F-16C, F-16E vs F-14D

Unread postPosted: 07 Jan 2016, 02:04
by garrya
How would a F-16C or F-16E ( equipped with 6 Aim-120 , no CFT) fare again F-14D equipped with( 4 Aim-7 , 4 Aim-9 ) in dogfight?
No WVR or HMD on either side.

I used to think F-14 is a slug in dogfight but it turn out according to flight manual F-14 have very compatible sustain turn rate vs F-16 , and much better instantaneous turn rate at slow speed.
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It seem like F-16 turn better at high speed while F-14 is better at slower speed , I think that may translate to better vertical fight for F-16 , and better nose pointing for F-14 but iam not 100 % sure, so can anyone ( pointing especially at you guy : Johnwill , Gums , sprut :mrgreen: ) tell me which aircraft is better in that configuration mentioned at the start ? :mrgreen:

Re: F-16C , F-16E vs F-14D

Unread postPosted: 07 Jan 2016, 04:15
by sprstdlyscottsmn
Where did you get the NAVAIR chart for the F-14? I have been looking for source data on the Cats. Remember than the D model cat has ~40% more useful thrust. There is an quote floating around somewhere (I've heard too many to remember where I heard them all) by an Eagle driver, "We think we fly the best fighter in the world, but we don't get slow against the gents in the fourteens." I used to think that meant they didn't relax, but as you can see it means literally getting slow. Below 0.7M the F-14 will turn tighter in both sustained and instant capacities. This means you will almost always have a larger turn radius than a Cat flown in it's comfort zone. You need to go vertical. The old A model had a "T/W" of 1.0 when completely empty. Make it point up and it will slow down. The A+/B/D changed all that. Vipers and Eagles would still easily take them in the vertical but it was not the easy move it used to be. In a Viper or Hornet you could even try getting them REAL slow and using superior low speed handing from the FBW to out roll them. In the end I would say teamwork is the BIGGEST factor for success. One problem for the Cat is that it starts to fall apart as the wings go back as far as turning so if the opposing pilot sees wings back they know they have a turning advantage and this is when the Cat driver may go vertical.

Re: F-16C , F-16E vs F-14D

Unread postPosted: 07 Jan 2016, 04:27
by 35_aoa
You can get a little slower in a Viper than what I've seen an Eagle do, but it just never makes sense in either case. In a Viper in full AB, if you can unload to 0G for just even a couple seconds, you will go from that poorly chosen slow fight, to having enough airspeed to go up, which a Tomcat or Hornet in that scenario will not be able to do. Conversely, if you let the fight get both slow and close, it is pretty hard to not get flushed out. The Viper also does bad things when you get too slow and still try to go up, or you combine a lot of real aggressive combined roll/yaw at high AoA and let the sideslip/yaw rate get out of control. Two other good reasons not to get slow.

Re: F-16C , F-16E vs F-14D

Unread postPosted: 07 Jan 2016, 04:30
by sprstdlyscottsmn
Looking at the above "D" model chart and a previously posted A model chart "with maneuver Devices inop" the A model does better and sustained turning in the supersonic to the point of having a higher top speed as well. Plugging the glove vanes and suffering the full trim drag is the only reason I can think of.

Re: F-16C , F-16E vs F-14D

Unread postPosted: 07 Jan 2016, 04:34
by eloise
If iam not mistaken , from the graph their sustain turn rate is similar around 14-15 degree /second just at different speed


I can understand how normal turn fight would work because if one aircraft have superior turn rate then after a while it will end up behind enemy tail. However eventhough I also heard a lot about taking the fight to vertical but I have no idea how it done ,Ex : if the enemy pilot go climb up couldn't you just wait and fly in a horizontal circle instead of trying to follow him ? :shock:
and if enemy then try to go back down to make a pass at your aircraft I think you can observe where they come from to turn your nose to that direction :? it really hard for me to understand how vertical ( boom-zoom ) fight would work unless the enemy have no idea where you came from

Re: F-16C , F-16E vs F-14D

Unread postPosted: 07 Jan 2016, 04:38
by garrya
sprstdlyscottsmn wrote:Where did you get the NAVAIR chart for the F-14? I have been looking for source data on the Cats. Remember than the D model cat has ~40% more useful thrust. There is an quote floating around somewhere (I've heard too many to remember where I heard them all) by an Eagle driver, "We think we fly the best fighter in the world, but we don't get slow against the gents in the fourteens." I used to think that meant they didn't relax, but as you can see it means literally getting slow. Below 0.7M the F-14 will turn tighter in both sustained and instant capacities. This means you will almost always have a larger turn radius than a Cat flown in it's comfort zone. You need to go vertical. The old A model had a "T/W" of 1.0 when completely empty. Make it point up and it will slow down. The A+/B/D changed all that. Vipers and Eagles would still easily take them in the vertical but it was not the easy move it used to be. In a Viper or Hornet you could even try getting them REAL slow and using superior low speed handing from the FBW to out roll them. In the end I would say teamwork is the BIGGEST factor for success. One problem for the Cat is that it starts to fall apart as the wings go back as far as turning so if the opposing pilot sees wings back they know they have a turning advantage and this is when the Cat driver may go vertical.

I got the chart from a member here
http://forums.eagle.ru/showthread.php?t=157416&page=5

Re: F-16C , F-16E vs F-14D

Unread postPosted: 07 Jan 2016, 04:43
by garrya
eloise wrote:
I can understand how normal turn fight would work because if one aircraft have superior turn rate then after a while it will end up behind enemy tail. However eventhough I also heard a lot about taking the fight to vertical but I have no idea how it done ,Ex : if the enemy pilot go climb up couldn't you just wait and fly in a horizontal circle instead of trying to follow him ? :shock:
and if enemy then try to go back down to make a pass at your aircraft I think you can observe where they come from to turn your nose to that direction :? it really hard for me to understand how vertical ( boom-zoom ) fight would work unless the enemy have no idea where you came from

Interesting enough , X-31 with thrust vectoring totally demolished F-14 and F-18 but fail to get a positive kill ratio again F-16 and F-15 due to their superior T/W
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Re: F-16C , F-16E vs F-14D

Unread postPosted: 07 Jan 2016, 05:14
by sprstdlyscottsmn
One of my professors was involved from the AF side showing that the Eagle and Viper only had to wait for the X-31 to vector and then they could just climb.

Re: F-16C , F-16E vs F-14D

Unread postPosted: 07 Jan 2016, 05:21
by garrya
sprstdlyscottsmn wrote:One of my professors was involved from the AF side showing that the Eagle and Viper only had to wait for the X-31 to vector and then they could just climb.

wouldn't the X-31 successful point it's nose at F-16 , F-15 once it use vector ? ( Iike almost instant)
and when F-16/F-15 come down to attack shouldn't X-31 be able to turn it's nose at their direction too , making it a head on pass ?

Re: F-16C , F-16E vs F-14D

Unread postPosted: 07 Jan 2016, 05:59
by sprstdlyscottsmn
Nothing is ever that simple is it? If it was then the X-31 would not have scored zero victories against the AF jets. Many of these were neutral setups, like an escort gone bad. Turn into him, he pitches up into post stall and swings nose in direction you turned. If you stayed horizontal you shot out in front of him for the kill, but you go vertical. Now you are a few hundred knots faster and climbing up while he is mush as far as changing his velocity vector making his next movements very predictable. The F-22 has the engine power to not fall prey to this tactic. Sorry, we are way :offtopic:

Re: F-16C , F-16E vs F-14D

Unread postPosted: 07 Jan 2016, 07:09
by eloise
so here what I found about vertical-energy fighting again more agile fighter :
I don't about the accuracy nut sound reasonable enough , if flying fast can give your missiles more range it probably give your bullet more range too
outlaw162 wrote:Right On JP. Guns only from a butterfly. I like it. This reduces pretty much everything to mano v mano.

Remember, 20MM is a launch and leave all aspect weapon (admittedly a brainless one). Its' range is a function of muzzle velocity plus any velocity (closure) imparted to it by the aircraft doing the shooting.

So for the sake of the discussion, let’s assume the butterfly turns into a series of head on passes (pure closure) and that the thrust vectoring, post stall maneuvering X-31 “goes for it” on the first head on pass, playing to his supposed strength. The range of his 20MM is now solely a function of muzzle velocity.

I, in my X-29, being aware I cannot “out-nose-point” him, make only my first turn a bat turn and pass him close aboard on the first one.

From the butterfly at 450K, both of us are probably too close to use the gun this pass, and I keep my speed up and gain some separation for purposes of executing what will necessarily be, thanks to him, another head on pass. He may now be thrust vectoring like crazy, just pointing at me, maybe even post stall, and muzzle velocity is all he can impart to his 20MM.

I however make a relatively big sweeping optimum turn outside of 4000 feet and come back at him at the speed of stink.

The range of my 20MM is muzzle velocity + the speed of stink, and I open fire based on this and break off the head on pass in some optimum plane for E-M before I get within his “muzzle velocity only” range. Think of a strafe panel.

Maybe I hit him the first time, maybe I don’t, but I do the same thing each time until I do or he changes his tactic, possibly playing to my strength.

Thrust vectoring, post stall maneuvering, etc. (Cobras), these are all primarily defensive options. It’s nice to have available, but if someone insists on going slow with it in a gunfight, admittedly they definitely have proven whose more maneuverable, and it would probably be a nice gesture if the other guy assured it was written on their epitaph that they were “more maneuverable”.

Theoretically, all else equal, this could work no matter what weapon you’re using, as long as both guys are using the same one and you can get out of range of it on the first pass. You may just have to get further away.

From my experience, this is kind of like fighting A-10's with the F-4.

regards, OL

viewtopic.php?t=11020

Re: F-16C , F-16E vs F-14D

Unread postPosted: 07 Jan 2016, 07:18
by eloise
there probably some others factor too , Mig-23 , mig-21bis with superior T/W in theory should be able to defeat F-16 , F-15 by going vertical , but in reality they seem to lose horribly

Re: F-16C , F-16E vs F-14D

Unread postPosted: 08 Jan 2016, 06:31
by geforcerfx
eloise wrote:there probably some others factor too , Mig-23 , mig-21bis with superior T/W in theory should be able to defeat F-16 , F-15 by going vertical , but in reality they seem to lose horribly


uhh neither of those aircraft have a T/W over 1, how are they going to beat the F-16 and F-15 in the vertical?

Re: F-16C , F-16E vs F-14D

Unread postPosted: 08 Jan 2016, 07:18
by eloise
geforcerfx wrote:
eloise wrote:there probably some others factor too , Mig-23 , mig-21bis with superior T/W in theory should be able to defeat F-16 , F-15 by going vertical , but in reality they seem to lose horribly


uhh neither of those aircraft have a T/W over 1, how are they going to beat the F-16 and F-15 in the vertical?

at high speed dynamic thrust of Mig-23 is better due to engine design and variable inlet ,
mig-21 have something called Emergency Afterburner :mrgreen:

Re: F-16C , F-16E vs F-14D

Unread postPosted: 08 Jan 2016, 07:42
by geforcerfx
eloise wrote:
geforcerfx wrote:
eloise wrote:there probably some others factor too , Mig-23 , mig-21bis with superior T/W in theory should be able to defeat F-16 , F-15 by going vertical , but in reality they seem to lose horribly


uhh neither of those aircraft have a T/W over 1, how are they going to beat the F-16 and F-15 in the vertical?

at high speed dynamic thrust of Mig-23 is better due to engine design and variable inlet ,
mig-21 have something called Emergency Afterburner :mrgreen:


HIgh speed meaning not what they dog fight at, and the F-15 also has a intake ramp. The Mig-21 CSR mode could only be used below 13,000 feet and for less than 1 min in a dog fight, and had a chance of blowing up the engine.



Anyways back to the the post's topic, I would give the F-16E over the F-14D and the F-14D over the F-16C.

Re: F-16C , F-16E vs F-14D

Unread postPosted: 08 Jan 2016, 07:45
by 35_aoa
eloise wrote:
geforcerfx wrote:
eloise wrote:there probably some others factor too , Mig-23 , mig-21bis with superior T/W in theory should be able to defeat F-16 , F-15 by going vertical , but in reality they seem to lose horribly


uhh neither of those aircraft have a T/W over 1, how are they going to beat the F-16 and F-15 in the vertical?

at high speed dynamic thrust of Mig-23 is better due to engine design and variable inlet ,
mig-21 have something called Emergency Afterburner :mrgreen:


the 200/220 motors also have "max power"…..its a little switch below the throttle. IIRC it lets the motor burn about 20 deg C hotter than normally rated continuously. Similar in theory to "Emergency Afterburner". Doesn't really make a difference…..nobody is getting into a turning BFM fight at those speeds. If you tried, you would be arcing into east jesus while the other guy saddled in behind you. The MIG-23 is one of the worst "fighters" to ever be built. -21 had some game 40 years ago against a bunch of poorly outfitted F-4's that were flown by guys who didn't understand the fight the Fishbed was baiting them into. I give some respect to modern variants of the Flanker family, but there isn't much else out there that can hang with a 4G+ western jet of any type/model/series

Re: F-16C , F-16E vs F-14D

Unread postPosted: 08 Jan 2016, 17:21
by deadseal
35_aoa wrote:
the 200/220 motors also have "max power"…..its a little switch below the throttle. IIRC it lets the motor burn about 20 deg C hotter than normally rated continuously. Similar in theory to "Emergency Afterburner". Doesn't really make a difference…..nobody is getting into a turning BFM fight at those speeds. If you tried, you would be arcing into east jesus while the other guy saddled in behind you. The MIG-23 is one of the worst "fighters" to ever be built. -21 had some game 40 years ago against a bunch of poorly outfitted F-4's that were flown by guys who didn't understand the fight the Fishbed was baiting them into. I give some respect to modern variants of the Flanker family, but there isn't much else out there that can hang with a 4G+ western jet of any type/model/series

Meh...
I've been 9k defensive with a beagle...15 seconds later HCA is 180 / neutral / the radius defense and boom you are offensive. I don't know if an E could hang with any fighter not flown by a retard

Re: F-16C , F-16E vs F-14D

Unread postPosted: 09 Jan 2016, 03:59
by 35_aoa
deadseal wrote:
35_aoa wrote:
the 200/220 motors also have "max power"…..its a little switch below the throttle. IIRC it lets the motor burn about 20 deg C hotter than normally rated continuously. Similar in theory to "Emergency Afterburner". Doesn't really make a difference…..nobody is getting into a turning BFM fight at those speeds. If you tried, you would be arcing into east jesus while the other guy saddled in behind you. The MIG-23 is one of the worst "fighters" to ever be built. -21 had some game 40 years ago against a bunch of poorly outfitted F-4's that were flown by guys who didn't understand the fight the Fishbed was baiting them into. I give some respect to modern variants of the Flanker family, but there isn't much else out there that can hang with a 4G+ western jet of any type/model/series

Meh...
I've been 9k defensive with a beagle...15 seconds later HCA is 180 / neutral / the radius defense and boom you are offensive. I don't know if an E could hang with any fighter not flown by a retard


haha fair. I probably should have thrown out some caveats to my previous bold statement…….Beagle being one of them, or Growler for that matter. And to be clear, I'm also not considering the guy at the controls. A MIG-21 or -23 could still smoke a guy who doesn't know what he is doing; same reason we lost so many F-4's to seemingly "lesser" MIG-15/17/21 in NVN. So there are of course a lot of variables in this discussion. Radius defense also works pretty well against a Hornet that doesn't understand what you are doing. "See you on the deck when I have one million knots"

Re: F-16C , F-16E vs F-14D

Unread postPosted: 09 Jan 2016, 04:42
by sprstdlyscottsmn
35_aoa wrote: Radius defense also works pretty well against a Hornet that doesn't understand what you are doing. "See you on the deck when I have one million knots"

What is radius defense?

