Lockheed Martin F-22 Raptor

TomcatViP said:
F-22 2020 crash probably caused by smart probe contamination during washing operations:

View attachment 661661

www.nwfdailynews.com

A $201M maintenance error: Air Force releases cause of F-22 crash at Eglin AFB in 2020

The U.S. Air Force has traced the cause of the 2020 crash of an F-22 Raptor fighter jet at Eglin Air Force Base to a maintenance error.
www.nwfdailynews.com
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Sounds similar to the loss of the B-2 in Guam, water/moisture in the air data port/probes. In the B-2, the pilot did not turn on the air data port heaters to evaporate the moisture. During flight test and even in the desert, air port heaters were always turned on as part of the preflight checklist.
 
@Hydroman : nice one.
The cover for the probe is even compliant with the increases in temperature expected if the cover is left on the probe while the probe heating is ON.

It seems that what could have obstructed the probe was not something expected in SOP.
 
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Reposting from the F-35 thread, this AFM article covering a roundtable with journalists by USAF advanced aircraft PEO BGen White discusses some of the challenges of integrating a new engine to an existing airframe.

www.airforcemag.com

USAF: New Engine Technologies May Not Retrofit to Existing Fighters | Air & Space Forces Magazine

Existing USAF fighters won't be able to be retrofitted with new engines being developed by the Adaptive Engine Transition Program, officials say.
www.airforcemag.com www.airforcemag.com

That said, there was this interesting tidbit.

Changing the propulsion system on a fielded aircraft is “extremely complex, and there’s a lot that goes with that,” White said. “So you have to think about what the return on investment might be, there.”

He called out the F-22 as one platform where the directorate is looking at its Pratt & Whitney F119 engines for improvements “and whether or not we’re getting the most out of that system and [whether] we can do more for it.”

“Everything’s on the table” to make improvements on engine performance, regarding “climate, to efficiency, to thrust,” he added, touting a close working relationship with Air Force Life Cycle Management Center’s propulsion directorate.
Click to expand...
 
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www.businessinsider.com

A US F-22 Raptor pilot describes the challenge of going up against F-35 red-air aggressors

"It is challenging, even flying the Raptor to have good [situational awareness] on where the F-35s are," the pilot said.
www.businessinsider.com www.businessinsider.com

An interesting perspective on how challenging an F-35 aggressor can be even to an F-22. These lines from an F-22 IP stands out.

"It is challenging, even flying the Raptor, to have good [situational awareness] on where the F-35s are," he said.
...
The F-35s "have better detection capabilities kind of against everybody just because of their new radar and the avionics they have," he said. "It definitely adds a level of complexity."
...
"I've flown against red F-35s locally," Bowlds said, telling Insider that "it's always challenging." That challenge is amplified in a large exercise like Red Flag. "There's a lot of different things out there that want to hurt you, and that's where you can start to lose track of the stealth adversaries," he said.
Click to expand...
 
www.documentcloud.org

F-22 Export Configuration Study

A study the US Air Force conducted that explored a notional exportable F-22 Raptor stealth fighter configuration, dated March 2010. This document was released via the Freedom of Information Act.
www.documentcloud.org www.documentcloud.org

F-22 export study, although it has been highly redacted. A whole host of changes to radar, CNI, and other assorted avionics was to be expected, and likely very costly. Understandably there are technologies in the F-22 that USAF wants to keep for itself.
 
One interesting take I saw from that document is that there is a classified store or weapon system available to the F-22. Wondering what it may be....
 
BDF said:
One interesting take I saw from that document is that there is a classified store or weapon system available to the F-22. Wondering what it may be....
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Probably is bright. Like SPF 1000000 bright.
 
Hydroman said:
TomcatViP said:
F-22 2020 crash probably caused by smart probe contamination during washing operations:

View attachment 661661

www.nwfdailynews.com

A $201M maintenance error: Air Force releases cause of F-22 crash at Eglin AFB in 2020

The U.S. Air Force has traced the cause of the 2020 crash of an F-22 Raptor fighter jet at Eglin Air Force Base to a maintenance error.
www.nwfdailynews.com
Click to expand...
Sounds similar to the loss of the B-2 in Guam, water/moisture in the air data port/probes. In the B-2, the pilot did not turn on the air data port heaters to evaporate the moisture. During flight test and even in the desert, air port heaters were always turned on as part of the preflight checklist.
Click to expand...

Oh gosh... reminds me of that airliner that crashed because some stupid bugs went into the pitot tubes - not properly sealed during a stay on the ground.
This very one...
en.wikipedia.org

Birgenair Flight 301 - Wikipedia

en.wikipedia.org en.wikipedia.org

While nobody died in the B-2 and F-22 crashes, stealth aircraft (and particularly those two !) cost US taxpayers an arm, a leg, and a testicle back inthe 2000's .
Plus of course way too few airframes were built (187 and 21, ain't much).

Losing one such precious airframe to such silly mishap... really... must be pretty irritating.
 
