Pilots asleep
10 min read

More of a factor than you might think…

Some years ago I got interested in the role of pilot incapacitation in serious general aviation accidents. What started me looking at this was a statement in the Air Safety Foundation’s Nall Report that in a recent year there were no cases of pilot incapacitation leading to accidents.

I faxed ASF seventeen NTSB reports from that year citing pilot incapacitation as a cause or factor in serious accidents. Some other folks found even more.

Pilots asleep

The airplane can fly itself, but only for so long…

There are some who think sugar-coating helps on things like this. I don’t and later, and still some years ago, did a lot more research on the subject. What I found was revealing and it is worth a review.

The NTSB found pilot impairment or incapacitation to be a factor in about ten-percent of the fatal general aviation accidents. (I used fatal accidents only because that is the usual result of established impairment or incapacitation.)

That is not a big number but when you examine the records there is another ten-percent where no smoking gun is found. Good weather, no mechanical problems, no reported other problems, nothing revealed in an autopsy, yet the flight terminates with a catastrophic crash.

Look first at the established cases. This is where the heart attacks would be found. There are few. While the well-intentioned aviation medical community would like for us to believe that they are safety sentinels, they are not. The exam is brief, not complete at all, and from six months to three years goes by without further contact.

Between physicals, pilots self-certify that there is nothing going on that would affect their ability to fly. If the questions on the physical application are answered honestly and all the answers are correct, then, in effect, pilots self-certify almost 100-percent of the time.

Legal and illegal drugs and alcohol also fall into the established causes, with legal drugs an ever-increasing factor.

The alcohol part is pretty simple. Just follow the FAA bottle-to-throttle rules and understand the effects of a hangover. The latter is an individual thing and only the pilot can tell if a night of hooting with the owls will affect the ability to fly like an eagle the next day.

As one who has enjoyed beer and expensive bourbon for almost 65 years, since age 14, I could tell when it was okay to go flying after a night on the town. Like anything else, a cold for example, this might depend a little on the complexity of the flight at hand. It also depends a lot on whether thinking about the ailment is distracting.

Many safe hours have been flown by pilots who were technically hung over (if there is such a thing) and there is seldom a problem unless the pilot doesn’t know what he is doing. If the pilot is really hung over and not still abuzz, then nothing would show on an autopsy and the hangover could indeed be a factor that would show up only in the pilot’s inability to manage the flight.

On legal drugs, the rule says no flying if impaired by the drug. The FAA does have a list of permissible drugs but I don’t think I would fly if using some of those, based on my reaction to drugs in general.

There is no question that some of the strong stuff has no place in a pilot flying. In the accident reports you can find cases where someone who should know better, like a doctor, was self-medicating and flying.

I’m too old to have been around when recreational drugs became popular and always wondered about the difference between being “stoned” and “loaded.” I found out last summer.

prescription drugs

Prescription drugs and flying do not usually mix, but it probably happens a lot more often than reported.

I had a hernia repaired and, when I walked out of the surgical center, the nurse told me to take the oxy-something if pain started to appear. Taking it after the pain got bad wouldn’t do nearly as much good.

A while after I got home, I thought pain might be starting so I took half the maximum dose, relaxed in my chair, and found out what it is like to be stoned. Zonked is more like it and I can sure see why you can’t mix that stuff with flying.

If a pilot would think logically about drugs and alcohol and flying, he would be extra careful. Just consider that few pilots are caught doing this. The bad stuff is usually detected during an autopsy. In other words, pilots catch themselves. No second chances.

Things get more complicated with the ten percent where there is no reason found for the accident. Here we can only speculate.

My favorite guess here is fatigue. This is a hard thing to measure, or detect, yet all pilots suffer some degree of it some of the time or even much of the time.

I did some research flying with a sleep-deprived pilot a good while back. The first day he just made small mistakes but as the flying continued and the level of fatigue built, the mistakes became more serious. Finally, on an approach to a minimum-length runway, the airplane started to get way ahead of him. I let it progress for as long as I could but finally had to take control of the airplane and fly it out of the developing bad situation.

