F-22 Prang at NAS Fallon, Nevada

[Airbubba]

With a picture in the article below provided by an anonymous Hornet driver.

F-22 Raptor Came To A Rest On Its Belly During Major Mishap Friday At NAS Fallon

Few solid details are available regarding this incident but USAF officials have confirmed that it did indeed occur and the damage is extensive.

By Tyler Rogoway April 14, 2018

An F-22A Raptor belonging to Elmendorf Air Force Base's 3rd Wing was involved in a major mishap this weekend. Details remain sketchy and are likely to change, but a source told The War Zone that the jet may have retracted its gear too early during takeoff, with the aircraft slamming back down on the runway at relatively high speed and skidding its way to a stop. Thankfully the pilot was able to egress from the aircraft without major injuries.

We contact[ed] the public affairs office at Joint Base Elmendorf-Richardson who jumped right on the story and quickly confirmed that the aircraft had been involved in a mishap at Fallon and although the damage is extensive, it is hoped that it can be repaired at this time. An investigation into the incident is currently underway.

The F-22 was at NAS Fallon to support the Navy Strike Fighter Tactics Instructor program, better known as Topgun, providing a dissimilar adversary for students to fight against as part of a class graduation exercise. This is a widely known event in which Topgun students take part in a 1v1 fight against an unknown 'surprise' enemy aircraft. Aircraft of all types, from warbirds to foreign fighters, have been brought in to take part in the exercise over the decades.

For a relatively small cadre of fighter aircraft—roughly just 125 out of 183 jets are combat coded at any given time—the F-22 community has experienced a number of gear-up and runway mishaps over the last half-decade or so.

On May 31st, 2012 a student pilot on his second solo flight in the F-22 didn't apply enough power before retracting the jet's landing gear during departure. The F-22 sunk down and careened its way across the runway on its belly before coming to a stop. The cost to repair that jet was a whopping $35M and took six years to accomplish the task.

F-22 Raptor Came To A Rest On Its Belly During Major Mishap Friday At NAS Fallon - The Drive (http://www.thedrive.com/the-war-zone/20129/f-22-raptor-came-to-a-rest-on-its-belly-during-major-mishap-friday-at-nas-fallon)

The Topgun adversary pilot was last seen filling out a Cathay Cargo application to fly rubber dogs**t out of HKG. ;)

[Lima Juliet]

http://imagesvc.timeincapp.com/v3/foundry/image/?q=70&w=1920&url=https%3A%2F%2Ftimedotcom.files.wordpress.com%2F2018%2F04 %2Fakhdda81.jpg%3Fquality%3D85

“Cancel the steps...”

[Treble one]

Jester and Viper would never have done this....

[RAFEngO74to09]

After the interview with no coffee:

https://getyarn.io/yarn-clip/2f122ab4-2bfc-41ea-a248-e74cca318037

"Maybe I could learn how to be a truck driver.

Mav, you got the number of that truck driving school we saw on TV - Truckmaster I think it is ?

I might need that !"

[Jobza Guddun]

At least they've got a team fully up to speed in fixing this sort of thing....

https://www.flightglobal.com/news/articles/damaged-f-22-makes-comeback-after-six-year-repair-jo-444022/

[Planet Basher]

Plagiarism

https://www.youtube.com/watch?v=f7Lu6LEQ0zo

[West Coast]

That’ll buff out.


It had to be said.

[TBM-Legend]

Even a Top Gun knows it takes full power to taxi the jet back to the lines!

[charliegolf]

Wasn't it Winkle Brown who trialled the rubber bed landings?

CG

[TheWestCoast]

Is anyone able to explain how it took six years to repair the other jet?

[hoss183]

Is anyone able to explain how it took six years to repair the other jet?

Five years of standing around scratching their chins and saying ' it'll buff out probably' one year to repair it

[Cows getting bigger]

Never mind the F22, what about the nasty scratch on the runway? :)

[AR1]

All the tech in the world - same old incidents.

[Ewan Whosearmy]

On May 31st, 2012 a student pilot on his second solo flight in the F-22

As opposed to what? His second dual flight? :ugh:

[sandiego89]

Another caught by a weight on wheels burble? Aircraft gets light, or a bump in the runway....

[Airbubba]

Looks like a flameout on takeoff and an airborne reject from this unofficial social media report:

UPDATE from sources: "Info on the Raptor mishap at Fallon: The slide happened on takeoff. Appears to have been a left engine flameout when the pilot throttled up to take off. By the time he realized the engine was dead, he had already been airborne for a few seconds and raised the gear. The jet bounched for around 1500 feet, and then slide for about 5000 feet. They got it off the ground and on its landing gear last night, so the runway is clear. Chain is wanting it to be quiet still. It's very fresh obviously. But it's looking like the second engine failure on Elmo jets in a 7 day period."

More pictures in this Aviationist article:

https://theaviationist.com/?p=53286

[Flap62]

So an F22 can’t lose an engine at lift off and still climb away? With all that power? Really?

[tdracer]

So an F22 can’t lose an engine at lift off and still climb away? With all that power? Really?
I was thinking the same thing - there must be more to it than that.

[Tech Guy]

I wonder what the runway friction coefficient is if the plane slid for 5000 feet.
I would have thought it would be lucky to travel that far if it had its wheels down.

[sandiego89]

Of possible interest, from way back in 1992 with the YF-22 belly landing- an 8,000 foot slide cited there. Not inferring any link to the 2018 incident, but interesting comments about pitch changes with gear retraction, PIO, and thrust vectoring. In the photos of the Fallon bird one engine does look vectored down. A flame out may have presented a real hand full.


