F-35 and Airshows

Discuss the F-35 Lightning II
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gta4

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Unread post02 Feb 2019, 09:20

My thought?
It is revealed that the minimum airspeed is less than 100 miles / hour, and if we know the corresponding angle of attack, it would be easy to estimate other performances (init. turn rate, etc).

The minimum airspeed is significantly slower than Mig and Sukhoi, which proves the effectiveness of its lifting body design.

https://www.youtube.com/watch?v=RRW0sLs ... e=youtu.be
slow speed pass at 13:00. Estimated AOA = 30 deg.
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sferrin

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Unread post02 Feb 2019, 13:31

Heh. 1:43

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Unread post02 Feb 2019, 18:01

I'm glad the low speed pass was brought up with a reference to the F-22 pass.

From the F-22 Demo Parameters:

Target -
Altitude 1,000'AGL
KCAS 80
Power Setting Cruise to Mil
AoA 36

Limits -
Altitude 900'AGL
KCAS 75
Power setting MIL
AoA 40

Description notes: performed into the wind.
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Unread post03 Feb 2019, 02:48

And F-22 demo is done with full internal fuel
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sprstdlyscottsmn

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Unread post03 Feb 2019, 03:56

gta4 wrote:And F-22 demo is done with full internal fuel

It needs too. It can burn through it's full fuel load at the same rate an F-16 can.
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Unread post03 Feb 2019, 04:17

Well I think you overestimate the fuel burn in a normal airshow. In 1979 paris Le Bourget F-15A consumed 2700kg and F-18A consumed less than 2000kg each time. Not every maneuver requires full afterburner, and during the reposition between each maneuver there is no need to use afterbuner.
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Unread post03 Feb 2019, 04:23

Older members in this forum may still have the impression about a brochure distributed by Lockheed Martin comparing Mig-29 and western jets. I have a translated version of that brochure in another language. There was a chart named "estimated fuel comsumption for ordinary 9-min show" (or something similar), Mig consumes 2000kg while F16 consumes 1455kg.
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Unread post03 Feb 2019, 05:16

I didn't say it burned all the fuel, though I see how what I did say could be taken as such. With a nominal 70,000lb of thrust in AB and a nominal TSFC of 2.0, the F-22 would burn in the neighborhood of 40lb of fuel per second in AB. The 20 second min radius turn? 800lb. 10 seconds for the followup vertical climb? 400lb. 20 seconds to reposition from slow pass? Another 800lb. 30 seconds for an AB take-off into a vertical climb and a power loop? 1,200lb. 40 seconds for vertical climb, power loop, and pedal turn? 1,600lb. 5 seconds for the loaded roll? 200lb. 10 seconds for each use of a Split-S reposition? 400lb. We are at a ballpark 5,400lb (2,455kg) fuel burned in just those maneuvers. This is looking at the AF Demo Routine document for when MAX power is specified.

Look at the thrust ratings of the planes you mention.
F-15A 47,600lbt, 5,940lbf, 8.0 t/f (nominal thrust rating over fuel consumed)
F/A-18A 32,000lbt, 4,400lbf, 7.3 t/f
MiG-29 36,000lbt, 4,400lbf, 8.2 t/f
F-16A 23,800lbt, 3,200lbf, 7.4 t/f

Looks fairly consistent. This would say that for a "9-min" airshow we could expect the F-22 to burn 8,540-9,589lb of fuel. If it took off at 50% fuel, it might flameout before landing. Figure the reserve is around 3,000lb, and another 1,000lb burned while on the ground before takeoff, and we are looking at 13,500lb being the minimum fuel for the routine. A 57,500lb plane is not going to perform much worse with another 4,500lb of fuel (<8% increase in weight), so you might as well bring it.
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Unread post04 Feb 2019, 03:09

Screen grab from a LMT video of F35 demo pilot Dojo visiting LMT to discuss his airshow manoeuvres with Billie Flynn. Will i see 2 AMRAAMs and 2 MK-84 JDAMs when the F35 does its weapons bay door pass? That will be unprecedented for any airshow demo!
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Unread post04 Feb 2019, 04:17

WotNOvideo? That screengrab could be from anywhere. Why no video URL?
RAN FAA A4G Skyhawk 1970s: https://www.faaaa.asn.au/spazsinbad-a4g/ AND https://www.youtube.com/channel/UCwqC_s6gcCVvG7NOge3qfAQ/
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Unread post04 Feb 2019, 05:24

gc wrote:Screen grab from a LMT video of F35 demo pilot Dojo visiting LMT to discuss his airshow manoeuvres with Billie Flynn. Will i see 2 AMRAAMs and 2 MK-84 JDAMs when the F35 does its weapons bay door pass? That will be unprecedented for any airshow demo!

I doubt you'll ever see a flyby with weapons bay doors open showing internal.weapons.
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Unread post04 Feb 2019, 07:41

spazsinbad wrote:WotNOvideo? That screengrab could be from anywhere. Why no video URL?



Here you go! At 0:40 mark. https://twitter.com/thef35/status/10914 ... 22752?s=20
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Unread post04 Feb 2019, 08:14

Thanks - I'm not a twatter user so I would never find/go there. However to me the screenshot means not a lot - random. However I'll concede that looking at artificial horizon may indicate they are 'demonstrating' to one another on travel sim.

F-35A Lightning II Demonstration Pilots Talk DOJO & Flynn Sim https://www.youtube.com/watch?v=8B28VZsjHCM

RAN FAA A4G Skyhawk 1970s: https://www.faaaa.asn.au/spazsinbad-a4g/ AND https://www.youtube.com/channel/UCwqC_s6gcCVvG7NOge3qfAQ/
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sferrin

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Unread post04 Feb 2019, 17:41

sprstdlyscottsmn wrote:I'm glad the low speed pass was brought up with a reference to the F-22 pass.

From the F-22 Demo Parameters:

Target -
Altitude 1,000'AGL
KCAS 80
Power Setting Cruise to Mil
AoA 36

Limits -
Altitude 900'AGL
KCAS 75
Power setting MIL
AoA 40

Description notes: performed into the wind.


Thing looks like it's on a rail in that shot. Rock solid.
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Unread post05 Feb 2019, 07:15

I remember LM published the 1G flight test envelope of F35A/B/C. F-35A could sustain 1G level flight at Mach 0.29 and at 36000ft. This could give us some idea on estimating the drag polar.
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