Crash after loss of conciousness
 

This is a breaking story out of Indiana. Looks like a Mooney pilot lost conciousness and was shadowed by an F16 for about an hour before augering in.

Small plane crashes in eastern Indiana field - Yahoo! News

Fortuneately no one on the ground was hurt. Condolences to the pilot's family.

25,000 feet is very high for a mooney. Sounds like he was trying to fly as high as possible, then passed out, the plane kept climing then entered a spiral dive.

I'm sure a lot of pilots go above 10,000 feet, or even 14,000 without oxygen. It's a tricky subject. It's not like as soon as you go about 14,000 you will pass out, but you do need to keep track of how long you've been at such a high altitude.

I may think twice the next time i'm tempted to try and find the absolute ceiling for an aircraft.

I have flown a Piper Seneca Five at FL230 on oxygen. On the Five I was still seeing 800 fpm passing 20000 feet yet the service ceiling is quoted as 25000 feet. I have heard of a Piper Seneca Five topping nearly 30,000 feet in the right conditions.

Beyond quoted service ceilings is possible be interesting to know what others have been up to in their aircraft? and the highest you have been unpressurised on oxygen.

in this situation there is no reference to the flight being a record attempt or the reasons for the pilot being incapacitated which could have been something other than lack of oxygen.

Also to consider are air conditions which could have lifted the aircraft to those levels which is a very real possibility.

Pace

SoCal

The fact he was in class A suggests that it was not some sort of altitude attempt and unlikely to have been a requested cruise level.
It is possible he was lifted up there. I can remember flying in a Citation 2 to Nice.

There were warnings of severe turbulence between FL290 and FL240. I warned the pax, reduced speed and expected the worst only to be embarassed by silky smooth air to a Nice landing.

Leaving for the UK now empty and taking the more northerly departure over the Alps climbing through FL240 all hell let loose. 45 degree wing drops, items flying around the cabin, severe turbulence like I had never experienced. The jet was almost uncontrollable. Asked for an immediate climb to FL320. at FL240 the Citation 2 normally climbs at around 1000 fpm I had 4000 fpm all the way to smooth air at FL320.

This poor guy was hardly up there in a mooney by choice? any other ideas as lift could be one theory?

Pace

SoCal

Just discovered this was a turbocharged 270 HP Mooney Bravo with a service ceiling of 25000 feet. It is therefore very likely that he was cruising at FL250 and either ran out of oxygen or had a supply problem.

Having said that not all pilots would pass out at 25000 feet although their judgement would be severly impaired, smokers I beleive are at 5000 feet higher than non smokers so equivalent of 30K if a smoker. In tests in a pressure chamber some passed out at 25K others didnt with many factors effecting who did or didnt.

Pace

Good to see they got in the obligatory reference to panicking school children.

Pace, everyone would pass out at 25,000 feet.

Even if Superman was a smoker - so would he.

Runaway Gun

Not so ! climbers have climbed mountains higher than that without oxygen and with exertion which pilots dont have although I add they are conditioned to it first.

I have taken my oxygen mask off for short periods at 20K and once ran out of oxygen in 70 kt headwinds over the alps at X :) for a short time.

While I agree plus 30K you have had it 25 K is marginal and depends on your fitness, Whether you compress breathe, your lung capacity, how tired you are, whether your a smoker, your weight, general health etc as well as how long you are there.

But in tests not all pass out at 25 K

Have a read of this extract from a test pilot of old it makes interesting reading

1943 | 1754 | Flight Archive

Pace

Pace; " , , , over the Alps climbing through FL240 all hell let loose. 45 degree wing drops, items flying around the cabin, severe turbulence like I had never experienced. The jet was almost uncontrollable. Asked for an immediate climb to FL320. at FL240 the Citation 2 normally climbs at around 1000 fpm I had 4000 fpm all the way to smooth air at FL320."

Sounds like classic mountain wave - in the rotor at first, then into the smooth lift. But I expect you knew that.

In a glider, getting into wave is eerie - the smoothness and silence are awesome. AIUI, the air mass goes into laminar flow.

Returning to the original incident, or rather to cases which might arise like it (as I don’t have any more facts about the event in question), it is quite possible to fly straight and level into a continuous band of rising air which adds several hundred, or even a thousand or more, feet per minute to whatever one was trimmed for in still air. Wave bars can run for many miles. In Scotland last year, a glider pilot did over 1500km in one day using wave bars, but mainly staying at intermediate levels and using the energy to fly fast rather than climb.

Chris N. (edited to add last paragraph.)

