F-35B crashes after mid-air collision with tanker

[durahawk]

CLAW problem?

I’ll point it out and ask again —

Given the damage to the engines — forward of the leading edge of the wing — what failure mechanism is going to transport a jet from a position well aft of the wing to a position where it makes contact with propellers without damaging that part of the wing between the jets starting position and the props?

Nothing is off the table at this point. I am thinking a momentary loss of attention, PIO, or some combination of both. Refueling is a high gain task with potential for the pilot to get out of phase with the aircraft trying to make corrections and close the control loop. The result could be oscillatory motion in the pitch or roll axis with increasing amplitude. It doesn't really explain why the F-35 was so far forward as to collide with the props, unless the pilot bumped up the throttle as a reactionary measure. (The CLAW could be a contributing factor in this scenario, but not necessarily the primary cause.)

Here is a video of a C-17 getting into a roll PIO on the boom:


A significantly less likely scenario would be a loss of throttle control... which would we require communications to be lost between the VMC's and both FADEC's simultaneously.

[35_aoa]

The F-35 is automatic, using appropriate controls as it sees fit in the circumstances. Why do we compare an F-18 tanking or any other fast jet to an F-35? F-35 test pilots figured out the limits behind all the tankers so there is that to rely upon.

For what its worth, I don't think this has anything to do with why this mishap occurred. Was just commenting on the question about whether 250 knots was slow for tanking, which is much faster than I ever saw a KC-130 fly a tanker track at. Anyway, F/A-18's have been successfully tanking off KC-130's for decades, so I wouldn't imagine an F-35 would have an inherent issue either.

[spazsinbad]

"...Here is a video of a C-17 getting into a roll PIO on the boom:"

That is some wing waggle. Should be called a WOGGLE but that is taken by the SCOUTS (be prepared).

[spazsinbad]

F-35 Development Is Nearly Complete, but Deficiencies Found in Testing Need to Be Resolved
Jun 2018 GAO Firstly here: viewtopic.php?f=60&t=27109&p=395612&hilit=extendable#p395612

“...Aerial refueling probes:
Aerial refueling probes: The F-35B and F-35C variants use a “hose and drogue” system where an aerial refueling tanker aircraft extends a long, flexible refueling hose and a parachute-like metal basket that provides stability, and the receiving aircraft then connects to the drogue basket with its extendable refueling probe. From April 2014 to August 2017, 21 incidents have occurred where the F-35’s aerial refueling probes broke off while conducting aerial refueling, leading to a restriction of aerial refueling operations. The Navy and Air Force are investigating the issue and implementing improvements to reduce these incidents:

1. Pilot training improvements have been completed.

2. Improved inspection of KC-10 aerial refueling equipment has been implemented.

3. Software improvements to reduce the pilot’s workload during refueling are planned to enter flight testing in May 2018.

4. A stronger refueling probe is in development.”

Source: https://www.gao.gov/assets/700/692307.pdf

[quicksilver]

“I am thinking a momentary loss of attention, PIO, or some combination of both. Refueling is a high gain task with potential for the pilot to get out of phase with the aircraft trying to make corrections and close the control loop. The result could be oscillatory motion in the pitch or roll axis with increasing amplitude. It doesn't really explain why the F-35 was so far forward as to collide with the props, unless the pilot bumped up the throttle as a reactionary measure. (The CLAW could be a contributing factor in this scenario, but not necessarily the primary cause.)“

So, by your logic...high-performing, hand-picked F-35 guy, engaged in a “high-gain task” decides to become a spectator and go out for a mental cup of coffee some place while plugged or attempting to plug behind a KC-130? And, he does so for so long and in such a way that he (and the observer in the KC-130) completely miss the fact that he is about to swap the lead with the tanker and thereby run into the props on both starboard engines without damaging the wing? Day, VFR...

Not a chance.

[quicksilver]

The F-35 is automatic, using appropriate controls as it sees fit in the circumstances. Why do we compare an F-18 tanking or any other fast jet to an F-35? F-35 test pilots figured out the limits behind all the tankers so there is that to rely upon.

For what its worth, I don't think this has anything to do with why this mishap occurred...

x2

[quicksilver]

Think about this...

How would a jet get from one of these relative positions to a location forward enough to damage (remove) the propellers without damaging the rest of the wing structure?