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icyplanetnhc (Steve) said:
Who were the original developers of some of the key avionics?

APG-77 - Westinghouse/Texas Instruments
ALR-94 - Sanders/General Electric
CIP - Hughes

Who originally developed the AAR-56?
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A very belated update on this; I believe I’ve found evidence that Martin Marietta was the original contractor of the AAR-56. An older article covering the F-22 mission systems stated that the MLD was from Lockheed Martin’s Missiles and Fire Control division in Orlando, FL, which corresponds with Martin Marietta’s Electronics & Missiles Group prior to the company’s merger with Lockheed in 1995.
 

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FighterJock said:
I am actually surprised at how the USAF never actually tried to upgrade the F-22 by installing some of the F-35 avionics that could help them save a lot of money in the process plus perhaps replacement more powerful engines as well.
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Its already overpowered. Its already the king Kong of air dominance. Money better spent on ngad or b21 or a new icbm or aim260.
 
Archibald said:
Hydroman said:
TomcatViP said:
F-22 2020 crash probably caused by smart probe contamination during washing operations:

View attachment 661661

www.nwfdailynews.com

A $201M maintenance error: Air Force releases cause of F-22 crash at Eglin AFB in 2020

The U.S. Air Force has traced the cause of the 2020 crash of an F-22 Raptor fighter jet at Eglin Air Force Base to a maintenance error.
www.nwfdailynews.com
Click to expand...
Sounds similar to the loss of the B-2 in Guam, water/moisture in the air data port/probes. In the B-2, the pilot did not turn on the air data port heaters to evaporate the moisture. During flight test and even in the desert, air port heaters were always turned on as part of the preflight checklist.
Click to expand...

Oh gosh... reminds me of that airliner that crashed because some stupid bugs went into the pitot tubes - not properly sealed during a stay on the ground.
This very one...
en.wikipedia.org

Birgenair Flight 301 - Wikipedia

en.wikipedia.org en.wikipedia.org

While nobody died in the B-2 and F-22 crashes, stealth aircraft (and particularly those two !) cost US taxpayers an arm, a leg, and a testicle back inthe 2000's .
Plus of course way too few airframes were built (187 and 21, ain't much).

Losing one such precious airframe to such silly mishap... really... must be pretty irritating.
Click to expand...
Needing to bring back a plane the predates whole lotta love must be equally irritating.
 
bring_it_on said:
Click to expand...
I was going through some older discussions in this thread, and I can’t help but notice, is this Gentex representative Jim Sandberg, the YF-23 PAV-2 test pilot?

EDIT: It does seem to be the case.

http://www.sldforum.com/2012/05/“just-do-it”-a-test-pilot-speaks/

Colonel Sandberg flew A-4 Skyhawks in the early 1970s. Graduating from USAFTPS in 1977, he served as operational test pilot in VX-4, Point Mugu, California, flying the A-4, F-4, F-14, and new F-18. He was the 31st pilot to ever fly a Hornet. After leaving active duty in 1982, he worked for Northrop as an engineering test pilot and finally as Director of the F-35 Integrated Test Team at Pax River. A former president of the Society of Experimental Test Pilots, he now works as an independent consultant. One of his clients is GENTEX Corporation, an HMD developer.
Click to expand...
 
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Listening through The Fighter Pilot Podcast episode with F-22 pilot Col. Terry Scott, his description of his first BFM exercise against an F-16 in Alaska stuck out to me. Despite being very seasoned in the F-15, he struggled in his first set against the F-16 when flying the F-22 and only decisively won in his third set. It turns out that his struggle is due to going into post-stall too soon and expending his energy, likely as a consequence of not being familiar with how much alpha the F-22 can pull compared to the F-15.

View: https://youtu.be/AguVV7SH9eY&t=1765


This made me think of the 2015 F-35 flight test report which notes a lack of energy when fighting an F-16; since it was a flight control test that put the aircraft into high AoA, I think the ability of the aircraft to provide the pilot with so much alpha also allows him/her to potentially make the mistake of putting the aircraft in a low energy state by expending too much energy early. It’s a similar mistake as what Col. Scott made in his first set in the F-22, who struggled even in an aircraft with enormous excess power.

Back to the F-22, it’s interesting that the stick sends a g command above 275 knots and pitch rate command below that airspeed. I recall a test pilot with callsign C-dip (don’t remember his name) who gave a presentation to us UCLA aerospace students at Edwards in 2016 said something similar. He also mentioned that the amount of g that flying the F-22 subjects the pilot to compared to other airplanes is not a pleasant experience.

I do wish I still have all the notes that I took from his talk, they’re quite interesting.

https://www.intelligent-aerospace.com/military/article/14187849/bae-f-22-friend-or-foe

Mode 5 IFF and MIDS-J box certified November last year.
 