My dad used to regularly decompress navy pilots to 25000' and they would swear blind they never passed out...until they opened their shirts to find all the writing on their chests ;) Something I want to try one day, maybe when I visit the USA I can find somewhere. Not heard about anywhere in the UK that offers this service to private individuals.

But I agree, not everyone would pass out, people survive for days at > 25000, but these tend to be the fit, mountain climbing types, not pilots :)

By the way the 250000 ceiling is just an FAA number as this prevents having to have the high altitude endorsement to fly the aeroplane at any height. Likely the TC'd mooney could reach much higher.

25k is a normal ceiling for a decent turbocharged IFR tourer.

I fly a TB20 which is non-turbo and has a 20k ceiling and I've been up there a few times, and routinely go to 18k or 19k as necessary to remain VMC above weather. Recently I had to sit for 6 hours at 18-19k, to stay above weather.

This pilot would definitely be on oxygen.

His oxygen may have run out (you will need a LOT of it at 25k, using a mask; he would have had a fitted o2 system but regular flights at 25k will deplete the cylinder pretty quick, and refills are not available everywhere, even in the USA), his 1st stage regulator or demand regulator may have failed (there is a well known brand of electronic demand reg which fails SHUT when the battery goes flat, although it does give you lots of audio warnings), or of course he may have become otherwise incapacitated.

At 20k, one merely needs to stop breathing for say 20 secs it takes to do a long ATC readback and one feels the need for another good long sniff. At 25k, any oxygen issue and you will be out of it pretty fast.

I don't think one could get a non-turbo plane (with typ. a 20k ceiling) to go to 25k. The engine would not be making anywhere near enough power to stay above Vs. I reckon my TB20 would make 21-22k absolute max, at the lowest possible weight. The plane flies just fine (the turbocharged TB21 will make 25k) but engine just runs out of steam, and you stall. I've tested this a few times. If the pilot was unconscious when this happens, one would be in a spiral dive more or less instantly because no plane will recover from a stall by itself with wings level and keeping them level, and no normal plane will recover to wings-level from a major roll axis disturbance in the absence of a pilot. Also the autopilot (if used) would have wound the pitch trim all the way back, to maintain altitude (or VS, or whatever was the target) so when the full stall actually occurs, the nose isn't going to conveniently pitch down to let the speed build up (Turkish 737 at Amsterdam e.g.) because the plane has already been trimmed for Vs.

IMHO, pilots who fly IFR (airways) without oxygen are less than smart. At typical European airway MEAs (FL100 is where the routings start to work OK) not only are they not functioning optimally (esp. during a long flight) and arrive knackered, but they are also cutting off a huge portion of their operating ceiling, which is by far their best weather handling strategy. A portable o2 kit cost peanuts, relatively.

Oxygen is desirable at 10k for long periods, 13k for almost any time, 15k absolutely, and at 18k few pilots would be functioning. At 25k nobody would be functioning (not saying they would pass out totally) after some minutes and looking at the average GA pilot fitness probably a lot sooner.

Mountain climbers go up slowly, over days, and all the serious ones are super fit. Even climbing that little hill called Kilimanjaro (19.7k) which is just a straight walk up a path, people just manage it over 3-4 days on the way up, with a few hard core types doing it over 1 day. But a turbo Mooney can get to 25k in half an hour.

10540

I am not saying you can fly along at 25 K without oxygen. I am saying that in pressure chamber tests not all pass out maybe 50% at that level.

I am also not saying that those who do not pass out would be wired up correctly :)

In the link to the test pilot article I posted you will see that he often flew to 18000/19000 feet without oxygen and on one occasion above 20K.

I think it is more than likely that this pilot passed out maybe unaware that he had NO oxygen feeding his mask at 25 K. One strange point is airways he is unlikely to have been hand flying and would have been on autopilot. The Bravo is ultra stable even off auto.

You would have thought that passing out the plane would have flown along until the fuel ran out at its programmed level?

I would also agree that at 10/12K it is a good idea to whiff some oxygen now and again to keep you sharp and especially before a night approach.

Pace

The recommendations I have seen for O2 flying at c FL250 seems to suggest hyper-alertness to pins and needles, headache, numbness and a frequent check on your pulse oximeter. I too have found that talking to ATC puts a drain on the O2 sat and have a basic mask with the mic penetrating so that I can keep breathing when talking.

FL190/FL220 seems much more manageable and you are that much closer to air if something goes wrong on the O2 delivery.

