years ago...and he had three detailed discussions on ‘spec’ changes on his blog that you can find with a simple search.


I was reading through smsgtmac's blog posts before I posted on this thread. As I recall, he hadn't noted or specified at what weight / altitude the spec change had occurred (or I missed it). He may have just guessed it was at 15k feet, dunno. That's also kinda what prompted me to ask in here.


Istr that it was a specified kpp and thus not public info.

Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 12 Feb 2020, 19:24
by f-16adf
I guess, for the great podcast material. If someone has a problem with what the Lt. Colonel implied (or as how he implied it), perhaps they should take a ride up to KMSN and ask him?

I had reservations about not posting it 3 months ago because I figured this was going to happen. But as Steve said, it changes the convo/discussion. Frankly there are probably many who couldn't take any more of the other discussion topics. I.E., the great Gripen circlejerk-

Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 12 Feb 2020, 19:35
by quicksilver
f-16adf wrote:I guess, for the great podcast material. If someone has a problem with what the Lt. Colonel implied (or as how he implied it), perhaps they should take a ride up to KMSN and ask him?

I had reservations about not posting it 3 months ago because I figured this was going to happen. But as Steve said, it changes the convo/discussion. Frankly there are probably many who couldn't take any more of the other discussion topics. I.E., the great Gripen circlejerk-


I missed it. What did he say?

Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 12 Feb 2020, 19:48
by steve2267
quicksilver wrote:
f-16adf wrote:I guess, for the great podcast material. If someone has a problem with what the Lt. Colonel implied (or as how he implied it), perhaps they should take a ride up to KMSN and ask him?

I had reservations about not posting it 3 months ago because I figured this was going to happen. But as Steve said, it changes the convo/discussion. Frankly there are probably many who couldn't take any more of the other discussion topics. I.E., the great Gripen circlejerk-


I missed it. What did he say?


Lt Col Merkel is the head of the F-35 unit conversion office here and is enthusiastic about the forthcoming fighter, highlighting what new capabilities it will bring. “Number one is its ability to process and share information across networks. It may not have the sheer performance the F-16 has like climb and turn, but that’s not really a key metric anymore.
“These days we’re not as concerned about physical performance of the airplane as we are about sensors, integration and things like that. The F-35 is meant to operate stealthily and attack before it is detected. It doesn’t need to manoevre, it just needs to find things and shoot them.”

from p. 46 of the article adf just posted, November 2019 #330, Badger Militia


Personally, I have no issues with what the good Colonel said. It seems to fit with everything else I've read and seen discussed.

Lighter F-16's are rate machine beasts. Something I've come to appreciate more. The Bee driver with whom I corresponded said an airshow Viper would outrate him a bit, but he could outradius them (and implied "and kill him.") So too, a (light) Hornet may be able to outradius him, but he could outrate the Hornet (and implied "and kill him.").

I'm a numbers guy. Its what I do. And I'm seeing numbers, pulling numbers out of old charts & threads, developing numbers from things as silly as racing a $2M sports car... and all the numbers are supporting the notion that the F-35 is a beast in its own right. (But really, why should we be surprised? At 50% fuel -- either approaching target or coming off target -- the F-35 TW & wing loading is very competitive with the Viper, which everyone "raves" about. So yeah, what you said earlier, QS, about journos lacking even a little curiousity, is very disappointing. Actually, that should be the story -- the abysmal state of blogging / journalistic writing rather than F-35 performance, which is what LM has said all along -- that it is meeting requirements.)

Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 12 Feb 2020, 19:58
by sprstdlyscottsmn
Wasn't the Blk 30 the hottest of the hot? Lightest GE equipped Vipers? The F-35 is compared to the Blk 50 favorably, so... no shame in not matching a rocket ship. That would be like comparing the J79-GE-19 powered F-104A to the F-15 and saying "Yeah, it doesn't have the climb, speed, or ceiling that the F-104 has, but that big radar and big wing let it find targets and turn into them like no ones' business, and that is the name of the game now."

Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 12 Feb 2020, 20:05
by steve2267
sprstdlyscottsmn wrote:Wasn't the Blk 30 the hottest of the hot? Lightest GE equipped Vipers? The F-35 is compared to the Blk 50 favorably, so... no shame in not matching a rocket ship. That would be like comparing the J79-GE-19 powered F-104A to the F-15 and saying "Yeah, it doesn't have the climb, speed, or ceiling that the F-104 has, but that big radar and big wing let it find targets and turn into them like no ones' business, and that is the name of the game now."


I am going to say yes... until... the ANG Blk42's got the PW-229EEP motor. Using the uninstalled thrust from the acceptance test, and running numbers on the actual aircraft, it is my understanding these Blk42's had the highest TW ratio of all Vipers then in service. (Perhaps a good question would be if the Blk 30's were in service at the time the Blk42's got their -229EEP motors?

Something that may not be appreciated about those PW-229EEP motors is that they go 6000hrs before overhaul/inspection (or whatever you call it). Not sure how long the F110-GE motors go before overhaul. But jumping from 7-9 years to something like 12 years on overhaul sounds like a big deal.

Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 12 Feb 2020, 20:09
by quicksilver
Ref the Colonel — Ahh, I did see that. I have no problem with it.

Those kinds of comments are not unusual as units and individuals transition from one type to another. In this case, they were made before he had even flown the new jet.

It’s kinda axiomatic that pilots love most (and forever) the jet that they loved first. And in an aircraft transition, everything new is often the source of considerable discomfort because what was once so familiar and reflexive in the old jet is now unfamiliar in the new one, requiring consciously deliberate thought and action to do the most routine things. New flight equipment, new helmet, new way to strap in, new hotas, new displays and symbology, new switchology, new sounds. In many ways ya gotta go back to being a newb and that’s not just very, very uncomfortable, it’s unsettling to many. They get over it as everything becomes more practiced and familiar, and they establish proficiency in the new jet.

It’s also very typical to hear, ‘I don’t like this...I don’t like that’ about the new jet — not necessarily because it’s bad, but rather because it’s different and unfamiliar. Eventually, like the Major in the podcast, they learn to appreciate what the new thing does much, much better.

Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 12 Feb 2020, 20:17
by steve2267
QS, maybe you can answer this question for me. If it's too complicated, just say so.

Two hypothetical planes, say at 15k ft:
  1. Aircraft A can sustain 7g @ 450kts (0.8 Mach) (+/-) yielding about 15°/sec
  2. Aircraft B can sustain 5.5g @ 375kts (06.65 Mach) (+/-) giving the same rate of 15°/sec

Is this contest, from a turning perspective anyway, a wash? I see that Aircraft A has an advantage in energy a bit, but Aircraft B will be flying a smaller radius. I am thinking Aircraft A needs to go to Plan B.

If, when unloaded, Aircraft B can accelerate as fast as A, perhaps even faster, then I'm unsure that initial energy advantage A has would be of much use if he decided to try to go vertical. If B can also outpoint A when speeds drop off... then I think A is in trouble.

Am I tracking here?

