Mid-Air Collision in Marine Training Exercise

2 Oct 20 14 Comments

Last week, on the 29th of September 2020, two US Marine aircraft collided over the Naval Air Facility El Centro in California while taken part in a refuelling exercise as a part of a seven-week training event, the Weapons and Tactics Instructor course.

The fighter was an F-35B (Lockheed Martin F-35 Lightning II), a single-seater, single-engine, 5th-generation fighter aircraft which costs $122 million brand new. It collided with a KC-130J (Lockheed Martin KC-130 Hercules), a four engine turboprop military transport aircraft carrying eight personnel.

The Hercules was from the Marine Aerial Refueler Transport Squadron 352 (The Raiders) and was flying under the callsign RAIDER 50. The flight crew contacted ATC before crossing the military operations area over Kane West and were cleared to enter at 17,000 feet. The F-35B Joint Strike Fighter was callsign VOLT 93.

Directly after the collision, KC-130J contacted air traffic control. A cleaned-up version focusing on the incident was posted to the LiveATC.net forums by user JetScan1. The recording is from the frequency for Los Angeles Air Route Traffic Control Center, referred to as LA Center.The audio starts with American Airlines flight 237 receiving clearances.


AA flight 237 All right. We’re going to report that there was some sort of flare, some sort of pyrotechnic device at our 2 o’clock position less than ten nautical miles, maybe five miles away, at an altitude of probably 25,000 feet?
LA Center American flight 237, roger. How far away? About five miles, you said?
AA flight 237 It’s kind of hard to determine. It’s right over the desert so yeah, we’ll say five miles.
LA Center Ok and you said it was pyrotechnics, so an explosion or something like that? Or…?
AA flight 237 Yeah, I’m thinking it was probably like a rocket that you know, the kids send up. A sounding rocket or something like that. And then we also saw where it hit the ground too, the plume down there, so…
RAIDER 50 LA Center LA Center, RAIDER 50 declaring an emergency. Mid-air collision with VOLT 93. We have two engines out, we’re leaking fuel and might be on fire and in emergency descent at this time. RAIDER 50
LA Center RAIDER 50 you are in the Kane West right now?
LA Center RAIDER 50, I think you got stepped on there. You said you are going down now?
RAIDER 50 We declare an emergency. We still have partial control of the aircraft. Two engines out. We are aiming towards–
LA Center RAIDER 50 You said you are heading to El Centro … I’m sorry, El Centro airport (Naval Air Facility) or Imperial (Imperial County Airport)?
LA Center RAIDER 50, LA. RAIDER 50, LA.
Unknown I believe they said they had a mid-air and two engines out.
N979CF And Center, not to clog the frequency… 979CF . We got a plume of black smoke on the ground in that MOA (military operations area), that you know, happened at about the time he called for the emergency, so there’s at least one aircraft down, it looks like.
LA Center OK. Thank you
Unknown Impact was prior to his last transmission though.
LA Center RAIDER 50, Thank you. RAIDER 50, I’m sorry, you said you are going to Thermal (Jacqueline Cochran Regional Airport in Riverside county)) now?
LA Center RAIDER 50, roger.
LA Center RAIDER 50, I understand that you said you are about 20 miles away and …you are looking for the winds? Um, yeah let me get you the winds for you.
LA Center RAIDER 50, the wind is 150 at 08 knots.
LA Center And RAIDER 50, I just want to understand… Can you repeat the nature of the emergency.
LA Center OK RAIDER 50, you said number four and number three?
LA Center RAIDER 50 I just want to confirm you have the airport in sight?
LA Center RAIDER 50… Do you have the airport in sight? It’s at your 12 o’clock about one five miles.
LA Center RAIDER 50 I think I stepped on you, can you repeat that.
LA Center RAIDER 50 Can you call LA Center on the ground, can I give you a phone number
LA Center And RAIDER 50, the Thermal unicom frequency 123.0

The pilots commenting on ATC were perhaps not as helpful as they thought they were being; however, they were correct that the explosion on the ground happened while the Hercules was still speaking. The pilot of the F-35B ejected and his jet crashed into the ground. A video has been posted by vlad vlad on Twitter showing the crash.