AW&ST Articles on YF-22 Crash (http://pages.erau.edu/~rogers/as309/Videos/YF-22%20Crash.htm)





Report Pinpoints Factors Leading to YF-22 Crash
Aviation Week and Space Technology / November 9, 1992
Michael A. Dornheim / Los Angeles
The Lockheed/Boeing/General Dynamics YF-22A advanced tactical fighter prototype that crashed early this year was operating in a condition that was very prone to pilot-induced oscillation (PIO), according to Air Force accident investigators.
The airplane was performing a planned go-around using afterburner with thrust vectoring activated when it entered a pitch oscillation at 175 kt. and an altitude of 40 ft. After a severe series of pitch oscillations, the YF-22 crashed onto the runway and slid to a stop in flames (AW&ST May 4, p. 20).
Gen. Ronald W. Yates, commander of the Air Force Materiel Command, delayed release of the public "collateral board" investigation report to Oct. 22 to add segments from the confidential safety mishap report, including an engineering evaluation headed by David J. Moorhouse, currently the chief engineer for the F-15 STOL/MTD test program.
The report concluded there were no aircraft malfunctions and that it performed as designed. The investigation was aided by extensive telemetry data that were recorded during the accident.
In brief, the report stated the YF-22A was operating in a regime that was susceptible to PIO. The PIO was stimulated by retracting the landing gear during a pulse of full forward stick, which increased aircraft sensitivity. This, along with a nose-up bias from trim and software, started the PIO as Lockheed test pilot Thomas A. Morgenfeld briefly tried to fly a smooth climb-out.
Control surface actuators become rate limited, introducing further control log and worsening the oscillation. Morgenfeld was not aware he was in a PIO and thought the aircraft had malfunctioned. At 40 ft., he did not have many options and bellied the aircraft onto the Edwards AFB concrete Runway 22. The aircraft slid 8,000 ft. before stopping 185 ft. left of centerline.
The PIO-sensitive flight condition was "thrust vectoring on" at low altitudes and the lower airspeeds. The main contributor was not the thrust vectoring itself, but the flight control system gains that are in effect when thrust vectoring is activated. The aircraft would still be PIO-sensitive if these gains were used and the vectoring nozzles were disconnected.
At low airspeeds, YF-22A stick deflection basically commands a pitch rate, with zero deflection ideally giving a constant body attitude. From 200-260 kt. calibrated airspeed (KCAS), the pitch command blends to a g-command. The airspeed in the accident varied between 175 and 215 KCAS, so the aircraft was largely in the pitch command mode.
The accident investigators applied the "Ralph Smith PIO prediction criteria" to data from the accident go-around and four prior go-arounds, all using thrust vectoring. Smith is a consultant in Tehachapi, Calif. His criteria are not universally accepted but "they've been validated a lot," Moorhouse said.
Analysis of the early part of the accident PIO showed the pilot stick input was lagging pitch rate by 0.15 sec, the stabilator lagging the stick by 0.05 sec., and the pitch rate lagging the stabilator by 0.35 sec., for a total of 0.55 sec. lag in the pilot control loop. The period of oscillation was twice that -- 1.1 sec -- meaning that the lag was 180 deg. out of phase, making the aircraft "extremely susceptible to a PIO," the report found.
Analysis of the four previous go-arounds using military thrust gave similar results, predicting moderate PIO when the pilot attempts to closely track pitch angle.
From the time the gear was retracted in the accident, the stabilator was moving at its software rate limit of 60 deg./sec. and the vectoring nozzles were closely tracking the stabilator, with 0-0.2-sec. lag. Because the surfaces were rate-limited, they introduced a further 0.3-sec. lag in the pilot control loop, making the aircraft more difficult to control.
The Smith criteria assume the pilot tries to control load factor instead of pitch or pitch rate when in a PIO. "It's controversial, but Smith assumes the pilot switches to what he feels instead of what he sees," Moorhouse said. The accident data showed a 1.2-sec. delay in the control loop between pilot and load factor response while the oscillation was occurring with a 1.85-sec. period, for a phase lag of 234 deg. "Given the magnitude of the control inputs [full up/down deflections], this suggests a well-developed PIO in which it would be impossible for the pilot to recover unless he got out of the control loop," the report concluded.
The YF-22A had made a smooth go-around with thrust vectoring at military power 2 min. before the accident, and the report investigated the differences between them:

Afterburner was used in the accident go-around. The report judged this to not be a factor because afterburner only adds 14% pitching moment authority compared with military thrust.
The gear handle was raised while the stick was in the full down position for 0.2 sec. The gear transient with full stick deflection is the key item that stimulated the PIO at a 40-ft. altitude where there was little room for recovery. This is because the gear handle commands a large instantaneous change in the flight control laws, and because of the anti-transient logic for the control surfaces.
Three sets of pitch rate-stick deflection curves are possible. In order of increasing sensitivity, they are connected with landing gear down, vectoring off ("power approach"); gear up, vectoring off; and gear up, vectoring on. Placing the gear handle down automatically disables vectoring.
At full 0.26-in. nose-down stick deflection, a pitch rate of -2.6 deg./sec. is commanded in the power approach mode, while -10.5 deg./sec.-- four times greater -- is commanded with gear up and vectoring on, when at 205 KCAS. Similarly, at full 0.52-in. aft stick deflection, the power approach mode commands a 5.25-deg./sec. pitch rate, while gear up and vectoring on gives 17.1 deg./sec.
Stick force for the YF-22A's sidestick controller is 31 lb. full aft and 16 lb. full forward. It has a ± 0.03-in. deadband. The pitch rate curves are nonlinear and intermediate stick force gradients vary.
When other factors are included, analysis shows the YF-22A became 23-155% more sensitive when the gear handle was raised in the accident go-around, depending upon commanded pitch rate.
However, the control surfaces did not twitch instantly to follow the new gains because of anti-transient logic, called a "sump," located between the flight control laws and the surfaces. The sump adds an opposing bias to the control surface inputs equal to the amount of the transient due to the change in control laws. This bias washes out in 4 sec.
With the stick pressed full forward when the gear handle changed the control laws, the sump added an airplane nose-up bias initially worth about 8 deg./sec. pitch rate to prevent the stabilator from twitching further nose down. The aircraft also had some nose-up trim. When the pilot released the stick 0.2 sec. later, the 6-7-deg./sec. sump bias made the aircraft unexpectedly rotate nose up. That bias is worth more than full aft stick in power approach mode. The pilot countered with 0.3-sec. full down stick with the high-gain control laws freshly in effect, the control surfaces became rate-limited, and the PIO was underway as the pilot briefly tried to maintain a shallow climb-out.
"You can't predict when PIO will happen," Moorhouse said, explaining why PIO had not shown up before. "You can predict that an aircraft is susceptible to PIO, that at some time circumstances will make it happen."
Moorhouse said that the Smith criteria and other PIO measures are in Mil-Std-1797 handling specifications, but that "it's typical to not check for PIO during design," particularly if the aircraft is designed to have good Level 1 handling qualities.
The YF-22A thrust-vectoring system is intended mainly to enhance control at high AOA and to improve "g" capability at high supersonic speeds, both of which were tested at high altitude. "We did not do a lot of thrust-vectoring work on the simulator at sea level," Gerald T. Joyce, General Dynamics lead engineer for F-22A control laws development, told investigators.
The fixed-base YF-22A simulator was used to evaluate PIO under the accident conditions. When starting at 14 deg. to capture a 10-deg. attitude with the vectoring-on control laws, "the initial pitch down ... was very rapid and ... startling to the pilot," the report said. "Attempts to aggressively capture the desired pitch attitude always resulted in a large amplitude, undamped pitch oscillation with a period of 1.4 sec. Again, [control surface] rate limiting was apparently largely responsible."
But when the pilot was less aggressive, "the response was much different. The pitch down rate was smooth, but not abrupt, and capture easily performed." And when in a large PIO, "the oscillations died [rapidly] if the pilot let go of the stick."
The oscillations started about 1 sec. after the gear handle was raised, and the aircraft hit the ground 7.5 sec. later. Morgenfeld told investigators he did not understand what the problem was. "[I lit] the afterburner, gear up ... I thought I felt maybe a little bit of a bob," he said.
"The first time I knew something really was wrong, I felt a very strong nose-over pitch. [I was] looking at a lot of runway and the airplane had never done anything like that before. It surprised me, it really shocked me .... I thought something had broken and I didn't see any [warning] lights .... I'll undo the only thing that was different between this pass and the other, I snatched it back out of burner, come back to low [thrust]."
"[I started] thinking about coming back on up with the power now to mil and continue the go-around and get this thing away from the ground. And at about that time it made another big nose-down plunge ... and then at the next strong nose-down movement I thought, boy, that's it, something's drastically wrong here .... I just tried to get the nose up so I didn't do the lawn dart trick in the runway." The aircraft hit the ground at about 205 KCAS.
During the investigation several days later, Morgenfeld said he "was extremely surprised to see that I had used so much forward stick." However, "almost by definition, a pilot is not aware he is in a PIO," Moorhouse said. He also noted that sidestick controllers tend to be used more in a full-displacement pulsed manner than large-throw center sticks do.
The airplane flight manual and operating limits had no restriction on the use of thrust vectoring, but the flight test card called for it to be off for landing. The two lead flight test engineers said this card instruction was a carryover from earlier testing and was to protect against a failure of the vectoring system at low altitude. Since the vectoring system had been reliable, they said they would have eliminated the card item if requested.
However, flight control engineers said vectoring should be off at low altitudes for "flight control reasons," but they did not issue an operating limit "because they had no known or suspected reason to do so," Not all individuals in the YF-22A program were aware of the card instruction, and whether it was being obeyed

