Evidence for the vertigo theory seems to me to be a bit thin.

“Japan's air force said vertigo likely caused one of its pilots to fly his F-35 stealth fighter into the Pacific Ocean in April - hitting the water at more than 683 mph.

The Lockheed Martin Corp jet disappeared from radar screens during an exercise with three other F-35s over the ocean off northwest Japan on April 9, killing the 41-year-old pilot.

Defence Minister Takeshi Iwaya told a briefing: 'We believe it highly likely the pilot was suffering from vertigo or spatial disorientation and wasn't aware of his condition.
……
By dismissing mechanical or software problems as a cause for the advanced fighter's crash, Japan's assessment is likely to come as a relief to other countries that operate or plan to introduce the jet, including the US, Britain and Australia.
……
The air force has yet to recover any intact data from the $126 million aircraft's flight data recorder to back its assessment, which is based on data and communication received by ground controllers and interviews with other pilots…”

https://mol.im/a/7123091

Ugh, spatial-D.

That gets a lot of pilots / aircrew flying over the ocean at night.

Not all crash but everyone who has flown a tactical fighter has had a case of "which way if up???".

quote:

Originally posted by Pipe Smoker:
... hitting the water at more than 683 mph.

Dang.

A strong circumstantial in favor of spatial disorientation is the lack of ejection. The aircraft impacted at high speed with the pilot inside, suggesting either disorientation or incapacitation.

Over the water can create lighting and reflective conditions that in daylight make depth perception and orientation nearly impossible, and at night absolutely impossible, with no physical sense of up. More so for someone who is maneuvering.

Spatial disorientation can be panic-inducing, or it can be insidious, in which one has no idea that one is disoriented, at each end of the spectrum. In between, it can make control challenging or difficult, and can create a strong disconnect between what the body is sensing, and what the instrumentation is indicating.

Coupled with the F-35 helmet's visual display can add to the SD.

That's what I was thinking as well.

There but by the grace of God go I. Vertigo is terrifying in flight.

Does the F-35 have the Automatic Ground Collision Avoidance System (Auto-GCAS) that the F-16 has? Would it even work over water as opposed to land? If not, why? Are they incompatible? I know it has saved some lives.

quote:

Originally posted by gearhounds:
Does the F-35 have the Automatic Ground Collision Avoidance System (Auto-GCAS) that the F-16 has? Would it even work over water as opposed to land? If not, why? Are they incompatible? I know it has saved some lives.

Not sure.

Navy F-18s have a warning system, but it doesn't automatically control the plane for you.

I had a good friend take a nap after a high-G turn and wake up nose low, 600kts & accelerating with a face full of water and pull the handle (eject). He lived but by a razor thin margin. It was also daytime or he could have very likely hit the water, since he likely wouldn't have the visual cue of impending death.

Only bright-side is this Japanese Pilot felt no real pain, life just ended.

quote:

Originally posted by sigmonkey:
Coupled with the F-35 helmet's visual display can add to the SD.

Yeah, there are going to be some painful lessons learned from this advance in technology and many of them will be written in blood - like the rest of the manuals.

quote:

Originally posted by arabiancowboy:
There but by the grace of God go I. Vertigo is terrifying in flight.

Vertigo is one thing, but often times in fast movers you don't even know you have Spatial D - yes you can get vertigo, but that often gets you on the instruments ASAP. It is insidious and you think you are level or recovering, but you are not.

Another F-14 crew I knew flew into the water, supersonic, middle of the night. The crew gave no indication of extremis and the pilot thought he was wings level, but he was 40+ deg nose low.

quote:

Originally posted by RHINOWSO:

quote:

Originally posted by gearhounds:
Does the F-35 have the Automatic Ground Collision Avoidance System (Auto-GCAS) that the F-16 has? Would it even work over water as opposed to land? If not, why? Are they incompatible? I know it has saved some lives.

Not sure.

Navy F-18s have a warning system, but it doesn't automatically control the plane for you.

I had a good friend take a nap after a high-G turn and wake up nose low, 600kts & accelerating with a face full of water and pull the handle (eject). He lived but by a razor thin margin. It was also daytime or he could have very likely hit the water, since he likely wouldn't have the visual cue of impending death.

Only bright-side is this Japanese Pilot felt no real pain, life just ended.

quote:

Originally posted by sigmonkey:
Coupled with the F-35 helmet's visual display can add to the SD.

Yeah, there are going to be some painful lessons learned from this advance in technology and many of them will be written in blood - like the rest of the manuals.

I only ask because taking active control of the plane is what the F-16's system does to avoid a crash; since the 35 went into the drink, I can only assume not, or that it can be disabled during low altitude maneuvers.

