[Updated] How Did an F-35 Fighter Jet Go Missing While on Autopilot?

[.Scott]

TL;DR Summary

A $135.8M (replacement cost) Lightning II jet aircraft went missing over South Carolina after its pilot bailed out with the aircraft running on autopilot.

According to news reports, the plane was left on autopilot.
The "Joint Base Charleston" posted this on facebook:

Personnel from Joint Base Charleston and Marine Corps Air Station Beaufort(MCAS Beaufort SC)are responding to a mishap involving an F-35B Lightning II jet from Marine Fighter Attack Training Squadron (VMFAT) 501 with the 2nd Marine Aircraft Wing.
The pilot ejected safely and was transferred to a local medical center in stable condition. Emergency response teams are still trying to locate the F-35.
The public is asked to cooperate with military and civilian authorities as the effort continues.
If you have any information that would assist the recovery teams, please call the 2nd Marine Aircraft Wing Public Affairs Office at 252-466-3827.

This jet has a range of 1,036 miles - plus the normal margins for a safe landing.

Of course, this is a stealth fighter - design to thwart any attempts at detection. I wonder how good it really is?

 

[berkeman]

Yeah, it seems like it must have crashed into a lake somewhere, or you would think it would be easy to track down. It looks like the wingman from this 2-ship followed the parachuting pilot down to be sure that he was located, and did not follow the errant fighter jet...

At the time of writing, the search for the jet — or its remains — has focused on two lakes north of North Charleston, namely Lake Moultrie and Lake Marion, CBS News reported.

Nancy Mace, a local congresswoman tweeted on Sunday: "How in the hell do you lose an F-35? How is there not a tracking device and we're asking the public to what, find a jet and turn it in?"

https://www.businessinsider.com/us-military-asks-help-from-public-finding-missing-f-35-2023-9

 

[hutchphd]

They should search under the streetlamp (very old joke...I should be ashamed) Good that the pilot got out OK.

 

[DaveC426913]

This jet has a range of 1,036 miles - plus the normal margins for a safe landing.

Yeah, it seems like it must have crashed into a lake somewhere,

Yeah. Lake Superior...

 

[Baluncore]

If the student ran it out of fuel, it would be quiet, and not leave a column of smoke on land, or an oil slick on a lake.

 

[.Scott]

Fuel exhaustion is very unlikely. There was likely someone on the ground as well as the wingman all tracking the fuel plan. On the other hand, fuel starvation would be possible.
I am both a pilot and a SW engineer. Personally, I suspect a SW or training issue.

 

[hutchphd]

Fuel exhaustion is very unlikely. There was likely someone on the ground as well as the wingman all tracking the fuel plan. On the other hand, fuel starvation would be possible.
I am both a pilot and a SW engineer. Personally, I suspect a SW or training issue.

That would then be fool exhaustion?

 

[.Scott]

That would then be fool exhaustion?

Yes "Fool Exhaustion", when there is plenty of fuel on board but you eject instead of sending pumping it to the engine.

On another note, this will cost US taxpayers the availability of an F-35B - but don't jump to the conclusion that this will cost those taxpayers that $135.8M replacement cost. Eventually it will. But in the mean time, it is saving $42,000 per flight hour - and with the Federal budget process and F-35B production already maxed out, it will be years (and likely thousands of lost flight hours) before it is replaced.

According to the F-35B wiki article, it relies on 8.6 million lines of Ada, C, and C++ code. So I'm thinking: an invisible plane, with vertical landing ability, and a mind of it's own has convinced its pilot to eject.

 

[Ibix]

According to the F-35B wiki article, it relies on 8.6 lines of Ada, C, and C++ code

That's pretty efficient code.

 

[Vanadium 50]

If I find it first, @dlgoff ;s daughter is going to get one heck of a birthday present!

The "pilot" wasn't a pilot. The Marine Corps doesn't have pilots. They have aviators.

The wingman should have concentrated on the ejecting officer. That's his job. Besides, what's he going to do following an empty jet?

erlies on 8.6 lines of Ada, C, and C++ code.