Re: F-16C , F-16E vs F-14D

Unread postPosted: 09 Jan 2016, 13:31
by basher54321
deadseal wrote:Meh...
I've been 9k defensive with a beagle...15 seconds later HCA is 180 / neutral / the radius defense and boom you are offensive. I don't know if an E could hang with any fighter not flown by a retard



:D

Re: F-16C , F-16E vs F-14D

Unread postPosted: 10 Jan 2016, 02:06
by eloise
geforcerfx wrote: The Mig-21 CSR mode could only be used below 13,000 feet and for less than 1 min in a dog fight, and had a chance of blowing up the engine.


The emergency afterburner of mig-21 seem to increase the power alot thought , in war time use they can be used for 3 minutes
the most dramatic WEP feature was found in the MiG-21bis fighter jet. This late variant of the standard Soviet light fighter plane was built as a stopgap measure to counter the newer and more powerful American F-16 and F/A-18 fighters until the next-generation MiG-29 could be introduced to service.

The MiG-21bis received the upgraded Tumanski R-25 engine, which retained the standard 42 / 65 kN normal and forsazh power settings of earlier R-13 powerplants, but added a new super-afterburning system. Use of this "diamond regime" provided a massive 97.4 kN of thrust for no more than 3 minutes in actual wartime use. Use of this temporary power gave the MiG-21bis slightly better than 1:1 thrust-to-weight ratio and a climbing rate of 254 meters/second, equalling the F-16's nominal capabilities in close-quarters dogfight.

In air combat practice with the MiG-21bis, use of WEP thrust was limited to 1 minute, to spare on the engines' 800 flight hours lifetime

Re: F-16C , F-16E vs F-14D

Unread postPosted: 10 Jan 2016, 13:15
by basher54321
eloise wrote:
The emergency afterburner of mig-21 seem to increase the power alot thought , in war time use they can be used for 3 minutes


Yes 3 mins is quoted in other sources - and an uprated thrust figure is given although difficult to tell what that really represents. (Yefim lists a contingency rating of 15,750 lbs then states some sources list contingency at 20,940 lbs)

The bis was supposedly optimised for low level dogfights and stressed to 8.5G - but was less agile than earlier versions according to pilots. Obviously the guy above doesn't know about the F-16A emergency AB power and incorrectly assumes that somehow with an equal T/W on paper it is similar in BFM. :doh:


Then I remembered I had a MiG-21Bis manual in English and all becomes clearer perhaps.

mig21bis.JPG


Static Mil thrust rating = 4100 kgf
Static Max reheat/AB thrust rating = 6850 kgf
Static Emergency thrust rating = 7100 kgf
Emergency thrust in flight at M1.0 near SL = 9900kgf


So the 21,000 lbs thrust figure is for an installed R-25-300 at M1 in flight (temperature unknown)

For comparison the charts estimate the F100-PW-200 puts out ~27,000lbs at M1 (Sea Level / Std Day temp)

Re: F-16C , F-16E vs F-14D

Unread postPosted: 10 Jan 2016, 13:29
by JetTest
F100=VMax, not sure if the F110 has a similar function, and if so, the name.

Re: F-16C , F-16E vs F-14D

Unread postPosted: 10 Jan 2016, 15:55
by basher54321
Added to above post

Re: F-16C, F-16E vs F-14D

Unread postPosted: 20 Dec 2016, 15:56
by f-16adf
It depends on what F-16C you are talking about. The Chart you show for 10k is for a Block 50. The Block 50 is far heavier than the Block 30. The big mouth Block 30 has a better instantaneous/sustained turn rate and smaller turn radius (since it is lighter) than the Block 50. Even the original F-16A has a smaller TURN RADIUS than the Block 50. The F-14A/B/D will give you a pretty good turn at around 300-325 KIAS (depending on altitude). However once you put more knots on the jet (go beyond corner velocity); the turn rate and radius suffer. And as the wings start to go back its maneuverability starts to decrease. I tried to post the charts, I do not know if it went through. However, you can find many of them with just a google search.

The F-14 is a nice jet, but some people wrongly think that it is the greatest ever created (probably from watching too much of Top Gun). And I think I know the site that you are talking about. Ironically, every chart they show is for comparing the heaviest bloated F-16C (in this case the Block 50) to the best F-14 viariant (in this case the B). Even if you look at the NAVAIR F-14B "G" chart, it is set at 6.5 @ 50,000lbs. This whole F-14B/D 9G thing is rubbish. The F-14 probably could venture into the 9-10G area instantaneously (since it has no limiter), but in NO WAY sustain it (look at how the P's decrease). I mean, there have even been occasions when F-4's back in Vietnam instantaneously pulled 9-10G in order to get the pilots out of dangerous situations. But every knows that an F-4 CANNOT SUSTAIN 9G.

The best turn rate (from watching youtube airshow demos) for a Viper that I have seen so far is from Solo Turk's Block 40 demos from 2011. Their jet usually completes the 360 turn in 15-16 seconds. The best F-14 demo video that I have seen shows the jet completing the turn in around 19.8-20.5 seconds (this video is from the mid 1980's when the jets were relatively new). And I have NEVER seen a F-14B/D video showing the jet completing the turn in under 21 seconds. But then again, he may have not been max performing the jet due to the aging airframes. However, he still is far and away from Solo Turk's time.

People tend to forget one thing, the F-14 with the wings forward at 20-22 degrees is a high aspect ratio jet (the wings are nearly straight). That is why is turns pretty good at low speeds. Ironically, the A-10 has a high aspect ratio wing, and at 270-300 KIAS can out radius any of the teen series fighters. But as an A-10 pilot once told me, who wants to be turning and bleeding airspeed at 270 KIAS in a dogfight?

Re: F-16C, F-16E vs F-14D

Unread postPosted: 23 Dec 2016, 19:54
by saberrider
f-16adf wrote:

The F-14 is a nice jet, but some people wrongly think that it is the greatest ever created (probably from watching too much of Top Gun). And I think I know the site that you are talking about. Ironically, every chart they show is for comparing the heaviest bloated F-16C (in this case the Block 50) to the best F-14 viariant (in this case the B). Even if you look at the NAVAIR F-14B "G" chart, it is set at 6.5 @ 50,000lbs. This whole F-14B/D 9G thing is rubbish. The F-14 probably could venture into the 9-10G area instantaneously (since it has no limiter), but in NO WAY sustain it
This video is for you https://www.youtube.com/watch?v=SsUCixAeZ0A

Re: F-16C, F-16E vs F-14D

Unread postPosted: 06 Jan 2017, 17:35
by mixelflick
Can't add much to this other than I love all these birds :)

Re: F-16C, F-16E vs F-14D

Unread postPosted: 18 Aug 2017, 08:08
by garrya
Due to recent discussion in ED, i just look at this thread again and found this, F-14 L/D ratio at various wing sweep and indicate Mach number.
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Re: F-16C, F-16E vs F-14D

Unread postPosted: 18 Aug 2017, 08:17
by MVSGas
lol, Is Hummingbird on here also? You guys have been arguing this for around a year now, right?

Re: F-16C, F-16E vs F-14D

Unread postPosted: 18 Aug 2017, 10:13
by garrya
MVSGas wrote:lol, Is Hummingbird on here also? You guys have been arguing this for around a year now, right?

I don't think he is here, but yes he is on Eagle.ru forum. Anyway, the charts are just for the next person who interested in F-14.

Re: F-16C, F-16E vs F-14D

Unread postPosted: 18 Aug 2017, 22:22
by magnum4469
Years ago flying the "A" blk 15 against F-14D doing BFM and ACM sorties. We were flying with centerline and 2 bag jets, the F-14s were clean. In fights with the 2 bag jets it was about an even match with slight advantage to F-14s. Centerline jets had huge advantage vs F-14. Clean vs clean jets the F-14 would be no match for the F-16. You can't just compare the turn rate you also have to look at the radius. The setups were all standard, 20k, 350kts, line abreast 1.5nm split, check away 30 degrees, at approx 2nm separation turn in and fights on. Meet 180 degrees out, the F-14 would go into horizontal break two circle turn, Vipers would pull vertical and roll and pull to 6 oclock. Employing either AIM-9 or gun. The F-14 provided a huge target compared to Viper for putting the pipper on. The tail stab of the F-14 (33' wide, compared to 32' wide of the F-16 wing) had almost the same area as the entire wing of the Viper. As soon as you saw the wings sweeping forward you knew he was out of energy and went in for the gun shot. Not to take anything away from the F-14, it was a great platform for what it was designed for, keeping Bear bombers away from carrier air group and shooting down cruise missiles but as far as a knife fighting dog fighter it came up short, even with the "D" model upgrades.

Re: F-16C, F-16E vs F-14D

Unread postPosted: 19 Aug 2017, 02:51
by tailgate
I think someone once told or I read maybe, that getting "low' or "slow" or both in ACM was a sure fire way to end up on someone's sill as a kill marking....... :D

Re: F-16C, F-16E vs F-14D

Unread postPosted: 19 Aug 2017, 22:00
by f-16adf
I just spoke with an F-22 Raptor pilot who prior flew all the GE powered Vipers. And as he put it, 'the big mouth Block 30 is the best BFM jet of that group (Block 30,40,50).'

So this initial comparison, from other site, is rendered superfluous and incorrect.

Re: F-16C, F-16E vs F-14D

Unread postPosted: 20 Aug 2017, 02:04
by garrya
I was curious about F-14 lift curve relative to its wing sweep and its ITR performance so i decided to ask Spurt about that,
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i found his reply very informative so i put it here as well

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Re: F-16C, F-16E vs F-14D

Unread postPosted: 20 Aug 2017, 09:05
by madrat
So without some evolution, like Su-27 gaining a canard to become Su-30, the F-14 design was basically maxxed out for WVR combat. And with its big RCS, you had the nail in the coffin.

Re: F-16C, F-16E vs F-14D

Unread postPosted: 20 Aug 2017, 14:59
by f-16adf
Garrya and Spurts,

Here is the F-14B, 35k chart with maneuvering devices on auto:


http://imgur.com/a/UcFmW

Re: F-16C, F-16E vs F-14D

Unread postPosted: 20 Aug 2017, 15:08
by f-16adf
After .8 Mach, everything basically goes down the toilet.

Re: F-16C, F-16E vs F-14D

Unread postPosted: 20 Aug 2017, 15:22
by f-16adf
A good comparison on the ability of the "lifting body" of the F-14 is to compare the Mirage 2000 15K chart (remember to include 6AAM vs 2AAM loadout) against the 15K Tomcat chart. Even with 6AAM, the Mirage 2000 still has a superior ITR, smaller turn radius.

Re: F-16C, F-16E vs F-14D

Unread postPosted: 20 Aug 2017, 15:47
by madrat
In all fairness, fighting at such high speeds in a turning fight wasn't real ideal until WVA and LOAL became possible. Honestly, the most likely opponents for F-14D were not exactly modern.

Re: F-16C, F-16E vs F-14D

Unread postPosted: 20 Aug 2017, 17:55
by sprstdlyscottsmn
f-16adf, thanks for the chart. It confirms my calculations well.

These are the sheets garrya sent me and the data lines I used in them.

VN_CL focus.png

Sweep_auto.png


The following picture is the "raw data" I pulled from the sheets garrya sent me.

CL data 1.JPG


I included the formula I used to calculate CL and all the variable data. When I started pulling data from the charts I did not know the results. I then wanted to plot the CLmax against wing sweep and Mach. The Mach is more telling of the two, honestly, because you can see the sweep effects and pressure change effects combined more easily. I then took these CLmax values and plotted ITR to 6.5G using the (G^2-1)^.5 method to account for needing to not lose altitude and to be consistent with my F-16 and F-15 data.

CL data 2.JPG


The F-16 has a reducing AoAmax and thus a reducing CLmax as speed increases from the CAT-I limiter. The FBW control system has lots of tricks to keep the center of pressure in the right place. In full disclosure, the F-15 data is under the assumption that it can hit its max CL of 1.64 (which occurs at ~40 aoa) all the way up to 9G. I then corrected the Gmax for the OWS which did not have an impact until over 1.1M. As an FYI, the "Stall Speeds" chart in the F-15-1 gives a much lower CLmax than the "Lift Limit" lines in the flight envelope diagram. I make the assumption that the "stall speed" charts use ~20 AoA as the stall limit. The text of the -1, as well as the DCS flight model, both indicate that stalling begins well before maximum AoA.
AoA 1.1.JPG

AoA 1.2.JPG

AoA 2.JPG


Before Garrya brought this up I assumed CLmax was constant on the F-14. Flight test data tells me otherwise. For performance modeling purposes I can modify my F-16 CAT-I system to give a similar end result, or I can just get to work on my more complex spreadsheet I have been kicking around.

