LM F-35 kinematics ‘better than or equal to’ Typhoon/Shornet

Discuss the F-35 Lightning II
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by spazsinbad » 07 Feb 2013, 21:53

IN FOCUS: Lockheed claims F-35 kinematics ‘better than or equal to’ Typhoon or Super Hornet
07 Feb 2013 Dave Majumdar

http://www.flightglobal.com/news/articl ... et-382078/

The BEAT GOES ON DaDumDumDum DumDahDeDum... Whatever. Just verbalising without having the stats and not with apples to apples so to speak is ridiculous. But hey it is interesting. No? :roll:

http://www.youtube.com/watch?v=umrp1tIBY8Q


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by bigjku » 07 Feb 2013, 22:44

The F-18 pilot sounds like a man off his rocker a bit. I am not sure what he is talking about but he sounds flat crazy. I also get the impression the F-22 pilots are being quoted slightly out of context.


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by disconnectedradical » 07 Feb 2013, 22:46

Oh wow, I just posted the exact same article in another thread. My bad. Also, what is this F-22 Dash-1 manual that they were talking about?


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by megasun » 07 Feb 2013, 22:48

If he is just to remind people to compare F-35 with only LOADED legacy fighters, I think that makes sense.
I believe F-35 kinematics better than or equal to most Gen-4 when loading 2*2000lb bomb + 2*AMRAAM.

Plus SHornet is not a fast aircraft anyway. But in AA config, I'm sure Typhoon will out accelerate F-35 when loading with 4 AAM, significantly, so will F-16. Wingtip missiles add only small amount of drag; and the 4 tandem, semi-conformal, fuselage stations of Typhoon are even low-drag.
Image

Looks like this 43-second decrease in acceleration draws lots of attentions. I wonder if C-variant can still hit Mach 1.6, it shouldn't be very draggy. I believe for legacy fighters like F-16 / F-18, if in any config that they can reach Mach 1.6, it won't take 100 seconds to accelerate from M0.8 to M1.2. May there be some other reason besides transonic drag?

And don't forget F-22's kinematics is not in the same league of Gen-4 fighters.


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by bigjku » 07 Feb 2013, 23:01

If we are going to match up the weapons outfit to compare you also need to match up the gas and range. A Eurofighter with no gas tanks is not going very far.


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by the32notes » 07 Feb 2013, 23:41

Some one please correct me if im wrong

the way I understand it, now that the F-35s sustained Turning Gs have been reduced to 4.5 - 5Gs, it should still be able to make some preaty sharp sustained turns, however it has to give up more speed now, so in a close in DACT training , guns only, F-35 pilots might use hornet tactics, using superior slow speed manuverability and extreme AOA to point the nose.

And lastly is this lowering of the Bar thing permanent? Or is it going to be fixed,
A graph by Spazinbad on
http://www.f-16.net/f-16_forum_viewtopi ... t-240.html
Indicates that the original objective was for all F-35 variants to sustain 6G turns,
If they can only do 4.5Gs sustained, then something must be well.........out of place,

Thanks.


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by spazsinbad » 08 Feb 2013, 00:07

Probably best to have the 'Bowman ' Graphic here again (from same page source): http://www.f-16.net/attachments/scoreca ... 08_316.gif

Image

There are 'Objectives which 'the32notes' quotes but also there are 'Threshold' [requirements] which I gather the F-35 should NOT go below. So the aircraft has not achieved an 'objective' but has it gone below the 'threshold'? And if so is this acceptable? Apparently yes.


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by the32notes » 08 Feb 2013, 00:56

Thanks for posting the graph again Spazinbad, so are these lowered standards the new KPPs for the Lightning II or should we wait for further developments? Still hope they can meet or even exceed the original 6G sustained turn rates, fingers crossed,


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by spazsinbad » 08 Feb 2013, 00:59

No these are not KPPs. Have a look at a recent thread about this issue:

http://www.f-16.net/index.php?name=PNph ... kpp#241365

There are very few actual KPPs and the F-35 has rarely had them changed. The most recent change was to increase the USMC flat deck STO to 600 feet from original 550 feet and then a small change to the combat radius of the F-35A from 600 nm to 590 nm as I recall but I could be wrong. I'll look for the recent thread (now at end of first sentence above - look around those pages).

I can see that perhaps the 'KPP' is perhaps misleading out of context with an arrow pointing to the actual KPP in the graphic above. But hey dems de breaks.

Here is a KPP chart amended to current KPPs AFAIK: http://www.f-16.net/attachments/kppsjpooct2007_928.gif

Image

HERE IS AN AMENDED 'Bowman' Graphic WITH TEXT as it appears in the PDF on physical page 15 & 16 [numbered page 8 & 9] available here: http://www.f-16.net/f-16_forum_download-id-14791.html (0.25Mb) Always best to read the original PDF but here is the text as shown in the graphic below:

Scorecard | A Case study of the Joint Strike Fighter Program
by Geoffrey P. Bowman, LCDR, USN 2008 April

Figure 3 text/graphic page number 8 & 9

http://www.f-16.net/f-16_forum_download-id-14791.html

(ADDITION) Footnote text for the table graphic:

1. Configuration: 2 x empty external 370 gallon tanks internal fuel for 540nm combat radius, 4 x JDAM Mk-84, 2 x AIM-120, gun with 150 rounds. Airspeed <0.9M.