Wow. Must be strung together with lots of semicolons.

The plane almost certainly carried a transponder. Given the modernity of the jet, it almost certainly is cryptographically secure and can provide information like position. However, it is highly likely that there was some problem with the aircraft. Aviators don't just eject for the fun of it.

It is possible that the plane landed itself. After all, those nearly nine lines of code must do something. However, the earlier comment about damage applies.

 

[FactChecker]

Of course, this is a stealth fighter - design to thwart any attempts at detection. I wonder how good it really is?

During normal, non-combat use, a stealth fighter has attachments to create a large radar cross-section. That allows it to be flown in practice and transport without giving away any RCS secrets.

 

[berkeman]

According to the F-35B wiki article, it relies on 8.6 lines of Ada, C, and C++ code.

That's pretty efficient code.

Wow. Must be strung together with lots of semicolons.

I think we've found the root cause of the problem. 0.6 lines of code will almost always cause strange behavior...

 

[Vanadium 50]

The average family has 2.3 kids. I figured the 0.6 lines was written by two of the 0.3's.

 

[hutchphd]

Pretty efficient kids

 

[Vanadium 50]

Pretty efficient kids

In the top 0.3 of their families.

 

[Vanadium 50]

Personally, I suspect a SW or training issue.

Software? But it's Ada! We were promised Ada code is bug-free! DoD promised!

 

[.Scott]

That's pretty efficient code.

Or they used very long lines. I corrected the post.

 

[.Scott]

Breaking news - They found it "two hours to the north". I thought it was us New Englanders that measured distances in units of time.

 

[berkeman]

Breaking news - They found it "two hours to the north". I thought it was us New Englanders that measured distances in units of time.

Link?

 

[Vanadium 50]

I thought it was us New Englanders that measured distances in units of time.

And we Relativists.

 

[.Scott]

Link?

https://www.nbcnews.com/news/amp/rcna105534
I was actually watching the CBS Evening news on TV.

I notice the debris was found to the northeast - maybe DC - maybe New England

 

[berkeman]

https://www.nbcnews.com/news/amp/rcna105534
I was actually watching the CBS Evening news on TV.

Thanks.

The debris was discovered Monday evening about two hours northeast of Joint Base Charleston, an air base in North Charleston, officials said, without providing further details.

The jet was in autopilot mode when the pilot ejected from the aircraft, Jeremy Huggins, a spokesman at Joint Base Charleston, said. Authorities believed there was a possibility that it could have remained airborne for some time.

That's actually pretty scary if a stealth jet could just deadman through commercial airspace for a couple hours, with no return squawk to flight controllers and low radar visibility (modulo the comment above about radar visibility augmentation during training). It may be a lucky thing that it did not come close to unsuspecting commercial and private aircraft...

 

[.Scott]

It may be a lucky thing that it did not come close to unsuspecting commercial and private aircraft...

We don't know it's course yet. Did it fly over NYC?

 

[Vanadium 50]

just deadman through commercial airspac

I dunno. Commercial airspace is pretty big. Collisions during cruise are pretty rare, and often caused by ATC goofs - not an issue in this case.

I think the bigger risk would be ig, for whatever reason, the plane decided to navigate itself somwhere with a lot of people and aircraft. Like CLT.

 

[berkeman]

the plane decided to navigate itself somwhere with a lot of people and aircraft. Like CLT.

I wonder if it's auto-landing software includes contacting the associated tower...

 

[Vanadium 50]

I'm not sure how "smart" the software is. The code base is ~30% the size of Firefox. I would hope that there is some way tp tell the plane how and where to put itself down, but I don't know for sure if it actually does this, nor how well if it does. We also don't know why the aviator ejected. Normally, they don't like to do this with a perfectly working aircraft.

 

[.Scott]

I wonder if it's auto-landing software includes contacting the associated tower...

Better to sneak up behind a refueling truck with that VTOL.

It is likely to include a Flight Management System that could be preprogrammed to complete a landing. But I have never heard of an FMS that can do radio work.

