Air Show Sustained Turn Rates. F-35a,b,c.

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rowbeartoe

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Unread post11 Oct 2021, 00:04

Hi Everyone. I hope everyone is having a great day when they read this.

Ok, So I've seen all three models at airshows do low altitude 360 sustained turns. The F-35a is the only 9g model.
At Miramar in 2018 I saw the F-35b model do a turn in over 30 seconds- now I'm not sure if this was trying or not. But I sure hope not.

The F-35C demo team and F-35a demo team both performed at Huntington Beach. The 35c did a 360 sustained turn in 23 and 24 seconds. The 35a did it in 25 seconds both days. Same altitude and same weather. I assumed the 9g 35a model would have provided it with better turn rates but it seems like the bigger wings of the c model with less g forces can turn better.

Thank you everyone.
Last edited by rowbeartoe on 11 Oct 2021, 00:34, edited 1 time in total.
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disconnectedradical

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Unread post11 Oct 2021, 00:09

Minimum radius turn is the turn that gives the smallest radius, not necessarily the fastest turn rate or the most g.

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Unread post11 Oct 2021, 01:04

Don’t get wrapped up about airshow routines. Airshow guys and gals don’t necessarily max perform a jet every time they go fly. ‘Close’ is good enough for government work when it comes to what you see or don’t see in most airshow routines; unless a jet is completely inferior, a few degrees/sec here and there in an airshow routine don’t matter.

Did the Blues or the T-Birds do a ‘min radius turn’ in airshows before Hornets and Vipers? Did anyone care about ‘min radius’ turns before the 4th Gen jets showed up?
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Unread post11 Oct 2021, 09:27

rowbeartoe wrote:Hi Everyone. I hope everyone is having a great day when they read this.

Ok, So I've seen all three models at airshows do low altitude 360 sustained turns. The F-35a is the only 9g model.
At Miramar in 2018 I saw the F-35b model do a turn in over 30 seconds- now I'm not sure if this was trying or not. But I sure hope not.

The F-35C demo team and F-35a demo team both performed at Huntington Beach. The 35c did a 360 sustained turn in 23 and 24 seconds. The 35a did it in 25 seconds both days. Same altitude and same weather. I assumed the 9g 35a model would have provided it with better turn rates but it seems like the bigger wings of the c model with less g forces can turn better.

Thank you everyone.


I think here is F-35B doing 360 degree sustained turn in about 26 seconds or so (at 1:04):


Anyway, I think F-35C can have equal turn rate to F-35A with the bigger wing allowing it to fly slower while turning. But on the other hand F-35A will be able to keep turning harder at higher speeds. Correct me if my understanding here is wrong. I wonder how the bigger wing of C-model affects higher altitude performance?
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rowbeartoe

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Unread post11 Oct 2021, 17:07

A week earlier the 35c and 35a demo teams performed at Sacramento which has an altitude of just under 100ft and so no surprise they both duplicated what they did at Huntington beach.

These sustained turn (minimum radius turns) are impressive considering that could probably do the same with weapons inside. I was just surprised that the C model did better than the A model at low altitude. Of course the speeds at the turns should favor each craft at that respected speed.

Now i know the game changes with instantaneous turns as the aircraft slows down greatly to achieve the better turn rate. The cost of doing such a thing of course is you are no longer maintaining energy vs these sustained turns where each aircraft has not lost any energy as i'm led to believe.

I know the hornet and Falcon both turn at different sustained speeds to demonstrate their max sustained turn rates. The Hornet C model is around 23 seconds and the "Viper" is 20 seconds at sea level.

Just to be clear- as most know, sustained turning at low altitudes is not the be all end all of best fighter Jet.
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hkultala

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Unread post11 Oct 2021, 18:21

rowbeartoe wrote:A week earlier the 35c and 35a demo teams performed at Sacramento which has an altitude of just under 100ft and so no surprise they both duplicated what they did at Huntington beach.