[SATCOS WHIPPING BOY]

Video of the YF-22 incident?
The article falsely suggest the vid is of the latest prang.


https://www.youtube.com/watch?v=_pZ3Q_hz5ck&feature=player_embedded&app=desktop

[BEagle]

Another ridiculous YoofToob video with robotic voice and imagery from a different event...:mad:

[ORAC]

Accident report link

https://www.kunsan.af.mil/Portals/6/180413-PACAF-JB%20Elmendorf-Richardson-Alaska-AIB%20NARRATIVE%20REPORT.pdf?ver=2018-11-15-200849-187

Alert 5:

On Apr. 20, an F-22A assigned to the 90th Fighter Squadron had failed to take off and the jet slid about 6,514 feet down the runway before coming to a stop. Investigators determined that the pilot had incorrect Takeoff and Landing Data (TOLD) for the take off and he failed to apply any corrections to the incorrect TOLD. He had prematurely retracted the landing gear while the jet had insufficient speed to maintain level flight.

The board also found that other F-22 pilots are rotating their aircraft during take off at a lower speed than that calculated by the TOLD. And there is an organizational acceptance to this incorrect technique.

Investigators also found that the F-22 community is overconfident in the aircraft’s ability to take off due to the high thrust generated by the engines. This lead to a decreased emphasis on the take off data.

[meleagertoo]

"Egress from..."

Oh dear. :(

[Onceapilot]

Surprisingly sort of gash way to get your F-22 airborn, or more precisely NOT airborn:

“There is a technique that I heard from somewhere (I don't know where, whether it was at the B-Course or the 90th) to initiate [rotation] – if you have a 136 [rotation speed], kind of standard below 2,000 feet – that you initiate aft stick pressure at 120 so that the nose is up at that rotation speed, and that has been my habit pattern” (Tab V-1.10).

But this guy is only doing what he has been "taught". Just look at these statistics! These are worthy of a third-rate rubber dog-**** freight outfit in S.America! :eek:

Data from five sorties flown over a five-month period prior to the mishap clearly shows that the MP initiated rotation at 120±5 KCAS (Tab CC-3 to CC-4). This technique of rotating early does not appear to be limited to the MP. Data from multiple sorties flown by 90 FS pilots are presented in Figure 1 and Figure 2. The data shows that in 64.3% of sorties, rotation was initiated greater than 5 knots prior to the calculated rotation speed; in 52.1%, rotation occurs at 120±5 KCAS (Tab CC-3, Figure 1). In 80.4% of these sorties, takeoff was accomplished greater than 5 knots prior to takeoff speed (Tab CC-3, Figure 1). All pilots who were interviewed noted that they check their TOLD before takeoff (See, e.g., Tab V5.1, V-9.1, V-13.1). After the mishap, at a pilot meeting attended by 20 to 30 F-22 pilots, about half noted that they consistently use an early rotation technique (Tab V-2.16, V-4.14, V-4.17). There is a clear trend of rotating early among a significant number of F-22 pilots, including the MP, despite being aware of computed TOLD.

Is this the best the USAF can do today? Unbelievable :ooh:

OAP

[MPN11]

OAP ... agreed. And very evocative language you used there!!

That presents a dismal picture of USAF fighter operations, despite all their briefings and form-filling. I found it very uncomfotable reading. Gash, casual, ignorant and gung-ho arrogant are other adjectives that spring to mind.

[sandiego89]

Gotta look snazzy when taking off at a Navy base! Awfully quick on the gear lever....

[MPN11]

Gotta look snazzy when taking off at a Navy base! Awfully quick on the gear lever....
In fairness, I do believe the occasional RAF FJ pilot has committed a similar 'Oh sh*t"

[Harley Quinn]

In fairness, I do believe the occasional RAF FJ pilot has committed a similar 'Oh sh*t"
Don't forget the C130 doing circuits with a circuit breaker pulled.