Re: F-16C, F-16E vs F-14D

Unread postPosted: 20 Aug 2017, 18:25
by eloise
sprstdlyscottsmn wrote:Image

You are one of the most knowledgeable about aerodynamic in here. But I think there could be a mistake in your estimate. F-14 in your diagram only has ITR = 5.8 at Mach 0.5, equal to F-16?. But in the 10k ft EM diagram from garryA in page1, F-14 ITR at Mach 0.5 is much better than F-16 (23 deg/sec vs 17 deg/sec) . What close the gap at 35k ft?

Re: F-16C, F-16E vs F-14D

Unread postPosted: 20 Aug 2017, 19:22
by sprstdlyscottsmn
eloise wrote: F-14 in your diagram only has ITR = 5.8 at Mach 0.5, equal to F-16?. But in the 10k ft EM diagram from garryA in page1, F-14 ITR at Mach 0.5 is much better than F-16 (23 deg/sec vs 17 deg/sec) . What close the gap at 35k ft?


The F-16 is always under the effects of the CAT-I limiter for A-A loads. Look at the chart f-16adf posted for 35kft with that same F-14D. It looks like my chart. The sweep system being different at higher altitude may be to blame. Maybe the high AR wing of the Tomcat is less effective at higher altitudes? It can, however, be empirically seen even within the official F-14D charts that at 35kft the Tomcat has poor turning ability with a decreasing Clmax as speed increases.

Re: F-16C, F-16E vs F-14D

Unread postPosted: 20 Aug 2017, 22:17
by f-16adf
Everything that the Block 50 is doing as far as turning is happening at a higher speed than the lighter Vipers. That was confirmed by some of Gums posts from years back. And even the F-22 pilot whom I spoke with yesterday attested to that. The Block 50 is around 1400lbs heavier than the Block 30, and generally 3300-3800lbs heavier than the A models, notably the early small tails.


Block 30 with MCID aka Big Mouth:

http://imgur.com/a/XKW5c


Block 50:

http://imgur.com/a/ARjoV




Since everyone has the HAF supplement, compare the Block 50/52 at 5K CLEAN vs the -220 Block 15 at 5K with 2 AAM and half internal fuel.



Now I really don't know the validity of this chart (I do not have the USAF T.O. Block 15 -1-1). However, if you do the comparison (a -220 Block 15 vs a Clean Block 50/52 all at 5K) you will see that even though the Block 15 has a weaker engine and it has more internal fuel + 2 Aim-9's; it has basically a smaller turn radius and better ITR than either or them and is hardly behind in STR. And if you were going to equalize the charts (Block 50/52 with 2 Aim-9 + 1/2 internal fuel) their numbers get even worse against a similarly equipped light A model. And some F-16A guys have said that it has a "lighter nose" than the heavier C models.


Block 15 F-16A at 5K (1/2 internal fuel + 2Aim-9):
http://imgur.com/a/bVSUI

Block 52 F-16C at 5K CLEAN:
http://imgur.com/a/4cZJT

Block 50 F-16C at 5K CLEAN:
http://imgur.com/a/7BMnt


So even though the Block 50/52 have tons of power, that power doesn't always translate into better performance metrics; Because they also gained a significant amount of weight that many people generally seem to forget. If someone actually has the USAF T.O. -1-1 for the Block 10/15 please post the 5K Clean chart (if my calculations are in error).

The small tail Block 10 and the MCID Block 30 seem to be the best at BFM (with maybe the latter having a slight edge).



So once again, why would you want to compare the best fighter version of the Tomcat (in this case the B) against the heavier Block 50 which is NOT the best BFM version of the F-16? It is just a nonsensical, illogical juxtaposition.

Re: F-16C, F-16E vs F-14D

Unread postPosted: 21 Aug 2017, 02:01
by garrya
f-16adf wrote:Everything that the Block 50 is doing as far as turning is happening at a higher speed than the lighter Vipers. That was confirmed by some of Gums posts from years back. And even the F-22 pilot whom I spoke with yesterday attested to that. The Block 50 is around 1400lbs heavier than the Block 30, and generally 3300-3800lbs heavier than the A models, notably the early small tails.
Block 30 with MCID aka Big Mouth:
Image
Block 50:
Image

From what i heard block 30 has always been the best F-16 for dogfight according to pilot.

Re: F-16C, F-16E vs F-14D

Unread postPosted: 21 Aug 2017, 02:06
by garrya
sprstdlyscottsmn wrote: In full disclosure, the F-15 data is under the assumption that it can hit its max CL of 1.64 (which occurs at ~40 aoa) all the way up to 9G

It is certainly not my expectation that F-15 turn out to have the best ITR, i have always thought F-14 has the best ITR since F-16 is AoA limited and F-15 doesn't have high lift devices.
Btw, isn't it a bit far fetch to assume F-15 can be at AoA of 40 degrees at 9G?

Re: F-16C, F-16E vs F-14D

Unread postPosted: 21 Aug 2017, 02:31
by garrya
Some more charts about the hard wing behavior Spurt mentioned earlier
Image
Image

Re: F-16C, F-16E vs F-14D

Unread postPosted: 21 Aug 2017, 02:39
by garrya
f-16adf wrote:A good comparison on the ability of the "lifting body" of the F-14 is to compare the Mirage 2000 15K chart (remember to include 6AAM vs 2AAM loadout) against the 15K Tomcat chart. Even with 6AAM, the Mirage 2000 still has a superior ITR, smaller turn radius.

Do you have 15k ft chart of F-14 for comparison? I can only find Mirage chart
Image

Re: F-16C, F-16E vs F-14D

Unread postPosted: 21 Aug 2017, 02:50
by f-16adf
I do not know the apparent field DA, but I thought I would show this to illustrate my point.



1986 Abbotsford demo, F-16A Block 10 small tail 360 degree turn starts at 2:41:58

https://www.youtube.com/watch?v=5u5IH04Qp2E

Completed in a little over 16 seconds.





Solo Turk's F-16C Block 40 360 degree turn starts at :34 second mark

https://www.youtube.com/watch?v=TcBlEU62e8c

Completed in around 15 seconds.

Funny thing is the Block 30 is around 700lbs lighter than the 40, so expect a slightly faster turn. :D





Here is a Block 30 from back in the old days. Turn starts at 4:06

https://www.youtube.com/watch?v=goluWOE3q74





Sorry, but I have never ever seen any F-14A/B/D or F-15A/C turn anywhere close to those numbers. And if anyone can find a video proving otherwise (even from our friends on that other site), feel free to prove me wrong.



And in the event people try and attempt to infer that the F-16A has a "large turn circle" lets listen very, very, very carefully to Mr. Randy Ball (the most high time Mig-17 pilot in the United States) at the 4:45 mark.


https://www.youtube.com/watch?v=V2-LprWf3NI



Yep, the F-16A can turn inside a Mig-17, of which the F-14A and F-15A were unable. He explicitly says that the Viper was the FIRST jet to turn inside the Fresco.

Re: F-16C, F-16E vs F-14D

Unread postPosted: 21 Aug 2017, 02:56
by madrat
Surely FBW adds significantly to the Mirage 2k and F-16 figures. The F-14 would have benefit from FBW research across its entire flight envelope. FBW probably would have been a bigger leap in performance than adding F110's in the F-14D. Didn't the ADV from Panavia enjoy quite a bit of control freedom with its FCS in comparison to F-14?

Re: F-16C, F-16E vs F-14D

Unread postPosted: 21 Aug 2017, 03:11
by eloise
sprstdlyscottsmn wrote:The F-16 is always under the effects of the CAT-I limiter for A-A loads. Look at the chart f-16adf posted for 35kft with that same F-14D. It looks like my chart. The sweep system being different at higher altitude may be to blame. Maybe the high AR wing of the Tomcat is less effective at higher altitudes?

I can totally see the resemble between the two. But i don't understand why :(.
At the same velocity, the wing sweep at higher altitude is lower, so i expected the gap in ITR to be widened but it goes the opposite direction. Why do high AR wing become less effective at higher altitude?

sprstdlyscottsmn wrote:It can, however, be empirically seen even within the official F-14D charts that at 35kft the Tomcat has poor turning ability with a decreasing Clmax as speed increases.

isn't the instantaneous turn rate of F-14 limited by it's airframe G limit?

Re: F-16C, F-16E vs F-14D

Unread postPosted: 21 Aug 2017, 05:03
by hummingbird
F-14B, 4x AIM-7's + 4x AIM-9's, 15,000 ft:

Re: F-16C, F-16E vs F-14D

Unread postPosted: 21 Aug 2017, 05:13
by eloise
F-14B 4AIM-7, 4AIM-9 can pull 3G at 0.4M
Mirage 2000 2R550 can pull 3.9G at 0.4M
I guess they have approximately the same or very similar instantaneous turn rate if both both equipped with 4 air to air missiles.
@sprstdlyscottsmn, what would be the ITR of F-22, F-35, F-18 in the same conditions? combat radius, AB time, 4 air to air missiles.

Re: F-16C, F-16E vs F-14D

Unread postPosted: 21 Aug 2017, 05:24
by hummingbird
To illustrate the importance of G relative to speed >

F-14B/D, 4x AIM-7 + 4x AIM-9, 10,000 ft. Min turn radius = 1,525 ft:
http://i.imgur.com/InP8mkf.png

F-16C, 4x AIM-120 + 2x AIM-9, 10,000 ft. Min turn radius = 1,935 ft:
http://i.imgur.com/XXswnBj.png

Sustained load factors up to Mach 0.75:

F-14D @ 55,620 lbs (50% fuel) w/ 4x AIM-7's + 4x AIM-9's @ 10,000 ft:
Mach = G-load
0.2 = 1.2
0.3 = 1.95
0.4 = 2.95
0.5 = 4.0
0.6 = 5.0
0.7 = 5.3
0.75 = 5.6

F-16C @ 26,000 lbs w/ 2x AIM-9 + 4x AIM-120's + 2x FT pylons @ 10,000 ft:
Mach = G-load
0.2 = CAT limited
0.3 = 1.8
0.4 = 2.7
0.5 = 3.55
0.6 = 4.5
0.7 = 5.5
0.75 = 6.0

F-15C @ 41,000 lbs (50% fuel), w/ 4x AIM-7's + 4x AIM-9s @ 10,000 ft:
Mach = G-load
0.2 = 1.0
0.3 = 1.8
0.4 = 2.6
0.5 = 3.4
0.6 = 4.3
0.7 = 5.25
0.75 = 5.7

F-15C, 4x AIM-120 + 4x AIM-9 sustained load factor chart:
http://i.imgur.com/PqJTTl9.jpg

Re: F-16C, F-16E vs F-14D

Unread postPosted: 21 Aug 2017, 05:32
by f-16adf
Pretty funny, since I have proven the Big Mouth Block 30 kicks the **** out of any Tomcat or Eagle, we are now moving on to the Mirage 2000.

See you tomorrow children.

Re: F-16C, F-16E vs F-14D

Unread postPosted: 21 Aug 2017, 05:41
by garrya
f-16adf wrote:Pretty funny, since I have proven the Big Mouth Block 30 kicks the **** out of any Tomcat or Eagle, we are now moving on to the Mirage 2000.

See you tomorrow children.

Calm down F-16adf, Mirage always credited to have very good ITR even though, its STR is bad. More aircraft for comparison is always better

Re: F-16C, F-16E vs F-14D

Unread postPosted: 21 Aug 2017, 05:55
by garrya
More charts guys:
Image
Image

Re: F-16C, F-16E vs F-14D

Unread postPosted: 21 Aug 2017, 15:52
by tailgate
f-16adf wrote:Pretty funny, since I have proven the Big Mouth Block 30 kicks the **** out of any Tomcat or Eagle, we are now moving on to the Mirage 2000.

See you tomorrow children.



Tangling with any F-16 tested one's ability to the max.....but I agree with F-16Aadf here......the block 30 F-16 just had that perfect blend going on and it was tough to defeat.......kinda made you happy that they were on your side......

Jim

Re: F-16C, F-16E vs F-14D

Unread postPosted: 21 Aug 2017, 18:07
by f-16adf
Once again, do you not understand that the Block 50/52 is not the best BFM version of the Viper? Yet you keep comparing it to the best fighter version of the Tomcat (in this case the F-14B).



Here is the DI chart for the F-14B, please add them up (for 4 Aim-7, 4 Aim-9, and NO fuel tank pylons are mentioned):

http://imgur.com/a/cBu3l


Here is a USAF T.O. DI for a USAF early 1990's Block 50 (note its weight compared to HAF -1-1):

http://imgur.com/a/FTzEK



Additionally, your numbers for the F-16 are incorrect, the 370 gallon fuel tank includes the pylon. So when the pilot jettisons the tanks, the pylons go with it.

T.O. DI's are broken down into 50's, they do not represent a specific load out. So go over your numbers for 2 Aim-9, 4 Aim-120, and no tanks (isn't it only fair if the Tomcats tank pylons are not included)?


Also, note that the Block 30 has a 1.6 degree advantage in sustained turn rate at .6 M against the Block 50. Now superimpose that to this from your DCS website (adjust it for 10K):


http://imgur.com/a/YvFt2



The Block 30 over shadows the F-15C, F-16C Block 50, and matches or exceeds the F-14B at its best STR of .6 M, and after that completely leaves it in the dust.


The Block 30 also has a 1.3 degree per second ITR advantage and smaller turn radius vs Block 50.


Hence the Viper pilot will sit comfortably in his Corner Plateau, not a Corner Spike like the Tomcat or Eagle.

Re: F-16C, F-16E vs F-14D

Unread postPosted: 21 Aug 2017, 18:57
by madrat
And until just recently - and only a tiny fraction of them built - did the F-15 or F-14 enjoy FBW and a digitized flight control system that optimized your performance. I'm going to predict the F-15SA with a true FBW and all digital FCS improves the performance in comparison to previous variants even though the control surfaces did not fundamentally change.

Re: F-16C, F-16E vs F-14D

Unread postPosted: 21 Aug 2017, 19:03
by hummingbird
F-16adf,

Why would I want to compare a 2006 F-14 with a 1980's F-16, where's the point in that ? :|

Also do you not understand this was never an aircraft pissing contest?

It seems to me that you think the comparison was set up to somehow prove either aircraft superior, something which was never the case. The comparison was to showcase relative performance and how the F-14 despite an "official" wing loading of 600+kg/sq.m. was still able to maneuver with the best of them. Furthermore things are what they are, all the information we need has already been exhaustively tested and charted out, so there's really no need to be making guesses or claims about anything.