This pilot had clearly become too tired to do anything very demanding with the airplane.

I know of cases where pilots went to sleep with control either lost, or an errant autopilot or altitude misjudgment resulted into flight into terrain.

All of us have flown along fighting the urge to nod off. For some reason, the tendency to do that tends to fade with age.

Nobody condones turning the autopilot on and taking a nap but that is and has been done. On all those long record breaking flights, naps were inevitable. For the rest of us a nap might also be inevitable but it is best taken after a landing and a time out. A quick snooze, even one taken in a chair, can charge one’s battery quickly.

A huge percentage of accidents are attributed to pilot error but not enough thought is given to why pilots make so many fatal errors.

I think a fairly high percentage of these involve impairment or incapacitation of the pilot’s ability to cope, or, to think. A pilot whose brain freezes is just as incapacitated as one who is numb from alcohol or drugs, or who becomes physically ill.

A380 engine failure

Seeing an engine explode on an Airbus A380 would be enough to panic most pilots.

We make much of pilots or crews who do well under fire. Captain Sullenberger was idolized for his cool in landing that Airbus in the Hudson River after both engines quit. An even more challenging event involved a superjumbo Airbus A380 operated by Qantas, the Australian airline.

This behemoth had one of its four jet engines suffer an uncontained failure, meaning that pieces of the engine impacted other parts of the airplane disabling systems and other things and leaving the crew with a thoroughly crippled airplane that they landed safely.

Captain Sullenberger had his copilot and the A380 crew had two check airmen on the flight with them.

Even airline crews can lose the ability to think. The Air France A330 that crashed in the Atlantic did so after the crew stalled it at 38,000 feet and never recognized that it was stalled during the long drop to the surface of the ocean. For more on this, look at Air France 447 on Wikipedia.

When general aviation pilots have a brain freeze they are most often alone. We have to catch it all by ourself.

There are many cases on record where you can see that the pilot lost it. Some of these are related to mechanical problems, some to confusion and some to weather issues.

I lost a good friend to an apparent mechanical problem. He was a well-trained and experienced pilot making a long night flight in a Cessna 340. He was at Flight Level 210, in and out of the cloud tops, when a controller informed him of an altitude deviation.  He replied that he had a gyro failure. Control of the airplane was lost and the airplane entered a spiral dive and reached the ground in less than a minute.

The NTSB did not find a reason for the loss of control other than spatial disorientation on the part of the pilot.

Whatever happened, it was enough to confuse this pilot enough that he lost control. All of his friends speculated on possible causes but there was never a consensus.

There is plenty of confusion potential in autopilots and avionics systems. That is why it is so important to understand the systems and make peace with them in good conditions before using them in poor weather.

I have read numerous accident reports where it was obvious that the pilot got so far behind things that he lost the ability to think and to plan. At times pilots will confess to a controller that they are confused but more often than not the clue comes from the flight path and altitude of the airplane. Being temporarily misplaced is a different matter than being hopelessly lost. The former has more potential for solution than the latter.

In bad weather, I think that more airplanes are lost because while the pilot retained the ability to think, he lost the ability to reason, with the airplane transitioning from the air to the ground in an unsuitable location.  Going below published minimums without good visual contact and scud running come to mind along with continued flight into icing conditions.

An area where thinking, and thinking about the right thing, is critical is flight in bad turbulence, whether in or away from a thunderstorm.

When a pilot flies into a thunderstorm the question that comes to my mind is, “What was he thinking?”

Thunderstorm cloud

Stumbling into one of these monsters requires calm and focus to make it out the other side.

Pilots don’t intentionally penetrate thunderstorm cells in light airplanes so one who winds up in that bad place was apparently thinking he could miss the storm.

In the storm, there are two huge distractions. The turbulence is almost unbelievable and the noise from the rain is substantial.

The pilot has to concentrate on keeping the wings level with the power set to yield maneuvering speed at a level flight pitch attitude. The altitude cannot remain constant. The airplane has to be allowed to ride with the currents.

