Forgot your password?
typodupeerror
Transportation News

NTSB Says a Downdraft Killed Steve Fossett 101

Posted by kdawson
from the windy-up-here dept.
jd writes "The National Transportation Safety Board has now released the text of its examination (full narrative available) into the crash of Steve Fossett's aircraft on Sept 3rd, 2007. It concludes that downdrafts were the likely cause of the crash, dragging the plane into the mountain with such force that, even at full power, it would have been impossible to escape the collision. Pilots experienced in the area report that those winds can rip the wings off aircraft; and Mark Twain remarked that they could roll up a tin house 'like sheet music.' One must wonder why such a skilled aviator was taking a gamble with such hostile conditions, given that he was looking for a flat stretch of land to race cars on, but that is one mystery we shall probably never know the answer to."
This discussion has been archived. No new comments can be posted.

NTSB Says a Downdraft Killed Steve Fossett

Comments Filter:
  • One must wonder ... (Score:4, Interesting)

    by qoncept (599709) on Friday July 10, 2009 @11:49AM (#28650783) Homepage

    One must wonder ...

    ...how pilots experienced in the area and are still alive know that these downdrafts can rip the wings off an airplane?

    • by Sir_Lewk (967686) <(moc.liamg) (ta) (kwelris)> on Friday July 10, 2009 @12:01PM (#28650981)

      Perhaps they've seen wreckage where it was evident that's what happened.

      • Re: (Score:3, Insightful)

        by qoncept (599709)
        Then maybe instead of "pilots experienced in the area," it should have said "pilots who have seen wreckage."
        • by maxume (22995) on Friday July 10, 2009 @12:15PM (#28651153)

          Are those two things mutually exclusive?

          Perhaps experienced pilots in the area, who have seen such wreckage, choose not to fly when the weather indicates such winds are likely.

        • by Jay L (74152) *

          Then maybe instead of "pilots experienced in the area," it should have said "pilots who have seen wreckage."

          No, because as any Slashdotter knows, "area" is a two-dimensional measure. So if they flew over the wreckage, they were experienced in the area. They just weren't experienced in the volume.

          • by JWSmythe (446288)

            None of that matters, until you find the hard part, down at the bottom of your volume. It's the whole secret of flying. Throw yourself at the ground and miss. As long as you're still doing the miss part, you don't have to worry about too much (except a stray bird or 747). Now, when you do fail at the miss part, things can get messy. Usually it's done in a pretty controlled manner, so it doesn't hurt too much. Just remember next time you take a flight somewhere, any landing is just a controlled crash

      • by JWSmythe (446288) <jwsmythe@[ ]mythe.com ['jws' in gap]> on Friday July 10, 2009 @06:49PM (#28655819) Homepage Journal

            In searching for Fossett, they found numerous unreported or otherwise undocumented crashed planes. More than likely, any aviator who said that they "knew" it could happen were witnesses to another plane crashing, helped with the search and rescue of a fellow aviator, or simply accounted for the forces and the strength of small aircraft.

            I had discussed this with some people who are very experienced aviators, and they all came to the same conclusion. It was most likely wind that brought him down. The second guess would be a mechanical failure and attempted crash landing. They ranked the second one way behind the first.

            If I read the NTSB review correctly, his altimeter was reading above the mountain peaks, but adjusted for current temp and pressure that would put him a bit lower than them, which should have been ok. They lost radar contact with him approx 1km from the crash site. In that time, he went about 1km (obviously) and a dropped a few thousand feet.

            The report does state that the entire plane was present at the accident site. Well, except for the burnt off parts. They indicate the wingtip lights were present, which would imply the wing came down with the plane. If they had broken off, they would have likely been found at a different location.

            I'm sure he did everything he could. Sometimes that's just not enough, even for people who are really good. :(

    • by vertinox (846076) on Friday July 10, 2009 @12:20PM (#28651223)

      ...how pilots experienced in the area and are still alive know that these downdrafts can rip the wings off an airplane?

      Experienced pilots experienced the phenomena by experiencing the event from a safe distance because they were experienced.

    • by DoofusOfDeath (636671) on Friday July 10, 2009 @12:20PM (#28651227)

      One must wonder ...

      ...how pilots experienced in the area and are still alive know that these downdrafts can rip the wings off an airplane?

      Yes, it's odd. Almost as though they can somehow communicate amongst themselves or even read NTSB reports.