 

[.Scott]

Apparently "two hours northeast" means two hours by car.
https://www.live5news.com/2023/09/18/debris-field-found-search-f-35-jet-williamsburg-county/

 

[Baluncore]

When motor vehicles first appeared in mass production numbers, there was a huge increase in fatal railway crossing accidents, because neither the vehicles nor the drivers had any horse-sense.

Back then, when a traveller was thrown by their horse, the rider would get back home, to find the horse waiting outside the stable. Dogs and bicycles are more loyal, and do not run off like that.

So how come, with all that code, did that F35 not go home and wait next to the fuel bowser. That would be the obvious place to look.

 

[Vanadium 50]

Apparently "two hours northeast" means two hours by car.

And about two seconds by plane.

Seriously, it's an interesting distance. That means the plane was in the sky for some minutes after ejection. So whatever triggered the ejection left the plane in flying condition for some minutes. Wonder why the ejection happened when it did.

 

[Flyboy]

... you guys never heard of the Cornfield Bomber, did you?

In 1970, an F-106 Delta Dart interceptor went into a flat spin during a training flight. Pilot fought it down to 15,000 feet, including deploying the drag chute to try and force the nose down. No luck. Dude punches out because by all rights the plane should be unrecoverable.

And yet, by ejecting, the plane pulled out of the flat spin. The change in CG, aerodynamics, and the rocket blast from the ejection seat caused the plane to recover, and given that part of the process the pilot went through was to trim it to a low-speed configuration and throttle back, it happily belly landed in a nearby cornfield.

Kicker of the whole thing is, they pulled the plane out of the field, shipped it to the maintenance depot, and they fixed it up and returned it to service, where it served the rest of the career of the type in 1986.

That exact airplane now sits in the National Museum of the US Air Force.

So yeah, punching out of a seemingly dead plane and having it go zombie isn't unheard of. Not going to pass any judgement until we hear more about the circumstances leading to his ejection.

That said, the fact that it's an F-35B, the STOVL variant, is interesting, because iirc, there's an automatic ejection seat initiation system that is supposed to detect a failure of the lift fan and eject the pilot, as there wouldn't be enough time for a human to react before the plane flipped over. Not saying that's what might have gone wrong, but it's a possibility that is unique in active-service aircraft.

 

[DaveC426913]

...in the mean time, it is saving $42,000 per flight hour - and with the Federal budget process and F-35B production already maxed out, it will be years (and likely thousands of lost flight hours) before it is replaced.

This gives me the mental image of a counter running all the time any plane is in the air, ticking over at 11.67 cents per second for each plane. I imagine they have a budget for any given military engagement. What if that budget runs out?

Time for a reimagining of THX-1138?


^{(If you don't get this reference we can't be friends.)}

 

[Vanadium 50]

an F-106 Delta Dart i

If we are going to discuss the Century Series, why not the F-104 Lawn Dart?

If you want to own a F-104, what do you do? Buy a plot of land and wait.

 

[Tom.G]

I thought it was us New Englanders that measured distances in units of time.

Not quite the only ones. We here in Southern California are familiar with the term, especially during the three-hour long "rush hour."

 

[Vanadium 50]

My favorite directions when I lived in New England was "Well, if I were going there, I wouldn't start from here."

 

[russ_watters]

What if that budget runs out?P

The plane shuts off and the pilot has to eject.

 

[DaveC426913]

So it travelled about 64 miles on auto. At, say, 500mph That'd be about 8 minutes.

Detours, according to the article:
"Traffic traveling north on Old Georgetown Road should turn right on Midway Road, left on Baptist Road, left on Bartells Road and right on Old Georgetown Road.

Southbound traffic should turn left on Bartells Road, right on Baptist Road, right on Midway Road and left on Old Georgetown Road."

... suggest the debris field is right about here:

33.7531, -79.5746

To match that detour area, the debris field would look something like this:

 

[DaveC426913]

News article:

https://digg.com/digg-vids/link/f-35-crash-witness-williamsburg-county-DO7XFNrJp0

This guy, whom the reporter shows as living at this address, heard it over head while he was shaving.