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NJ5HI7KSRNGTBGGWCMETEW37HM.png


www.airforcetimes.com

Pilot lost control of wobbling F-22 that spiraled to the ground in secretive crash last year

In the confusing aftermath of the crash, F-22 and F-35 fighter jets almost collided in midair as well.
www.airforcetimes.com www.airforcetimes.com
 
"“maintenance error made after the aircraft was washed” that “impacted control inputs transmitted to the aircraft.”"

Maybe water was where it shouldn't be and affected the air data system?
 
sferrin said:
"“maintenance error made after the aircraft was washed” that “impacted control inputs transmitted to the aircraft.”"

Maybe water was where it shouldn't be and affected the air data system?
Click to expand...
Didnt the same thing happen to that B2 that crash?

Or something similar to that effect.

Honestly I wonder if the Air Force is going to look into a test to ensure it doesnt happen anymore...

Or assualt the maintainers to not be lazy if they already do have the test.
 
Regarding the link further down that AFT article, if accurate, it does not paint a pretty picture of the 325th at all.
 
sferrin said:
"“maintenance error made after the aircraft was washed” that “impacted control inputs transmitted to the aircraft.”"

Maybe water was where it shouldn't be and affected the air data system?
Click to expand...

Or perhaps they installed plugs in the air data system to prevent water intrusion while washing the plane and forgot to remove one when they were done.
 
Worst part is that one

A confusing mission to inspect the crash site and find the pilot nearly resulted in another collision between an F-22 and an F-35 Lightning II.
Click to expand...

Three stealth jets lost in a single day: would have made USAF wallet bleed.

Reminds me of that unfortunate collision years ago, between two naval Rafales. It was murderous, and also wiped out by itself a not-insignificant percentage of the CdG fast jet fleet...
 
icyplanetnhc (Steve) said:
The aircraft in fact did give a flight control warning, but the pilot chose to proceed with the mission.
Click to expand...
I always thought what exists a protocol shutdown of the flight computer in case of suspicion critical failure of control system
why the flight computer continues turn control surfaces in the time when for pilot is already clear that it's work did not correctly? according the story time for this manipulation have been
 
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TomcatViP said:
The F-22 is a fly by wire airplane. You can't fly it without the computer.
Click to expand...
why, I mean Direct law
the problem was in the wrong sensor data, so turn off automatic response to this data and use control by hands

Direct law
Direct law (DIR) introduces a direct stick-to-control surfaces relationship: control surface motion is directly related to the sidestick and rudder pedal motion. The trimmable horizontal stabilizer can only be controlled by the manual trim wheel. All protections are lost, and the maximum deflection of the elevators is limited for each configuration as a function of the current aircraft centre of gravity. This aims to create a compromise between adequate pitch control with a forward C.G. and not-too-sensitive control with an aft C.G.

DIR is entered if there is failure of three inertial reference units or the primary flight computers, faults in two elevators, or flame-out in two engines (on a two-engine aircraft) when the captain's primary flight computer is also inoperable
Click to expand...
en.wikipedia.org

Flight control modes - Wikipedia

en.wikipedia.org en.wikipedia.org
 
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AN/AWW-14(V) said:
why, I mean Direct law
the problem was in the wrong sensor data, so turn off automatic response to this data and use control by hands
Click to expand...

Unlike an airliner, given that the F-22 is by design a relaxed stability aircraft, i.e. statically unstable, a direct law would not render the aircraft controllable, unless somehow the wing control surfaces or some other system can be scheduled to shift the neutral point further back (unlikely). The FLCS is required for flight.

The aircraft did give a FLCS advisory during the takeoff roll, but it’s not going to stop the pilot from taking off if he chooses to proceed, and that’s what he did, rather than aborting.

Edit: The report did say that the pilot was trying to burn fuel in a holding pattern, so perhaps he was trying to land at a reduced weight. That said, I’m not aware what the landing weight of the F-22A is and I’d be surprised if the aircraft doesn’t have a fuel dump function, or if Eglin runways can’t accommodate a fully fueled F-22 for landing.
 
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If the first F-22 mishap at Nellis, a maintenance redball situation resulted in bypassing the complete flight control self check, and the aircraft took off with 2 bad rate gyros. System voted 2 vs 1, and voted the good rate gyro off, resulting in the flight controls trying to follow the bad inputs from the other two rate gyros. Updated software and Dash-1 procedures were implemented to prevent that from happening again. But it may be something similar happened with the air data system following the maintenance error and the pilot electing to continue the mission with the active warning.
 
Back to the F-22, it’s interesting that the stick sends a g command above 275 knots and pitch rate command below that airspeed. I recall a test pilot with callsign C-dip (don’t remember his name) who gave a presentation to us UCLA aerospace students at Edwards in 2016 said something similar. He also mentioned that the amount of g that flying the F-22 subjects the pilot to compared to other airplanes is not a pleasant experience.
Click to expand...

The YF-23 had basically the same pitch schedule. According to Metz's YF-23 book, pitch command it was for AoA below cornering speed and G above that.
 

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