You also have to ignore the noise from the rain and resist the temptation to look at the windshield which seems the source of the noise as well as the most visible sign that you are playing submarine with your airplane. The flight instruments require 100-percent attention.

I know from experience that this is difficult to do and I suspect that some airplanes are lost to storms because the pilot panicked, turned into a passenger, and the airplane flew itself outside the flight envelope and the airframe failed because of excessive speed.

It is often pointed out that most accidents are caused by pilot error. That is more or less correct but not in the sense that a pilot made a mistake in handling the airplane. More often than not it is because the pilot failed to manage the airplane properly. Probably half the serious accidents are related to incapacitation or impairment of the pilot’s ability to think.

Is there any way we can teach pilots to avoid this?

Richard Collins
62 replies
  1. Carlos Brand
    Carlos Brand says:

    Great article,I’m only a student pilot with barely 24 hours under my belt but this is one of the things I think about the most becoming incapacitated while flying.

    • Dick Collins
      Dick Collins says:

      Carbon monoxide can certainly cause incapacitation but in the relatively rare accidents caused by this it is included in the probable cause. Hypoxia is more frequently involved but is also generally included in the probable cause. Thus the accidents related to these items don’t fall into the “undetermined” category.

      • Lawrence Zingesser, M.D.
        Lawrence Zingesser, M.D. says:

        I don’t think that we know that accidents caused by CO
        poisoning are rare. If the carboxyhemoglobin at autopsy is high (90%, for example) then we know. However individual variation in susceptibility exists. Furthermore smokers may have up to 9% to begin with.
        Anything above say 9% may or may or may not be important.
        In the case of hypoxia individual susceptibility also varies considerably. Older people are certainly more susceptible. I think it’s difficult or impossible to say that hypoxia did not play a role in some significant proportion of fatal accidents.

        • David Jack Kenny
          David Jack Kenny says:

          Fair enough. I think it’s also fair to say that accidents KNOWN to be caused by carbon monoxide poisoning or hypoxia remain rare — usually no more than two or three a year.

          That certainly doesn’t mean that they haven’t played roles in a larger number of fatal accidents; on the other hand, there’s no conclusive proof that they have.

          — DJK

          • Lawrence Zingesser, M.D.
            Lawrence Zingesser, M.D. says:

            Next to gastrointestinal problems exposure to fumes and CO are the largest percentage of non-fatal pilot incapacitation reports (in the reference I cited).
            It’s no big jump to assume that these play a significant role in fatal accidents.
            But going back to the starting point we are discussing unexplained fatal accidents. That means no there is no proof of the cause. My guess is that multiple causes are usually involved. Most of the theories in this thread are conjectures based on anecdotes…not conclusive proof.

    • Nico van Niekerk
      Nico van Niekerk says:

      I just received an email from author “RNC” which I couldn’t find in the list of comments here. However, RNC recalled an incident that happened in the early 70s in which he overnighted in a rescue squad building and only an alarm that went off prematurely saved them from CO2 poisoning. They only discovered how close they came to being a fatality much later.

      That reminded me of a VFR night flight from Gaberone in Botswana to Johannesburg many years ago. I was at 9,500′ and ATC asked me what my intentions were seeing that I was steering a heading about 30 deg off the cleared course. The only Nav Aid was an ADF, so keeping the needle on the nose didn’t alert me to anything.

      I double-checked the heading and confirmed to ATC that I was on the correct heading as cleared upon which they suggested that I have the compass checked the next day.

      The compass swing revealed nothing wrong and the snag was cleared. This incident nagged me all this time.

      Not too long ago I saw a video which induced hypoxia in a test chamber (which can be seen on http://www.facebook.com/commanderflight and scroll to Feb 14 or watch it directly on youtube at https://www.youtube.com/watch?v=WTNX6mr753w) to study its affects. It dawned on me, about 40 years after that flight, that I probably suffered from hypoxia and couldn’t properly interpret a simple compass heading.

      It is, indeed, a silent killer and during a cold night flight where the oxygen levels are lower, one should use oxygen from perhaps as low as 8,000′.