[ORAC]

In fairness, I do believe the occasional RAF FJ pilot has committed a similar 'Oh sh*t" But an entire squadron?

In truth, however, I remember the 8 Sqn Shackleton crash and what it revealed about supervision.

Is the F-22 for e so small that the same flaws apply?

[Ewan Whosearmy]

There was a reason for the C-130 CB to be pulled. Whether it was appropriate or not is another issue.

Can anyone give a reason as to why they are rotating early outside of thoughts of being “punchy”? Are they concerned about acceleration and gear limiting speeds? Something else that is deemed to be a greater threat that leads the pilots to thinking rotating early is better than the alternative?

Gear limiting speed.

The rotate at 120 knots thing may have come over from the Eagle community, where that was the standard number for decades.

[beardy]

Why weren't FDRs regularly monitored? Amongst other things they are there to pick up on dangerous trends before they lead to accidents.

[Bob Viking]

FDRs are there for accident purposes. I assume you’re actually talking about some form of useage monitoring system.

Whilst these systems are monitored they are looking for levels and exceedances for fatigue reasons. In this case there was no fatigue issue (until the jet settled onto the runway!) so no ‘flags’ would have been raised.

Also, consider who would be looking at the data. Pilots don’t sit down after flights and pore over fatigue statistics. That’s an engineers job. Can we honestly say that an engineer would know if the pilot had rotated at too slow a speed?

There are many issues here but sadly I think it is the collective responsibility of the pilots that could have prevented it.

In the UK we have a Sqn QFI role to ensure flying skills are kept well honed. I suspect (I do not know for sure) based on knowledge of the USAF that this role may have been lacking.

On the Raptor fleet I wouldn’t be surprised to find a culture based around tactics and aircraft awesomeness and a lack of focus on flying skills due to a belief that the aircraft ‘flies itself’.

I fear similar mistakes could be made on other fleets with ‘awesome’ aircraft. Even in this day and age the Sqn QFI role still has its benefits despite what many might think.

BV

[beardy]

In the civil world FDR is used to flag non SOP events to highlight any developing trends. Machines scour the data, not people. People decide which events to look for and interpret the results.
​​​​​​Using FDR solely for post accident investigation is a waste of a resource

[Onceapilot]

Well, unless someone who knows can tell us, I do not know what the level of skills supervision or evaluation is used to monitor F-22 Pilot skills. Likewise, I do not know what parameters the F-22 on board data recording can cover? However, I can read an accident report that reveals fleet wide routine mishandling of the F-22. :oh: Certainly, the RAF has had superb multiple parameter FDR available for diagnostic analysis in the Widebody tanker/transport fleet for over 30 years. Notwithstanding the support of well structured continuous assessment and recurrent crew training, the unbiased filtering of flight parameters provides early awareness of unwanted trends or problems with aircraft operation. The parameters generally include all parameters of flight, configuration and engine performance. Software filters the records for instances where tolerances or exceedance levels are reached. This might include fast rotation, configuration speed limits, angle of bank or, events such as EGPWS and TCAS, etc,etc... Such tools should be used within a supportive training environment, to avoid alienation of crews or the "spy in the cab" response. Professional aircrew will however, respond positively where the monitoring is used in a positive manner. Obviously, the flight profile of a modern FJ will differ somewhat from that of a large transport. Off the cuff, I would guess that the F-22 fleet does use this kind of tool but, has somehow failed to pick-up this dangerous handling trend? :ouch:

OAP

[Bob Viking]

Firstly my point about not using FDR is more of a nomenclature point. My current aircraft has an FDR, CAR and HUMS. It is the HUMS that would provide this sort of routine data, not the FDR. I think the spirit of what we are saying is essentially the same.

Secondly, I don’t think you can read across everything from widebody to FJs but I understand your point.

I’m thinking about how a unit might have caught the slow speed rotation problem. On my FJ unit we would not be using HUMS (or call it FDR if you wish) for handling issues. It is great for catching overstresses though. Handling issues could either be debriefed in cockpit or using post fight debrief. But the F22 is a single seat jet. How would anyone know to even look for the problem? FDR wouldn’t help in that regard. What parameter would someone be looking for to discover a slow speed rotation unless they knew they were looking for it?

There are many important lessons to come out of this accident but using FDR (on a FJ) isn’t one of them.

Just my opinion of course.

BV

[Ewan Whosearmy]

In the UK we have a Sqn QFI role to ensure flying skills are kept well honed. I suspect (I do not know for sure) based on knowledge of the USAF that this role may have been lacking.


Can't comment on the specifics for F-22 units, but in general USAF fighter squadrons have safety evaluators (SEFE) who are supposed to take on the equivalent role of a QFI.

[Onceapilot]

Hi BV,
I am using FDR as a generic term, as in Flight Data Recording. Yes, there are different systems. :) As I read the report, this was an early rotation issue, leading to unstick well below target speeds. How would anyone know you ask? Same as any other pilot skills...look for what is done on line ops. I am not going to describe how they should do that on your jet, or any other, that comes down to specific types. However, the routine flight data recording will include control inputs, AOA, speeds etc. It is not difficult.
Do I detect a little resistance to data capture and monitoring? I strongly suspect that it will come more widely into FJ ops, if dudes keep throwing $400,000,000 jets on their bellies. Cheers

OAP

[Bob Viking]

There is no resistance on my part.

I understand how these things may be pored over on bigger aircraft but I am struggling to see how this level of monitoring will make it onto FJ fleets.

If a jet is not overstressed I don’t see anyone paying any interest. Honestly I wouldn’t expect anyone to sit down and look at an FDR trace for an entire sortie to detect any anomalies.

The kind of detail we are talking about (rotate speed) would require a pilot’s input to detect. We already debrief at great length for every sortie. There aren’t enough hours in the day to look at FDR traces as well as everything else.

HUMS data (what I’m used to calling it) is already monitored and would pick up anything untoward. With the best will in the world what engineering team would correlate rotate speeds with control inputs unless specifically asked to look for it?

FDRs are great for a lot of things but I still can’t see any FJ unit in existence catching this particular trend by monitoring FDR traces.

BV

[Onceapilot]

Hi Bob,
Just to check understanding here, how do you perceive the the process of data monitoring is conducted?