If true, it is, in a nutshell I think, why the F-35 is so dangerous and why even the Bee with its "7g limit" is so dangerous as well.

Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 12 Feb 2020, 20:22
by basher54321
steve2267 wrote:I am going to say yes... until... the ANG Blk42's got the PW-229EEP motor. Using the uninstalled thrust from the acceptance test, and running numbers on the actual aircraft, it is my understanding these Blk42's had the highest TW ratio of all Vipers then in service. (Perhaps a good question would be if the Blk 30's were in service at the time the Blk42's got their -229EEP motors?



Fat chance based on the 42s weight given in the early 90s manual. Yes Block 30s are still in USAF front line service albeit very upgraded. No what would be more interesting is to see if the GE-100 actually puts out more dynamic thrust over the PW-229 in places. :P

Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 12 Feb 2020, 20:35
by steve2267
basher54321 wrote:
steve2267 wrote:I am going to say yes... until... the ANG Blk42's got the PW-229EEP motor. Using the uninstalled thrust from the acceptance test, and running numbers on the actual aircraft, it is my understanding these Blk42's had the highest TW ratio of all Vipers then in service. (Perhaps a good question would be if the Blk 30's were in service at the time the Blk42's got their -229EEP motors?



Fat chance based on the 42s weight given in the early 90s manual. Yes Block 30s are still in USAF front line service albeit very upgraded. No what would be more interesting is to see if the GE-100 actually puts out more dynamic thrust over the PW-229 in places. :P


Will have to take your word for it. http://www.f-16.net/f-16_versions.html has the Blk30 and Blk42 both with an empty weight of 18,238lb. Oh, well.

Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 12 Feb 2020, 20:40
by sprstdlyscottsmn
basher54321 wrote: Now what would be more interesting is to see if the GE-100 actually puts out more dynamic thrust over the PW-229 in places. :P

From the charts I see in the old HFFM pdf, the -229 had SOME areas of advantage over the -100, but that was all at the far right end of a given altitude.
For example at 40,000ft
The -229 shows rising through 14,000lbt at 1.4M, cresting around 17,500 at 1.75M, then back down to 14,000 at 2.1M.
The -100 shows rising through 14,000lbt at 1.3M, cresting around 19,000 at 1.65M, and dropping to 14,000 by 1.9M.
I don;t know if this was a CFD and thermal model or if they were able to get actual data.

Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 12 Feb 2020, 20:42
by quicksilver
Steve, all that goes into understanding where and how ones jet fights best before one ever gets in the jet for one’s first bfm ride.

One of my favorite observations about teaching bfm was the search for keys that would unlock someone’s understanding. For some, quantifiable parameters helped most; ‘pull your nose up between 30 and 40 degrees until you see... then roll 90 degrees etc. For others, word pictures and use of stick models. Some just needed to see it in the jet; all the academics in the world weren’t gonna do. Everyone’s brain was a little different when it came to developing understanding and proficiency in bfm. Some who were very good in everything else simply couldn’t process the dynamics of maneuvering in 3D space.

So, your quantifiable example doesn’t consider maneuver in three dimensions — two aircraft engaged in fluid and highly dynamic out-of-plane maneuvering.

I think what makes any fighter dangerous in bfm are those performance characteristics that generate rapid/superior ‘rates of change‘ in three-dimensional space for positional advantage or weapons employment relative to an adversary.

Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 12 Feb 2020, 20:55
by steve2267
quicksilver wrote:Steve, all that goes into understanding where and how ones jet fights best before one ever gets in the jet for one’s first bfm ride.

One of my favorite observations about teaching bfm was the search for keys that would unlock someone’s understanding. For some, quantifiable parameters helped most; ‘pull your nose up between 30 and 40 degrees until you see... then roll 90 degrees etc. For others, word pictures and use of stick models. Some just needed to see it in the jet; all the academics in the world weren’t gonna do. Everyone’s brain was a little different when it came to developing understanding and proficiency in bfm. Some who were very good in everything else simply couldn’t process the dynamics of maneuvering in 3D space.

So, your quantifiable example doesn’t consider maneuver in three dimensions — two aircraft engaged in fluid and highly dynamic out-of-plane maneuvering.

I think what makes any fighter dangerous in bfm are those performance characteristics that generate rapid/superior ‘rates of change‘ in three-dimensional space for positional advantage or weapons employment relative to an adversary.


Copy, thanks.

Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 12 Feb 2020, 20:57
by basher54321
sprstdlyscottsmn wrote:From the charts I see in the old HFFM pdf, the -229 had SOME areas of advantage over the -100, but that was all at the far right end of a given altitude.
For example at 40,000ft
The -229 shows rising through 14,000lbt at 1.4M, cresting around 17,500 at 1.75M, then back down to 14,000 at 2.1M.
The -100 shows rising through 14,000lbt at 1.3M, cresting around 19,000 at 1.65M, and dropping to 14,000 by 1.9M.
I don;t know if this was a CFD and thermal model or if they were able to get actual data.



Good point thanks.

Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 12 Feb 2020, 20:59
by spazsinbad
ON previous page JPGs of five pages of an AirForces Monthly Nov 2019 story 'BADGER AIR MILITIA' was posted - now below.

Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 12 Feb 2020, 21:22
by quicksilver
steve2267 wrote:QS, maybe you can answer this question for me. If it's too complicated, just say so.

Two hypothetical planes, say at 15k ft:
  1. Aircraft A can sustain 7g @ 450kts (0.8 Mach) (+/-) yielding about 15°/sec
  2. Aircraft B can sustain 5.5g @ 375kts (06.65 Mach) (+/-) giving the same rate of 15°/sec

Is this contest, from a turning perspective anyway, a wash? I see that Aircraft A has an advantage in energy a bit, but Aircraft B will be flying a smaller radius. I am thinking Aircraft A needs to go to Plan B.

If, when unloaded, Aircraft B can accelerate as fast as A, perhaps even faster, then I'm unsure that initial energy advantage A has would be of much use if he decided to try to go vertical. If B can also outpoint A when speeds drop off... then I think A is in trouble.

Am I tracking here?

If true, it is, in a nutshell I think, why the F-35 is so dangerous and why even the Bee with its "7g limit" is so dangerous as well.


A couple more thoughts —

Situational timing (the geometry) of any given maneuver/counter relative to one’s adversary can be all-important. For example, if I already have 3/9 control inside the adv’s turn radius, I may want to use the ability to very rapidly shrink my turn radius (‘rapid change’) in-plane to park in my adversary’s control zone, and still have enough energy to point and kill or force him back down if he makes a move in the vertical.

Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 12 Feb 2020, 21:37
by steve2267
quicksilver wrote:
A couple more thoughts —

Situational timing (the geometry) of any given maneuver/counter relative to one’s adversary can be all-important. For example, if I already have 3/9 control inside the adv’s turn radius, I may want to use the ability to very rapidly shrink my turn radius (‘rapid change’) in-plane to park in my adversary’s control zone, and still have enough energy to point and kill or force him back down if he makes a move in the vertical.