I don't know about the Mooney Bravo, but the TNIO-550 in the Bonanza (a broadly similar configuration) will maintain 30 in MP all the way to the certified ceiling of FL250 as long as you are turning more than 2500/2600 rpm. In any event, he almost surely had planned the flight at, or consciously climbed to FL250 and then had a problem.

Sure, mountain climbers require aclimatisation to ascend to great heights.
This takes days, even weeks, and even then, the individual might not succeed.

Every time I've been in the Hypobaric Chamber, and I've probably done a dozen runs at altitude without oxygen now, I've lasted less than 4 mins before requiring assistance (whether that was deciding to put on my mask, or requiring help from another - which is normally wiped from my memory). And that was whilst on 100% Oxygen during the climb. And I'm pretty average, meaning others last less, and others have lasted maybe a minute or two longer.

The rapid decompressions are even more fun, actually alarming, but if you're about to eat I won't go into that right now. :ok:

The report states

A single-engine plane crashed into an Indiana field on Wednesday after the pilot, who was seen slumped over, lost consciousness and the aircraft started flying out of control, officials said. Military officials do not believe the crash was terrorism-related but said the pilot may have had a health problem or have been suffering from a lack of oxygen. After air traffic controllers lost contact with the pilot, F-16s from Indiana National Guard intercepted the plane and followed it for about an hour until it crashed.
which suggests he was on autopilot, otherwise the F16 would not have been having a look for long enough to see him slumped at the controls. A spiral dive will always take place pretty fast, in the absence of roll axis input. 1 hr is far too long.

Re the pilot in your 1943 report, I think this just proves that it can be done (20k without o2) but would you want to try it? That was a different era, when men were men, girls were girls, and life was real :) And if something needed to be done, a real man was on hand to go and do it. And if he didn't come back, a telegram got sent to his last known address...

Runaway Gun

Ok :) wont fight you on it! Got to shoot off now anyway.

Have to meet my mate Robin for a luch time drink and the Batmobile will get a parking ticket if I leave it much longer and dont move it :E


10540 and now Men are Girls, Girls are men and a real Man gets ????
:O

Pace

Is the most important line

Allowing time for the problem to develop, for ATC to notice the pilot not responding, ATC to then decide they have an emergency and ask for fighters, Fighters to scramble, get there and observe for an hour ... sounds like more than enough to run out of fuel. The A/P would then wind in a fair amount of trim before it disengaged and the aircraft would develop a spiral at modest speed above stall.

This clearly lasted long enough to identify where it was likely to crash and implement the 'get everyone inside' strategy.


All very consistent with an O2 failure at altitude while on autopilot.

Yes, upon a sudden fuel exhaustion the AP would wind the trim back for the certified limit of 16 (??) seconds before disconnecting.

Only at LGMT :)

Sorry Pace, I only just saw the link you posted which was very interesting reading.

The author did state he flew up 18,000 ft maybe 8 times per day, and that it was tiring and he knew his test figures were not accurate. Sounds like he did indeed have a pretty good tolerance, and it also appears that he was a little aclimatised from his regular climbs. Even his climb to 20,000ft sounds pretty dodgy - I doubt he stayed up there for very long. I particularly enjoyed his reference to drag on a cigar at 20,000ft.

I've been fortunate to have experienced hypoxia many times, fortunate only that it was in a controlled environment, with a Doctor present. The effects for me are confusion, difficulty with basic maths, poor memory, selective hearing (my ex-wife could have already couched for those points). I also noticed a slight tingling in my fingertips, and most scarily, a euphoric feeling. And then the shakes. In fact I felt great - why are those other guys puting their masks on, when I've never felt so great? I likened it to having my drinks spiked with very strong alcohol without my knowledge. The worst point is though, that sometimes I can catch it, and decide when I need to put on my mask, and hopefully actually achieve it. Other times though - no good, I simply would have collapsed.

Another scary aspect is when the 100% oxygen is placed back on, the hypoxic effects actually worsen initially, with some users actually trying to again remove their masks.

Only once to my knowledge have I experienced this in an aircraft. just the initial symptoms, including tingling in fingertips and lips. I voiced my concerns and the flying pilot decended. Once on the ground we discussed it, and turned out that he knew nothing about hypoxia. He probably concluded that I was just a bit of a girl...

Runaway Gun

Nowadays I am happy at up to 14 K without oxygen but in the past did have a nasty situation in the very high teens over the Alps where I could not descend ran out of oxygen partially due to a leak and very strong unforecast headwinds. I had No choice but to stay there till the terrain lowered ( am still here although the girlfriend argues that point with me sometimes :O )

Tolerance is a very individual thing

Take care

Pace