Now wether or not the F-14 chart includes two tank pylons or not really is irrelevant to the chart figures, each pylon constituting a measly DI figure of 1. Instead consider the amount of fuel the aircraft can carry internally and wether or not the tanks are needed for a similar range mission between the two aircraft.

As for the comparison charts you've created, you're making the mistake of comparing rate figures instead of looking at the load factor measurements which are more accurate and what the rate figures are based on. Looking at the load factor figures you will find that the F-15C at no point until after M 0.75 has a higher STR than the F-14B/D:

F-15C measured load factors:
Image

From the chart above =
F-15C @ 41,000 lbs (50% fuel), w/ 4x AIM-7's + 4x AIM-9s @ 10,000 ft:
Mach = G-load
0.2 = 1.0
0.3 = 1.8
0.4 = 2.6
0.5 = 3.4
0.6 = 4.3
0.7 = 5.25
0.75 = 5.7

Compared with the F-14B/D's sustained load factor chart:

F-14D @ 55,620 lbs (50% fuel) w/ 4x AIM-7's + 4x AIM-9's @ 10,000 ft:
Mach = G-load
0.2 = 1.2
0.3 = 1.95
0.4 = 2.95
0.5 = 4.0
0.6 = 5.0
0.7 = 5.3
0.75 = 5.6

Finally I really don't understand the derogatory tone towards any discussion that takes place on Eagle.ru, as if they are automatically less valid than any that goes on in here. The notion that more can be "revealed" here because it isn't a Russian forum is chuckle worthy considering everyone and anyone has direct access to see exactly what is written here. Besides I'm sure there are several Russian members here too. So no need for the silver hats.

Re: F-16C, F-16E vs F-14D

Unread postPosted: 21 Aug 2017, 19:38
by f-16adf
The F-14 manual is dated to 1990.

The HAF F-16 Block 50 manual is dated to 2003 I believe.


Why do you think I included an early 1990's USAF T.O. page for the early Block 50, to show you that it gained weight in 10 years.


My point is, it's disingenuous to compare an F-16 that is 100% multi-role (hence the additions to 2003) against a Tomcat from circa 1987-1990 that was at that time used strictly for Air to Air. Don't you think?


If anyone is initially guilty of making rough estimations and going contrary to charted info it is you, not I. I know the F-14 has no G limiter, yet I am not going to sit here and attempt to "extrapolate" the line out to 9G. Also, that is border line hypocrisy. You can make your "estimations" while I cannot make my own?

Finally, I do not understand why you are posting F-15 info? My whole argument centered around comparing what is generally considered the best BFM Viper version, the Block 30 against the best BFM Tomcat version, the F-14B. I really could care less about the Eagle v Tomcat, it is a tired and exhausted subject.


I will say this: against an F-15C the F-14B/D is a fairly even match (assuming equal pilots). Probably with some points going to the Tomcat (such as a smaller turn circle, better ITR at lower speeds)/ while the Eagle has a slightly better T/W ratio and higher STR at certain speeds (generally at the higher end of the spectrum)). Even the original F-14A was a good dog-fighter (regardless of problems from the TF-30). I have spoke with 4 A pilots and they infer that if flown correctly it in many circumstances beat F-15's (some saying thanks to the added SA of the RIO, reference VF-1 and VF-14 DACT exercises from the late 1970's).

Re: F-16C, F-16E vs F-14D

Unread postPosted: 21 Aug 2017, 20:06
by basher54321
magnum4469 wrote:Years ago flying the "A" blk 15 against F-14D doing BFM and ACM sorties. We were flying with centerline and 2 bag jets, the F-14s were clean. In fights with the 2 bag jets it was about an even match with slight advantage to F-14s. Centerline jets had huge advantage vs F-14. Clean vs clean jets the F-14 would be no match for the F-16. You can't just compare the turn rate you also have to look at the radius. The setups were all standard, 20k, 350kts, line abreast 1.5nm split, check away 30 degrees, at approx 2nm separation turn in and fights on. Meet 180 degrees out, the F-14 would go into horizontal break two circle turn, Vipers would pull vertical and roll and pull to 6 oclock. Employing either AIM-9 or gun. The F-14 provided a huge target compared to Viper for putting the pipper on. The tail stab of the F-14 (33' wide, compared to 32' wide of the F-16 wing) had almost the same area as the entire wing of the Viper. As soon as you saw the wings sweeping forward you knew he was out of energy and went in for the gun shot. Not to take anything away from the F-14, it was a great platform for what it was designed for, keeping Bear bombers away from carrier air group and shooting down cruise missiles but as far as a knife fighting dog fighter it came up short, even with the "D" model upgrades.



Nice Magnum - you've been here a while - were you flying in the 1980s & 90s? - and did you fly any other blocks outside the 15?

Re: F-16C, F-16E vs F-14D

Unread postPosted: 22 Aug 2017, 02:47
by eloise
hummingbird wrote:F-15C measured load factors:
Image

From the chart above =
F-15C @ 41,000 lbs (50% fuel), w/ 4x AIM-7's + 4x AIM-9s @ 10,000 ft:
Mach = G-load
0.2 = 1.0
0.3 = 1.8
0.4 = 2.6
0.5 = 3.4
0.6 = 4.3
0.7 = 5.25
0.75 = 5.7


For some strange reasons F-15A/C with F-100-PW100 has higher sustained G factor than F-15 with F-100-PW200.
Image
Mach = G-load
0.2 = 1.4
0.3 = 2.2
0.4 = 3
0.5 = 3.8
0.6 = 4.7
0.7 = 5.6
0.75 = 6.1
0.8 = 6.6
0.85 = 7.1
Image
Mach = G-load
0.2 = 1.2
0.3 = 2
0.4 = 2.8
0.5 = 3.6
0.6 = 4.4
0.7= 5.3
0.75 = 5.65
0.8 = 6.2
0.85 = 7

Re: F-16C, F-16E vs F-14D

Unread postPosted: 22 Aug 2017, 03:09
by madrat
What advantage is the older A model if it cannot get into firing position before being fired upon? The A is at a serious technical disadvantage. By the time you gain those abilities in the A/C you become overweight and at a disadvantage to the E models. At best you might be able to use the ASRAAM without any surefire knowledge if the WVA seeker on its head acquired the target or a wingman.

Re: F-16C, F-16E vs F-14D

Unread postPosted: 22 Aug 2017, 03:43
by sprstdlyscottsmn
And the five percent weight difference.

Re: F-16C, F-16E vs F-14D

Unread postPosted: 22 Aug 2017, 03:48
by garrya
sprstdlyscottsmn wrote:And the five percent weight difference.

Spurt, just in case my earlier chart wasn't accurate, can you check this one out too
Image

Re: F-16C, F-16E vs F-14D

Unread postPosted: 22 Aug 2017, 04:32
by sprstdlyscottsmn
garrya wrote:Spurt, just in case my earlier chart wasn't accurate, can you check this one out too

That one is far more precise. I was able to refine my sweep schedule, but it doesn't change MUCH.

Also, on those F-15 charts, I overlooked the content.

hummingbird posted a 41klb F-15C with 8 AAM and a CL pylon with a -220 motor. and gives some mostly correct data (I zoomed way in to try and fine tune the estimates a bit),

Then eloise quoted hummingbird and added two charts for -100 powered eagles, one in the same config but light, the other the same weight but in a draggier config. I weight corrected all of them to 41klb. and came up with the -100 bird having an edge at the low end of the envelope but the -220 bird taking the lead just before 0.8M. If anyone remembers the development of the -220, and IIRC, it was rated at less thrust STATIC but increased thrust at higher dynamic pressures over the -100. These charts seem to play that out.

eloise, do you have the full -1 for the old -100 powered F-15? I only have -220 and Strike Eagle when it comes to F-15s.

Re: F-16C, F-16E vs F-14D

Unread postPosted: 22 Aug 2017, 05:39
by eloise
sprstdlyscottsmn wrote: eloise, do you have the full -1 for the old -100 powered F-15? I only have -220 and Strike Eagle when it comes to F-15s.

I sent it in your direct message.
What if the engine is at 100% trim with Vmax switches on?

Re: F-16C, F-16E vs F-14D

Unread postPosted: 22 Aug 2017, 07:27
by garrya
f-16adf wrote:Additionally, your numbers for the F-16 are incorrect, the 370 gallon fuel tank includes the pylon. So when the pilot jettisons the tanks, the pylons go with it.
T.O. DI's are broken down into 50's, they do not represent a specific load out. So go over your numbers for 2 Aim-9, 4 Aim-120, and no tanks

Are you sure the pylon went with the tanks? I thought only F-22 is like that
Anyway drag index of F-16 with 6 missiles + no fuel tank pylons
4 x LAU-129's + adapter (4x6) = 24
4 x AIM-120's (4x4) = 16
So total DI= 40, down to 32 if it spent 2 missiles for BVR.
P/s: you are correct indeed, the tank and pylon are a single unit.
Image
Image

Re: F-16C, F-16E vs F-14D

Unread postPosted: 22 Aug 2017, 13:10
by f-16adf
Sferrin has a vid of a Strike Eagle demo with no CFT. And it sure seems like a beast. But it still is a few thousand Lbs heavier and draggier because of the 2 seat bigger canopy than the traditional F-15C w/220's.

https://www.youtube.com/watch?v=YuhPrxFFiA8


But even with more power, I still think it's at a disadvantage at slower speeds because of the hard wing (no variable camber) and the higher wing sweep. I have a book that says in the F-15 section (by an Eagle pilot) "We think we have the best dog-fighter in the world, but we do not get slow against the gents in the F-14's."

The F-15 pilot ( i'm sure some pilots of other jets would probably disagree with his statement) is meaning that at slower speeds he has to be very, very careful because he is at a disadvantage against a wing with LE slats and of less sweep like the F-14A's. And when Eagle pilots found themselves in a dangerous situation in a horizontal angles fight, they generally would go vertical. And in those days, not many jets could follow them up.

I think the original F-14A was a good dog-fighter. And it did at many times embarrass the Eagle community in ACM.

Re: F-16C, F-16E vs F-14D

Unread postPosted: 22 Aug 2017, 13:31
by sprstdlyscottsmn
f-16adf wrote: I have a book that says in the F-15 section (by an Eagle pilot) "We think we have the best dog-fighter in the world, but we do not get slow against the gents in the F-14's."

I heard that quote years ago and have never been able to find a source for it. If you manage to come across that book could you look it up if it isn't too much trouble?

Re: F-16C, F-16E vs F-14D

Unread postPosted: 22 Aug 2017, 13:50
by f-16adf
Spurts,

It's from "The Great Book of Modern Warplanes", Salamander Books, pg. 638 of the F-14 Performance and Handling section (by Mike Spick). I believe you can just buy the F-14 section on amazon, and not the whole book.

Re: F-16C, F-16E vs F-14D

Unread postPosted: 22 Aug 2017, 14:55
by sprstdlyscottsmn
f-16adf wrote:Spurts,

It's from "The Great Book of Modern Warplanes", Salamander Books, pg. 638 of the F-14 Performance and Handling section (by Mike Spick). I believe you can just buy the F-14 section on amazon, and not the whole book.

I KNEW IT!!! I have that book and scoured the F-15 section looking for it and just completely spaced checking the F-14 section. I need a new copy of the book though, the cover came off mine years ago. Amazon here I come. Thanks again!

Re: F-16C, F-16E vs F-14D

Unread postPosted: 22 Aug 2017, 15:04
by eloise
f-16adf wrote: "We think we have the best dog-fighter in the world, but we do not get slow against the gents in the F-14's.

Sound like F-14 is very similar to F-18, Mig-29. I heard the gents in F-16 said they don't want to get slow with F-18 or Mig-29. From pilots testimony, F-35 also has this characteristic.

Re: F-16C, F-16E vs F-14D

Unread postPosted: 22 Aug 2017, 15:11
by hummingbird
f-16adf wrote:If anyone is initially guilty of making rough estimations and going contrary to charted info it is you, not I. I know the F-14 has no G limiter, yet I am not going to sit here and attempt to "extrapolate" the line out to 9G. Also, that is border line hypocrisy. You can make your "estimations" while I cannot make my own?


I didn't really make any estimations, and I certainly nowhere went contrary to charted info (!)

What I did do was provide the actual charted lift curve for the F-14, and from it can be observed that no real change occurs until Mach 0.85, which is where the high lift devices stop operating. Thus I could/can correctly state that the F-14 will be able to pull the 9 G's instantanuous at lower alts before the F-16, as the lift curve straight away lets us know this. Thus whilst I can't provide the exact G @ specific speed past 7.5 Gs I can instead positively state it would hit 9 G long before M 0.85 at for example 10 kft.

Finally, I do not understand why you are posting F-15 info? My whole argument centered around comparing what is generally considered the best BFM Viper version, the Block 30 against the best BFM Tomcat version, the F-14B. I really could care less about the Eagle v Tomcat, it is a tired and exhausted subject.


Because that's how the discussion garrya linked you guys started originally, as a comparison in performance between the "current" F-14, F-15 & F-16 in order to illustrate the typical expected performance of the aircraft as seen on duty. How you got that twisted into a "best version vs best version irrespective of time frame" debate I don't know..

I will say this: against an F-15C the F-14B/D is a fairly even match (assuming equal pilots). Probably with some points going to the Tomcat (such as a smaller turn circle, better ITR at lower speeds)/ while the Eagle has a slightly better T/W ratio and higher STR at certain speeds (generally at the higher end of the spectrum)). Even the original F-14A was a good dog-fighter (regardless of problems from the TF-30). I have spoke with 4 A pilots and they infer that if flown correctly it in many circumstances beat F-15's (some saying thanks to the added SA of the RIO, reference VF-1 and VF-14 DACT exercises from the late 1970's)


Sure, no disagreements there at all.

Re: F-16C, F-16E vs F-14D

Unread postPosted: 22 Aug 2017, 15:14
by hummingbird
magnum4469 wrote:Years ago flying the "A" blk 15 against F-14D doing BFM and ACM sorties. We were flying with centerline and 2 bag jets, the F-14s were clean. In fights with the 2 bag jets it was about an even match with slight advantage to F-14s. Centerline jets had huge advantage vs F-14. Clean vs clean jets the F-14 would be no match for the F-16. You can't just compare the turn rate you also have to look at the radius. The setups were all standard, 20k, 350kts, line abreast 1.5nm split, check away 30 degrees, at approx 2nm separation turn in and fights on. Meet 180 degrees out, the F-14 would go into horizontal break two circle turn, Vipers would pull vertical and roll and pull to 6 oclock. Employing either AIM-9 or gun. The F-14 provided a huge target compared to Viper for putting the pipper on. The tail stab of the F-14 (33' wide, compared to 32' wide of the F-16 wing) had almost the same area as the entire wing of the Viper. As soon as you saw the wings sweeping forward you knew he was out of energy and went in for the gun shot. Not to take anything away from the F-14, it was a great platform for what it was designed for, keeping Bear bombers away from carrier air group and shooting down cruise missiles but as far as a knife fighting dog fighter it came up short, even with the "D" model upgrades.