      Yes... this definitely is something we need to understand better.

    • by tnk1 (899206) on Friday July 10, 2009 @01:22PM (#28651881)

      Experience could certainly mean that they have flown the area and frequented places where fellow pilots who know about incidents congregate. They may have also experienced lesser effects of this phenomenon personally and then read about reports of similar incidents which match their (not as extreme) experience.

      I am an experienced system administrator for large numbers of high-end systems. This means I know about all sorts of threats to my hosts, active and historical, because I am experienced and have had to explore the possibility of intrusions and read studies of those that went too far. That is a function of my experience that you would have trouble obtaining without time in front of the keyboard, if only because you'd usually have no interest in such things if you never had to deal with the real possibility of them happening to you. I have never experienced an intrusion personally, but my experience is why I would know about them.

      While it is not "first-hand" experience, these mountain conditions are something that an "experienced" pilot would know about because it is their best interests to know about it... or they may die. That is why it is interesting that Mr. Fossett, who we all know is experienced, seemed to be either ignorant of these conditions, didn't care, or something else happened. This would seem to be pretty basic stuff for general aviation flyers to know, so we would be allowed to wonder what happened.

    • One word.

      Parachutes.
      • if these downdrafts are so strong that they can rip the wings off a airplane, one would think that the downdraft could collapse a parachute.

        just a thought.
      • Parachutes don't work well in downdrafts, or very turbulent conditions where the risk of a parachute collapse is high. But I doubt he would have had the height and time to jump. Which is one of the reasons flying near mountains is so dangerous.
    • by Ash Vince (602485)

      ...how pilots experienced in the area and are still alive know that these downdrafts can rip the wings off an airplane?

      Parachutes?

    • by insnprsn (1202137)
      "Geronimo" ?
    • by sjames (1099)

      Perhaps lucky and experienced pilots witnessed a less lucky nearby pilot having the wings ripped off of his plane or slightly less lucky pilots had their planes severely damaged but made it back to the ground safely and then concluded based on the damage that another unfortunate encounter would have done them in.

    • by cyn1c77 (928549)

      One must wonder ...

      ...how pilots experienced in the area and are still alive know that these downdrafts can rip the wings off an airplane?

      Parachutes and radios, my friend.

    • "how pilots experienced in the area and are still alive know that these downdrafts can rip the wings off an airplane?" In the incident I know best, the pilot parachuted and survived, though I believe he suffered significant injuries. See page 36 in http://www.quovadis-aero.com/pdf_ext/2004_winning_on_the_wave.pdf [quovadis-aero.com] for a description. But that describes a very different day in terms of wind conditions compared to the day Fossett was killed. The article referenced above is describing strong mountain wave wh
  • With due respect (Score:3, Insightful)

    by mewsenews (251487) on Friday July 10, 2009 @12:06PM (#28651051) Homepage

    To Mr. Fossett,

    "The only thing that makes life possible is permanent, intolerable uncertainty; not knowing what comes next."
      -- Ursula K. LeGuin

  • by Em Emalb (452530) <ememalb@gm[ ].com ['ail' in gap]> on Friday July 10, 2009 @12:13PM (#28651119) Homepage Journal

    Sudden deceleration is what killed him.

    • Re: (Score:1, Funny)

      by Anonymous Coward
      Pfffft, hardly. He was perfectly still the whole time. It was the earth that flew into him.
      • Re: (Score:1, Insightful)

        by Anonymous Coward

        If you are using him as your reference frame, then it was the sudden acceleration that killed him.

        • by j79zlr (930600)

          If you are using him as your reference frame, then it was the sudden acceleration that killed him.

          It was still the rapid deceleration of the organs internally that killed him.

    • That's absurd. It was probably due the inability of his body to continue to supply vital organs the nutrients they require. Pretty sure it was multiple organ failure. With the brain shutting down first.
    • by kpainter (901021)
      It was not sudden deceleration that killed him. It was the trauma caused by sudden deceleration that killed him.
      • Or, you know, maybe he had a heart attack, stroke, whatever, and was already deceased prior to ground impact. We will never know.

    • Also wrong. Earth collided with him.

      What was he doing on earth's extra-wide lane anyway?
      Searching for is mom?
      *ducks* (Too early? Ok. Bad hurricane78*! *slap*)

      [* By the way: How do I rename myself. I could not find anything, and I do not like that name anymore. While I like to keep my ID.]