The Hercules did not make it to Thermal Airport but landed about half a mile short of the runway in a carrot field. You can see the fuel pouring from the wing and additional damage, presumably done during landing. The KC-130 can carry up to 60,000 pounds of fuel.

Marine KC-130 missing engines three and four. US Marine Corps photo

This close up was posted to PPRuNe with no attribution:

Close up of engines three and four

The Marine Corps Air Station at Yuma, Arizona made a statement a few hours later, which was quoted in U.S. Naval Institute News:

At approximately 1600 it was reported that an F-35B made contact with a KC-130J during an air-to-air refueling evolution, resulting in the crash of the F-35B. The pilot of the F-35B ejected successfully and is currently being treated.

The KC-130J is on deck in the vicinity of Thermal Airport. All crew members of the KC-130J have been reported safe.

The cause of the collision is under investigation. The seven-week training takes place in Yuma twice a year. It is not clear whether the personnel involved were students or instructors. The accident took place in daylight in clear conditions. Retired Marine Corps Col Pete Field told the Desert Sun that fighter pilots learn to these manoeuvres during their training. “It’s a basic thing. This shouldn’t have been done badly.”

Most importantly, all personnel are safe with only minor injuries. The F-35B is clearly a write-off and I don’t have much hope for the Hercules.

Category: Military,


  • I’d hazard a guess that fuel is pouring from the left wing because they never retracted that drogue and it got torn off while landing. All the collision damage is to the other wing (as far as I can tell – although #1 is missing a couple of blades. Landing damage?).

    Wonder what the Herky Bird cost… J.

    • Wikipedia says the J model tanker cost $71 million as of 2014. (That’s almost $4 million more than the base J model.) The landing damage is the real question; at that price, ISTM that it would be worthwhile to skid it to the nearby runway, put it up on jacks, and see whether there’s more than surface damage — that could have been a relatively soft landing given that the soil is soft enough for carrots to start growing out of it (all the rows have greenery a few inches high).

      • Looks like the whole refueling device is gone–not just the drogue and hose assy. And giving prof’s to the aircrew–for simply getting the bird on the ground in mostly one piece. But it will sure be a mess to haul it out of the field, unless they do a major dis-assembly. And after a major incident–it might not remain a safe option to repair and put it back into service–cheaper to simply allow the taxpayers to purchase them a new one. Problems with refueling F/A18s and the F-35 is the different speeds of each aircraft versus the speed of the KC-130. While it is a jet/turboprop design–it lacks the speed to fly faster than most jet stall speeds–and this becomes an issue. Sort of like trying to refuel early jets, with the KC-97s. When the KC-135 and other pure jets became available–refueling became more common place.

        • The KC-130 cruises at 315 Kts. I flew F4 Phantoms, at full load and clean{flaps and gears retracted}, the F4 stall speed was 220Kts with the rudder shaker waking you up at 240Kts.

          That is 75 Kts to spare. I have plugged into KC-130s over 50 times, never below 300Kts.

          I have never flown the F16, F35 or F/A18 but without a doubt they all have a lower stall speed than the Phantom.

          The trick to Navy/Marine refueling is flying in formation. Something we did from the day we took our first flight in the T-34. Preflight, startup, taxi, fly and recover, if you could not do it in formation, you found a different MOS.