Hi Magnum,

Don't worry we are also taking the radius into account since this is where the F-14 has the real advantage versus the Viper, whilst at the same time the Viper enjoys a higher max sustained rate. Thus in a pure horizontal contest it would end up a rate vs radius fight.

Also I notice you pointed out that the std. tactic for the Viper was to go vertical straight away after the merge, which incidentally mirrors exactly what F-15 pilots would do, whilst they ofcourse did this out of nessecity as they knew they would never win a straight out turn contest with the Cat. Doing it anyway would end the fight very quickly in the Cat's favor. By comparison the Viper is on more equal grounds, but again I suspect they went vertical for a reason.

Btw, were these top gun students you were flying with?

Re: F-16C, F-16E vs F-14D

Unread postPosted: 22 Aug 2017, 15:43
by eloise
hummingbird wrote:I didn't really make any estimations, and I certainly nowhere went contrary to charted info (!)
What I did do was provide the actual charted lift curve for the F-14, and from it can be observed that no real change occurs until Mach 0.85, which is where the high lift devices stop operating.
Thus I could/can correctly state that the F-14 will be able to pull the 9 G's instantanuous at lower alts before the F-16, as the lift curve straight away lets us know this. Thus whilst I can't provide the exact G @ specific speed past 7.5 Gs I can instead positively state it would hit 9 G long before M 0.85 at for example 10 kft.

I think because the charted lift is at 35k ft, the wing swept is delayed compared to low altitude
Image
and F-14 has lower G limit than F-16.
hummingbird wrote:Because that's how the discussion garrya linked you guys started originally, as a comparison in performance between the "current" F-14, F-15 & F-16 in order to illustrate the typical expected performance of the aircraft as seen on duty. How you got that twisted into a "best version vs best version irrespective of time frame" debate I don't know

Current F-14 has retired

Re: F-16C, F-16E vs F-14D

Unread postPosted: 22 Aug 2017, 15:55
by garrya
eloise wrote:I think because the charted lift is at 35k ft, the wing swept is delayed compared to low altitude
and F-14 has lower G limit than F-16

That indeed true but iam wondering, does F-14 wing has only 2 mode of operation such as below 14k ft and higher than 20k ft or the two line is only for reference and the sweep will varied with altitude?
For example: if the altitude is 50k ft, will the wing fold back later than at 21k ft? Or does the automatic system treat all altitude higher than 20k ft the same.
P/s: nevermind, i found the answer:
Image

Re: F-16C, F-16E vs F-14D

Unread postPosted: 22 Aug 2017, 16:15
by sprstdlyscottsmn
garrya wrote: if the altitude is 50k ft, will the wing fold back later than at 21k ft? Or does the automatic system treat all altitude higher than 20k ft the same.

Everything below 14k is the same and everything above 20k is the same.

hummingbird wrote: What I did do was provide the actual charted lift curve for the F-14, and from it can be observed that no real change occurs until Mach 0.85, which is where the high lift devices stop operating.

Except I ran the math and showed that the CLmax is indeed changing the entire time. The simplest evidence is this, with 1G occurring just after 0.3M then 4G should be occurring just after 0.6M, instead of 0.75M, if the Clmax was constant at this altitude.

Re: F-16C, F-16E vs F-14D

Unread postPosted: 22 Aug 2017, 16:22
by garrya
sprstdlyscottsmn wrote:Everything below 14k is the same and everything above 20k is the same

But it said the auto program is adjusted for altitude biasing, doesn't that mean it will operate using information from the pitot tube?

Re: F-16C, F-16E vs F-14D

Unread postPosted: 22 Aug 2017, 16:38
by f-16adf
"Furthermore things are what they are, all the information we need has already been exhaustively tested and charted out, so there's really no need to be making guesses or claims about anything."

I ascertained that was directed towards me, that is why I include my diatribe about your "estimations" vs my own.


Exactly, you can draw the line out to 9G, but technically do not know its actual parameters on the curve. Neither you nor I have ever flown for VX-4 or are actual fighter pilots.


This original discussion thread never included any F-15 posted data. Go back to pg 1-3 and look. No F-15 charts.

Re: F-16C, F-16E vs F-14D

Unread postPosted: 22 Aug 2017, 16:57
by f-16adf
Magnum is talking about entire turn circles. You are getting that confused with instantaneous turn radius (your initial "max lift" turn pull). That sounds a little goofy, but i'm at my desk, so excuse my odd composition.



Here is the F-14B at 10k.

http://imgur.com/a/nuDmP



Here is the heavies of the GE vipers, the Greek Block 50 at 10K.


http://imgur.com/a/2r745




For the initial (meaning the beginning of the turn), the Block 50 is on its CAT 1 limiter. The Tom is not. The first few seconds of the turn (I will call it instantaneous turn radius), the Tom is superior. No disagreement here. :D


However, lets examine them both doing 5g sustained turns:

The Tom at 5g, 13.9DPS, at almost .6 Mach, has a sustained turn radius of a little over 2700ft. The B 50 at 5g, 13.3DPS, around .65 Mach has a sustained turn radius of 3100ft. Remember at .61 Mach the Tom has its BEST STR of 14 or 14.1 DPS.


It's hard to tell exactly tell, but for a 6g sustained turn, the Tom has a sustained turn radius of 4000ft. The B50 at 6g has a sustained turn radius of 3500ft.

At 7g the B50 is at 14.2 DPS, yielding a 3750ft radius.


With the benefit of the corner plateau, meaning, you have options-




See the trend.


And once again, the B 50 is one of the heaviest Vipers. B30 and B10 are lighter so expect smaller turn radii.




Lastly, pull out the Mirage 2000, 15k chart. See, it's great for the first few seconds; after that, the shows is all over.

Re: F-16C, F-16E vs F-14D

Unread postPosted: 22 Aug 2017, 17:02
by garrya
F-16adf,you can put the link in the image tag so the image will display

Re: F-16C, F-16E vs F-14D

Unread postPosted: 22 Aug 2017, 18:34
by sprstdlyscottsmn
garrya wrote:
sprstdlyscottsmn wrote:Everything below 14k is the same and everything above 20k is the same

But it said the auto program is adjusted for altitude biasing, doesn't that mean it will operate using information from the pitot tube?

I am pretty sure that is why there is a <14k and an >20k line in the program.

Re: F-16C, F-16E vs F-14D

Unread postPosted: 22 Aug 2017, 19:05
by garrya
f-16adf wrote:Magnum is talking about entire turn circles. You are getting that confused with instantaneous turn radius (your initial "max lift" turn pull). That sounds a little goofy, but i'm at my desk, so excuse my odd composition.
Here is the F-14B at 10k.

http://imgur.com/a/nuDmP
Here is the heavies of the GE vipers, the Greek Block 50 at 10K.
http://imgur.com/a/2r745

Come to think of it, if F-14 sustain the same turn rate as F-16 at slower speed, shouldn't the radius be smaller.?

Re: F-16C, F-16E vs F-14D

Unread postPosted: 22 Aug 2017, 20:00
by sprstdlyscottsmn
Same rate and lower speed is smaller radius, yes. That's why you don't fight your opponents fight. You don't go horizontal at low speeds with a Tomcat, you go with vertical maneuvers.

Re: F-16C, F-16E vs F-14D

Unread postPosted: 22 Aug 2017, 21:58
by f-16adf
You need to look up Gums old posts on the F-16A. He flew the very light small tails from 1979-84 at Hill AFB. I believe he said that at 9G, he had a turn radius between 1100-1200ft. Now I do not know if he was at an ACM range in that general area, or above Hills elevation of 1459ft., or sea level.


http://imgur.com/a/gMzYO


This is a small tail data sheet from 1979/80, as you can see EMPTY WEIGHT: 15,137lbs, which is 4k or more lighter than Block 50. Hence it has a FAR smaller turning radius than later F-16's.

This agrees with Mig-17 demo pilot Randy Ball's statement about the early A model Viper being the first jet to have a smaller turn circle than the Mig-17 (I posted his interview earlier). I'm sure with the wings out at 20-22 degrees the Tomcat gets pretty close, but it seems that the small tails could do better.

Randy's interview, listen at 4:45 mark:

https://www.youtube.com/watch?v=V2-LprWf3NI

I emailed CDR Chesire, who flew the F-14A against the Mig-17 in the late 1970's after his deployment with VF-1, the same question; his answer was that even with the wings forward the F-14A did not have a smaller turn circle than the Mig-17.


But once again, you keep adding weight to the jet (like the later Blocks) and turn radius will obviously suffer.




The problem is a USAF T.O. -1-1 is nearly impossible to come by for any of the A models, so I will defer to CDR Chesire and Mr. Ball's statements as fact.

Re: F-16C, F-16E vs F-14D

Unread postPosted: 22 Aug 2017, 22:25
by hummingbird
eloise wrote:I think because the charted lift is at 35k ft, the wing swept is delayed compared to low altitude
Image


By a magnitude of ~0.03* mach compared to below 14,000 ft, so it changes nothing.

*EDIT: Initially wrote 0.3 Mach which was a giant typo.

and F-14 has lower G limit than F-16.


That is just the regulatory operational load limit, and this "limit" (which isn't actually a limit, just a "regulations tell me not to") was set by the Navy based on ensuring maximum airframe longevity. The projected operational load limit was initially set at 7.5 G's by Grumman, reduced 1.5 G's from 9 G to account for the extra stresses of carrier operations. However when F-14 orders were cut short, and each airframe therefore suddenly had to last a lot longer, this was reduced first to 7 Gs and then later 6.5 G's by the Navy.

In terms of actual airframe strength the F-14 is no more limited than the F-15, both aircraft featuring the same ultimate load limit. In truth Grumman could even pride themselves with abit more assurance as to this limit as it was derived from an unprecented amount of airframes tested, Grumman subjecting more F-14 airframes to stress tests during development than with any other US aircraft before and I think also since.

Utlimately though, as any fighter pilot will tell you, in a life or death dogfight G limits don't exist and you pull as many G's as you can endure to ensure you get out of there the victor. In the case of the F-16 this is just an enforced 9 G by the FCS.

Current F-14 has retired


I know, hence the "" ;)

In other words I was comparing the usual 2000's F-14, F-16 & F-15.

Re: F-16C, F-16E vs F-14D

Unread postPosted: 22 Aug 2017, 23:24
by f-16adf
Garrya,

What link are you referring to? I might have missed something?

Re: F-16C, F-16E vs F-14D

Unread postPosted: 23 Aug 2017, 01:14
by basher54321
hummingbird wrote:In other words I was comparing the usual 2000's F-14, F-16 & F-15.


Ha it's the first time I have seen the F-16 & F-14 compared together where the F-16 looks the superior BVR jet. :wink:

Re: F-16C, F-16E vs F-14D

Unread postPosted: 23 Aug 2017, 02:14
by garrya
eloise wrote:Sound like F-14 is very similar to F-18, Mig-29. I heard the gents in F-16 said they don't want to get slow with F-18 or Mig-29. From pilots testimony, F-35 also has this characteristic.

AFAIK the corner speed for Super hornet is even slower than F-14 Tomcat.
In a BFM (Basic Fighter Maneuvers ie a dogfight) engagement, the pilot has to think about energy management. Fighter pilots always talk about a Rate vs a Radius fight, which in layman terms means how fast can you go around the circle you are turning versus how short of a radius can you make your circle. Some Fighters perform better in a rate fight while others perform better in a radius fight.

For example, if a Tomcat was in a BFM engagement with a Super Hornet, the Tomcat's best chance to win the fight (we are assuming "Sticks and Stones" meaning each fighter has only a gun remaining) is to try and force the Super Hornet to bleed off energy at the first pass. The Tomcat would force the Super to honor his nose position, make a neutral pass at the merge and then go vertical. The Tomcat's ability to add energy and head into the vertical was a serious advantage over the Super Hornet. Conversely, the Tomcat would not want to get into a slow speed fight with the Super. With both jets at slow speed, the Super has a better ability to maneuver his nose for a shot than the Tomcat.

The F-15C is probably the premier BFM fighter and more capable in that area than the Tomcat. You have to remember, the F-15C has a 9G turning capability versus 6.5 to 7.0 G for the Tomcat. But the F-15C is strictly air-to-air, so there are trade-offs in capabilities between the two jets.They don't drop bombs, we do. Another thing: a lot of success in BFM has to do with the pilot's ability to maximize the jet's capability. Fortunately, the best trained guys who fly the F-15C are on our side!

https://www.google.com.vn/amp/foxtrotal ... 043625/amp

Re: F-16C, F-16E vs F-14D

Unread postPosted: 23 Aug 2017, 02:23
by garrya
f-16adf wrote:Garrya,

What link are you referring to? I might have missed something?

I meant you can put these links to imgur inside the [image] tag so they could display.
Regarding turn radius, i meant that if you look at charts in page 1, the Tomcat sustain around the same turn rate as F-16 but at lower speed regime. Thus, the turn radius of F-14 would be smaller.
On the otherhand, that chart is the data for the heavier F-16 block 50 and taken at DI 50 instead of 40 (pylons gone with tanks) or 32 (assuming that F-16 uses 2 missiles for BVR combat). Since lower DI mean the fighter can sustain higher G and lower weight reduce lift induced drag so i guess magnum4469 and Gums statements still make sense.

sprstdlyscottsmn wrote:
garrya wrote:
sprstdlyscottsmn wrote:Everything below 14k is the same and everything above 20k is the same

But it said the auto program is adjusted for altitude biasing, doesn't that mean it will operate using information from the pitot tube?

I am pretty sure that is why there is a <14k and an >20k line in the program.

In that case what happened when the altitude is in between 14k and 20k?

Re: F-16C, F-16E vs F-14D

Unread postPosted: 23 Aug 2017, 03:49
by f-16adf
Yes, but I chose G for a reason, you could also compare them at the same speed .6 Mach, .7 Mach, .8 Mach.