  • One must wonder why such a skilled aviator was taking a gamble with such hostile conditions, given that he was looking for a flat stretch of land to race cars on, but that is one mystery we shall probably never know the answer to."

    Stated as though it was soooo-oo obvious that eeeveryone knew not to fly in that area.

    • Re:Insulting summary (Score:5, Informative)

      by AB3A (192265) on Friday July 10, 2009 @04:37PM (#28654673) Homepage Journal

      To someone who isn't an experienced pilot, it isn't obvious. But you should know that it is a significant part of the training for all private pilots.

      I've been licensed for more than 20 years as a private pilot. I've taken mountain flying instruction. I've flown around and over the Rocky Mountains. This hazard is a simple issue of flight planning.

      I know exactly what performance my aircraft is capable of, as should every pilot who sits in the left seat. I read reports of the winds aloft. I set personal minimums for what I'm willing to fly in. I know, for example, that if the winds aloft at 3000' are approaching 30 knots, that I can expect significant turbulence and down-drafts from the Appalachian mountain chain for up to 100 miles East. I might fly in those conditions if I'm going Eastward. However, if the winds aloft are 35 knots or greater at 3000, I know I'm staying on the ground.

      It's not that I can't handle those situations; I can and I have. My goal is to have a reserve in case the forecast is wrong. I've seen blown forecasts more times than I care to think about.

      Steve Fossett had a momentary lapse of judgment. It happens to the best of us. Every year, people crash while flying around mountains and canyons from exactly the same damned thing that bit him. There is little room for error when flying in the mountains. Each flight should include a careful evaluation of local and regional weather conditions, terrain, and aircraft performance. Yeah, there are people who launch in to the blue without checking this stuff. Most of the time, they survive without incident.

      Those who don't do adequate flight planning in this terrain are accidents waiting to happen.

  • One must wonder why such a skilled aviator was taking a gamble with such hostile conditions, given that he was looking for a flat stretch of land to race cars on, but that is one mystery we shall probably never know the answer to."

    Even if we did know the answer, I doubt it would be very interesting. It's probably a little of Steve being an adrenaline junkie mixed with underestimating the danger.
  • by Chris Burke (6130) on Friday July 10, 2009 @12:22PM (#28651241) Homepage

    One must wonder why such a skilled aviator was taking a gamble with such hostile conditions, given that he was looking for a flat stretch of land to race cars on, but that is one mystery we shall probably never know the answer to.

    I wondered, but in about a second I came up with this: An adventurer and thrill-seeker, in the course of looking for a place for future thrill-seeking, decided to seek some thrills?

    Sure it's just idle speculation... but based on what little I know of the man, taking gambles with danger while tooling around alone in his private plane sounds exactly like something he would do. It makes enough sense for me, at least.

    • by Lil'wombat (233322) on Friday July 10, 2009 @02:01PM (#28652529)

      There are BOLD pilots
      There are OLD pilots

      But there are no OLD BOLD pilots

  • by PolygamousRanchKid (1290638) on Friday July 10, 2009 @12:24PM (#28651259)

    When you register your flight, does the FAA (or whoever) give warnings about dangerous areas?

    During your flight does the ATC tell you, "Be careful, you are about to enter a dangerous area?"

    I guess what I want to know, is if he had a chance to know what the local pilots knew.

    • Re: (Score:2, Informative)

      by ubergamer1337 (912210)
      If your flying "general aviation" (private flying, non-commercial), then the answer is no. Once your in the air, the ATC doesn't talk with you. General Aviation does its own thing once their airborne. General Aviation pilots just have to stay out of restricted airspace that is used for commerical, controlled-by-ATC flights. As to filing a flight path, I'm not sure whether General Aviation has to do that or not, but I am pretty sure the FAA wouldn't give them a warning based on what they filed. It's up to
      • by ColdWetDog (752185) on Friday July 10, 2009 @12:57PM (#28651611) Homepage
        Your basically correct. This page [wikipedia.org] has a nice brief explanation. Even if Fosset were flying IFR (Instrument Flight Rules), where the pilot would file a flight plan, it's not clear that a Notice to Airmen (NOTAM) [wikipedia.org] (sexist assumption noted) would mention winds over the Sierra Nevada. Now, one of the pilots the investigators talked to who had flown over the general area that day said the weather was "weird". Perhaps, if enough pilots had mentioned some unusual conditions, the local controllers might have issued a NOTAM, but this is pretty much in the middle of nowhere so it may not have attracted much attention.
        • by bluefoxlucid (723572) on Friday July 10, 2009 @01:08PM (#28651723) Journal

          Notice to Airmen (NOTAM) [wikipedia.org] (sexist assumption noted)

          (illiterate lesbian noted)

        • by mcgrew (92797)

          sexist assumption noted

          A woman (wo'man) is a man with a womb. Mankind includes both sexes.