OAP

[Bob Viking]

A fair question. Apparently I do not perceive it in the same way you do! I’m more than happy to be educated.

Please explain how a trend of pilots rotating below the correct speed could have been caught with routine FDR scrutiny.

BV

[beardy]

How was the trend caught in order to be identified and used in the report? I don't know, but evidently it is possible.

I suppose it's like the invisible spaceship at Lord's that used the SEP (somebody else's problem) cloaking device to avoid being seen. (Douglas Adams)

[Onceapilot]

A fair question. Apparently I do not perceive it in the same way you do! I’m more than happy to be educated.

Please explain how a trend of pilots rotating below the correct speed could have been caught with routine FDR scrutiny.

BV

Hi Bob,
The parameters that the operator (StanEval, QFI, Company Senior Pilot etc.. as decreed ) wish to have flagged-up are decided and programmed. The monitoring goes along recording all parameters and every flight goes into the system record. The records are all routinely and automatically trawled and a print or electronic copy of the trends and levels is produced at whatever period is decreed (often, monthly), the monitoring agent (on the Sqn) then formally reviews the stats, reports, action a/r and signs off the file . The severity of the parameter thresholds is simply altered to achieve the level of alert required. For instance, if a G-Loc profile was worth watching for, a suitable threshold profile could be decided and tracked. Generally, there will be some thresholds that should imply remedial action before next flight and, it is possible to do that. However, the primary aim is really trend and performance monitoring.
Now Bob, I believe that you are a QFI? Can you not think of a way to use flight data monitoring to monitor early initiation of rotation and unstick ?

OAP

[MPN11]

Could one assume, in such a hi-tech airframe, that very basic piloting skills/discipline don't feature on the Supervisory radar? The focus may be more on the utilisation of the airframe in its intended environment ... off the ground and in a combat scenario?

[Bob Viking]

I can now, of course. We are operating with the benefit of 20/20 hindsight.

I never debated whether or not FDR data would show if someone had rotated too slow. What I’m debating was whether any FJ unit would have ever thought to look for such a thing. Until now.

I know what is recorded on such devices and I appreciate the benefit of it.

I’m just using my knowledge of FJ operations to work out how such a trend could have been spotted before anyone knew it was an issue.

FWIW in a high performance aircraft such as Raptor I can see how it is entirely possible for such a misconception to breed unchecked. They don’t operate with such fine margins as transport aircraft and routinely operate at extremes of the flight envelope.

Whereas as a multi engine pilot will work out mass and balance and Vstop etc ad infinitum a Raptor guy can probably quite happily point the aircraft down the runway and push the noise lever forwards with almost complete impunity. I said almost!

It was an expensive mistake but I, for one, can see how it happened. Hindsight is a wonderful thing.

BV

[ShyTorque]

It's an old enough mistake to make. An RAF student colleague of mine was criticised by his QFI after a dual training flight for applying the toe brakes during the takeoff roll (they were normally given a quick application to stop the wheels after lift off before they were retracted into their bays).

Shortly after the sortie debrief the line chief asked to speak to the instructor. The main undercarriage doors had an inch of metal missing off the lengths of the outer edges. The brakes possibly hadn't been applied after all, but the gear had been retracted too early and as the aircraft settled slightly, the doors had scraped the runway.

A similar thing happened to one of the Red Arrows pilots in the late 1980s - but he ended up riding on the belly tank as the rest of the formation took off around him. He decided to leave the aircraft.

[Onceapilot]

Well Bob, I guess that the Raptor Guys are just going to have to live with the same jokes and songs that the Eagle drivers used to get at Red Flag....unless they raise their game. But, its a bit late! :E
Professional aviators should realise that there is no shame in having your performance monitored. Even if you don't screw-up, it might save your life to have an early call on trends or weaknesses in your outfit. :)
Hmmm, Four-Hundred Million Dollars! They certainly should be good to fly that!
Cheers

OAP

[Bob Viking]

I’m terribly sorry but I think I must be a bit thick. I still don’t quite get your point.

I have no problem with devices which monitor flight parameters as I’m sure none of my peers would. Nobody is trying to hide anything.

The point we are discussing, very specifically, here is the underspeed rotate of a Raptor. How do you honestly expect that routine FDR monitoring would have caught this particular trend?

I understand how other trends might be caught and I fully appreciate the benefits to be had. I just really can’t get my head around how you think this trend could have been caught when nobody could honestly have guessed it was going to be an issue worth looking for in the first place.

As I said, maybe I’m being thick, but could someone please enlighten me?

BV

[Onceapilot]

Because Bob......all phases of flight have critical handling aspects. Careful analysis can reveal the important skills and parameters that need to be tracked and monitored. Comparison with other aircraft/systems may reveal other considerations that need tracking. Just look at the Handling Manual, the ODM, the FRC's, the Abnormals etc... Now, Take-Off is a very dynamic and historically risky event. Even a FJ has a considerable amount of critical handling on Take Off (even if you don't think so). Some of the most critical factors on Take-Off are weight, configuration, engine performance and handling. The handling includes rotation initiation speed, rotation rate, Alpha and pitch attitude(s). Individual types may have additional Take-Off handling specifics. :)

OAP

[Lordflasheart]

SESMA ........... No need to guess. ;) ...... LFH ... cfs ;);)

........

[BEagle]

There is a clear trend of rotating early among a significant number of F-22 pilots, including the MP, despite being aware of computed TOLD.

Why bother having any computed TOLD if you promptly ignore it?

[Fortissimo]

BV

Just to keep the nomenclature straight, we are talking about flight data monitoring, not FDR monitoring. FDM is usually extracted from the FDR, but it can also be picked off from elsewhere in the system that feeds the FDR, especially when it's digital data. The data frame is set by the operator, as OAP pointed out, which means you decide what parameters (Key Point Values) you are particularly concerned about and set the alerts accordingly. I am not an expert in setting KPVs but a programme that looked at control inputs, pitch attitudes and pitch rates on take-off would show when you were getting low pitch rates compared with stick position. Match that with expected airspeed (because a FBW platform like the F22 is likely to know...) and you have a clear indication of the size of the problem. You are right that you would have to know what to look for, but routine monitoring would have picked this problem up.

There is work going on at the moment looking at FJ FDM for the RAF (it's already being done for Chinook and Puma). Some people get it, but the more senior FJ guys don't. They will eventually, whether they like it or not.