F-14B at .6 Mach = 2700ft, 14 DPS
F-14B at .7 Mach = 3500ft, 13 DPS
F-14B at .8 Mach = 4100ft, 12.7 DPS


F-16C at .6 Mach = 2900ft, 12.9 DPS
F-16C at .7 Mach = 3300ft, 13.5 DPS
F-16C at .8 Mach = 3600ft, 14 DPS


(All rough estimations, sorry i'm tired and in need of sleep, I was not too precise in observing charted material)



It still concludes that the Tomcat is best at .6 Mach, which I said in my earlier post.
Additionally, after .6 Mach the Tomcat's STR and radius is on a rather sharp decline.



But my main argument is that as you keep adding weight to a jet, namely 4,000lbs. your turn radius suffers. That is what is happening to the Block 50 against the other lighter Vipers.


For example, when I fly my RG, and i'm the only soul on board; obviously it will be more nimble and responsive than when i'm with 3 passengers. It's the same air-frame, but total weight of the airplane has gone up by a few hundred pounds and its lifting agent (namely the wing) is still of the same area. Remember that Lift opposes Weight (the 4 forces). So it's wing loading has increased-


Now since I do not have the T.O. F-16A -1-1, I do not know their actual rate/radius numbers. But compare the Block 30 sea level chart to the Block 50 sea level chart. Note the Block 30's increase in rate and decrease in radius at .6 Mach. And that proves my whole point. Additionally, the radius numbers improve even more with the small tail 15Klbs. Vipers.

Re: F-16C, F-16E vs F-14D

Unread postPosted: 23 Aug 2017, 03:56
by eloise
hummingbird wrote:That is just the regulatory operational load limit, and this "limit" (which isn't actually a limit, just a "regulations tell me not to") was set by the Navy based on ensuring maximum airframe longevity. The projected operational load limit was initially set at 7.5 G's by Grumman, reduced 1.5 G's from 9 G to account for the extra stresses of carrier operations. However when F-14 orders were cut short, and each airframe therefore suddenly had to last a lot longer, this was reduced first to 7 Gs and then later 6.5 G's by the Navy

G limits could be there to reduce airframe fractures because F-14 has to carry a big a$$ radar, swing wings or because of sea corrosion, carrier operation, whatever, i don't care, we follow the limit set by Grumman. Neither you nor I have ever flown F-14, we don't know how it behaves at 9G, how dangerous is it to over g the airframe. By the time we have the F-16block 50/52, F-14s are at the end of their services so they will be even more prone to over stress.

hummingbird wrote:In terms of actual airframe strength the F-14 is no more limited than the F-15, both aircraft featuring the same ultimate load limit. In truth Grumman could even pride themselves with abit more assurance as to this limit as it was derived from an unprecented amount of airframes tested, Grumman subjecting more F-14 airframes to stress tests during development than with any other US aircraft before and I think also since

F-15 has higher load limit.
Image

Re: F-16C, F-16E vs F-14D

Unread postPosted: 23 Aug 2017, 03:57
by f-16adf
Here is an interesting article about F-14A v F-14B.


http://imgur.com/a/9rShn


and pg.2 of it,


http://imgur.com/a/vaaRZ

Re: F-16C, F-16E vs F-14D

Unread postPosted: 23 Aug 2017, 04:06
by eloise
hummingbird wrote:By a magnitude of ~0.3 mach compared to below 14,000 ft, so it changes nothing

0.3 is a whole lot for a dogfight and we will find CLmax i
changing the entire time before Mach 0.85 if we run the math
f-16adf wrote:This agrees with Mig-17 demo pilot Randy Ball's statement about the early A model Viper being the first jet to have a smaller turn circle than the Mig-17 (I posted his interview earlier). I'm sure with the wings out at 20-22 degrees the Tomcat gets pretty close, but it seems that the small tails could do better.

Randy's interview, listen at 4:45 mark:

https://www.youtube.com/watch?v=V2-LprWf3NI

I emailed CDR Chesire, who flew the F-14A against the Mig-17 in the late 1970's after his deployment with VF-1, the same question; his answer was that even with the wings forward the F-14A did not have a smaller turn circle than the Mig-17.


But once again, you keep adding weight to the jet (like the later Blocks) and turn radius will obviously suffer.




The problem is a USAF T.O. -1-1 is nearly impossible to come by for any of the A models, so I will defer to CDR Chesire and Mr. Ball's statements as fact.

How did F-4 pilots and F-8 pilots defeat Mig-17 :mrgreen:

Re: F-16C, F-16E vs F-14D

Unread postPosted: 23 Aug 2017, 04:29
by f-16adf
They used the vertical and kept the fight above 440 knots. The Fresco was superb in the 300 knot range. Almost unbelievable. If you are in the States, try to get to an airshow that Randy Ball is flying at. His Mig-17 demo will make your jaw drop-





I use to have a 20K Mig-17 chart, but I seemed to have misplaced it. I will try and find it tomorrow.

Re: F-16C, F-16E vs F-14D

Unread postPosted: 23 Aug 2017, 12:28
by f-16adf
Actually back in Hoser's VX-4 days (i think circa 1974) he took out an early F-14A to 8.5G:




Read this entire page:


http://imgur.com/a/KWGr6




Now VX-4 is a "test and evaluation" squadron, so I do not know how this would translate into normal squadron operational performance. But it shows that the original Tomcat A model was a good performer.

Re: F-16C, F-16E vs F-14D

Unread postPosted: 23 Aug 2017, 12:36
by garrya
eloise wrote:How did F-4 pilots and F-8 pilots defeat Mig-17 :mrgreen:

Vertical fight it is
f-16adf wrote:They used the vertical and kept the fight above 440 knots. The Fresco was superb in the 300 knot range. Almost unbelievable. If you are in the States, try to get to an airshow that Randy Ball is flying at. His Mig-17 demo will make your jaw drop-
I use to have a 20K Mig-17 chart, but I seemed to have misplaced it. I will try and find it tomorrow.

I would also love to see the chart

Re: F-16C, F-16E vs F-14D

Unread postPosted: 23 Aug 2017, 13:31
by basher54321
f-16adf wrote:They used the vertical and kept the fight above 440 knots. The Fresco was superb in the 300 knot range. Almost unbelievable.


There was a famous Cunningham / Driscoll 1 v 1 dogfight in 1972 that served as what I feel is an example of how not to do this.

90% of the time the VPAF MiG-17s had no intention of stopping for a dogfight let alone trying to dogfight an F-4J in the vertical and this might have led to the assumption the MiG-17 would never follow him up. Anyway this one did (twice) and was described and illustrated as a rolling vertical scissors.

Being in that position against a jet with 30/37mm cannon and amazing low speed handling doesn't seem the best tactic to employ to me and the MiG-17F (as demonstrated) had a fairly respectable T/W if you try to go up with one with high energy. Luckily he got away with it when the MiG broke off and ran ( and promptly got shot in the back :P ).

But the lesson seems to be that to employ such a tactic you first need a distinct energy advantage. With the F-14 in most cases communicating its energy state as Magnum stated to the other pilot meant this was a great help in not getting into situations as above.

As for turn radius - dogfights happen in a 3D plane - e.g. what is the horizontal turn radius of a jet doing a high Yo Yo? well it can be a lot smaller than any level horizontal turn. Not only that the jet low on energy below me has to defend something above him which mean expending pretty much anything left in trying to get the nose up and turn - so even if the first defense succeeds it is in no position to defend the second one.

Re: F-16C, F-16E vs F-14D

Unread postPosted: 23 Aug 2017, 22:19
by hummingbird
eloise wrote:0.3 is a whole lot for a dogfight and we will find CLmax i
changing the entire time before Mach 0.85 if we run the math


Hehe, indeed it would be if 0.3 wasn't a giant typo on my end ;) It is 0.03 mach, you can see by checking the sweep chart. Thus as stated it makes no difference.

G limits could be there to reduce airframe fractures because F-14 has to carry a big a$$ radar, swing wings or because of sea corrosion, carrier operation, whatever, i don't care, we follow the limit set by Grumman. Neither you nor I have ever flown F-14, we don't know how it behaves at 9G, how dangerous is it to over g the airframe. By the time we have the F-16block 50/52, F-14s are at the end of their services so they will be even more prone to over stress.


The F-14 features no limiter, so the pilot can pull as many G's as he wants, and there are plenty of cases of 12+ G's being pulled without issue. Infact 14 G's has been pulled on old airframes without failure. So to artificially limit the F-14 to 6.5 or 7.5 G's in a comparison like this would only lead to a very inaccurate result as no pilot would ever limit himself to this in a real fight. Mock fights is another matter ofcourse, and here F-14 pilots are ofcourse at a disadvantage when G's past 6.5 are required and they don't want to ruin their relationship with the ground crews ;)

F-15 has higher load limit.


Operational load limit, yes. The ultimate load limit, which is what the operational load limit is calculated from based on operational demands, is the same. The F-14 & F-15 both feature a 13.5 G ultimate load limit. Thus had the F-14 been used exclusively as land based fighter it would've recieved a 9 G operational load limit as well.

In short the F-14 airframe can take just as high a G load as the F-15 or F-16 without any issues at all.

Re: F-16C, F-16E vs F-14D

Unread postPosted: 25 Aug 2017, 03:12
by eloise
hummingbird wrote:Hehe, indeed it would be if 0.3 wasn't a giant typo on my end ;) It is 0.03 mach, you can see by checking the sweep chart. Thus as stated it makes no difference.

The widest point is around 0.1 Mach, I think it makes a noticeable difference for sustain turn rate.
Wingsweep.png

@ 0.7 Mach @ altitude > 20k ft, the wing sweep is at 21° auxiliary flaps are extended, below 14k ft, the wing sweep is at 31-33°auxiliary flaps are retracted
@ 0.85 Mach @ altitude > 20k ft, the wing sweep is at 47.5°main flaps are extended, below 14k ft, the wing sweep is at 53-55° main flaps are retracted.

The chart provided by Garry shows the L/D ratio reduced as wings sweep back.
Image

The calculation provided by sprstdlyscottsmn shows CLmax reduced as well
Image

I also think F-15 can excess F-14 instantaneous turn rate.
Lift = 1/2 * air density *Reference Wing Area * Lift Coefficient * airspeed ^2 and Lift = aircraft weight * amount of G aircraft pulls;

Wing loading = Aircraft Weight / Reference wing area ; or we can say: aircraft weight = wing loading * wing area;
For a level flight condition; if we are to put this into lift formula it becomes;
Wing loading * aircraft G load = 1/2 * air density * Lift coefficient * airspeed^2
In other words, Lower wing loading=> smaller Cl needed.

F-15 wing loading: 41,000/608 = 67.4 lb/ft²
F-14 wing loading: 55,620/565 = 98.4 lb/ft²
F-14 has 46% higher wing loading so for an equivalent instantaneous G, F-14's CLmax need to be bigger than F-15's CLmax by 46%

NASA test shows F-15's CLmax = 1.6 at AoA 40° so F-14 needs CLmax = 2.33 for equal G, higher than what we calculated for F-14 from the lift chart.
cft.jpg

F15 Cl Cy.jpg

Re: F-16C, F-16E vs F-14D

Unread postPosted: 25 Aug 2017, 03:56
by eloise
hummingbird wrote:The F-14 features no limiter, so the pilot can pull as many G's as he wants, and there are plenty of cases of 12+ G's being pulled without issue. Infact 14 G's has been pulled on old airframes without failure. So to artificially limit the F-14 to 6.5 or 7.5 G's in a comparison like this would only lead to a very inaccurate result as no pilot would ever limit himself to this in a real fight. Mock fights is another matter ofcourse, and here F-14 pilots are ofcourse at a disadvantage when G's past 6.5 are required and they don't want to ruin their relationship with the ground crews ;)

Personally, i haven't heard about the story of F-14 pilot who pulls 14G but it wouldn't surprise me, I heard that some pilots did it in IAI Kfir and Mig-21 or F-4 as well. However, in my opinion, limits are there for safety, it was carefully calculated by Grumman based on the airframe and how they are used, some pilots are very lucky to pull off these crazy stunts and get away with it but that isn't recommended for all pilots.
If we go for a comparison without any G limit then I think we also need the sustain G diagram for F-15, F-16 with V-max switch engaged (102% engine thrust instead of 97%). There are many restricted maneuvers that more impressive than over G the aircraft. In one documentary that was posted here, one F-4 pilot backflip to make Mig-17 overshot. I will try to find it.

hummingbird wrote:Operational load limit, yes. The ultimate load limit, which is what the operational load limit is calculated from based on operational demands, is the same. The F-14 & F-15 both feature a 13.5 G ultimate load limit. Thus had the F-14 been used exclusively as land based fighter it would've recieved a 9 G operational load limit as well.

In short the F-14 airframe can take just as high a G load as the F-15 or F-16 without any issues at all.

Where did you get the ultimate load limit for F-14, F-15 and F-16?

Re: F-16C, F-16E vs F-14D

Unread postPosted: 25 Aug 2017, 05:01
by garrya
eloise wrote:one F-4 pilot backflip to make Mig-17 overshot. I will try to find it.

This documentary?

Re: F-16C, F-16E vs F-14D

Unread postPosted: 25 Aug 2017, 05:23
by garrya
eloise wrote:The widest point is around 0.1 Mach, I think it makes a noticeable difference for sustain turn rate.
Wingsweep.png

@ 0.7 Mach @ altitude > 20k ft, the wing sweep is at 21° auxiliary flaps are extended, below 14k ft, the wing sweep is at 31-33°auxiliary flaps are retracted
@ 0.85 Mach @ altitude > 20k ft, the wing sweep is at 47.5°main flaps are extended, below 14k ft, the wing sweep is at 53-55° main flaps are retracted

You can see retracted and extended envelope of maneuver flaps from graph below:
Image
At sea level, maneuver flaps are fully extended below Mach 0.51, partially retracted from Mach 0.51 till Mach 0.58 and fully retracted at higher speed
At 35K ft, maneuver flaps are fully extended until Mach 0.86, partially retracted from Mach 0.86 till Mach 0.87 and fully retracted at higher speed
Difference of approximately 0.3 Mach between sea level and 35K ft.
P/S: Come to think of this, since maneuver flaps start to be retracted at some specific wing sweep, does this mean wing fold back sooner at sea level than at 14k ft?