  • ATC seems not to have been very helpful, certainly not as helpful and professional as in the Southwest 1380 incident.
    In that event, the crew took the lead when telling ATC in very concise terms what kind of assistance they were expecting and told ATC not to make them switch frequencies, etc.
    Although most of this transcript records what ATC were saying, it seems that they were not very concise.
    In the end, nobody lost their lives and that is after all what matters.
    I agree with Jon: a lot of the damage shown is to the two starboard engines (nos. 3 and 4). It may be because the pilot of the fighter did not control his speed and rammed into the starboard wing or -engines from behind. A high performance jet can be a handful if it has to fly at low speed behind a much slower transport, like the Herc.
    Of course I have no experience in this kind of operations, but I have once tried to fly in formation with a PA18 Super Cub. I was in a Cessna 310. It was very difficult, and that was without any slipstream causing turbulence. So yes, I reckon that Jon’s observation is correct: the drone was sheared off and fuel kept streaming from the pipe.

    • The F-35B is the STOVL version; I don’t find specs on whether it’s supposed to be able to set the engine nozzle at any angle and so ~fly at any speed, but if it was built with refueling in mind I’d think it would be designed to handle tolerably when flying at tanker speeds. OTOH, it’s new enough that the pilot might not have practiced slow flight as much as they should have.

      I’m not convinced ATC is weak here; they don’t seem to have gotten nearly as complete information from the tanker crew as Philadelphia got from the SW crew.

      I wonder how much of that field will still be usable after that dose of fuel — looks like it’s pouring right into a crease that could help it spread.

  • Excellent reporting as always. Interesting to see clear severe damage to three of four propeller units… Given the circumstances a safe conclusion for the C-130 was NOT a foregone conclusion, kudos to the crew.

  • Thanks for that Chip. I am not so up-to-date with modern military aircraft any more.
    I have a collection of over 100 aviation books. Maybe it is telling that my newest books date from about the late 20th century and my oldest from 1909, 1916 and 1919, with many dating from before WW II (originals, not reprints !).
    Could it be that the fighter suffered from a malfunctioning nozzle?
    About my comments of ATC: the transcript is a bit too one-sided to really determine what was going on. But ATC should have stopped other aircraft from chipping min (pun not intended), it seemed that they interfered with their communication with the tanker. There also seemed to have been a bit of confusion about the intentions of the stricken Herc, which does not come across as having been clear.
    But, lacking direct transcripts of most of the transmissions from Raider 50, it is indeed difficult to make a reasonable assessment.

  • I’m pretty sure that the intentions of the stricken Herc weren’t real clear to the very pilots themselves, as more different damage to their aircraft became more and more obvious. Giving them a hard time is a bit of victim blaming, imho. J.

  • Jon,
    I never made any critical remarks about the Herc crew, they had their hands full controlling their bird. The 737, even with a window blown out and an engine severely damaged, still would have been fully controllable. This enabled the pilots to stay on top of the situation. From what I read here, it is clear that Raider 50 probably suffered severe control problems. Just trying to retain control must have been a very demanding task, requiring all their concentration. It just struck me that ATC did not tell other aircraft to refrain from interfering, they seemed a bit confused about the best way to handle the situation, allowing comments from other pilots to add to the confusion. Of course, we do not have the full facts. We are only giving our opinion, based on whatever expertise and information – in both cases limited – we have.
    So my comments about ATC being less helpful than could be expected is no more than an opinion, based largely on a small amount of information. We are not writing an official report here, we are just trying to make sense of what is presented and share this with others on this platform. By doing this, we hone our critical and analytical skills. No more, but also: no less.

  • Everything being conjecture at this point, other than the obvious collision, this reminds me of the dangers of ATAR if things go wrong. Remember back in the 60s when the RAF were bringing the then brand new EE Lightning into UK squadron service. Very quickly an ATAR refuelling probe was fitted when it was realised just how little endurance this extraordinary fighter had, with two such immensely powerful afterburner engines. Pilots quickly had to learn this tricky manoeuvre which led to inevitable accidents, one being oscillation building into whiplash in the refuelling hose and drogue. There was more than one occasion when a young, embarrassed, fighter pilot returned to base with the severed hose end and drogue still attached to his probe! I understand that there was then a requirement for said offender to then have to stand his CO and entire squadron of fellow pilots a round at the bar!

    This incident, sadly, went well beyond a ‘mishap’ as above.

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