[beardy]

Just to keep the nomenclature straight, we are talking about flight data monitoring, not FDR monitoring. FDM is usually extracted from the FDR, but it can also be picked off from elsewhere in the system that feeds the FDR, especially when it's digital data
Quite. It depends on the sophistication of the FDR whether it can be used to pick up and record the data that you are interested in. Most modern machines can and do, but are not mandated to do so.

[Onceapilot]

There is work going on at the moment looking at FJ FDM for the RAF

That is interesting Fortissimo. Do you have any update on FJ TCAS please?

OAP

[Bob Viking]

I am clearly not articulating myself very well but I will try one last time to get an answer to the question I’m trying to ask.

I understand the system we are discussing. I realise what parameters are recorded and how they can be used to find data.

My question relates to how it would have fit into daily operations on the Raptor Sqn such that the trend for underspeed rotates could have been spotted and eradicated.

So, for instance, jets go flying then come back. FDR traces are downloaded. Somebody sits down and looks at the data, having previously been notified of key points to look out for. That person looks at all the fight parameters and says “‘ere guv’, that’s the third time this week I’ve seen aft stick pressure applied at a speed several knots less than the correct rotate speed of the day given the prevalent meteorological conditions”. The guv’ says “do you know what mate, you’re right I must go and see the Sqn Boss and let him know I’ve noticed several of the Sqn pilots apparently rotating at a speed below the ideal” (because the FDR analyst guy has an encylopaedic knowledge of the TOLD computer as well as being a trained FDR guy).

The Boss says “by Jove buddy, you’re quite right. Good spot. Thanks for bringing it to my attention. I must put a stop to this dangerous and incorrect habit immediately”.

A $400,000,000 jet is thus saved by the clairvoyant FDR guy who just happened to be looking at a parameter at a certain stage of fight that nobody had told him to look for.

I realise this appears like I am being glib and facetious but do you at least understand the point I’m making?

How could this accident have been prevented by FDR monitoring without the benefit of the hindsight this accident has provided us with?

If I have not made my point my now I will give up.

BV

[MPN11]

Bob Viking ... you made it clear to me. The technology exists. It just needs the will, time and manpower to look at the data.

[Treble one]

You should do stand up BV. That made me chuckle.

I wish you a safe rotate and landing on your next sortie.

[beardy]

So, for instance, jets go flying then come back. FDR traces are downloaded. Somebody sits down and looks at the data, having previously been notified of key points to look out for. That person looks at all the fight parameters and says “‘ere guv’, that’s the third time this week I’ve seen aft stick pressure applied at a speed several knots less than the correct rotate speed of the day given the prevalent meteorological conditions”. The guv’ says “do you know what mate, you’re right I must go and see the Sqn Boss and let him know I’ve noticed several of the Sqn pilots apparently rotating at a speed below the ideal” (because the FDR analyst guy has an encylopaedic knowledge of the TOLD computer as well as being a trained FDR guy).

Data is downloaded from each aircraft, as is presumably the case for engine health monitoring. Data is uploaded to a computer. Man (Flight Safety Officer?) decides which parameters need to be monitored. Computer scans data looking for events when parameters are exceeded (Vr below set figure in this case, rate of change of G loading between say 5g and 9g in another case with perhaps significant stores loading.) Computer churns out number of occasions parameters have been exceeded (may be de-identified in first circumstances, but open to further investigation if serious issues arise). Man looks at printout, daily, weekly or even monthly. Man does not have to study and interpret raw data.Trends can be highlighted for specific aircraft, mission profile, operating unit or individual pilot. Protocols are put in place for remedial action depending on circumstances and severity of events.

Never having used TOLD I have no idea whether it is calculated on board or not, nor what the usual range of Vr is. If it is calculated on board then it is recordable, if not then I would imagine that deciding a gross estimate would not be difficult and could, if required, be modified for for daily analysis depending on the exercises being flown, averaged gross weights, altitude etc...

The idea of studying graphical traces doesn't really come into this scenario until detailed investigation is warranted. Most airlines seem to be able to manage this type of analysis without necessarily employing an extra individual solely for the task. Perhaps it would benefit the military if they were to look at other aviation sectors to see if they can learn anything that helps.

Before you ask, yes I am ex RAF FJ, QFI and airline.

[ORAC]

Data from five sorties flown over a five-month period prior to the mishap clearly shows that the MP initiated rotation at 120±5 KCAS (Tab CC-3 to CC-4). So, achieving how many live hours, versus sim, a year?

[BigDotStu]

Man (Flight Safety Officer?) decides which parameters need to be monitored.

Bob's point is: Why does the FSO make this decision unless there is already some hint/suspicion that such a parameter needs monitoring.

You may think it obvious that such a parameter should be routinely monitored, but it appears that view is not universally shared.

[MPN11]

So, achieving how many live hours, versus sim, a year?
And what was his rotation speed in the Sim? Did anyone notice/bother?

[beardy]

Bob's point is: Why does the FSO make this decision unless there is already some hint/suspicion that such a parameter needs monitoring.

You may think it obvious that such a parameter should be routinely monitored, but it appears that view is not universally shared.
Well I suppose he could start with the manoeuvre envelope and then expand through the order book and add commonsense like not going the wrong side of the drag curve at low altitude.
On the other hand he could just assume that all FJ pilots are skygods and turn a blind eye to tools available since they're not required

[Bob Viking]

Thankyou. I thought I was going mad but I’m glad somebody else has finally understood my point.

Beardy you say you are an ex FJ QFI but now an airline guy. Think back to your time on FJs and apply what you now know about FDR monitoring.

Imagine yourself on a FJ unit with a jet that has more performance than virtually any other aircraft ever made. Imagine you have an FDR that monitors every known parameter and you are the guy who is responsible for deciding what parameters to specifically monitor. Can you honestly say you would have thought to monitor rotate speeds?

I’m an experienced guy and quite possibly the kind of guy that might have been responsible for setting parameters. I wouldn’t have thought of it.

On most FJs someone (probably a QFI) would have been responsible for trawling the ODM and devising a list of SOP rotate speeds, Vstops etc for various aircraft fits, temperatures and altitudes.

Would you, as the QFI, then suspect that your Sqn mates were routinely ignoring the rotate speed that you had so kindly calculated?