Randolph White says "I was in the bathroom takin' a shave and I heard a screechin' sortta between a screech a whistle ... AAAAAAAAAAAAAA!!!!!!! ... * then I heard a boom!"

*_{Sortta loses something in the translation. Gotta hear it for yourself.}Here's a capture of his house from the news clip:

And here is Google street view:

That's at 33.7599, -79.5781

^{Debris field is estimated.}

(I hope this doesn't qualify as doxxing. This is basic Google maps stuff.)

 

[Baluncore]

(I hope this doesn't qualify as doxxing. This is basic Google maps stuff.)

Judging by the mast, antenna and rotator, he is a ham radio operator, callsign?

 

[Vanadium 50]

NBC reports that eyewitnesses say the plane was flying inverted. I am not sure what to make of this - determining the orientation of a plane, especially an unfamiliar one, is non-trivial, especially when it is far away. But that's what they are saying.

 

[DaveC426913]

... the plane was flying inverted...

...determining the orientation of a plane, especially an unfamiliar one, is non-trivial...

Nonsense. Everyone who saw Top Gun became an instant expert on the subject.

 

[Tom.G]

determining the orientation of a plane, especially an unfamiliar one, is non-trivial,

Aw, come on! If the tail do point at da ground, it be downside-up.

 

[DaveC426913]

Let the memes begin...

 

[berkeman]

NBC reports that eyewitnesses say the plane was flying inverted. I am not sure what to make of this - determining the orientation of a plane, especially an unfamiliar one, is non-trivial, especially when it is far away. But that's what they are saying.

Lordy, can you imagine if the "mishap" were that the plane flipped inverted at 1000' and the pilot could not recover it? Deciding to eject inverted at that low altitude would be a tough decision...

 

[nsaspook]

Lordy, can you imagine if the "mishap" were that the plane flipped inverted at 1000' and the pilot could not recover it? Deciding to eject inverted at that low altitude would be a tough decision...

Thank goodness it's got a great zero-zero seat.

 

[Vanadium 50]

great zero-zero seat.

If you are inverted, doesn't a zero-zero seat shoot you into the ground?

 

[berkeman]

If you are inverted, doesn't a zero-zero seat shoot you into the ground?

Yeah, that's what I was wondering. Hopefully it has the "brains" to vector you sideways and up as soon as you clear the plane, but who knows. I'm off to Google...

 

[berkeman]

And Google led me straight to Wikipedia...

The minimal ejection altitude for ACES II seat in inverted flight is about 140 feet (43 m) above ground level at 150 KIAS, while the Russian counterpart – K-36DM has the minimal ejection altitude from inverted flight of 100 feet (30 m) AGL. When an aircraft is equipped with the NPP Zvezda K-36DM ejection seat and the pilot is wearing the КО-15 protective gear, they are able to eject at airspeeds from 0 to 1,400 kilometres per hour (870 mph) and altitudes of 0 to 25 km (16 mi or about 82,000 ft). The K-36DM ejection seat features drag chutes and a small shield that rises between the pilot's legs to deflect air around the pilot.[12]

https://en.wikipedia.org/wiki/Ejection_seat

 

[Vanadium 50]

"Russian counterpart" - I am imagining Boris and Natasha saying "Seat automatically buries pilot. Saves cost of funeral."

It's an interesting safety question - seat design can probably make some incidents have a much better outcome at a cost of making some other outcomes worse. I suppose by now there is unfortunately enough data to make an informed engineering choice.

I presume that these days avionics are sufficiently advanced enough to decide on their own to eject the pilot. Yes, it has an element of HAL9000 about it, but at 9g's or more the pilot may be in no condition to do it herself.

* Yes, I know they were Potsylvanian, not Russian.

 

[.Scott]

If you are inverted, doesn't a zero-zero seat shoot you into the ground?

Yes, but most people don't do it that way.
It's easier to do it directly under an I beam in a hanger.