Am unfamiliar with the phrase "3/9 control" -- are you on your adv's 3-9 line (or close to it) and pointed at your adv (or close to it)?

How do you "force your adv back down" if he decides to go vert? Is this where all-aspect, HOBS heaters like AIM-9x come into play? "Sure, go vert, see what I care, as soon as I get my nose around, you're toast..." ?

AIM-9x et al shirley have complicated the game, haven't they?

Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 12 Feb 2020, 21:51
by quicksilver
steve2267 wrote:
Am unfamiliar with the phrase "3/9 control" -- are you on your adv's 3-9 line (or close to it) and pointed at your adv (or close to it)?

How do you "force your adv back down" if he decides to go vert? Is this where all-aspect, HOBS heaters like AIM-9x come into play? "Sure, go vert, see what I care, as soon as I get my nose around, you're toast..." ?

AIM-9x et al shirley have complicated the game, haven't they?


3/9 = behind his wing-line

Force him down? ‘Point’; he has to honor my nose position or he dies sooner rather than later.

Of course, this is all ‘classic’ bfm, and to arrive at an in-plane control zone I’ve already flown through a whole bunch of the missile’s employment envelope.

Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 12 Feb 2020, 21:57
by sprstdlyscottsmn
steve2267 wrote:
How do you "force your adv back down" if he decides to go vert?


Speaking from a sim perspective, sometimes as I get position on an enemy plane it goes vertical. I need to be aware of my energy state, nose position, distance, low speed behavior, and other enemies in order to decide what to do next.

Examples of gunshots
I'm in an F-14 at 0.6M, half a mile separation, and am still 30 degrees off from putting the guy in my hud. I can roll vertical to follow and pull ~2/3 stick to put him in my hud by the time I am coming over the top. The enemy now has to dive to get away from me assuming I don't pop him near the top.

I'm in an F-14 at 0.5M, a mile separation, the guy was almost in my hud when he went up. If I pull 2/3 stick to vertical the deflection angle will be too high and I may lose visual. If I pull to keep him in view I will overshoot and I don't have the speed to go beyond about 1/2 stick pull. I cannot threaten him worse than a brief raking snapshot.. He has the option to roll out at the top and go horizontal, my energy will be low no matter what I do and I will be using rudders to turn.

I'm in an F/A-18, anything over 200KIAS, any distance within a mile, any angle within 30 degrees, no other enemies. Grip it and rip it. I have gone over the top at 37KTAS feeling like I'm in full control and nearly 1,000ft below the enemy plane, but all the enemy saw is during his entire vertical maneuver I had my nose on him so he dives to get his energy back to turn.

Same as above but another enemy at play. Abort. Go horizontal to try and catch him on the back side or disengage altogether. Do not go vertical with a starting speed under about 300KIAS or else I will get splashed.

Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 12 Feb 2020, 22:19
by steve2267
Thanks all.

QS, was there ever a point in time during the F-35 development, when you read or heard something and realized or decided right then that "Well, I'll be... LM got it right... this thang is going to be a beast to be reckoned with..." ?

Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 12 Feb 2020, 22:48
by quicksilver
steve2267 wrote:Thanks all.

QS, was there ever a point in time during the F-35 development, when you read or heard something and realized or decided right then that "Well, I'll be... LM got it right... this thang is going to be a beast to be reckoned with..." ?


I never thought it would be anything but a beast. I knew/know some folks who flew the X-jet and others who are familiar w its development, DT and fleet intro.

Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 12 Feb 2020, 22:59
by steve2267
quicksilver wrote:
I never thought it would be anything but a beast. I knew/know some folks who flew the X-jet and others who are familiar w its development, DT and fleet intro.


Cool beans.

Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 12 Feb 2020, 23:12
by quicksilver
steve2267 wrote:
quicksilver wrote:
I never thought it would be anything but a beast. I knew/know some folks who flew the X-jet and others who are familiar w its development, DT and fleet intro.


Cool beans.


As one of the first MDAPs of the ‘age of information’ and social media, I did have some doubts about whether it would survive the acquisition system.

Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 12 Feb 2020, 23:20
by steve2267
quicksilver wrote:As one of the first MDAPs of the ‘age of information’ and social media, I did have some doubts about whether it would survive the acquisition system.


That was probably the biggest achievement of LM and the JPO.

I recall all the stink 8-12 years ago, though I didn't follow it as closely then, and more or less just dismissed all the naysayers out of hand. After all, how could the manufacturer of the F-16 Viper not know how to create a jet that performs? I think I was also suitably impressed by several of Dr. Bevilaqua's papers on the development of the lift fan and how that also folded into the overall design of the X-35.

Hopefully the defense industry has paid attention and learned some things about how to best develop products in this age of social media.

Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 13 Feb 2020, 01:44
by quicksilver
This is the podcast I referred to...(from the Favorite Quote thread...:doh:)

http://tun.in/tjA2rX

Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 14 Feb 2020, 05:40
by garrya
f-16adf wrote:Steve, here are a few:

F-16A Block 15 turn charts.jpg


F-16 Block 15 and Block 42 P&W F100-220.jpg


Wow where did you get these charts from?

Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 14 Feb 2020, 07:13
by steve2267
FWIW, I was just looking again on the Blk 15 @ SeaLevel E-M chart that F-16adf posted a few days ago. The red dot below is an F-35B performing at show center -- 350 KIAS (0.53 Mach). Not an Aye, but a 7g limited Bee.

F-35B 5.5g @ SL (on F-16A Blk15 E-M Turn Performance @ SL).png


Here is what a Bee driver told me:

For example, in this video from the 2016 Miramar Air Show: https://www.youtube.com/watch?v=OoQbAj_ICYA at the 1:25 mark the pilot is hitting show center at 350 kts and executes a 5 - 5.5G turn in full a/b for 180 degrees of turn, pulls the throttle out of a/b to mil power for the next 90 degrees of turn to bleed off some energy (the jet will accel at 5.5G's in a/b at sea level), and then plugs blower back in for the last 90 degrees of turn for the "acoustic" effect... 30deg/sec is probably a bit high.




Now, this is not quite apples to apples... We don't know the fuel load in the Bee. It probably is not armed with AIM-120's for its routine. But still... this is a 7g limited F-35B rating around like a slick Blk 15 Viper with a full fuel load. Pretty damned impressive IMO... and speaks to the absolute beast to which QS refers earlier.

Also, I timed that turn at 32.4sec. Assuming it was a 360° turn, that works out to 11°/sec. Not quite 5.5g, eh? So, don't know what to say. If the pilot had to pull back out of AB to keep from accelerating, then maybe he backed off to 3g as well.

But my point remains: an F-35B will accel @ 5.5g at sea level, not something even the vaunted F-16A Blk15 could do @ 350kts. (NOTE: The F-16 really likes it faster. Get that rocketship up to 450kts, and it's sustaining around 18.5°/sec, and really rates around at 18°/sec from 7g @ 0.65 Mach (430KIAS) to 9g @ 0.83 Mach (545KIAS).

I guess this is yet another data point bearing out the comment by a test pilot or higher ranking officer that F-35 pilots should be really pleased with the performance of their jet, even the F-35B, which will not be noticeably different.

Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 14 Feb 2020, 07:32
by marsavian
Steve, you can accelerate and hold a tighter turn at Ps=0 too, in the F-16A example above it can go up to Mach 0.7 at 8g without losing height while turning tighter. It can then continue to ride the Ps=0 curve up to Mach 0.9 at 9g losing turn rate before falling back again and losing speed regaining turn rate as it it holds the 9g turn. Also wasn't the F-35B limited to 5.5g in 2016 as well, Block 2B ? It was the F-35A that was limited to 7g at Block 3i in the same time period.

Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 14 Feb 2020, 08:08
by steve2267
marsavian wrote:Steve, you can accelerate and hold a tighter turn at Ps=0 too, in the F-16A example above it can go up to Mach 0.7 at 8g without losing height while turning tighter. It can then ride the Ps=0 curve up to Mach 0.9 at 9g losing turn rate before falling back again and losing speed regaining turn rate as it it holds the 9g turn.


Yes, I see that the F-16A can rate a bit higher @ 0.7 Mach. Didn't I acknowledge / state that in my post? Now, I'm not sure that you will turn tighter. The turn radius lines aren't drawn on this chart, and I have not sacrificed the brain cells to those calcs. Going faster suggests the radius might open up a bit. ("Turning tighter" means a smaller radius to me.)

Having said that... if the Viper is @ 0.53 Mach as well, on his Ps=0 curve, so right about 5.3g (?), since he's on Ps=0, he has no excess energy to accelerate, correct? Or am I understanding Ps incorrectly? Since he's already at SeaLevel, he can't descend... so he needs to relax some g's to go Ps>0, at which point he can accelerate up to 0.7 Mach, then pull to 7g (at which point he'll be Ps=0, and will not be accelerating anymore.)

This example demonstrates that the Viper's "sweet spot", if you will, is up around 0.7 Mach to 0.9 Mach. While this is only one point for the F-35, it suggests the Lightning is happier at a bit slower speed than the Viper: with a rate band maybe from 0.6(ish) to 0.8(ish).

IMO, the other thing to note here is that @ 5.5g, the Bee is rating around 17°/sec, (and for all we know it can also get the full 7g too, here). The Viper can rate 18°/sec (maybe 18.5°/sec) up between 0.7 Mach (7g) to 0.83 Mach (9g). BUT, one thing I've learned around here is that 1°/sec difference is not a deal breaker, it is not clearly superior. In fact, from what I've heard, a 1°/sec difference is equal, for most intents and purposes. So, even at 5.5g the Bee can hang with with the Viper. The Viper has an energy advantage... could he go vert? I suppose, but two things. As QS said... the Viper has to respect the nose of the Lightning. Also, the Lightning is also over 300KIAS. The rule of thumb I have heard from two different pilots is... if over 300kts, you can take it up. So if the Viper goes vert, the Lightning would seem to be able to go up as well. Viper & Lightning in a vert rolling scissors... there's a question for "Dolbe" or Dojo or somebody...

Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 14 Feb 2020, 09:36
by marsavian
Yes, I meant rate higher rather then turn tighter. Strictly speaking you are correct about Ps = 0 but the reduction in G needed to ride the Ps = 0 curve is basically infinitesimal, Ps only has to turn slightly positive before gaining more speed to unlock more G. Boyd's original thesis on energy-maneuverability if you have not already read it ...

https://www.archives.gov/files/declassi ... 2-doc1.pdf

Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 14 Feb 2020, 10:24
by quicksilver
So...

Your discussion has assumed in-plane (2-dimensional) maneuvering only, and situationally ignored geometric position and radius. What was the position of each fighter in 3-dimensional space relative to the other at the notional start of the engagement? Did one enjoy an offensive advantage or were they neutral, and how will their relative position(s) change as a consequence of maneuvering — to include not only nose position resulting from an achieved turn rate — but geometric position as a result of changing velocity (TAS) and turn radius?

After you grok that a bit — when and how does each fighter use 3-dimensional space to gain or neutralize an advantage versus the other fighter as the engagement progresses?

Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 14 Feb 2020, 14:30
by steve2267
marsavian wrote:Yes, I meant rate higher rather then turn tighter. Strictly speaking you are correct about Ps = 0 but the reduction in G needed to ride the Ps = 0 curve is basically infinitesimal, Ps only has to turn slightly positive before gaining more speed to unlock more G. Boyd's original thesis on energy-maneuverability if you have not already read it ...

https://www.archives.gov/files/declassi ... 2-doc1.pdf


OK, I see what you are saying there about riding the Ps=0 curve. Makes sense. I'm not sure it is easily determined how quickly one could change from 5.5g to 7g, i.e. is it near instantaneous, does it take a few seconds, or is it sluggish (tens of seconds), but I sense that would be a function of whether the Ps curves are closely spaced, or spread apart.

Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 14 Feb 2020, 15:18
by steve2267
quicksilver wrote:So...

Your discussion has assumed in-plane (2-dimensional) maneuvering only, and situationally ignored geometric position and radius. What was the position of each fighter in 3-dimensional space relative to the other at the notional start of the engagement? Did one enjoy an offensive advantage or were they neutral, and how will their relative position(s) change as a consequence of maneuvering — to include not only nose position resulting from an achieved turn rate — but geometric position as a result of changing velocity (TAS) and turn radius?

After you grok that a bit — when and how does each fighter use 3-dimensional space to gain or neutralize an advantage versus the other fighter as the engagement progresses?


QS, while I have perused Shaw, and conceptually grok a hi yoyo, low yoyo, barrel roll etc, I do not have a good feel for what those 3D situations look. I was fascinated to read in Shaw how Johnson defeated a "more maneuverable Spitfire" with his Jug by taking advantage of its zoom climb and esp. roll performance, but I am hard pressed to visualize the engagement he described, let alone how that would play out on an E-M diagram. I am not sure these E-M diagrams describe, for example, roll performance, nor how quickly one can brake or accelerate. I suspect an experienced hand can look at one at a glance and say.... hmmm... turns pretty good here... slow energy addition there... don't fight over here... pretty good energy addition here, maybe consider going vert at this speed. But that's about all I got.

I suspect one of the reasons the F-35 is such a beast is that it can quickly decel and accel, move quickly move from a rate fight to a radius fight (Dolbe's comment about "sticking like glue" comes to mind) and back. To me that means moving quickly left and right on the E-M chart, but hard to visualize with the plethora of F-35 E-M plots available to us. I suspect it's rolling performance, especially at high alpha is a strength, but have no idea how that would "look" on an E-M diagram.

Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 14 Feb 2020, 15:45
by quicksilver
“I suspect one of the reasons the F-35 is such a beast is that it can quickly decel and accel”

Exactly. And, in the hands (feet, eyes, and brain) of an experienced pilot, provides the wherewithal to dictate most engagements on his or her terms.