These sustained turn (minimum radius turns) are impressive considering that could probably do the same with weapons inside. I was just surprised that the C model did better than the A model at low altitude. Of course the speeds at the turns should favor each craft at that respected speed.

Now i know the game changes with instantaneous turns as the aircraft slows down greatly to achieve the better turn rate. The cost of doing such a thing of course is you are no longer maintaining energy vs these sustained turns where each aircraft has not lost any energy as i'm led to believe.

I know the hornet and Falcon both turn at different sustained speeds to demonstrate their max sustained turn rates. The Hornet C model is around 23 seconds and the "Viper" is 20 seconds at sea level.

Just to be clear- as most know, sustained turning at low altitudes is not the be all end all of best fighter Jet.


Minimum radius turn is a totally different thing than maximum turn rate turn.

And f-35a benefits more from increasing the speed than f-35c.
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Unread post11 Oct 2021, 22:47

Salute!

Ineresting EM above for the CJ Viper. Of course, gross weight is 5,000 pounds more than the birds I flew last century... heh heh. The Drag Index was not representative of our std A2A loadout of two or four Limas. and no tanks.

Back then, our corner was bout 360 KCAS and in full AB below 10,000 ft you could hold 9 gees until you ran outta gas. The chart above shows about 7 gees with Ps = zero. No wonder we watered people's eyes.

The biggie is the gee at the same speed as the enema. If you can pull more, then you can turn inside, go vertical or so forth. The Hornet and the deltas can lay on huge pitch rates, but only for a few seconds before losing the big E. Our flyoff JTF folks frequently commented that the YF-16 held the turn rate much better than the YF-17, but did not have the best instantaneous rate due to the limiter. At real slow Q, we also had less nose-pointing authority than most other folks for the same reason. The big tail helped, but the limiter ruled.

Regardless, it is impressive to see a turn radius under 2,000 feet for a machine zipping along at 350 - 400 knots.

Gums recalls....
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Unread post12 Oct 2021, 09:05

Gums wrote:Salute!

Ineresting EM above for the CJ Viper. Of course, gross weight is 5,000 pounds more than the birds I flew last century... heh heh. The Drag Index was not representative of our std A2A loadout of two or four Limas. and no tanks.

Back then, our corner was bout 360 KCAS and in full AB below 10,000 ft you could hold 9 gees until you ran outta gas. The chart above shows about 7 gees with Ps = zero. No wonder we watered people's eyes.

The biggie is the gee at the same speed as the enema. If you can pull more, then you can turn inside, go vertical or so forth. The Hornet and the deltas can lay on huge pitch rates, but only for a few seconds before losing the big E. Our flyoff JTF folks frequently commented that the YF-16 held the turn rate much better than the YF-17, but did not have the best instantaneous rate due to the limiter. At real slow Q, we also had less nose-pointing authority than most other folks for the same reason. The big tail helped, but the limiter ruled.

Regardless, it is impressive to see a turn radius under 2,000 feet for a machine zipping along at 350 - 400 knots.

Gums recalls....

Gums, the later F-16 can't turn as well as the early F-16 because they are heavier, but they also accelerate much faster due to their better engine. In your experience, would you rather have better turn rate or better acceleration in close combat?
acceleration of various F-16.jpg

acceleration of various F-16.jpg
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Unread post12 Oct 2021, 19:48

Salute!

Thanks, eloise.

On thing that stands out is the accel from 0.4M to the mach. I doubt anyone but a golden arm test pilot could demonstrate more than 5 or 6 seconds difference, if that much. The transonic and above the mach is better, as you say. The thing accelerated like a dog above the mach and mostly due to the fixed intake from what the JTF folks said.