2. With 60% of internal fuel load required for 540nm combat radius and JDAMs jettisoned/released"

“Maneuverability is addressed in both general and specific terms. The requirement for all three variants is to provide a platform that will have a positive exchange ratio during air combat maneuvering (ACM) engagements against "high performance threats that employ helmet mounted cueing and high off-boresight weapons."17 The JSF must further possess high angle of attack (AOA) capabilities "similar in nature to (or better than) the F-18C."18 The fuel levels and payloads at which maneuverability is calculated differs for each variant but generally focuses on a post-weapons release payload and fuel state at 50% of the required combat radius. Figure 3 below lists the specific maneuverability requirements and shows the differences among the variants.19 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....”
Attachments
BowmanF-35parameters+TEXT.gif
Last edited by spazsinbad on 08 Feb 2013, 22:12, edited 7 times in total.


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by the32notes » 08 Feb 2013, 01:11

Thanks,
so are these changes in transonic acceleration and sustained Gs subject to change also?
I guess what I mean is, are the lowerd standards permanent? Or do they normaly change overtime


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by Gums » 08 Feb 2013, 01:34

Salute!

I read the Flight article before signing in here.

From experience, I understand the awesome nose-pointing capability of the Bug, and even the Eagle. That capability could be used in a very small envelope of a "dogfight" - you know. a fight in a telephone booth.

The Viper could be rolled to the limit at our max AoA and that usually gave us the advantage.

The sustained gee numbers need to be explained for the criterion profile. Is that max A/B? Level flight? I can tellya that a sustained 4 or 5 gee fight is not very pleasant. If you have to pull that much for more than 30 seconds, then you are way behind the fight. Think going vertical or just extend and get outta the fight to gain some "E".

I flew the Deuce, and we could get way above 50 deg AoA, but we lost speed like you could not believe. Great nose pointing, but then dead in the water.

I think the Bug pilot suffers from pride in his jet. I would go with the other dude that the article quoted.

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by delvo » 08 Feb 2013, 03:11

But at issue is exactly what constitutes a combat load out. An F-35 loaded up with two 2000lbs bombs and two air-to-air missiles internally is not carrying an equivalent payload to a Eurofighter Typhoon with four 2000lbs bombs and five air-to-air missiles or a Super Hornet armed with a mix of bombs and air-to-air missiles... Another point that must be considered, however, is that the F-35 will only be relying on its internal weapons payload during operations against a very robust threat environment. "Internal carriage is only required if you need the stealth," another F-22 pilot says.
This is actually a good point, which might not work out in F-35's favor (at least on the specific issue of "kinematics", although it wouldn't affect other ways it has advantages over other planes). F-35 only gets "clean" aerodynamics when it's only partially armed: two AMRAAMs & whatever you put on two more heavier-duty hardpoints. So its clean aerodynamics can only be compared to that of another plane that's also carrying that much. (Do these other planes ever fly with only that much?) As soon as you put four bombs on another plane, the F-35 you're comparing it to needs to have at least two on the outside. (Only half as many, but not zero.) If the other carries six, its equivalently loaded F-35 has four outside. (Only two thirds as many, but not zero.) So its internal bays still give it some aerodynamic advantage, but when the total load is high enough that external carriage is called for, that advantage doesn't get any bigger and could even get smaller, relatively speaking.

These reports we've been getting haven't been informative enough about how much stuff was being carried when those flight observations were made.

The first F-22 pilot says he is surprised to hear that there are already E-M diagrams available. "...'real' E-M diagrams come from OT/DT [operational test/developmental test], not the contractor."
Why would he be acting like these DID come from Lock-Mart instead of from the huge piles of tests that have actually been going on?


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by handyman » 08 Feb 2013, 04:04

Nobody seems to mention that the F35 is carrying all its fuel internally into combat.


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by popcorn » 08 Feb 2013, 04:33

bigjku wrote:If we are going to match up the weapons outfit to compare you also need to match up the gas and range. A Eurofighter with no gas tanks is not going very far.

Not to mention any sensor, EW, etc. pods needed to approximate the F-35.


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by Gums » 08 Feb 2013, 05:08

Salute!

You have it nailed, Popcorn.

I'll take a clean jet with great LO characteristics into the arena with a half-dozen SDB's and a missile or two anyday.

The Bug and other jets have the RCS of a barn door, even without all the tanks and such. In the Stubbie, I'll get close enough to do serious harm before they even know I am there. Not as LO as the Nighthawk, maybe, but close enough to the RCS of a sparrow or cats-eye marble for me.

Just thinking about sustaining 5 gees for 10 or 15 minutes makes me tired already, and I was used to the Viper when we could do that easily if below 20K or so. Of course, nobody did that. Other ways to skin a cat, ya think?

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