F-35 performance at Haboob Havoc 2019

Discuss the F-35 Lightning II
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wooster

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Unread post23 Jul 2019, 01:41

1. Maneuvering fighters are not relevant for several years now. Unless you are talking about avoiding another missile. In which case its better to be stealthier to avoid being sighted in the first place.
2. The aircraft cannot hit or maintain even marginal supersonic speed in level flight and clean without AB. Even most business jets today can hit supersonic speed in shallow dives. So finding quotes about accidental supersonic speed are meaningless with fighters as they can achieve flight attitudes far beyond civilian aircraft which while not designed for supersonic flight sure have no problem achieving it with thrust to weight ratios not even 0.5. The f-35 acheiving marginal supersonic speed with the worlds most powerful engine in dives isn't an achievement.
3. The USAF had to relax the acceleration requirements when the 35A could not achieve the requirement
4. If I can find the quotes I will post.
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steve2267

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Unread post23 Jul 2019, 01:48

I politely suggest you stop (and read a LOT of what is on this forum) while you are ahead.
Take an F-16, stir in A-7, dollop of F-117, gob of F-22, dash of F/A-18, sprinkle with AV-8B, stir well + bake. Whaddya get? F-35.
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nathan77

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Unread post23 Jul 2019, 09:45

wooster wrote:When pilots report that pulling the throttle back is akin to hitting the speed brakes, that is a draggy airframe.


Actually, if you read pilots reports of trying to land the "B" model vertically - the hardest thing is getting it to slow down as it doesn't want to even after you've eased back the throttle.

I think what you're confused with is "pulling back on the stick is akin to hitting the speed brakes". This is because the F-35 has a higher angle-of-attack than many other fighters. So if you pull back on the stick you're flying with the belly of the plane towards the direction of travel. This slows the plane down fast (and if you read pilot blogs like Hanche's it's a common dog-fighting technique in the F-35 to force the opponent to overshoot).


wooster wrote:There is something wrong with a fighter having that much thrust and not able to go past 1.6 totally clean.

Note that the 1.6 top speed is when carrying a combat load of 2 x 2000lb bombs and 2 x AIM-120's. Some other fighters can't even carry 2000lb bombs (which are designed to take out bunkers). And carrying 5000lb of combat weight decreases the F-35's thrust to weight ratio. The top-speed of a 'clean' F-35 isn't actually known (and it's operationally irrelevant anyway) - but certainly we know that the F-35 has exceeded Mach 1.6 in testing. Certainly the feature that prevents the F-35 from being Mach 2+ capable is the fact is lacks variable geometry inlets (which effectively speed limits it).

It's worth reading the thread: viewtopic.php?f=55&t=25735&start=780
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zero-one

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Unread post23 Jul 2019, 11:50

wooster wrote:1. Maneuvering fighters are not relevant for several years now. Unless you are talking about avoiding another missile. In which case its better to be stealthier to avoid being sighted in the first place.


Are you basing this on combat simulations or actual combat, because you're wrong either way.

Actual Combat
If you listen to Dozer's retelling of his engagements over Bosnia, you'll notice that he did not fly straight and level, there was maneuvering involved even if he was still at BVR ranges. A common misconception is that agility is only needed in WVR, its very important in BVR as well.

Combat simulations (Relatively modern Su-30 vs 3 F-16Cs)
one Su-30 vs three F-16 in a BVR scenario. Again, we pushed the envelope, manoeuvred between 3000 ft to 32000 ft, pulling up to 8 g, turning, tumbling, firing and escaping missiles in a simulated engagement. The crew co-ord between us in the cockpit and the fighter controller on the ground was the best that I have ever seen! The results in a mock combat are always contentious but with ACMI, they are more reliable. End score one F-16 claimed without loss. When we got out of the cockpit we were thoroughly drenched in sweat and tired from the continuous high G manoeuvring but all smiles for the ecstasy that we had just experienced.”

Lastly, F-35 test pilot Tom Morganfeld can be quoted by saying
"Even with HOBS and LOAL, Maneuverability will "Always" be relevant in a fighter"
https://www.youtube.com/watch?v=0sTsjQ_ud8E

wooster wrote:2. The aircraft cannot hit or maintain even marginal supersonic speed in level flight and clean without AB. Even most business jets today can hit supersonic speed in shallow dives.

-But it's subsonic acceleration is like a clean F-16C even with weapons carried internally, that means its better than a
practically almost every other plane barring the F-22, so thats better than a Flanker, better a fulcrum.

wooster wrote:3. The USAF had to relax the acceleration requirements when the 35A could not achieve the requirement

Isn't this the 2012 report, if you read it, it says the DoD "expressed the desire to reduce sustained G and acceleration goals due to accelerated degradation on the Stealth coatings on tail"

1. They only expressed the desire, it was never implemented IIRC
2. the issue was never the result of drag or power at all, it was the stealth coatings that were not holding up, newer stealth coatings should completely mitigate that. In fact the blistering in the stealth coatings in the tail seem to happen when the B and C versions fly beyond Mach 1.3 at extreme altitudes also. But they have mitigated the problem.
https://www.defensenews.com/air/2019/06 ... h-coating/
News that the department has taken steps to mitigate the problem with an improved spray-on coating
Last edited by zero-one on 23 Jul 2019, 14:21, edited 1 time in total.
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quicksilver

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Unread post23 Jul 2019, 13:58

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outlaw162

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Unread post23 Jul 2019, 21:30

"Sir, he's gaining on us."

"Don't worry, I read on F16net that biz-jets can go supersonic in a shallow dive. We'll just leave him in the dust."

"But sir, VNE is .92 Mach."

"Don't worry, those numbers don't mean anything. Hold my beer and watch this."
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marauder2048

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Unread post23 Jul 2019, 22:22

IIRC, the record was Mach 0.995 for the G650 in a 15 degree dive.
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wrightwing

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Unread post24 Jul 2019, 01:03

wooster wrote:When pilots report that pulling the throttle back is akin to hitting the speed brakes, that is a draggy airframe. When a single engine airplane with 45,000lbs of thrust cannot maintain even 1 Mach without AB in a clean configuration, that is a draggy airframe. There is something wrong with a fighter having that much thrust and not able to go past 1.6 totally clean. People can only assume that its stealth is good enough as the insiders say it is to make up for its kinematic handicaps.

No pilots have said such a thing. They have uniformly said that it's easy to overspeed the aircraft, and that the plane wants to fly fast. M1.6 isn't the aerodynamic speed limit, by the way.
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