  2. Will EIfert
    Will EIfert says:

    As a student pilot, what is most frightening to me about these thoughts are that one would assume that in a serious situation that any pilot would hunker down, understand the risks and take the proper action. Yet if it is possible for experienced pilots to fall victim to becoming “frozen,” it seems very daunting as a student to prepare for these situations.

    • Thomas
      Thomas says:

      I agree, seeing that 3 experienced pilots flying Air France 447 couldn’t recognize a stall, you’re shocked and you say to to yourself “That won’t ever happen to me”, but they were experienced airline pilots! Creepy.

      • R Watters
        R Watters says:

        Few accidents are caused by a lack of system knowledge. This was one. The least experienced pilot was in control of the plane and the other two failed to realize this. As a professional pilot I wouldn’t classify the junior FO as experienced.

  3. Meredith
    Meredith says:

    One thing that might help is understanding the importance of confessing (to ATC if single piloted) when you get in over your head, get confused or disoriented, etc. Plus, coming from a military background, we are continually required to perform various risk assessments, including self assessments on stress, medical factors, etc. GA could benefit from making similar procedures a routine part of flight planning.

  4. Sean
    Sean says:

    A good friend of mine has a battle with his AME every year come medical time. I ask him what he’s going to do when the time comes that the good doctor doesn’t give him his medical. He says he’d fly anyway. I believe he would.

  5. Steve Phoenix
    Steve Phoenix says:

    I’ve known some pilots through the years that shouldn’t have lasted; flying drunk, IMC in ice not on a flight plan, not rated, etc. But they lived to die of old age. What seemed to separate them from other, fully compliant pilots, was their high native intelligence and lack of fear in a given situation. They never quit flying the airplane and were always able to think through a bad situation and act to recover.

    I compare those guys to accident pilots that, for example, dive an airplane to the ground while trying to recover airspeed from a frozen pitot tube and wonder if there isn’t something to be learned. Can’t do much about basic intelligence although I think most have enough of that, but I think the fear factor could be greatly reduced with increased emphasis on simulators. Fear emanates from the unknown and if one has seen it before it is much less fearful. Simulating difficult conditions (ice, t’storms, fire etc) accurately could help a lot. The airlines have been doing that for a long time with good success. Although nobody likes mandating stuff, maybe that’s what needs to be done.

  6. Brad Johnson
    Brad Johnson says:

    Great article! Having flown with my wife to varios locations, for various reasons, I’ve had those flights that, when you land and reach the hotel, you instantly dose off. Thanksfully, my wife attends a fair amount of FAAST seminars with me, and knows that I am safe in my decision making, so, an unscheduled stop for a quick nap or recharge is met with respect for a good decision made! For those who are flying with non-pilot passengers, take the time to explain your decision making process. They will appreciate it.
    Lastly, are there any locations in the midwest for flight into Convective Conditions practice? I would rather have a little experience in a sim prior to flying into an area of bad air, then have it be my first experience in the air.

  7. M. Light
    M. Light says:

    Interesting piece-but having been flying for many years I still don’t believe there actually is a single answer. I am a 2nd generation flight instructor. I was taught from my teens by my father that you have to know your own limitation and the limitations of the aircraft. My father always said most accident scenarios start before you ever get to the airport (e.g. a dear friend of his who was also a 20,000+hr. pilot took his own classic biplane out when he had a head cold and was loaded up on cold medication). You can guess the outcome of that.

    Another factor in my life time pilots have become way too dependent on electronics (practically addicted) and have failed to fly the airplane first. I have a classic Cub which I do not take out in windy conditions-not because I don’t know how but my own limitations have changed over the years and small light taildraggers can get very tricky in that situation.

    I could go on and on – but it’s not just one answer and a lot of it is
    mental-not physical.

  8. John Townsley
    John Townsley says:

    “I think that more airplanes are lost because while the pilot retained the ability to think, he lost the ability to reason”

    Dick, In this snippet from one of your sentences I believe you captured the essence of the problem.