I assume the profiles were one gee, st and level. Just slightly unloading the jet resulted in awesome accel and you could go supersonic in mil power when in the A2A config. Some pilots would trim to zero gee before the fight and then just relax the stick grip for the min drag acceleration ( remember, the FLCS pitch was gee command, not physical movement of the slab or anything). At 40,000 ft we could bump up to 1.1M in burner, and stay there in mil for maybe 2 or 3 minutes before having to bump the burner again. I routinely demoed this with my students coming back from Mountain Home to Hill in a family model after an A2G mission - 2 ters for the BDU's and a centerline tank.

As far as accel versus turning? I'll take the turning capability, even tho staying in a bogey-gathering level 360 is kinda dumb. Looks good for the airshow, gotta admit.

My other demo for the students was a three gee level turn starting from 400 knots in full AB. Just 90 degrees, but normal speed when rolling out and pulling off the power was about 700 KCAS. Whew!

Gums sends...
Last edited by Gums on 13 Oct 2021, 16:39, edited 2 times in total.
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f119doctor

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Unread post13 Oct 2021, 00:24

And just think, that was with lowly F100-200 engine….! Weight matters.
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Unread post13 Oct 2021, 20:36

Gums wrote:Salute!
On thing that stands out is the accel from 0.4M to the mach. I doubt anyone but a golden arm test pilot could demonstrate more than 5 or 6 seconds difference, if that much.
As far as accel versus turning? I'll take the turning capability, even tho staying in a bogey-gathering level 360 is kinda dumb. Looks good for the airshow, gotta admit.
My other demo for the students was a three gee level turn starting from 400 knots in full AB. Just 90 degrees, but normal speed when rolling out and pulling off the power was about 700 KCAS. Whew!
Gums sends...

So If i understand correctly, the reason you choose turning instead of acceleration for F-16 is because there isn't significant acceleration different between different version of F-16 in the range from Mach 0.4- Mach 1 where dogfight happen?.
How about F-16 vs F-14 or F-16 vs F-18? would you rather have the acceleration of F-16 or the superior ITR and nose pointing of the other two in close combat?. And why?.
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Unread post13 Oct 2021, 22:21

eloise wrote:would you rather have the acceleration of F-16 or the superior ITR and nose pointing of the other two in close combat?. And why?.


Why not both? :drool:

I'll even toss in a disappear switch for free. Sorry, no family model though. :mrgreen:

:devil:
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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Unread post13 Oct 2021, 23:08

High Gs are achieved at the onset of the turn, so instantaneous turn rate. Or turns at high speeds.
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Unread post13 Oct 2021, 23:32

Salute!

Good points, Eloise.... and for Kim...

The Hornet and F-series of Soviet fame can lay on immense gee/pitch rate in the break, but then wind up at 120 knots with no gee available, and a basic strafe target.

The good A2A pilots do not yank and pray, but manage their energy after a few seconds of a hard break and assess the situation. If on the offense from the beginning, then take the lip shot or even a Winder if set up has the bandit in front quandrant unaware of you. My best break was due to poor wingie and my own failure. But when the bandit came over the ridge behind me I pulled 8.7 gees for maybe 5 or 6 seconds, then tried to get my wingie to take a shot..... Oh well...

At the time we got the Viper, we had awesome turning capability and also super accel if we unloaded.

Let's face it, you ain't gonna get into a dogfight in a telephone booth at 1.4M. So if you look at the Viper EM charts, note the 0.85M peak in many favorable conditions.

For now, I like the turning aspects of the old Viper and the new F-35.

Gums sends...
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"God in your guts, good men at your back, wings that stay on - and Tally Ho!"
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Unread post15 Oct 2021, 09:07

Gums wrote:For now, I like the turning aspects of the old Viper and the new F-35.
Gums sends...

Your comment fit very nicely with this
https://theaviationgeekclub.com/soviet- ... ngagement/
so it would seem that superior sustained turn rate is still some what preferable to superior acceleration, but why is that ?, I would assume that an aircraft with superior acceleration can always extend and escape the engagement or go vertical to left the one with superior turning behind?
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