Do pilots with spatial disorientation not even check the instruments because they don't know they even have a problem? What is the sequence of errors that leads to a crash?

quote:

Originally posted by jhe888:
Do pilots with spatial disorientation not even check the instruments because they don't know they even have a problem? What is the sequence of errors that leads to a crash?

Typically yes. There are numerous spatial-D events that can happen which give them the feeling that they are in a safe attitude (wings level or climbing) when in fact they are not.

Thats why vertigo isn't usually fatal, since you feel wacked out, so you get on instruments - because they are telling you the truth (attitude / airspeed / bank angle).

GLOC or Partial GLOC are also possibilities, as well as hypoxia.

quote:

Originally posted by RHINOWSO:

quote:

Originally posted by jhe888:
Do pilots with spatial disorientation not even check the instruments because they don't know they even have a problem? What is the sequence of errors that leads to a crash?

Typically yes. There are numerous spatial-D events that can happen which give them the feeling that they are in a safe attitude (wings level or climbing) when in fact they are not.

Thats why vertigo isn't usually fatal, since you feel wacked out, so you get on instruments - because they are telling you the truth (attitude / airspeed / bank angle).

GLOC or Partial GLOC are also possibilities, as well as hypoxia.

Vertigo isn’t usually fatal to those who are proficient on instruments and recognize it. It kills the heck out of those not proficient on instruments or unable to recognize it and immediately transition to instruments.

I was blessed to get vertigo hard several times while training for my instrument rating. One day I was cruising along under the hood and I started laughing hard. My instructor asked what was so funny. “I’m in a diving left turn, accelerating. Feels like the bank is tightening.” Why was that funny? Because I “knew” that was the state of the airplane and yet I could see on the instruments that I was straight and level, constant speed, droning along very boringly in that 172. After a little while (maybe 30 seconds, maybe a minute), my head and body sync’d up with what my eyes were seeing and everything settled back to normal. There was definitely a bit of cognitive dissonance going on for that little while though. For the folks who never experience vertigo in training, I’ve got to imagine it is terrifying if/when they run across it on their own...

I’m chalking this up to one of those things that I could only relate to if I experienced it. Looking from the outside it doesn’t seem possible, however from those in the know, it’s a real thing. Any way to simulate the experience for the average person? Would be interesting to feel the effects.

Vertigo is a real killer in tactical aircraft, especially at night in a thunderstorm and/or over water.

quote:

Originally posted by MattW:

Any way to simulate the experience for the average person?

Yes, sort of. Many years ago, maybe 50 years or so, I read an article titled "178 Seconds."

It was about a study re vertigo and disorientation. Pilots who did not have instrument training were tested. I do not remember whether the study used simulators, or airplanes with the pilots wearing vision-restricting devices ("hoods").

The study found that every pilot, without exception, lost control of the airplane (or simulator) when there was no outside visual reference available. Without a visual horizon, pilots who were not instrument trained wound up in a terminal spiral. Every pilot. This happened in a matter of a few minutes. The best of the pilots tested managed to last almost three minutes. Two seconds shy of three minutes, thus the title of the article, "178 Seconds."

This, by the way, is what killed JFK Jr.

V-tail - was it merely the deprivation of visuals that lead to the disorientation and/or vertigo? By that, I mean was it simply being isolated from visual input that caused the disorientation?

Wow. I don't doubt you, but I might have thought it would take some additional input to convince one that the plane was no longer traveling straight and level.

I’ve read that, with light aircraft, just turning loose of the controls will return the plane to mostly level, mostly straight flight in most conditions. Maybe different for an F-35.

quote:

Originally posted by MattW:
I’m chalking this up to one of those things that I could only relate to if I experienced it. Looking from the outside it doesn’t seem possible, however from those in the know, it’s a real thing. Any way to simulate the experience for the average person? Would be interesting to feel the effects.

It is a complex interaction of the motion you are in (flying in a plane) and the human body. They teach military pilots / aircrew about they human body, namely inner ear and visual acuity / illusions which help you recognize SD and how to overcome / deal with it.

Here is a decent website that shows some examples / explanations

http://goflightmedicine.com/spatial-disorientation/

quote:

Originally posted by Pipe Smoker:
I’ve read that, with light aircraft, just turning loose of the controls will return the plane to mostly level, mostly straight flight in most conditions.

Ah, not true. Really depends on the plane, it's operating environment, and when the controls are released.

Some military planes will start to 'recover' if in a 'departed state / stall' when the controls are released, but that is often into a nose low condition.

A pilot with spatial D needs to get on the instruments and level the plane.