    Not mentioned in your article are organic reasons why a person cannot reason. A quick search of the NTSB db reveals an increasing (still small, but growing!) number of pilots involved in fatal accidents who had Alzheimers or other dementia issuess. Tragically, several of those accidents involved passengers or other pilots who they had along for the ride. There is ample research that a large majority of drivers are unable to ‘self certify’ as fit to drive. Obviously, an individual with dementia is incapable of assessing their condition, using reasoning to determine the risks are unacceptable, and hanging up the key. If drivers are unlikely to refrain from taking to the road when unfit, why should we fantacize that pilots will ground themselves?

  9. Mort Mason
    Mort Mason says:

    Much of wintertime Alaska flying is done with all vents closed and full cabin heat. I made it a habit to install hard-wired CO detectors in all my airplnes exxcept for the Super Cubs, which are usually breezy enough inside.

  10. Steve in New Orleans
    Steve in New Orleans says:

    Good article, and good insight by Steve in Phoenix.

    Also, I always thought ‘stoned’ only meant intoxication by cannabis.

  11. paul cullman
    paul cullman says:

    Many years ago while flying ag. I partied quite late and with only a few hours sleep went to work. After flying one field I returned to base and parked the aircraft as my coordination was missing!

  12. Mort Mason
    Mort Mason says:

    Hey Paul – – – looking back on it, I suppose you’d have parked the plane before the first flight of the day. At any rate, wise choice. Glad to see you’re still alive and well.

  13. Warren Smith
    Warren Smith says:

    The CO factor is very real and hideous… no odor! I agree with Dr. Zingesser and the others on this. It has long been a phantom killer on the highways where people drive hour after hour with a relative head or tail wind and the other traffic CO builds in their bodies to the point of stupid incapacitation. CO builds in the blood and takes a long time to leave. It can accumulate over days to the point of toxic death or incapacitation.
    Having worked as an A & P in addition to my years of flying I have seen exhaust system failures that were scary. I do not believe CO is a factor considered in autopsies, as it usually isn’t in the case of highway accidents.

  14. Dave Oberg
    Dave Oberg says:

    Great article, Dick! I especially appreciated your comments about fatigue and its contribution to pilot incapacitation. In years past it was common practice in Alaska air taxi operations for pilots to work to the maximums of the flight/duty time regs (ie. 14 hour duty days, 8 flight hours/day) for weeks on end in the summer. Because our busy season spanned the months of mid-May to mid-September, and the way the FAA regs for Part 135 duty and flight times are written, it was entirely possible and legal for a pilot to fly the entire summer without a real day off. All he had to do was have the requisite 13 days off in the quarter and not exceed the maximum quarterly flight hours (500). Consequently, I can remember many summers when, by the middle of July, most of the crew were probably not hitting on all cylinders.

    I always thought it was a setup for disaster, and took every opportunity I could grab for a day, or even half a day, off. Many of my colleagues, however, had to make that summer pay stretch over the slim times of the winter, so felt obligated to take advantage of every opportunity to fly.

    I have to chuckle at the FAA’s most recent changes to the Part 121 duty time regs. I know many Part 135 pilots who would love to change places with those big iron drivers in terms of rest time. Don’t get me wrong – I think the changes were a step in the right direction, a very tiny step. Those changes did not really solve the problem – only a drastic change in the way regional airlines pay their crews will do that – but it does make the FAA and the public feel better.

    The bottom line is that conscientious pilots have to truthfully assess their own fitness for flight every time they get in the cockpit. No one knows just how I feel except me.

  15. Ronald Usher
    Ronald Usher says:

    Great insight into “what you only learn by experience” preferably with a second that knows the ropes, aircraft can be like galloping horses, take you mind off what you should be doing and the horse (aircraft) gets the bit between it’s teeth, and you can’t get back control. So you must be alert all the time, I had an eagle dive bomb me at 3000 ft thought initially it was a cloud ? the PA28 would have taken on a different attitude had we connected, especially when I was in heavy mountainous country.
    At 68 I started taking Pharmacuetical grade nutrition (with no band substances) so olympic athletes can use, and more than 600 do, many in the USA and Canada, also here in Australia,so at now 78 I can think / reason / and all body systems normal, including angiogram, I can fly with confidence. If anyone would like me to send them information then forward me an email.