Re: F-16C, F-16E vs F-14D

Unread postPosted: 25 Aug 2017, 07:22
by eloise
garrya wrote:
eloise wrote:one F-4 pilot backflip to make Mig-17 overshot. I will try to find it.

This documentary?

yes that it

Re: F-16C, F-16E vs F-14D

Unread postPosted: 25 Aug 2017, 10:41
by garrya
f-16adf wrote:People tend to forget one thing, the F-14 with the wings forward at 20-22 degrees is a high aspect ratio jet (the wings are nearly straight). That is why is turns pretty good at low speeds. Ironically, the A-10 has a high aspect ratio wing, and at 270-300 KIAS can out radius any of the teen series fighters. But as an A-10 pilot once told me, who wants to be turning and bleeding airspeed at 270 KIAS in a dogfight?

I found the chart for A-10
Image
and one for F-86, Mig-15 (re-draw from Boyd chart)
Image

Re: F-16C, F-16E vs F-14D

Unread postPosted: 25 Aug 2017, 13:25
by basher54321
eloise wrote:Personally, i haven't heard about the story of F-14 pilot who pulls 14G but it wouldn't surprise me, I heard that some pilots did it in IAI Kfir and Mig-21 or F-4 as well. However, in my opinion, limits are there for safety, it was carefully calculated by Grumman based on the airframe and how they are used, some pilots are very lucky to pull off these crazy stunts and get away with it but that isn't recommended for all pilots.
If we go for a comparison without any G limit then I think we also need the sustain G diagram for F-15, F-16 with V-max switch engaged (102% engine thrust instead of 97%). There are many restricted maneuvers that more impressive than over G the aircraft. In one documentary that was posted here, one F-4 pilot backflip to make Mig-17 overshot. I will try to find it.

Where did you get the ultimate load limit for F-14, F-15 and F-16?




The standard structural margin is around 150% apparently (ref JWill)- so e.g. the USAF wanted a 9G 8000 hour airframe so this would have been tested on the F-16 under worse conditions to around 13.5G as I understand it.

I don't have any good sources on the F-14 design other than it had a 6000 hour requirement at either 7.5G or 6.5G - however if there is something out there confirming the original F-14 requirements that would clear that up. (Wasn't the SH a 6000 hr 7.5G carrier design?)




One aspect is definitely safety - departing an aircraft has been used tactically to gain an advantage since the beginning - there are a few examples from WW2 and the way that F-4 looks to flip over looks more impressive than the AI Jet fighter in the film Stealth!

Generally these few pilots have been A. Very Good and B. Very lucky.

What would be useful is a list of F-4s that were lost or put themselves into serious danger over Vietnam due to departure because from what I have read it was more than quite a few - and the list no doubt includes experienced pilots - so the one impressive backflip in all those years of war starts to look slightly unimpressive.

As well as safety the limiters allow any pilot to max perform the jet without being Chuck Yeager and you will note pretty much every Jet since the F-16 came along has had them in one form or another.

There is still the safety issue of being prevented from pulling up and hitting the ground. Some jets allow the pilot to override the limiters for emergency situations and some do not apparently - take for example a Mirage 2000 about to hit the ground at 300kts - the pilot can over G the jet but here it is probably AoA limited and if you went through the AoA limiter it could depart and crash anyway in theory.

You wonder if modern simulators have allowed pilots to get a better sense of how much room they have at low altitudes and depend more on that! The Auto GCAS sounds a good thing don't know if the pilot can disable that must be more info on it.

Re: F-16C, F-16E vs F-14D

Unread postPosted: 25 Aug 2017, 14:43
by f-16adf
My brother's squadron operates the A-10C. It literally can turn on a dime, yet generally has terrible sustainability.
Many of those air-frames have over 10k hours (time to go to the boneyard). Quite a few have tail code FY that date from the late 1970's. The teen series were great in their day. But by 2017 they need to go. Just too old, large RCS, and maintenance intensive.

Re: F-16C, F-16E vs F-14D

Unread postPosted: 25 Aug 2017, 15:51
by eloise
f-16adf wrote:My brother's squadron operates the A-10C. It literally can turn on a dime, yet generally has terrible sustainability.
Many of those air-frames have over 10k hours (time to go to the boneyard). Quite a few have tail code FY that date from the late 1970's. The teen series were great in their day. But by 2017 they need to go. Just too old, large RCS, and maintenance intensive.

A cannon dogfight between A-10 and the teen series will be an interesting one, from what i have heard A-10 airframe is protected up to 23 mm rounds so the teen series pilots will need some luck.

garrya wrote:You can see retracted and extended envelope of maneuver flaps from graph below:
Image
At sea level, maneuver flaps are fully extended below Mach 0.51, partially retracted from Mach 0.51 till Mach 0.58 and fully retracted at higher speed
At 35K ft, maneuver flaps are fully extended until Mach 0.86, partially retracted from Mach 0.86 till Mach 0.87 and fully retracted at higher speed
Difference of approximately 0.3 Mach between sea level and 35K ft.
P/S: Come to think of this, since maneuver flaps start to be retracted at some specific wing sweep, does this mean wing fold back sooner at sea level than at 14k ft?

Good observation

Re: F-16C, F-16E vs F-14D

Unread postPosted: 25 Aug 2017, 16:46
by f-16adf
Maybe in a 1 v 1 a very skilled A-10 pilot could have some luck on the initial pass??

I think in a 2 v 2 or many v many the A-10's would get murdered. Their opponents would just use the vertical, and wait for them to bleed down. Just my opinion.

Re: F-16C, F-16E vs F-14D

Unread postPosted: 25 Aug 2017, 18:56
by outlaw162
One aspect is definitely safety - departing an aircraft has been used tactically to gain an advantage since the beginning - there are a few examples from WW2 and the way that F-4 looks to flip over looks more impressive than the AI Jet fighter in the film Stealth!


basher,

Our reserve unit flew F-4s for 8 years, and during that time we only lost 2 Phantoms......both loss of control during 2v2 DACT against, of all airplanes, the lowly A-7. Both guys tried the drag chute before ejecting. Fortunately both crews were able to 'take the bus home' although one WSO sustained a broken arm. (1 kill for the Tulsa Guard, 1 kill for the ABQ Guard :D ) I flew remedial rides with both guys so they could demonstrate how much more conservative they had become. One of the pilots told the accident board, 'there were only two reasons for this accident' and then held up his left and right hands.

I 'spect the CGI rendering of that 'flip' is optimistic and that it was possibly a rapid loaded rudder reversal that reached a fairly high pitch attitude and was continued all the way underneath, maybe by momentum and not by choice. From the cockpit, violent departures can of course be disorienting, and a cockpit's eye description may not coincide exactly with the description offered from another aircraft.

In 1978, the ANG started conducting formal A-7 departure training (both high and low energy departures) based on the program the USN passed on to us. USAF did not have 'formal' departure training in their syllabus at the time. We only had single-seat A-7Ds at the time (no Ks) and all training was conducted with the instructor in the chase position. We did this for folks from every A-7D Guard unit including the PRANG at San Juan. Often the description the student would give of what the aircraft did when it departed did not always match what you saw from outside.

The A-7 recovery was 'hands off' and the recovery rate was 100% and totally predictable. A-7 always recovered......

.....which points to why the F-4 training units did not run formal departure training.

Re: F-16C, F-16E vs F-14D

Unread postPosted: 25 Aug 2017, 22:01
by basher54321
Thanks outlaw - I have seen another comment along the lines of them using a bit of artistic impression in that recreation :)

Good job those guys got out although I hope the court had a sense of humour!

Re: F-16C, F-16E vs F-14D

Unread postPosted: 25 Aug 2017, 22:12
by madrat
Protection from 23MM proximity fused rounds is very different from 20MM AP and incendiary rounds. And the engine can't really digest any of them.

Re: F-16C, F-16E vs F-14D

Unread postPosted: 25 Aug 2017, 22:36
by outlaw162
Good job those guys got out although I hope the court had a sense of humour!


basher,

at that time, there was either some justice in mil aviation or the regulars didn't really care what you did with the old junk.....the guy that spilled his guts was back in the front seat very shortly, while the other, less forthcoming, guy spent some time in the back seat before getting back in front.

in any case they both eventually ended up in F-16s.....where theoretically they couldn't hurt themselves....at least not in this way. :mrgreen:

edit: (BTW, you could go over the top in an F-4 unloaded at very slow speed and have it fall on its back, but it took a bit more vertical room than depicted in the CGI.)

Re: F-16C, F-16E vs F-14D

Unread postPosted: 25 Aug 2017, 22:37
by sprstdlyscottsmn
And the protection is only against single round destruction of the aircraft. There was only one location found where a single 23mm would down the plane (Canopy? Tail where H-Stab spar is?). Hit it with a few dozen and all bets are off.

Re: F-16C, F-16E vs F-14D

Unread postPosted: 26 Aug 2017, 00:16
by hummingbird
eloise wrote:The widest point is around 0.1 Mach, I think it makes a noticeable difference for sustain turn rate.


Yet it doesn't. Look at the charts for pete's sake, the lift curve doesn't experience a notch until at 0.85 mach, even at below 14 kft. You can check the doghouse plot if in doubt.

Also note that while the wing sweep starts earlier at lower alt, the point where the LE slats stop operating is STILL at 0.85 mach irrespective of alt.

Image

Wingsweep.png

@ 0.7 Mach @ altitude > 20k ft, the wing sweep is at 21° auxiliary flaps are extended, below 14k ft, the wing sweep is at 31-33°auxiliary flaps are retracted
@ 0.85 Mach @ altitude > 20k ft, the wing sweep is at 47.5°main flaps are extended, below 14k ft, the wing sweep is at 53-55° main flaps are retracted.


nvm the auxilliary flaps, they're used mainly for landing, the main flaps still work until 50.5 deg sweep, furthermore it's the LE slats that really make a difference and they work up until mach 0.85 and 55 deg sweep.

btw I probably should remind you that I'm the one who've provided all these fine charts, garrya got them from me.

The chart provided by Garry shows the L/D ratio reduced as wings sweep back.
Image


Ofcourse, that's a given at certain speeds as the AR goes down, but check out the points of intersection, do you understand these? If so, what's your point?

The calculation provided by sprstdlyscottsmn shows CLmax reduced as well
Image


Not sure what you want someone's seperate calculation for when you have actual flight test data right infront of your nose?

Want to know the F-14's min radius, max rate or Clmax, simply look at the charts. Simple as that.

I also think F-15 can excess F-14 instantaneous turn rate.
Lift = 1/2 * air density *Reference Wing Area * Lift Coefficient * airspeed ^2 and Lift = aircraft weight * amount of G aircraft pulls;


It can't, as so thuroughly proven by the charts.

Wing loading = Aircraft Weight / Reference wing area ; or we can say: aircraft weight = wing loading * wing area;
For a level flight condition; if we are to put this into lift formula it becomes;
Wing loading * aircraft G load = 1/2 * air density * Lift coefficient * airspeed^2
In other words, Lower wing loading=> smaller Cl needed.

F-15 wing loading: 41,000/608 = 67.4 lb/ft²
F-14 wing loading: 55,620/565 = 98.4 lb/ft²
F-14 has 46% higher wing loading so for an equivalent instantaneous G, F-14's CLmax need to be bigger than F-15's CLmax by 46%


Problem is you're using reference wing area and not effective lifting area, thus you're arriving at an inaccurate conclusion. The F-14's actual effective lifting area is way higher than the reference wing area:

Image

In short the F-14 doesn't need as high a CLmax as you'd think to equal the F-15 in G's.

NASA test shows F-15's CLmax = 1.6 at AoA 40° so F-14 needs CLmax = 2.33 for equal G, higher than what we calculated for F-14 from the lift chart.
cft.jpg

F15 Cl Cy.jpg
[/quote]

See above.

PS: there's a reason the F-14's features a lower stalling speed than the F-15, so what does that tell you about the CLmax & wing loading ? ;)

PS PS: I'm piss drunk, but couldn't refrain from answering anyway, so please excuse any misspellings :mrgreen: :mrgreen: :mrgreen:

Re: F-16C, F-16E vs F-14D

Unread postPosted: 26 Aug 2017, 05:12
by eloise
hummingbird wrote:Yet it doesn't. Look at the charts for pete's sake, the lift curve doesn't experience a notch until at 0.85 mach, even at below 14 kft. You can check the doghouse plot if in doubt.
Also note that while the wing sweep starts earlier at lower alt, the point where the LE slats stop operating is STILL at 0.85 mach irrespective of alt.nvm the auxilliary flaps, they're used mainly for landing, the main flaps still work until 50.5 deg sweep, furthermore it's the LE slats that really make a difference and they work up until mach 0.85 and 55 deg sweep.

The lift curve @35k ft experience a big notch @ 0.85M, this is the point where wing sweep back and manuever flaps are locked according to diagrams
Image


But if you look at the maneuver devices charts, when you reduce the altitude, clearly the wing sweep back sooner, maneuver flaps are also retracted at slower velocity, up to 0.3M different between sea level and 35k ft
Image
Image

Garry brought up good point when he said flaps are retracted at certain wing sweep angle, but they retracted sooner at sea level than at 14k ft, there is a big possibility that wing sweep backward even sooner at sea level.

Slats are the only things seem to be retracted at the same speed irrespective of alt, but maneuver flaps and wing sweep are also vital to generate lift. In short, you cannot say the lift curve is the same between 35kft and lower altitude.





hummingbird wrote:Not sure what you want someone's seperate calculation for when you have actual flight test data right infront of your nose?
Want to know the F-14's min radius, max rate or Clmax, simply look at the charts. Simple as that.

The flight test data doesn't give me lines above 6.5G curve, so to extrapolate over G values like you wanted i need to find CLmax.



hummingbird wrote:It can't, as so thuroughly proven by the charts.

What charts are you talking about? There isn't any instantaneous turn charts for F-15C. If you are referring to the sustain turn rate charts then it comes at no surprise that F-14 can sustain higher G values @ slow speed because its high AR wing has steeper lift curve than F-15's wing.

Re: F-16C, F-16E vs F-14D

Unread postPosted: 26 Aug 2017, 05:18
by eloise
hummingbird wrote:Problem is you're using reference wing area and not effective lifting area, thus you're arriving at an inaccurate conclusion. The F-14's actual effective lifting area is way higher than the reference wing area:
Image
In short the F-14 doesn't need as high a CLmax as you'd think to equal the F-15 in G's.