Anyway, in the absence of a crowd of people who can see my point I am starting to sound like a stuck record.

BV

[beardy]

. Would you, as the QFI, then suspect that your Sqn mates were routinely ignoring the rotate speed that you had so kindly calculated?
​Yes.
Normalisation of the deviation is a big problem, especially in small 'elite' units. Monitoring helps prevent it. We had formal interviews and pilots sent home from detachments for cowboy behaviour and cavalier attitudes. The monitoring then was human navigators and they only reported a part of the problem. We lost a crew a year in fatalities, I lost good friends.

[BEagle]

I'd be surprised indeed if any routine monitoring of rotate speeds was conducted. But for a Sqn QFI to devise SOP speeds from the ODM seems so last century - these days a simple software program should be able to provide the necessary 'on the day' values given aerodrome elevation, slope, OAT, W/V, QNH and aircraft AUW / fit.

Deviance from TOLD values should have been picked up by whoever was conducting the simulator training, surely? As there's no 2-seat F-22, it'd be difficult to check pilot standardisation any other way.

Back in the Stone Age, Pilot's Notes would include handling information, e.g.:


Take-off
[…]

(b) Keep straight initially by the use of gentle braking until the rudders become effective at 50-55 knots.

(c) Raise the nose wheel at 80-85 knots, maintain this attitude and fly the aircraft off at 105-110 knots at typical service load. At maximum all-up weight raise the nose wheel at 105-110 knots, the aircraft then becomes airborne at 120-125 knots.

[…]


Surely much more modern aircraft will have been assessed by test pilots and similar information included in the aircrew manual flying?

[Onceapilot]

I am clearly not articulating myself very well but I will try one last time to get an answer to the question I’m trying to ask.

I understand the system we are discussing. I realise what parameters are recorded and how they can be used to find data.

My question relates to how it would have fit into daily operations on the Raptor Sqn such that the trend for underspeed rotates could have been spotted and eradicated.

So, for instance, jets go flying then come back. FDR traces are downloaded. Somebody sits down and looks at the data, having previously been notified of key points to look out for. That person looks at all the fight parameters and says “‘ere guv’, that’s the third time this week I’ve seen aft stick pressure applied at a speed several knots less than the correct rotate speed of the day given the prevalent meteorological conditions”. The guv’ says “do you know what mate, you’re right I must go and see the Sqn Boss and let him know I’ve noticed several of the Sqn pilots apparently rotating at a speed below the ideal” (because the FDR analyst guy has an encylopaedic knowledge of the TOLD computer as well as being a trained FDR guy).

The Boss says “by Jove buddy, you’re quite right. Good spot. Thanks for bringing it to my attention. I must put a stop to this dangerous and incorrect habit immediately”.

A $400,000,000 jet is thus saved by the clairvoyant FDR guy who just happened to be looking at a parameter at a certain stage of fight that nobody had told him to look for.

I realise this appears like I am being glib and facetious but do you at least understand the point I’m making?

How could this accident have been prevented by FDR monitoring without the benefit of the hindsight this accident has provided us with?

If I have not made my point my now I will give up.

BV


Sorry to quote your whole post Bob but, you are a stuck record and, you keep missing the points, like the leader of the opposition! :)

I was going to try and cover some of this again but, I have re-read and, everything has been covered but you have a fixed opinion, in my opinion. :oh:

The simple reality is, Flight Data Monitoring does provide early heads-up on trends and errors.

On a happier note, it is a good thing that modern automated monitoring of flight parameters and crew performance will eventually cross over into FJ flying. It gives a real benefit in improving standards and is actually the friend of professional aircrew.

Cheers

OAP

[BigDotStu]

Thankyou. I thought I was going mad but I’m glad somebody else has finally understood my point.

Unfortunately BV, I am neither military nor a pilot (my qualifications in either category are limited to a few trips in the back of a Chipmunk with 5AEF in the 80s), but I am a software engineer (sometimes on projects in the military arena), and this approach to detecting 'defects' in pilots is remarkably similar to various of the testing approaches used in software. No matter how many things you instrument and test, you will always find a tester/end-user who finds new and interesting ways to abuse the product that are neither expected nor intended. It seems to me that pilots and aircraft are subject to the same sorts of issues - once you've seen someone do it, it's obvious it needs handling....

[Onceapilot]

No matter how many things you instrument and test, you will always find a tester/end-user who finds new and interesting ways to abuse the product that are neither expected nor intended. It seems to me that pilots and aircraft are subject to the same sorts of issues - once you've seen someone do it, it's obvious it needs handling....

Hi BDS!
Yes, there are always things that can jump up and surprise everyone. However, inaccurate flying and non adherence to targets/limits of flying SOP's, equipment use, procedures and the flight envelope are the bread and butter of automated flight data monitoring. In this case, any half-decent FDM application would have picked this up in short order. TBH, I do not know how such basic mishandling became so entrenched as the report seems to indicate. Of course, I know no detail of F-22 training and procedures, only what is listed in that unclassified report. I do wonder if the F-22 uses a FDM system but, they failed to consider the non-compliance with TOLD parameters as worthy of tracking or taking action on? If that was the case, they were plain dumb. Maybe that is the great unpublished part of this report? Anybody know? OTOH, I do know what an effective tool and contributor to Flight Safety FDM can be. Cheers

OAP

[BigDotStu]

I do wonder if the F-22 uses a FDM system but, they failed to consider the non-compliance with TOLD parameters as worthy of tracking or taking action on? If that was the case, they were plain dumb. Maybe that is the great unpublished part of this report? Anybody know? OTOH, I do know what an effective tool and contributor to Flight Safety FDM can be

Hi OAP,

I think your question above ties in with BVs perspective - he wouldn't have considered it worthy of consideration prior to this event. I can understand his perspective, especially if (like myself prior to now) he was not aware of what is considered standard coverage in FDM. I don't think anyone would deny it is a valuable tool which can only improve flight safety.

Every day is a school day...

Stu

[PPRuNeUser0211]

BV - I was in a similar situation to you when my unit introduced FDM .The mindset you're in is "what would I think is important to look at" and obviously rotate speed doesn't make the cut.

The misunderstanding is the mindset there - you don't look at what's important, you look at literally everything on the aircraft that has a limit or rule that has any chance of being machine processed.