          I like the way in Star Trek they call the women officers "sir".

          • sexist assumption noted

            A woman (wo'man) is a man with a womb. Mankind includes both sexes.

            A lovely bit of etymology, but, alas, not quite correct. It's from wif-man, where 'wif' originally meant 'female' (the word 'wif', of course, became 'wife'). 'Man' originally had both meanings (male and female), but lost the female sense over time, hence the newer - although still pretty outdated - 'mankind' for both sexes. There's a good discussion of it here [tafkac.org].

            PS always liked that about Star Trek myself...m'am never sounds right, for some reason.

      • If your flying "general aviation" (private flying, non-commercial), then the answer is no. Once your in the air, the ATC doesn't talk with you. General Aviation does its own thing once their airborne. General Aviation pilots just have to stay out of restricted airspace that is used for commerical, controlled-by-ATC flights. As to filing a flight path, I'm not sure whether General Aviation has to do that or not, but I am pretty sure the FAA wouldn't give them a warning based on what they filed. It's up to the pilots to make sure the area they are going to be flying in is safe, not anyone else.

        Most of the pilots I knew who follow your description and didn't get flight following for their private flights have crashed their own planes. Usually they didn't die to traffic, but it was part of a pattern of carelessness (landing with no lights at night is common among this same group).

        You're correct that private pilots aren't required to file flight plans, but when flying away from population centers most do anyway. It's true that it's up to the pilots to ensure their own safety and there are plenty o

      • by kckman (885561)
        Mod me troll.. but the improper use of "their" and "your" really gets under my skin.
      • Re: (Score:2, Interesting)

        by superdana (1211758)
        This is a curious description of how aviation works in the U.S. While it's certainly possible for GA flights to "do their own thing" if they stay out of any airspace more restrictive than Class E, this is by no means representative of GA as a whole. A Cessna flying under instrument rules will be in constant contact with ATC. Even if you're just flying under visual rules, you have to get landing and takeoff clearances at controlled airports, you need a clearance to enter Class B airspace, and you need permis
      • Re: (Score:1, Informative)

        by Anonymous Coward

        If your flying "general aviation" (private flying, non-commercial), then the answer is no. Once your in the air, the ATC doesn't talk with you. General Aviation does its own thing once their airborne. General Aviation pilots just have to stay out of restricted airspace that is used for commerical, controlled-by-ATC flights.

        This is so wrong in so many ways...

        First, GA (general aviation) is just about everything not "airline". Corporate jets, private jets, crop dusters, all the way down to home-built experimental airplanes. It's not just "private flying" or "noncommercial".

        Second, GA doesn't have to stay out of "commercial controlled-by-ATC airspace". GA uses the same airspace as everyone else. There is airspace where you MUST have an ATC clearance ("controlled by ATC"), but there is no distinction between GA and other users wh

    • by Abreu (173023)

      During your flight does the ATC tell you, "Be careful, you are about to enter a dangerous area?

      Yes, and using Majel Barrett-Roddenberry's voice, no less!

    • Re: (Score:3, Insightful)

      by CompMD (522020)

      He should have known about the possibility for dangerous winds given the area. He was probably flying VFR, instead of having filed an IFR flight plan, which is part of the reason it took so long to find him. He should have called a weather briefer before taking off to get the weather conditions and forecast for his trip. In flight he could have contacted FlightWatch for more up-to-date weather in case he noticed things were changing.

      Keep in mind that rarely does a single event cause an airplane crash. I

    • Re: (Score:3, Informative)

      by rand.srand() (243903)

      Any pilot can call for a weather briefing prior to a flight, but most don't. For most private traffic, the pilot never talks to anyone other than the other pilots in the area advising what they are up to... and technically don't have to do that even if the airport doesn't have a control tower (most don't).