  16. Alan Moore
    Alan Moore says:

    I think brain disorders don’t get enough consideration. I knew very well a pilot for a major airline who self grounded during the tour. This pilot recognized “being behind the aircraft” at a extreme level. While never in a clinical setting, this pilot exhibited the criteria for Borderline personality disorder [search Brandon Marshall BPD] possibly comorbid with PTSD. Depression and stress can also play a part in dis-associative behaviors. If you aren’t really there, then who can fly the aircraft? “Brain disorders” of the above listed types can usually be treated without medications. Bottom line, regardless if you are driving your car or flying an aircraft, if you notice you are behind the aircraft[car] its time to act as brave as the pilot in this post and self ground. Then toss out any stigma’s and seek some care for the brain

  17. Don Rieser
    Don Rieser says:

    Unfortunately, as several folks have mentioned above, self assessment is not reliable. Many conditions affect our ability to self certify. In this age of electronics and self help programs, it would be invaluable to have a short program that would assess cognitive and motor skills against our own performance history. We could take this test as part of our preflight to insure we are in as flight ready a condition as our aircraft.

  18. bill bedell
    bill bedell says:

    Actually, I did a double-take on the Sullenberger crew in a 380 too, but saw that Richard was correct. I too had misread the correct sentence. “Pilot complacency” mixed with some “expected outcome,” in my case I suppose.

    I never noticed that Qantas has no “U” in it. I had a chemistry teacher once congratulate an entire lecture hall of 300+ college students on their discovery of a new element on the last exam. He went on to describe the new element, “flowereen,” mentioned by 98% of the test-takers. Turns out that the element Fluorine, as in fluorecent lighting, with its unusual “uo” spelling, goes un-noticed for years too. Those of us who answered the test question “flourine” received zero credit, btw.

  19. David Jack Kenny
    David Jack Kenny says:

    There’s no question that fatigue, hangovers, and other forms of impairment pose a significant (and avoidable) hazard to flight. However, there’s also an important distinction between accidents demonstrably CAUSED by pilot incapacitation, whether medical, chemical, or hypoxic, and accidents in which the pilot’s ability to respond to an unexpected development might have been diminished by prescription or over-the-counter drugs, hunger, sleep deprivation, etc.

    For the Nall Report, the Air Safety Institute classifies each accident in exactly one category defined by the most crucial link in the accident chain. We base that assignment on our own independent review of the factual record; while it often agrees with the NTSB’s findings of probable cause, this is not required. If a pilot who’s short on sleep runs a tank dry, then can’t get the engine restarted before he reaches the ground, we’d count it under fuel mismanagement even though fatigue probably did contribute.

    As noted in the article, accidents known to have been caused by pilot incapacitation, whether medical or chemical, are consistently rare. Incapacitation probably also figures into some of the accidents that were never satisfactorily explained, but since we don’t know which ones we have no way to count them. ASI certainly agrees with the larger point that pilot impairment short of incapacitation can be the difference between successfully managing an emergency and adding another record to the accident database.

    However, the suggestion that ASI deliberately whitewashes inconvenient results betrays a lack of familiarity with our offerings. We are brutally honest with our readers because that offers the best chance to save the lives of fellow pilots and their passengers. Our recent No Greater Burden (http://www.aopa.org/asf/video/no-greater-burden.html) and 178 Seconds to Live (http://www.aopa.org/asf/psa/178seconds.html) videos are good examples, as are Accident Case Studies such as VFR Into IMC (http://flash.aopa.org/asf/acs_vfrimc/) and Airframe Icing (http://flash.aopa.org/asf/acs_airframe_icing/).

    The Nall Report represents the best efforts of a disciplined professional team to make sense of complex data that can often be interpreted in more than one way.