When you use lift equation to calculate lift, you need to use reference wing area. The differences in lift generated due to body lift, flaps, slats, aspect ratio... are included in CL value. That how you know which airframe is more efficient.
If you use effective lifting area instead and substitute it in the lift chart, you will end up with a very small CLmax for F-14. Don't believe me? Run the Math yourself.

hummingbird wrote: there's a reason the F-14's features a lower stalling speed than the F-15, so what does that tell you about the CLmax & wing loading ?

F-15 @ 42,000 lbs (about 1000 lbs heavier) @35k ft @ speed = Mach 0.35, has enough lift for 1G with CLmax (can't maintain it due to high AoA)
Image

F-14 @55,620 lbs @35k ft also needs 0.35M for 1G
Image

Anyway, landing speed of F-15 is much higher than F-14 because the landing approach AoA is 20-22° instead of 40° AoA where F-15 reaches CLmax according to NASA flight tests data.
Image

Re: F-16C, F-16E vs F-14D

Unread postPosted: 26 Aug 2017, 07:37
by garrya
hummingbird wrote:btw I probably should remind you that I'm the one who've provided all these fine charts, garrya got them from me

You gave me 10K ft turn chart, 35K ft lift chart and slat chart. Whereas wing sweep charts, flap chart and L/D are from the manual i downloaded.



hummingbird wrote: Problem is you're using reference wing area and not effective lifting area, thus you're arriving at an inaccurate conclusion

He isn't wrong. Reference wing area serves as a reference point, body lift is represented by CL
http://www.aerospaceweb.org/question/ae ... 0078.shtml

Re: F-16C, F-16E vs F-14D

Unread postPosted: 26 Aug 2017, 14:06
by f-16adf
You guys might want to get Quicksilver's opinion on fighting the two. He flew against Tomcats and Eagles at NFWS, I believe.

Re: F-16C, F-16E vs F-14D

Unread postPosted: 26 Aug 2017, 18:33
by hummingbird
Eloise wrote:But if you look at the maneuver devices charts, when you reduce the altitude, clearly the wing sweep back sooner, maneuver flaps are also retracted at slower velocity, up to 0.3M different between sea level and 35k ft


The maneuver flaps have speed restrictions due to pressure concerns, i.e. any speed above x mach @ x altitude will cause damage, thus when operating these you have to keep within the envelope, the CADC doing this automatically. i.e. said envelope has nothing to do with wing sweep, where on auto there are 2 fixed channels with a variable in between. By comparison the slats are entirely dependant on AoA vs speed out to M 0.85 irrespectice of altitude.

Eloise wrote:The flight test data doesn't give me lines above 6.5G curve, so to extrapolate over G values like you wanted i need to find CLmax.


The charts stretch to 7.5 G's and the lift curve does not change in shape between the two fixed sweep schedules for <14 kft & >20 kft, it is just moved back or forth with the points of flap & slat extension/retraction being a mere 0.03 mach apart.

Also I should note that looking at the 5 kft, 10 kft, 15 kft, 25 kft and 35 kft lift & Ps charts I see no change in the lift curve until mach .85.

Re: F-16C, F-16E vs F-14D

Unread postPosted: 26 Aug 2017, 19:51
by sprstdlyscottsmn
hummingbird wrote:Also I should note that looking at the 5 kft, 10 kft, 15 kft, 25 kft and 35 kft lift & Ps charts I see no change in the lift curve until mach .85.

I'm sorry, but here you are flat out wrong. Calculating CLmax is very easy with the charts you have provided. It is a straightforward thing with effectively no room for error. I have already plotted CLmax for the tomcat at 35,000 using the chart you provided and have proved that CLmax does indeed drop as speed increases the entire time, not just where the flaps stop working. If CLmax was the same then at twice the speed needed for 1G there would be 4G available, but there isn't. The max CL is steadily declining which is why it looks to you as though it is not changing. Run the numbers and you will see.

Since you are one of those "body lift" types then just use Lift Area (lift coefficient * area) LA

Lift=Weight*G=.5*.002377*sigma(ratio of density over sea level density)*(Mach*speed of sound in feet per second)^2*LA

Looking at how G changes with Mach (as everything else is constant) you can see how LA decreases as speed increases at any point on the 35,000ft chart.

Oh and to help out, at 35,000ft sigma is 0.309875 and the speed of sound is 972.885 feet per second.

I have not run the numbers on the lower altitudes, but at 35,000ft the maximum lift coefficient is dropping.

And please stop using the term "lift curve" here as it is incorrect. lift curve refers to the CL vs AoA chart.

Using the V-N diagram (gee vs speed) I made the CLmax vs speed chart. I then used that to make a Turn Rate vs Mach chart. Then someone posted an actual turn rate vs Mach chart, and what do you know, the math holds up to a reasonable margin, enough to be human error is grabbing the second or third significant digit from the V-N chart.

Re: F-16C, F-16E vs F-14D

Unread postPosted: 26 Aug 2017, 21:40
by madrat
What makes the lift drop off so much at .85 mach?

Re: F-16C, F-16E vs F-14D

Unread postPosted: 27 Aug 2017, 06:53
by hummingbird
sprstdlyscottsmn wrote:
hummingbird wrote:Also I should note that looking at the 5 kft, 10 kft, 15 kft, 25 kft and 35 kft lift & Ps charts I see no change in the lift curve until mach .85.

I'm sorry, but here you are flat out wrong. Calculating CLmax is very easy with the charts you have provided. It is a straightforward thing with effectively no room for error. I have already plotted CLmax for the tomcat at 35,000 using the chart you provided and have proved that CLmax does indeed drop as speed increases the entire time, not just where the flaps stop working. If CLmax was the same then at twice the speed needed for 1G there would be 4G available, but there isn't. The max CL is steadily declining which is why it looks to you as though it is not changing. Run the numbers and you will see.


Take a minute before you respond next time because you obviously didn't correctly interpret what I wrote. What I was talking about was the difference between the lift limit curve at different altitudes, specifically at the boundary of the flap/slat operating envelope, not wether or not the CLmax changes with speed which ofcourse it does as the wing gradually sweeps back changing the planform. In short what I was trying point out was that there's only a 0.03 mach difference at the point of flap/slat deactivation between the two CADC schedules for below 14kft and above 20 kft, i.e. basically none. That's it. How you read that as me saying the CLmax doesn't change, I don't know.

Since you are one of those "body lift" types then just use Lift Area (lift coefficient * area) LA

Lift=Weight*G=.5*.002377*sigma(ratio of density over sea level density)*(Mach*speed of sound in feet per second)^2*LA

Looking at how G changes with Mach (as everything else is constant) you can see how LA decreases as speed increases at any point on the 35,000ft chart.

Oh and to help out, at 35,000ft sigma is 0.309875 and the speed of sound is 972.885 feet per second.

I have not run the numbers on the lower altitudes, but at 35,000ft the maximum lift coefficient is dropping.


Again no disagreement regarding the fact that the CLmax drops, ofcourse it does.

And please stop using the term "lift curve" here as it is incorrect. lift curve refers to the CL vs AoA chart.


I am talking about the max lift limit curve, I just called it a lift curve out of convenience. We can call it a lift limit curve or IT load factor curve instead if that suits you better.

Re: F-16C, F-16E vs F-14D

Unread postPosted: 27 Aug 2017, 07:09
by hummingbird
madrat wrote:What makes the lift drop off so much at .85 mach?


The retraction of the maneuver slats & flaps.

Here's the 35,000 ft chart for when the maneuvering devices are not operating vs when they are (note the sharp dink to the Ps curve as well at the point of retraction):

Image
Image

Re: F-16C, F-16E vs F-14D

Unread postPosted: 27 Aug 2017, 09:37
by eloise
hummingbird wrote:The charts stretch to 7.5 G's

The Ps curve doesn't touch 7.5 G
hummingbird wrote:the lift curve does not change in shape between the two fixed sweep schedules for <14 kft & >20 kft, it is just moved back or forth with the points of flap & slat extension/retraction being a mere 0.03 mach apart

The slats are extended and retracted at a fixed speed at all altitudes and you can say 10° of wing sweep differences will not affect Clmax considerably but the maneuver flaps retraction point has approximately 0.35 Mach differences between sea level and 35k ft. That can not be ignored.


hummingbird wrote:Also I should note that looking at the 5 kft, 10 kft, 15 kft, 25 kft and 35 kft lift & Ps charts I see no change in the lift curve until mach .85.

The lift-speed chart at 15kft is cut flat at 0.67M due to G limit, you will not know about CLmax fluctuations after that point.
F-14 lift 15kft.png


I think we can know lift curve change without even without running the Maths because Clmax on Em diagrams are curves instead of straight lines
10k ftEM chart.png

F-14 EM 10k.jpg

Re: F-16C, F-16E vs F-14D

Unread postPosted: 27 Aug 2017, 13:49
by eloise
madrat wrote:What makes the lift drop off so much at .85 mach?

When sweep angle of the wing increase, the steepness of CL/AoA curve is reduced. But higher sweep wing will stall at higher AoA, so CLmax doesn't reduce as much as Cl/Cd ratio. In short, higher sweep reduce sustain turn rate more than it does to instantaneous turn rate.
With speed between @0.6M - @0.85M, F-14 uses higher AoA to compensate for a more gentle lift curve.
However @ 0.85M @35k ft both slats and flaps of F-14 are retracted, that reduce stall AoA. Stall AoA reduced =>Clmax will decrease => lift will drop.

edit: according to the manual, F-14 started to sweep the wing back after 0.45M, but @14k ft between 0.45M - 0.6M the wing only sweep back by 1°, while it sweep back by 47° between 0.6M-0.85M so i ignored effect of the initial sweep.

Re: F-16C, F-16E vs F-14D

Unread postPosted: 27 Aug 2017, 19:52
by hummingbird
eloise wrote:The Ps curve doesn't touch 7.5 G


We were talking about ITR, not STR. It was the max lift limit curve (or ITR curve) that I said would reach 9 G's before the that on the F-16, not the Ps (or STR) curve past M 0.65 where the F-16 is definitely ahead.

The slats are extended and retracted at a fixed speed at all altitudes and you can say 10° of wing sweep differences will not affect Clmax considerably but the maneuver flaps retraction point has approximately 0.35 Mach differences between sea level and 35k ft. That can not be ignored.


And it isn't, everything is on the charts.

The lift-speed chart at 15kft is cut flat at 0.67M due to G limit, you will not know about CLmax fluctuations after that point.


That is true, but I still have the curve for both with and without maneuver devices operating, thus I can draw the line from the point of maneuver device deactivation with the 2nd set of curves where they are not operating.

I think we can know lift curve change without even without running the Maths because Clmax on Em diagrams are curves instead of straight line


That is the max lift limit curve, same as on the other chart, the doghouse plot for operational use just only goes to the navy limit of 6.5 G's.

Re: F-16C, F-16E vs F-14D

Unread postPosted: 28 Aug 2017, 12:23
by madrat
I always wondered why it added sweep at high altitudes when the air thinned out. I would think it would benefit from less sweep as altitude increased. I can see torsion twisting being an issue at lower altitude, but not so much at 36,000 feet. Too bad we never got to see some of that wing engineering that went into the F-111 program make its way into the F-14 program.

Having ordnance under the wing and away from wing fences probably would have added some safety. Then again, the wings probably would have become fragile...

Re: F-16C, F-16E vs F-14D

Unread postPosted: 28 Aug 2017, 15:43
by eloise
hummingbird wrote:We were talking about ITR, not STR. It was the max lift limit curve (or ITR curve) that I said would reach 9 G's before the that on the F-16, not the Ps (or STR) curve past M 0.65 where the F-16 is definitely ahead.

I was actually comparing it with F-15.
F-16 has a hard aoa limiter so it never reach Clmax, i don't expect F-16 instantaneous turn rate to be good

hummingbird wrote:And it isn't, everything is on the charts.
That is true, but I still have the curve for both with and without maneuver devices operating, thus I can draw the line from the point of maneuver device deactivation with the 2nd set of curves where they are not operating.

It is a lot easier and more accurate if you just calculate Clmax with the diagrams value then put it in excel to draw the curve.

Re: F-16C, F-16E vs F-14D

Unread postPosted: 28 Aug 2017, 15:45
by eloise
madrat wrote:I always wondered why it added sweep at high altitudes when the air thinned out. I would think it would benefit from less sweep as altitude increased

The sweep is smaller at high altitude.

Re: F-16C, F-16E vs F-14D

Unread postPosted: 28 Aug 2017, 22:23
by hummingbird
eloise wrote:I was actually comparing it with F-15.


But why the sudden focus on Ps? We litterally have all the data for Ps since the F-14 is incapable of sustaining 9 G's, thus the 7.5 G limit never inhibits precise observation of the Ps curve.

F-16 has a hard aoa limiter so it never reach Clmax, i don't expect F-16 instantaneous turn rate to be good


The F-16 has a very good ITR despite of this, the FCS being AoA biased towards a high L/Dmax for best STR but still allowing for 9 G's ITR to be reached as soon as possible without risking a deep stall, hence the F-16's decreasing limit from 25 to 20 and finally 15 deg AoA.

hummingbird wrote:It is a lot easier and more accurate if you just calculate Clmax with the diagrams value then put it in excel to draw the curve.


Maybe, I wouldn't know as I don't use excel :P

Re: F-16C, F-16E vs F-14D

Unread postPosted: 03 Sep 2017, 17:37
by quicksilver
I am not a NFWS alum, but have fought Eagles and Tomcats many, many times. I learned BFM when it was G/H/P 'winders and exclusively LCOS gunsights. Lotsa maneuvering for envelope management that simply doesnt exist in the same context today.

'A' model Tomcat a much different BFM adversary than a B/D Tomcat, accepting for the moment an assumption of similar pilot proficiency (a big assumption...). The difference, of course, was the engines -- vastly different Ps and freedom to maneuver without fear of stalling the engine. TF-30 shortcomings in the 'A' are extensively documented in the public domain.

Eagle generally a tougher BFM opponent, but there were periods of time where pilots were getting less BFM exposure (cyclic budget stuff that affects everyone from time to time) and it was apparent in the apparent BFM proficiency of Eagle guys. You've got X number of sorties per month; do you spend it on BFM or BVR stuff? Always a delicate balance that COs/OpsOs/TrainingOs had/have to balance.

I know it's fun to compare the charts and the numbers but, in my experience, the quantifiable differences were always subordinate to pilot ability/experience -- always. That was then, this is now and things have changed.