      It is extremely unlikely that the weather briefer or ATC would inform pilots of mountain phenomena because it's like warning pilots that bright blue light shines from every possible direction when not obsc

      • There's a typo I want to correct in there. If the airport has an operating control tower you do have to talk to them to get clearances to operate (taxi out of parking, take off, land, enter their airspace, etc).

        Of course there's an exception to everything. If you don't have a radio or it is broken, there are procedures where the control tower shines a light at you and you see green or red and depending on the light pattern they can provide clearances to aircraft without radios. To take-off like this you'd n

    • by wsanders (114993) on Friday July 10, 2009 @02:59PM (#28653415) Homepage

      I used to fly out of the Bay Area, and the club I flew with specifically prohibited us from flying over the Sierra without supplemental training. Every pilot in California and Nevada is usually trained of the danger, not to cross the Sierra without several thousand fleet of ground clearance.

      And when I took hang gliding lessons, there were many many stories of pilots who tried to fly the huge lift coming off the eastern slope, only to return to earth under a parachute with pieces of their broken gliders falling all around them.

      Mountain flying can be tricky - one of my flight instructors was killed several years ago in the Rockies, flew into the end of a canyon. He was not a risk taker, and had been regularly flying between the Bay Area and Lake Tahoe for many years,

    • by wsanders (114993)

      Specifically, the answer is no. Flight plans are filed online.

      Even in the days of personalized weather briefings, you not always warned, you had to ask, because it's the pilot's sole responsibility to gather all information relative to the safety of the flight.

      I haven't flown recently, but NOTAMs would usually be issued about particularly dangerous weather days. But in a Super Decathlon over the eastern slope of the Sierra Nevada, every day is a potentially dangerous day. Your're going about two miles per m

  • Mountain Wave Action (Score:5, Informative)

    by Nobo (606465) on Friday July 10, 2009 @12:32PM (#28651347)

    The proper term for what they're describing is a mountain wave or wave action. http://en.wikipedia.org/wiki/Lee_wave [wikipedia.org] contains a good description of the effect.

    Mountain waves can be felt in small piston powered aircraft even flying significantly above the tops of the mountains, even several thousand feet above the peaks on either side of the valley you're crossing.

    If you're holding altitude, you see that you speed up when you're crossing falling terrain and slow down when you're crossing rising terrain -- because as you cross the rising terrain, you're in the downdraft and so to maintain altitude, your airplane "feels" like it has to climb to stay at the same altitude in the falling air. Climbing requires additional power over simple cruise flight, or you slow down.

    I've seen airspeed of an aircraft that should cruise at 150 knots, range from 90-180 knots, depending on whether you're on the uphill or downhill side of the wave. In severe conditions, you just cant' maintain altitude without slowing down too much, and you have to vary altitude to ride the waves.

    It can be a scary experience knowing you don't have enough power to out-climb the wave -- That's the reason that you typically fly significantly higher in the mountains, even with good visibility -- You're not worried about hitting the mountains because you can't see them, you're worried about getting sucked by these waves and not having enough altitude to ride them out.

    • The turbulence on the downstream side of the mountain peak, the "rotor", will!

      Just like in a stream, you can get trapped on the downflow side.