For semantic reference, I always thought that ‘maintaining’ or ‘preserving’ ones energy were bad descriptives. ‘Managing‘ ones energy was a better descriptive imv because it involved both the gaining and ‘giving up’ of ones energy package, circumstantially, based on what was happening in the fight. Of course, for most jets, ‘giving up’ is always easier, but those which can do both with relative ease can be absolute monsters. The case, in point, (amongst a few others) is F-35.

Can’t visualize yo-yos etc? Try using your hands to visualize; pilots have been doing so for over a century — it works. Large watch not required. :wink:

I haven’t read Shaw since it first came out, so I don’t remember how he addressed each maneuver, but a good starting place for visualizing what each maneuver does is to understand its purpose. For example, a hi yo-yo does what? Helps you control your closure, maintain 3/9 control, decrease angles, and increase nose-to-tail. Common errors? Too much, too soon, too little, too late.

Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 14 Feb 2020, 16:06
by steve2267
quicksilver wrote:Can’t visualize yo-yos etc? Try using your hands to visualize; pilots have been doing so for over a century — it works. Large watch not required. :wink:


Nah, I got the hands part and what they look like with models etc. The inate understanding or relating that to actual distance and actual sight picture, the sensation of closure rate etc I do not grok. And probably never will, unless I fork out the $$ to get in a piston popper warbird "trainer" with some ex-fighter jocks that sell "dogfight training" to the public. (Maybe what I really need do is sacrifice my intellectual integrity and write crap for some aerospace blograg, get a name for myself, then ingratiate my way into a cockpit to get "edjeemekated" so I will no longer write crap about XYZ, but of course I will, cuzz I need another hop to better understand... and because I have neither the t*ts nor smile to bat-my-eyelashes way into the backseat...)

quicksilver wrote:I haven’t read Shaw since it first came out, so I don’t remember how he addressed each maneuver, but a good starting place for visualizing what each maneuver does is to understand its purpose. For example, a hi yo-yo does what? Helps you control your closure, maintain 3/9 control, decrease angles, and increase nose-to-tail. Common errors? Too much, too soon, too little, too late.


I understand all that "conceptually," perhaps I need to go re-read and try to put the manuevers in simple terms as you just described. But the "too much, too soon, too late, oh sh*t" parts prolly only come from having done it.

Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 14 Feb 2020, 16:42
by quicksilver
Long ago, doing penance in a staff job after lotsa time in the cockpit, I bought myself an air war game (don’t remember the name) and a fairly representative control stick for my desktop — just to maintain some semblance of ‘air sense.’ It was pretty good — and it was fun. Selectable cockpits, scenarios and adversaries. Didn’t have to spend much money either. Will help you exercise that part of the brain that doesn’t rely on numbers...

Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 14 Feb 2020, 17:40
by outlaw162
I agree, some of the simulations are very good.

The ultimate BFM simulator was the TAC Aces two-cockpit visual simulator (with G seats) at Luke in the 80's. Coming from the 105 to the F-4, it was obvious most of the long time 105 guys were not really up to speed, not because they weren't capable but because generally you avoided prolonged maneuvering in that aircraft and BFM currency requirements were minimal & in DACT you generally just went fast and relied on mutual support.

We scheduled a unit deployment to Luke to use the TAC Aces sim for refresher. Conveniently, the cockpits were both F-4 cockpits (although E models). Having come from the Tucson ANG RTU (A-7/F-100), I acted as the instructor for a lot of the training.

The best feature of the sim was that you could freeze it at any point, from either cockpit with the NWS (nose wheel steering) button on the stick. This was ideal for showing the 'too soon, too much, too late, too little' as QS describes. You could then talk it over using the mics between the two cockpits.

I recall one session after lunch where the maneuver being trained was the nose high rolling nose-tail displacement maneuver, commonly called the 'barrel roll' attack. With the trainee set up on a perch, I'd start the defensive turn and look back and monitor his progress. Poor guy was really having problems consistently 'dishing out' of the barrel roll, quite nose low. Common error.

After 3 or 4 attempts in which I froze the sim to talk it over, we started the next one and about half way thru, HE froze the sim and it got quiet. I said "Brown, Brown are you there?" (Being a part-timer and a farmer, Brown was an appropriate call-sign for him). Finally you could hear him coughing, and he said "I think I've got a green bean stuck in my nose." That's how good the simulation was. :shock:

Now if you had big bucks, you could have something like that. :D

Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 14 Feb 2020, 18:05
by quicksilver
:lmao: :thumb:

Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 14 Feb 2020, 20:30
by steve2267
quicksilver wrote::lmao: :thumb:


X2

:thanks:

Dunno if you can answer these next questions, and I get them "it depends", but am looking for more "rule of thumbs" or typical averages.

Shaw admonished when performing a yo-yo, either hi or low, that a series of smaller yo-yos is better than one big one. Probably has to do with "too soon, too late, too much etc." For simple training wheels discussion where the bandit is in a level defensive turn, when one takes a bite with, say a high yo-yo... how much nose above the horizon are you "typically" going? 5°? 10°? 30°? How much altitude are you typically gaining at the top of the yo-yo? 100ft? 500? 1000? More? From the time you initiate the pitchup for the yo-yo, til your back down at the same altitude is how long? 1sec? 5? 20? Am just trying to get some context here.

Regarding the 'barrel-roll attack', how much angle-off-tail (AOT?) is there before you start thinking that way? 60°? 90°? More? How long does it typically take to complete the roll from the beginning of the pitchup? Am guessing about 9sec +/- (based on changing direction about 90°, and an "average" turn rate from Gen Olds day of 9°/sec for turn rate. But maybe as little as 7sec? So, 7-9sec?

TIA

Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 14 Feb 2020, 20:51
by steve2267
Am going to read through the Italian stallion's book, Art of the Kill; might answer some of my questions. Feel free to answer my previous questions (or not).

It's been a while since I had Falcon 3.0 on a PC. What sim, preferably that also does a good job of several aircraft, but most interested, I guess, in the Viper (unless an older or different aircraft would teach or expose me to these lessons better)? Prefer not to break the bank. Also, what stick / throttle quadrant would you suggest? (Can you get away without rudder pedals?)

TIA

Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 14 Feb 2020, 21:03
by outlaw162
The 'depends' in these academic rear-aspect employment setups really comes down to how much fuselage mis-alignment you were willing to temporarily accept to gain or preserve an advantage as you alluded to.

In the 'real' world, not knowing the opponent, I would be hesitant to accept much mis-alignment during offensive maneuvering initially until the opponent proved I could get away with it....or proved the opposite, in which case I'd be somewhat worried.

During daily with-in squadron training (in non FBW aircraft with limiters) you pretty well knew what your opponent was capable of....i.e. the squadron hierarchy or pecking order. Some guys you could get away with a lot, some not so much.
Win a few, lose a few.

(BTW "Brown", to his credit, was one of the few guys they allowed to transition from the C-124 to the F-105, so he knew nothing but the F-105 A2A philosophy initially, and eventually adapted well for a bomber pilot.)

Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 14 Feb 2020, 21:29
by quicksilver
“Shaw admonished when performing a yo-yo, either hi or low, that a series of smaller yo-yos is better than one big one.“

Agree. Why? A smart bogey will use the time you are not pressing him to regain energy and/or build more angles to force an overshoot and change the geometry of the fight — typically a scissors, rolling or horizontal/flat. (‘Probably has to do with "too soon, too late, too much etc’ — Yes)

“For simple training wheels discussion where the bandit is in a level defensive turn...”

Nose-low slice turn more common traditionally, but depends on perf of the jet and the set-up. Horiz turn can be highly effective for the right jet (eg —like a Viper).

“...how much nose above the horizon are you "typically" going?”

‘How high’ is in relation to the target’s plane of motion, not the horizon. How high? Go back to the purpose — until the problem that I saw building (angles, track-crossing rate, nose-to-tail) was relieved/manageable/under control. Lotsa little bites better than one big one unless you effed it up or it was just a really tough bogey.

‘How much altitude...?’ Never looked at altitude unless the airspace was capped.

‘From the time you initiate the pitchup for the yo-yo, til your back down at the same altitude is how long?

Never timed it. Didn’t care. ‘Until angles problem etc resolved‘ just like above. Remember, you’re watching the bogey the whole time you’re doing the yo-yo; the maneuver is not flown looking in the cockpit or HUD. Reference some discussions we’ve had around here about jets that give one proprioceptive feedback — eg different levels of G, or buffet that tells you what alpha range or general airspeed range you’re in. There is an element of ‘energy management’ in virtually everything you do in a jet, whether it is gaining it, spending it, or preserving/maintaining it. Sometimes it’s tactical, sometimes administrative, sometimes just wise for what might come later (like...they just shut down the deck because a tug broke down in the only landing spot not occupied by another aircraft).

Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 14 Feb 2020, 21:32
by sprstdlyscottsmn
steve2267 wrote:It's been a while since I had Falcon 3.0 on a PC. What sim, preferably that also does a good job of several aircraft, but most interested, I guess, in the Viper (unless an older or different aircraft would teach or expose me to these lessons better)? Prefer not to break the bank. Also, what stick / throttle quadrant would you suggest? (Can you get away without rudder pedals?)

TIA


Let's classify sims by the level of detail.
Study level - nearly every aspect of the plane will be modeled in the final release. Cockpit switchology, systems and subsystems, and a top notch flight model are expected here.

Professional level - A good attempt is made at a flight model to include idiosyncratic behavior at the limits, systems on the other hand may be greatly simplified even if basic function (e.g. radar range) is fairly accurate.

Casual - A basic flight model is designed where only a few parameters determine how a plane will fly (e.g. wing area, CL max, uninstalled thrust rating)

Arcade - Devs did whatever they wanted for the sake of the game (Ace Combat)

Falcon 4.0 on GOG.com ($10) and then get the BMS 4.34 update (free) for the best Study Viper for the Money. There are a few other Professional planes it tries to model well and a ton of Casual planes.

Digital Combat Simulator has the most Study level planes but it the most expensive by far. $55-80 per Study level aircraft and MOST of those are still in Early-Access Beta.

Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 14 Feb 2020, 22:34
by marsavian
Steve, if you haven't already I strongly suggest checking out the Growling Sidewinder channel on YouTube. It's primarily DCS based and the majority of his videos are BFM ACM dogfights where guns kill is the aim. What makes his channel quite unique is he runs through every twist, turn and yo-yo of each dogfight in Tac View in the second half of each video explaining who did each maneuver right or wrong WRT position or energy state. It will help you visualise the 3D nature of ACM.

https://www.youtube.com/channel/UCh2rDh ... LlzL3QEwgp

Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 14 Feb 2020, 23:06
by sprstdlyscottsmn
marsavian wrote:runs through every twist, turn and yo-yo of each dogfight in Tac View in the second half of each video explaining who did each maneuver right or wrong WRT position or energy state. It will help you visualise the 3D nature of ACM.

For every minute I spend in a mission in DCS I spend two in TacView analyzing everything that went right or wrong. I often see things like "Woah, I was lucky to survive that" or "Wow, I made that hard pull at just the right time"

Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 14 Feb 2020, 23:21
by steve2267
Is one monitor enough? Or how many horizontal pixels do you prefer?

Will a sim take advantage of 3 “wraparound” monitors?

Do any yet take advantage of VR goggles (e.g. Oculus Rift)?

Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 15 Feb 2020, 00:22
by steve2267
Aaah, I see that DCS describes required hardware etc and includes VR option.

Still curious about how many pixels you guys like.

Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 15 Feb 2020, 01:43
by sprstdlyscottsmn
Vr

Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 16 Feb 2020, 00:33
by count_to_10
sprstdlyscottsmn wrote:
Arcade - Devs did whatever they wanted for the sake of the game (Ace Combat)

The good Ace Combat games had the problem of always being Vietnam regardless of the aircraft (after you get past the order of magnitude too many missiles). The bad ones...could be like playing a weird version of Dance Dance Revolution.

Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 29 Feb 2020, 04:15
by lbk000
You don't need anything fancy to learn a lot with the computer.
Ironically for DCS old low-rez (1080p!) displays have an edge in combat exploiting the distance rendering. Fancy screen set-ups and VR are for immersion and visual pleasure, if you're really keen on learning about air combat mechanics you don't really need them. If your screen can show them getting bigger or smaller and moving across your FoV, you're golden.

What I'm gonna suggest might seem a little against the usual wisdom though -- if you really want to learn dogfighting on a budget, go with Warthunder. Yes, it's infested with gamer-types. No, you shouldn't expect flight models to be true to life. No, you won't get to fly your favorite modern jet. But the general flight dynamics are quite good and so does a perfectly adequate job of upholding fundamental air combat concepts, which are airframe agnostic anyways. It's got probably the best working mouse-control scheme on the market, and the jump-in-and-go grand furball format allows you to rack up a lot of experience quickly by letting you encounter tons of different engagement scenarios at a time.

DCS is good, the base is free and you can learn a lot with just the free Su-25.
By the by, I actually don't recommend learning on a FBW aircraft simulator straight off the bat. Powerful modern aircraft are very 'forgiving' and can easily lead you astray by allowing you to bruteforce your way out of mistakes. You'll gain a better foundation with something like the MiG-15 or F-86 simulator.
DCS is great for discovering how troublesome BVR combat is and why sensors are everything.

Edit: also x2 what Spurts said about TacView, it's the best way to review and analyze your DCS session. It also happens to be extremely easy to use, just having it on in the background will automagically log your mission.

Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 21 Mar 2020, 23:42
by quicksilver
steve2267 wrote:
quicksilver wrote::lmao: :thumb:


X2

:thanks:

Dunno if you can answer these next questions, and I get them "it depends", but am looking for more "rule of thumbs" or typical averages.

Shaw admonished when performing a yo-yo, either hi or low, that a series of smaller yo-yos is better than one big one. Probably has to do with "too soon, too late, too much etc." For simple training wheels discussion where the bandit is in a level defensive turn, when one takes a bite with, say a high yo-yo... how much nose above the horizon are you "typically" going? 5°? 10°? 30°? How much altitude are you typically gaining at the top of the yo-yo? 100ft? 500? 1000? More? From the time you initiate the pitchup for the yo-yo, til your back down at the same altitude is how long? 1sec? 5? 20? Am just trying to get some context here.