[outlaw162]

How would a jet get from one of these relative positions to a location forward enough to damage (remove) the propellers without damaging the rest of the wing structure?

Well nigh impossible, but.....

.....if the AAR was being done in a right turn race track pattern, as is often the case in MOAs or Rs, a split second of diverted attention in the obs wing position on the right side as the tanker started the race track turn puts you high relative to the down wing with mutual lateral closure, but maybe not high enough to avoid the prop tips as you employ an evasive maneuver to get out of the way.

Does the ops manual specify positional parameters for the observation position?

[quicksilver]

How would a jet get from one of these relative positions to a location forward enough to damage (remove) the propellers without damaging the rest of the wing structure?

Well nigh impossible, but.....

.....if the AAR was being done in a right turn race track pattern, as is often the case in MOAs or Rs, a split second of diverted attention in the obs wing position on the right side as the tanker started the race track turn puts you high relative to the down wing with mutual lateral closure, but maybe not high enough to avoid the prop tips as you employ an evasive maneuver to get out of the way.

Does the ops manual specify positional parameters for the observation position?

Agree, and you make the point that I was trying to lead everyone toward. IME, most of the dangerous stuff happens on, or to/from the obs position(s). Ref your question, I think so but I’ve long ago data-dumped the parameters.

[quicksilver]

Now...consider the question of how much time elapsed from the moment Raider 50 left the LA Center frequency, to the moment he returned to that frequency declaring an emergency; all of about 15-20 seconds, assuming the audio was not edited. That’s not enough time to go through the drill of establishing comms with the receivers (aircraft that will be taking fuel), effecting a rendezvous, going thru the ‘noses cold...switches safe‘, clearing the receivers to pre-contact, and so on.

All of which suggests that the AAR had not yet really begun.

[Meteor]

Never refueled off a KC-130, but I’ve got a lot of time on the KC-135 and KC-10 booms. A few observations:

1. There have been numerous collisions with tankers over the years. Virtually all of the ones I’m aware of had the receiver at fault. The tanker’s responsibility is to maintain a stable platform. The receiver’s responsibility is to not hit the tanker.

2. It would be highly unusual for a fighter to be refueling by itself. There were probably a minimum of 1-3 other fighters on the tanker at the time. There may have been 2 aircraft actually refueling plus an aircraft on each wingtip at the time of the accident. Regardless, there should be several witnesses in close proximity to explain what happened.

3. In light of #2 above, the visible damage to the tanker may have been caused by the mishap F-35 having been in the observation position on the right wing, and for whatever reason sliding across the top of the wing, taking out the #3 and #4 propellers. The missing left probe-and-drogue unit may be due to a receiver not being able to disconnect prior to the tanker going unstable. The missing propeller blade on the #1 engine and the missing right wing external fuel tank may be due to the rough landing in the field. All of the damage may be due to multiple causes.

4. If the #1 engine lost the propeller blade while in flight, it would have unbalanced the engine and caused severe vibration, requiring the crew to shut it down. In that case the aircraft would have been operating solely with the #2 engine, which assuming the tanker was still carrying the fuel it was planning to offload, would have not been sufficient to maintain level flight. The tanker crew did an incredible job getting the aircraft down and saving 8 lives. They are deserving of the highest accolades.

5. The mishap tanker lost 12 propeller blades of the right side, presumably while spinning at a high rate. The photos do not show the right side of the fuselage, but I would not be surprised if at least one of the blades did not impact and penetrate the fuselage, causing even greater damage.

6. The photos shows fuel pouring out of the left refueling unit hardpoint, indicating that it was likely violently removed, and the shutoff valve rendered inop. That may have created a fuel imbalance, further complicating the tanker crew’s issues.

7. Due to the location of the damage to engines #3 and #4, I’m GUESSING that the pilot of an aircraft in the observation position of the right wingtip got distracted and hit the tanker.

8. This was apparently a WTI exercise, not a newbie refueling training sortie or a long distance deployment. In those cases, pilots are fully engaged in the refueling evolution and not distracted by further missions. In the case of a WTI exercise, this refueling was just a minor portion of a much more involved combat exercise. There was probably a lot else going on to distract the mishap fighter pilot.