The challenge on a unit that flies dynamically rather than procedurally (FJ Vs multi as an example) is that last bit. For example, FDM would never be able to tell you that you were using too much or too little G in BFM to get a shot, but it could easily be programmed to recognise someone routinely using more G than the Sqn beefer is comfortable with on a VRIAB.

We had basically every parameter from the ODM, RTS and FOB looked at, plus all "standard" profiles that could be automatically analysed. The FDM provider was helpful in that regard. Even ground taxy speed was included.

All of the above said, I've yet to ever actually see anyone get booked by it, but I can conceive how it would have picked up the trend of underspeed rotating - the key is in looking at every bit of performance data and limitations/rules that you use when you fly, whether you think it'll be broken or not - it doesn't cost extra!

[beardy]

It's not about anyone 'being booked by it' it's about stopping people killing themselves or wasting valuable resources through unchecked human frailties (hubris etc..) if it's used wrongly it becomes counterproductive.

[Bob Viking]

Thanks for your explanation. I understand now.

Previous explanations had just tried to paint me as someone trying to resist the advent of a new bit of technology and (like a broken record) never gave me an answer to my original question that made sense (to me at least).

As an aside, I watched my own rotate during my morning trip. My jet has nowhere near the performance of a Raptor. I looked at my rotate speed (we do not have an EODM so we do have SOP speeds for each fit) and noted when I was 5 knots below it. The numbers in the HUD changed so rapidly it was hard to perceive. I say again, this is not a Raptor so the numbers probably change even quicker in that jet. In the back seat I would see the stick move and probably get a feeling for an underspeed rotate. There are no two seat Raptors and it was suggested that a sim instructor could have caught it.

I could not honestly say I would notice during a routine simulator sortie if someone was doing it incorrectly. Not with the likely rate of acceleration of a Raptor. And not with your likely average Raptor pilots level of concern about their rotate speed (I suspect they never believed for one second it could be so sensitive - in a Jaguar or Tornado, or similar older US jet yes, but not a Raptor).

I still think some posters here are using 20/20 hindsight and living in a perfect world if they think it could reasonably have been noticed before the accident though, but if you are telling me that FDM (we don’t know if such a system actually exists on Raptor) could have caught it then I have to believe you.

I accept I may be wrong and you may be right but I can’t help having my opinion based on my experiences to date.

BV

[artyhug]

Do people actually read the evidence before pontificating?

BV,

The rotate and take off speeds for the incident were 143/164 respectively.

The MP achieved 120/135.

That disparity was conclusively proven as common across the F-22 community. The high altitude of NAS Fallon compounded the incident because of slow acceleration at a high density altitude.

A blind man would have noticed the failure to adhere to TOLD let alone an automated monitoring system.

IF ANYONE HAD BEEN LOOKING.

[Bob Viking]

I will admit my error. I didn’t read it as closely as you. However, you are so keen to nitpick you completely ignore my other points.

20 knots during a Raptor acceleration could happen in the blink of an eye. And who the hell would have noticed the pilots doing it?

I think everyone is being too keen to cast aspersions without putting themselves in the same position as the mishap pilot.

It’s very easy after the event to find fault, apportion blame and think of ways to avoid it in future.

It’s just like the classic gear up landing. When it happens we all think ‘what an idiot, I would never do that’...

Apparently, I’m the only one on this forum who isn’t perfect.

Must have a word with myself.

BV

[artyhug]

I now remember why I don’t engage in discussions on the internet...

Raptor is an aeroplane not a spaceship, it’s engines are powerful but they aren’t warp drives.

At no point was I, or as I can recall anyone, impugning the MP. Organisational failures were large contributors to execution failures.

If you’d like me to be obvious I was actually impugning your ability to objectively assess the ability of appropriately devised monitoring mechanisms to recognise the normalisation of deviance and risky shift that had occurred in the Raptor community.

[Bob Viking]

You may not personally have impugned the MP but, if you had been reading the thread since the start, you would see that others definitely have.

I never wanted to start an argument but, against my better judgment, I appear to have done just that.

I had intended to present a different angle to the conversation which seemed to be heading down the route of blaming the pilot with the benefit of hindsight.

I think it’s terrible that an F22 has been severely damaged as the result of a handling error and I can now see how FDM could prevent it in future. I agree that it could have been avoidable but none of us are F22 pilots so we can’t honestly state we wouldn’t have made the same error or could have stopped it had we been there.

I understand the term ‘normalisation of deviance’ and I also understand why we make such efforts to stop it happening.

Anyway, I’ve said enough.

BV

[Tengah Type]

We seem to assume all FJ pilots are the same, regarding planning and procedures. My experience of operating with FJ on numerous AAR Trails and AAR supported operations and exercises over 40 years ,is that they are not.
As an example, an AAR Trail to Alaska via Goose Bay for Tornado GR1 and F3. At the Face to Face Brief at Goose Bay the GR1 crews all had Terminal Approach Plates for all possible diversion airfields and were aware of facilities available such as LOX. Also Runway lengths and Take Off requirements, as well as full chart coverage of the route. Not so the F3 crews.
After the brief the Sqn Cdr of the F3 squadron asked to borrow the 1:6 million scale chart of the whole of Canada/ Northern USA which had the route marked on it, together with Refuelling Brackets and Abort Points in such a way as to be visible at the back of the briefing room. When I asked him why he told me it was so he could photocopy it and gives his crews copies "so they had some idea of where they were going!". Several questions were asked about my choice of Diversion Airfields, one being " Why are we not using Lynn Lake, as it en-route?" " Because it is a lake! You need floats to land there!"
Unlike the tankers who were used to frequently operate at MTOW for the conditions and therefore calculated the Take Off Data accurately and flew within the narrow performance margins available, the F3s seemed to work on the principal that if the runway was 6000ft plus, all you did was "Bang it into Burner and Go". There was always Martin Baker if it went wrong.
In the case of this F22 incident, it appears that the training unit was teaching/accepting the 120kt rotation technique, as half the pilots were doing it. The TOLD Data was also wrong, but if nobody was using it that was no big deal. They were also retracting the undercarriage below Take off speed. Spicy!
If the person who was doing the FDM was an F22 pilot who used the 120kt technique, would he have flagged it up as a problem?

[Onceapilot]

If the person who was doing the FDM was an F22 pilot who used the 120kt technique, would he have flagged it up as a problem?

That would depend if he used to be an Eagle driver? :)

OAP​​​​​​​