Regarding the 'barrel-roll attack', how much angle-off-tail (AOT?) is there before you start thinking that way? 60°? 90°? More? How long does it typically take to complete the roll from the beginning of the pitchup? Am guessing about 9sec +/- (based on changing direction about 90°, and an "average" turn rate from Gen Olds day of 9°/sec for turn rate. But maybe as little as 7sec? So, 7-9sec?

TIA


So, Steve...

Exercising some ‘social distancing‘ now and for the next few weeks, I thought I’d revisit some of these threads...

Much of the online discussion about bfm generally puts the cart before the horse — ie intermediate or advanced concepts without any discussion and understanding of foundational basics. I’m guilty of it by assuming too much about someone’s contextual understanding of the questions being asked. ‘Foundational basics‘ around here should start with ‘are you a pilot?’ or ‘have you ever spent any time at the controls of an aircraft?’ Then, of course, ‘what kind‘ and ‘how much‘ because that makes a huge difference. Then we get to the question of whether or not one has flown any aerobatics and formation work, including tacform and maybe an A-A gunnery pattern. Why? Because by the time your Mark 1, Mod 0 Student Naval Aviator (or USAF equivalent) gets to his or her first BFM ride, they have a couple hundred flight and simulator hours, and multiples of that in academic course work. They’ve been exposed to and demonstrated proficiency in basic airwork, instruments, airways nav, aerobatics, and heavy doses of formation work.

Formation work, including formation aerobatics, is the first place one is exposed to control and maneuver of an aircraft in relation to another. It tends to be a significant filter in the flight syllabus. If you cant get good at form work, you’re gonna have a hard time being a military pilot, although there are occasional ‘quality escapes’ from the training command on that count. Most of the flying one does in the course of ones career involves some element of formation flying. But once again, wrt BFM, it is where we start to learn how to maneuver in relation to another aircraft. Some of it requires lotsa finesse, but all of it requires an ability to very rapidly (often almost instantaneously) discern aspect, distance, speed, and closure relative to another aircraft while controlling ones owns aircraft and maneuvering in 3-dimensional space.

Am about to run out of power so I’ll have to pick this up a bit later... :doh:

Ok, I'm back. There are also some informal elements of a syllabus that help build ones ability to not just maneuver a given jet, but to develop a 'feel' for how it responds to control inputs at different altitudes, airspeeds and AOAs. We used to call them 1v0. These sorties can be enormously helpful at mitigating performance errors that might occur later in the formal BFM syllabus due to a nascent familiarity controlling a new jet in aggressive maneuvering.

...and all of this just scratches the surface of the basics that are foundational to an understanding of bfm and development of the skills necessary to be successful at it. And we havent even gotten out of the training command yet (e.g. 2v1), much less fighting one's fleet jet, or fighting dissimilar types.

Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 22 Mar 2020, 00:36
by sprstdlyscottsmn
quicksilver wrote:
Ok, I'm back. There are also some informal elements of a syllabus that help build ones ability to not just maneuver a given jet, but to develop a 'feel' for how it responds to control inputs at different altitudes, airspeeds and AOAs. We used to call them 1v0. These sorties can be enormously helpful at mitigating performance errors that might occur later in the formal BFM syllabus due to a nascent familiarity controlling a new jet in aggressive maneuvering.


Hey QS, not to say that Sim are the same as the real thing, they aren't, but this concept applied to my buddy and I in the F-14 for DCS.

We got the plane for me to be his RIO but I had more time to play with the sim, so I did a LOT of time carrier landing and dogfighting. As a result, by the time we could fly together in BFM I died quickly because he tried flying it like a Hornet (we over alpha-ed and stalled on the first pull, and almost every pull after that).

We set up another flight where we would both fly separate Tomcats. I let him saddle up on my six before going to full Mil and started maneuvering. Within a few minutes I was glued to his six and he couldn't shake me, even with him using full AB and me in Mil. I knew more about how the jet felt as it was being maneuvered.

Sorry to ramble on about sims, but the experience was exactly what you described real pilots going through.

side note, we were both in VR and both using the same HOTAS Warthog stick.

Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 22 Mar 2020, 01:01
by quicksilver
:thumb: No substitute for ‘practical application.’

Modern sims are the exponential of “one picture is worth a thousand words.”

Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 22 Mar 2020, 01:28
by spazsinbad
However it is always great to bring whatever actual flying experience one may have to any sim because IME In My Experience (albeit with only simple desktop computer sims) that makes a difference. BFM is a brutal physical experience especially with the same aircraft with pilots of similar experience - it goes on and on until the hard deck reached under G.

Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 22 Mar 2020, 01:46
by quicksilver
"BFM is a brutal physical experience especially with the same aircraft with pilots of similar experience."

True, particularly in the A-4 series aircraft; half the fight was winning the battle against the parachute pack and the seat in your own jet. Harrier (AV-8 series in US usage) a lazy-boy recliner in comparison. Hornet had a very upright feeling.

I had the occasion to backseat in a 'D' Eagle jet a couple times. I found myself reflexively slapping my chest and lap straps to make sure I was still strapped in throughout each flight. Very comfortable...

Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 22 Mar 2020, 02:55
by spazsinbad
I ALWAYS strapped myself real tight with the seat with helmet buzzing the A4G canopy. I had permanent bruises on my shoulders, even more so with the MACCHI MB326H which - all things - leant forward! Weird as hell with the standard double visor and helmet which always slipped forward under sweat. :devil: FARK! :doh: Strapped in tight here as well.

Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 22 Mar 2020, 18:33
by lbk000
spazsinbad wrote:the MACCHI MB326H which - all things - leant forward!

Now what's the logic behind that?

Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 22 Mar 2020, 23:01
by spazsinbad
Could not have been more silly the way the MB Mk.4 ejection seat forced the front seat pilot especially to be leaning forward slightly. IF you have seen old ejection seats they have lots of stuff and the way the seat was that was the case.

The graphic from the RAN/RAAF Macchi MB326H flight manual of the Martin-Baker 4B seat shows the top part 'parachute assembly' bulging out, this is the 'forcing one forward' bit. There was no reclining in this seat. One old bold A4G pilot who had first flown the Sea Venom with the 4A seat then later from the A4G became a QFI Qualified Flying Instructor at RAAF Pearce had to spend his leave in the hospital there having his back stretched so that he could continue to fly the thing.

Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 23 Mar 2020, 01:09
by spazsinbad
A nice bunch of walkaround ejection seat for RAN/RAAF Macchi MB326H here: https://www.aussiemodeller.com.au/pages ... hi_P1.html
:shock: One may see how it all wants to FLOP FORWARD ffsake. :devil: (amalgamation of the three photos attached)
https://www.aussiemodeller.com.au/Image ... G_0322.jpg
&
https://www.aussiemodeller.com.au/Image ... G_0324.jpg
&
https://www.aussiemodeller.com.au/Image ... G_0371.jpg

I have lots of photos showing the front seat pilot leaning forward because that was the way - he was not being KEEN. 8)

Then lastly but not loosely strapped in the aforementioned front seat - the worst leaing forward offender for occupant.

https://www.aussiemodeller.com.au/Image ... G_0366.jpg

Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 23 Mar 2020, 19:27
by outlaw162
M-B seats have broken a few backs, primarily due to wrong body position. Had a UPT classmate permanently paralyzed from an M-B ejection. But his two options were to quickly use the seat or die.

I imagine the -16E in the F-35 has a number, if not all of the bugs from the earlier models corrected.

With respect to similar BFM, flew block 10 v block 10 two sorties in one day at 45 years of age. Got thru half of the first cold beer at the Club, put my head down on the bar just for a moment....and fell asleep. However, the 30 year olds I flew against never even showed up.

A little less than 400 hours in the A, got to hand it to the folks that do 2-3000 or more hours in the thing. A future windfall for orthopedic surgeons. :mrgreen:

But I've actually hurt worse from F-100 students unexpected 'yank and banks', while in the back seat and twisted around inopportunely. And then you had to tote that parachute backpack back to PE....had trouble one day getting it high enough to hang on an upper peg. Another advantage of instructing from the chase position, as in the F-35. :D

Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 24 Mar 2020, 00:20
by jbgator
Being a Viper Baby I had 1300+ hours in the F-16 when I went to fly the mighty Phantom II. I quickly learned to hate what I called the Martin Baker De Sade seat. Beside the parachute pack that drove your head forward there was the face curtain handles that, unless you were a midget (I'm only 5'8"), hit the back of your helmet and further pushed your head forward. Fortunately you were not going to do a lot of Gs in the Double Ugly so the leaning forward position was only a pain for the other 99% of the time you were flying the jet. Don't even get me started on the leg restraints which further increased the feeling the good Marquis De Sade had you under his control. I was so happy to go back to the luxurious ACES 2 recliner 18 months later. Never sat in one of those painfully upright British inventions again thankfully. I guess you need that stoic British fortitude...eh...what? Sad to see they won out and got their painful contraptions in the F-35. While I was still staff at ACC there was a strong effort to get the new ACES seat put into USAF jets. Guess that failed. I flew many long hours and pulled a lot of Gs in ACES 2, never a problem. Progress I guess.

Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 24 Mar 2020, 00:58
by spazsinbad
:doh: Heheh. BONDAGE! with Martin the BAKER. :devil: Most of my era first encounter was the Mk.3B seat with single overhead handle and one between legs in the VAMPIRE. BONDAGE! MB style. Yessir Nosir we had BOWYANGS (leg restrainsts as aforementioned). BONDAGE! MB style. SEA VENOM Mk.4 seat BONDAGE MBstyle BOUYANGS (alternate BONDAGE! spelling). The VAMPIRE seat had the raft rubber hole plugs packed directly under one's **** BONDAGE! MBstyle. Nothing could be done about it except SUBMIT. BONDAGE! MBstyle. At least with the stiffened carboard British Mk1A helmet with canvas inner web cushion with a cloth helmet inside that with the radio earplugs that combo was comfortable compared to that damn MACCHI double visor required helmet. Thankfully later the RAN Safety Equippos Head Honchos came to their senses allowing A4G/Macchi Pilots to wear the same single visor helmet with interchangeable oxygen masks. A win for the good guys. Not so my era we had to have and not change the regulation safety equipment with one exception the antiGpants which were interchangeable - the A4G had no pockets whereas the Macchi had voluminous lower leg pockets that could be filled with goodies even when the BOW YANGS were fitted. BONDAGE! MBstyle. :mrgreen:

The VAMP seat had a 120 knot 200 feet min ejection condition so staying low after takeoff for a turnback (for practice) was always fun in case the engine failed. We did similar takeoffs in the MACCHI but not Sea Venom it had better Mk.4.

The MACCHI Mk.4 MB ejection seat had a NEGATIVE G STRAP. BONDAGE MBstyle. Fun for strapping in passengers in seat.

Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 24 Mar 2020, 03:27
by Gums
Salute!

Gotta go with "Gator" about that ACES seat. Damned comfortable, as was the ESCAPAC seat in the Sluf, although we retained the Navy handles above and below, face curtain included, heh heh.

No serious back injuries to speak of in the Sluf I can recall, and the folks that punched in the Viper had praise for the smooth ride.The funny thing about that seat in the Viper was the 30 degree tilt was a non-player in a fight. We nmostly sat straight up so we could hold onto one of the "towel racks" and twist around.

Gums sends...

Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 24 Mar 2020, 04:57
by spazsinbad
Yep, ESCAPAC seat in the A-4 was comfy compared to the others SAT in - tight fit in cockpit though - butt OK never mind.

See the back of an ESCAPAC in the front seat of a TA-4K KAHU at NAS Nowra c.2000 + glimpses of the F-16-like avionics.

Supersonic Life - Fighter Jet Teaser No. 2.1 https://www.youtube.com/watch?v=SIaRph93frE


Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 24 Mar 2020, 11:55
by madrat
Nice.

Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 28 Mar 2020, 20:30
by spazsinbad
:devil: Just because we are having fun - WOT? A little something for these times as seen online elsewhere.... 8)
"Saw a news report yesterday where a doctor said that, to alleviate the boredom of the forced isolation in our homes, we should focus inward and look for inner peace. One way he said we could achieve this was to check around and find those projects we had started but never finished, for one reason or another. The satisfaction of finally getting them done would lead to a healthy, strong sense of satisfaction and accomplishment.

So I looked through my house to find those things I'd started and hadn't completed. I finished off a bottle of merlot, a bottle of chardonnay, a bodle of Baileys, a buttle a wum, tha mainder of Valiumun srciptuns, an a box a chocletz. Yu haf no idr how fablus I feel rite now! Sned this to all who need inner peez, an telum u luvum. And rember two hash yer wands!!

Haff a stafe day avrybobby!!!"

Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 28 Mar 2020, 21:37
by southernphantom
spazsinbad wrote:Yep, ESCAPAC seat in the A-4 was comfy compared to the others SAT in - tight fit in cockpit though - butt OK never mind.

See the back of an ESCAPAC in the front seat of a TA-4K KAHU at NAS Nowra c.2000 + glimpses of the F-16-like avionics.

Supersonic Life - Fighter Jet Teaser No. 2.1 https://www.youtube.com/watch?v=SIaRph93frE



Thanks for the video, Spaz! Not sure what's up with the music selection, though.

Re: F-35A maximum G rating lower than 5?!

Unread postPosted: 29 Mar 2020, 01:39
by spazsinbad
:( Not my video Not my music - does my music sound to loud in this when turned up to ELEVEN! A4Gs MELBOURNE https://www.youtube.com/watch?v=B8ola6f7jSE [GOOD 'TAXI ONE' ARREST at 5min 10sec - me heart stops here]