F-35 and Airshows

sferrin · by **sferrin** » 31 Jul 2018, 00:58

lrrpf52 wrote:Either way, we're looking at a powerplant that rivals the SR-71's J58 by a substantial margin when looking at thrust.

That F135 motor is a beast fighter engine. It smokes the MiG-31's D-30F6 motors as well.

Optimized for completely different regimes. I'd be surprised if the F135 could touch either of those engines at Mach 2 and 60,000 feet.

gta4 · by **gta4** » 31 Jul 2018, 07:10

BVR is always agility demanding. You need acceleration and climb rate to maximize the initial energy of your missile. You need f-pole maneuver to break radar lock. You need high g sustained turn to minimize the no eacape zone of enemy missile.

jetblast16 · by **jetblast16** » 01 Aug 2018, 01:32

I'd be surprised if the F135 could touch either of those engines at Mach 2 and 60,000 feet

I wouldn't be surprised if the F135 can make 25k LBS of thrust at high altitude in MAX AB. Further, as others alluded to here, the engine may be able to make up to 48k or so LBS of thrust in denser air at speed, with sufficient mass flow. That could explain the F-35A's exceptional rate of climb and thunderous noise of its engine.

jetblast16 · by **jetblast16** » 01 Aug 2018, 02:38

I dunno, maybe I'm reading into things. I could be flat out dead wrong. Using public figures, the F-35A would have, at least statically (assuming 43k LBS is installed static thrust), a T/W ratio of about 1.22-to-1 with 6k LBS of fuel, at MAX AB. Without knowing how much fuel was placed in the jet, it is difficult to determine what it's T/W ratio was. 8K starting; a typical "airshow" fuel level?

F-16ADF · by **F-16ADF** » 01 Aug 2018, 12:54

I thought the F-35 starts its demo with fuel internal fuel (just like the Raptor). I am I wrong here?

I believe I read that somewhere (a USAF doc). Will try to find it if I have time.

geforcerfx · by **geforcerfx** » 01 Aug 2018, 16:12

f-16adf wrote:I thought the F-35 starts its demo with fuel internal fuel (just like the Raptor). I am I wrong here?

I believe I read that somewhere (a USAF doc). Will try to find it if I have time.

That would be a massive waste of fuel, for 4th gens and the F-22 it makes sense they have fuel fractions near 25% the F-35A is 37% and would just be a waste of fuel having to haul the extra 9,000lbs around you don't need for the display. That's why most 4th gen demos don't have EFTs on for displays ( beyond the limited manuverability).

F-16ADF · by **F-16ADF** » 01 Aug 2018, 16:38

I believe in the doc they said they wanted to display the jets in "near combat form", meaning not flying on fumes like all the other previous displays. I could be wrong. When I have more time I will try and find it.

Here is a 1993 demo of a USAF Block 50 from SW. Note, that empty the jet is 19,260lbs. Airshow boss says that for today's display jet weighs in at 23,000lbs. So basically this F-16C has just around 3500lbs of fuel (half internal load) for the display. He also has a centerline pylon on (177lbs). The earlier displays tended to be a tad more aggressive, his 360 only takes 17 seconds. Not the 19 seconds of present day.

https://www.youtube.com/watch?v=jQ9PipSKGl8

fbw · by **fbw** » 01 Aug 2018, 17:02

f-16adf wrote:I believe in the doc they said they wanted to display the jets in "near combat form", meaning not flying on fumes like all the other previous displays. I could be wrong. When I have more time I will try and find it.

Yes, I read it too. 18,000lbs of fuel + inert weapons if applicable for F-22 airshows, less under specific conditions IIRC.
http://static.e-publishing.af.mil/produ ... -246v1.pdf

Found it Page 137

F-16ADF · by **F-16ADF** » 01 Aug 2018, 20:32

Yes, I guess I was wrong.

Billie Flynn (AWST interview) also said the the 35 flies its demos like the Raptor as "Combat Coded", so technically what is the definition of that? He also said that their demos are different from traditional legacy jets.

Since half internal fuel is 9250lbs, is he flying with say 10-12,000lbs of fuel. Modern day Block 50's fly a low show with only 4K (56%)of fuel. And 5k (69%)for a high show. So I am figuring "Combat Coded" means at least more than either of those percentages; which on a 35 translates to 10,332lbs. and 12,915lbs.

Maybe the AF wants to keep everyone in the dark concerning this.

sprstdlyscottsmn · by **sprstdlyscottsmn** » 01 Aug 2018, 21:28

Combat coded just means the plane could, at any time, abort the demo, land, re-fuel and arm, go to war. There are no systems removed to improve performance, no special airshow paint, nothing of the sort.

fbw · by **fbw** » 01 Aug 2018, 21:50

f-16adf wrote:Maybe the AF wants to keep everyone in the dark concerning this.

Doubt it will be a secret. Once the F-35 complete IOT&E and is allowed to do airshow demonstrations in the US, they’ll develop a demonstration program with recommended fuel load and be added to regulations manual. Afterall, the F-22 is in there.

On an aside, always found it interesting that USAF limits demonstrations to 7.5g with momentary over g for safety (well at least as of recently). Likely for airframe life. So much for YouTubers “9g turn” comparisons.

playloud · by **playloud** » 01 Aug 2018, 22:06

fbw wrote:
f-16adf wrote:On an aside, always found it interesting that USAF limits demonstrations to 7.5g with momentary over g for safety (well at least as of recently). Likely for airframe life. So much for YouTubers “9g turn” comparisons.

That caught my eye as well. Had the same thought on the YouTube comparisons.

jetblast16 · by **jetblast16** » 02 Aug 2018, 01:10

fbw wrote:
f-16adf wrote:Maybe the AF wants to keep everyone in the dark concerning this.

Doubt it will be a secret. Once the F-35 complete IOT&E and is allowed to do airshow demonstrations in the US, they’ll develop a demonstration program with recommended fuel load and be added to regulations manual. Afterall, the F-22 is in there.

On an aside, always found it interesting that USAF limits demonstrations to 7.5g with momentary over g for safety (well at least as of recently). Likely for airframe life. So much for YouTubers “9g turn” comparisons.

^ This

mixelflick · by **mixelflick** » 02 Aug 2018, 15:13

Speaking to an F-35 pilot at an airshow a few weeks back.... said it really has great legs. Much better than the F-15 he came from. Then said something about the F-22 like, "yeah in 20 minutes they're at their limit and have to return to base". Obviously, a lot depends on that scenario but my first thought was, "yeah, but 20 minutes is going to seem like forever to an adversary pilot. The F-22 can do a whole lotta' killing in 20 minutes".

He said, "true"...

spazsinbad · by **spazsinbad** » 02 Aug 2018, 16:20

UHoh!? (Teletubby exclamation) WATTLE THEY FINK OFF NXT? THERE WILL BE NO SCAPING Except the FUEL FOOL! :shock:

Farnborough 2018: Air display delivers new tracks 30 Jul 2018 Jenny Beechener
http://www.janesairport360.com/article/ ... new-tracks