9. I never flew in combat, but I was the mission commander on numerous Red Flag and FWS exercises involving dozens of aircraft refueling in both day and night. As flight lead I would refuel first, then go up to the observation position while the rest of the flight refueled. While up on the wing (with my wingman outboard of me) I would be very busy reviewing the next steps in the mission. I would make quick glances down at the timeline on my lineup cards on my thigh, and often be working a second radio to coordinate with AWACS and other flight leads. It required continuous rapid glances down into the cockpit, then back at the nearby tanker wingtip to maintain separation. If the tanker rolled into a 30 degree bank turn to remain on the refueling track and I was not prepared for the turn, impact was only a second away.

9. Bad news is that a brand new F-35 and KC-130 were destroyed. Good news is that nobody on the ground was hurt, and 9 Marines get to go home to their families.

[jessmo112]

If the pilot was found to be at fault what wilk be the consequences? Are we talking:

1. A slap on the wrist, recertify and back flying at some future time, maybe in a cargo plane?

2. Total loss of wings, maybe a desk job or instruction on the ground.

3. Article 15?

[35_aoa]

If the pilot was found to be at fault what wilk be the consequences? Are we talking:

1. A slap on the wrist, recertify and back flying at some future time, maybe in a cargo plane?

2. Total loss of wings, maybe a desk job or instruction on the ground.

3. Article 15?

People ask this type of question all the time. Accidents have happened for a long time, and they aren't likely to stop happening in the future. I understand that these airplanes are increasingly expensive, but that doesn't change many of the factors that lead to the majority of our mishaps, nor the way that they are administratively judged. Anyway, not sure how USAF does it, but in the DoN, the options are (in a simplified form....there are some sub options I won't cover) 1) put aviator on probationary status, they keep flying, and maybe get some extra attention....2) remove aviator from flying status permanently but they keep their wings......3) remove wings.

I've seen a few of the #1, normally for bad headwork that resulted in something bad happening, but the pilot was judged to be competent and capable of remediation. I've seen quite a few #2, which means "thanks but go find something else to do". Outside the scope of just purely mishap related FNAEBs, this is the most common decision I have seen across the board for struggling aviators who get FNAEB'd. I can't think of any examples off the top of my head of #3.....that is so far out of the norm you would have to have been the EA-6B Gondola crew to even get close to that.....I don't know if even they "lost" their wings. Wings really have nothing to do with whether you get to fly or not. TONS of winged aviators who do one tour, suck, and never fly again without ever having a mishap.

Back to your options......#1 would never happen. If you are judged to be incompetent in one airplane, the service considers you to be incompetent in all. Option #2....this one is a lot more uncommon than you think, as I said, and it probably only be the result of significant criminal wrongdoing......their bigger concern would probably be a courts martial in that serious of a scenario. #3....no that doesn't happen in mishap proceedings, that's ridiculous. Maybe in the Gondola, but that was criminal misconduct (the destroying evidence and lying part) and very different from your run of the mill accident.

That is a really long way of explaining the process in some detail, and also to say that in the event of a legitimate error that resulted in a mishap.....it is not uncommon for a guy/gal to get back on the saddle and have an otherwise normal career. Actually I omitted the 4th (or maybe first option) which is the aviator is immediately cleared of wrongdoing. Happens in the event of obvious mechanical failure that was clearly handled appropriately. I've had a class C and a class B, first being a wrench in the carrier landing area that was dropped and I sucked down an intake FOD'ing an F404 to death. Second was a bird I sucked up on short final at night in a Viper. Class C doesn't trigger an auto FNAEB, although Class B and A do. In the second example, the FNAEB was waived by a flag officer before I even knew a mishap had occurred.

[jessmo112]

I have been told that during these kinds of mishaps the ground crew can be under as much scrutiny as the aur crew. I have heard of ground crews being sequestered, and tools counted, or at times not being able to talk to each other. Lets just say that some how something wasnt fastened on the Tanker and it flew off causing the incident. I could see that being significant.
I have a friend who was a crew chief or something and a bomb fell off of a loader. He talks about the entire crew being decertified. Do people without wings get a harsher treatmentm

[spazsinbad]

Phew - glad you survived '35_aoa'. Hairy must have been that second one: "...Second was a bird I sucked up on short final at night in a Viper...." I guess the bird could not SEE & AVOID?! <sigh> MilJet aviation is not for the faint-hearted eh.