    • If "stuck" in one of these downdraft waves, is it possible to 180 to go with the wave and pick up airspeed?
    • by smellsofbikes (890263) on Friday July 10, 2009 @01:37PM (#28652135) Journal
      Mountain flying is technically challenging -- as challenging for an experienced pilot, as just flying is for a person who doesn't know how to fly. There are a lot of things you do when you train in mountain flying to minimize your risk, but if you're in a small piston-engined plane, there are a lot of places where you just don' t know what the best plan is, so you have to make a quick decision and hope you were right.
      First off: fly down valleys, not up them. That's not always possible, though: you sort of have to fly up one valley to go over the pass and fly down the next. Another is you don't fly up the middle of a valley. You fly up one side, so that you have room to make a quick turn if you find that you're in a narrow bit of the valley and you need to get out. But here's the tradeoff: there are sometimes strong upslope/downslope winds along the valley sides, so by preserving your ability to turn, you might run into an intense downdraft. (Generally, winds are faster, the higher you go, but in valley conditions, downslope winds known as foehn or scirroco winds tend to be intense right around the valley itself, particularly if you're flying up an old glacial valley with hanging valleys intersecting it: there are these big cold air currents flowing down them just like water would and pouring down into the main valley.)
      Likewise, once you're in a downdraft you have to make some hard decisions. You pull the nose up to best angle of climb, full power, and you hold it. What if you're aiming right towards a big rock? If you turn, your stall speed increases, and you're already fairly close to stall speed, so you have to weigh reducing your angle of climb (which in a microburst or downdraft means increasing your speed towards the ground) to make the turn, vs. trying to ride out your current heading and hoping you'll miss that big object. You don't know, a priori, which one is going to work. Maybe you'll break out of the downdraft. Maybe it's worse over there where you're about to turn. That's where skill, experience, and lots and lots of luck come into play.
      Where I live, sometimes the clouds from the mountain waves are visible in long rows at over 25,000 feet elevation, in lines for a hundred miles downwind of the mountains themselves, and every one of those is strong enough to shake a plane like a ragdoll. A B-52 bomber had its vertical tail ripped off and lost part of a wing [derkeiler.com] in clear air turbulence 5000 feet above the nearest mountain.
      • Where I live, sometimes the clouds from the mountain waves are visible in long rows at over 25,000 feet elevation, in lines for a hundred miles downwind of the mountains themselves, and every one of those is strong enough to shake a plane like a ragdoll. A B-52 bomber had its vertical tail ripped off and lost part of a wing in clear air turbulence 5000 feet above the nearest mountain.

        As another example of the danger of clear air turbulence from mountain waves, on March 5, 1966, BOAC Flight 911 [wikipedia.org], a Boeing 707 on a flight from Tokyo to Hong Kong, broke up as it was flying near Mt. Fuji in clear weather, possibly in order to give the passengers a good view of the mountain.

    • Is this anything like Dynamic Soaring as undertaken by some sea birds http://en.wikipedia.org/wiki/Dynamic_soaring [wikipedia.org] and those seeking more speed for radio controlled model gliders http://www.wired.com/gadgetlab/2009/06/dont-blink-400mph-rc-gliders-tear-through-the-air/ [wired.com]?
    • From experience, the steeper the ridges the greater the impact. My old partner picked me up at my local airstrip in a Piper Tri Pacer (a lighter, tube and fabric airplane). We had to climb and then cross perpendicular to the ridge line, the least you can do to avoid the well known affects of a hill that rises 1000' in less than a mile. Even though we had at least 500' above the ridge, it was a bumpy ride. And when we were well past ridge face, it tipped us really hard and really fast! Thank god for padded r
    • Mountain waves can be felt in small piston powered aircraft even flying significantly above the tops of the mountains, even several thousand feet above the peaks on either side of the valley you're crossing.

      A friend of mine who is an airline pilot tells of feeling the effect in an A320 at cruising altitude - think 30,000 feet or so. The autothrottles come back when you're in the lift part and then push forward when you get out of the lift.

  • Pilots experienced in the area report that those winds can rip the wings off aircraft; and Mark Twain remarked that they could roll up a tin house 'like sheet music

    Just thought I'd ask.. me thinks Mark Twain died before the aircraft age.

  • Who cares about this guy? He is called an "adventurer"? Our navy (Australian) already had to fish this idiot out of the sea after he failed *another* balloon flight. He was a billionare.. but he cant even have a fucking plan b? His many rescuers should get the credit, not this idiot.

    What sort of adventurer goes man vs nature... fails (often), lives only cause of others... but is still considered so brave / adventerous?

    Even I can fuck up and get saved by the professionals. Its not that impressive!

    Fossett fle

    • Relax, man.

      No once forced the navy to go grab him. They volunteered. Maybe they were excited to meet him.

      The trick is to not ridicule and get your blood pressure up, but to learn. You can even take it to the next level and let go of your own sense morals, ego, and ideals, and play his game. Then, you too can be brave and adventurous as your navy fishes you out.

      So Fossett underprepared in his last flight. That's yet another lesson to the rest of us. You don't have to rub it (the tragedy) in (does

  • It's interesting that the brief linked to mentions radar hits with readouts of 14500 and 14900 feet but doesn't say anything about whether the aircraft was equipped with an O2 system or not. Above 12500 the pilot would be required to use supplemental O2 by FAR. Extended periods near 15000 without oxygen would definitely set you up for impaired judgement. Maybe it's considered in another document but it's not in the brief.

    In contrast, the NTSB specifically mentioned lack of supplemental O2 in another crash:

You have a tendency to feel you are superior to most computers.

Working...