    — David Jack Kenny
    Manager, Aviation Safety Analysis
    Air Safety Institute

    • Dick Collins
      Dick Collins says:

      Thanks for your comments, David. I made it abundantly clear that the examples used happened some years ago and were factual. If you think the opinion I shared with our readers applies to your organization today, and requires you to be defensive, then so be it. The Nall Report remains flawed because it is based on preliminary information, especially in the case of fatal accidents. I hadn’t looked at it in quite a while but refreshed myself this morning and was glad to see that you now acknowledge where mistakes were made because of using preliminary reports.

      • David Jack Kenny
        David Jack Kenny says:

        Thanks. Because it has been taking the NTSB longer to resolve fatal accidents the past few years, we’ve revised our criteria and now do not begin carrying out the analysis until probable cause has been determined for at least 70% of that year’s fatal accidents.

        70% is still a lower threshold than I would ideally want, but there’s an inherent tension between completeness and timeliness. This seems to represent a somewhat reasonable compromise between those competing objectives.

        — DJK

  20. Bill
    Bill says:

    Just a few thoughts. In regards to incapacitation, many of the older population develop anemia from silent gi bleeds(non steroidal inflammatory agents) which makes one more susceptible to CO and hypoxia as well as G tolerances. Stuff also happens. Imagine if Sullenberger, et al would not of had those ferry boat captains rescuing all the passengers, none of whom had taken their life preservers from the cabin before it had sunk. Great landing but there was still work to do.

  21. Mort Mason
    Mort Mason says:

    But wouldn’t hypoxia disappear with a decrease in altitude? Certainly CO poisoning would, unless there were no opportunity for the afflicted to breath a more oxygen enriched atmosphere, as in having expired before breathing heavier air.

    • Lawrence Zingesser, M.D.
      Lawrence Zingesser, M.D. says:

      One pressumes that the hypoxia at altitude would be one link in the chain that led to the fatal accident.
      With regards to CO poisoning, CO has an affinity for hemoglobin that is 200 times greater than Oxygen.

      • Mort Mason
        Mort Mason says:

        Yes, of course, Dr. Zingesser, but isn’t my point still valid? If a pilot entered hypoxia at, say, 16,000-feet, however unlikely at that altitude, and his airplane fell off into a 2,000-fpm descent, he’d be entering ever oxygen-richer air for eight minutes!!! The same is true for CO poisoning. So, my questions remain. Wouldnn’t these manistations disappear within that time envelope? My point is that those effects might well be missing at autopsy, leaving the cause undetected. Just asking.

        • Lawrence Zingesser, M.D.
          Lawrence Zingesser, M.D. says:

          You are correct about hypoxia, which fact is not likely to be established at autopsy.
          However CO is tightly held to hemoglobin and there is a good chance that a suspicion or even proof that CO poisoning is present if chromatography or spectrophotometric tests are involved in the autopsy.
          Let me emphasize again that there is much individual variation in the effects of both anoxia and CO poisoning.

    • RNC
      RNC says:

      I once while sleeping at the rescue squad building, got a severe case of CO2 poisoning. We responded to an alarm at 0530 a.m. with pounding headaches; we were not aware of the cause. At 1300 that same day my vision was still not ‘stable’ and my headache was still throbbing. We found out that a new heat system had been installed incorrectly the day before… This was in the early 70s and it was only in hindsight that we determined the cause. If we had not had that alarm, the day shift would have found two fatalities.

  22. Bill Gerhard
    Bill Gerhard says:

    In this context: why are age of the PIC and existing medical conditions never mentioned in the accident reports? Are these data considered ‘private’, even though the accident occurs in the ‘public domaine’ and endangers people on the ground? Is SOMEBODY analyzing these?

  23. Eric Woods
    Eric Woods says:

    A good way of characterizing pilot error based on not doing something to keep control of the airplane vs. doing something wrong is:

    errors of OMMISSION vs. errors of COMMISSION.

  24. Richard F. Cooper, M.D
    Richard F. Cooper, M.D says:

    Dr. Z’s comment indeed indicates the extremely slow elimination of CO, and often requires hyperbaric O2 therapy (Always desirable if available)
    There is also a Wings course on fatigue which is very instructive.

  25. s mtz fallad
    s mtz fallad says:

    A los aviones no hay que tenerles miedo pero si mucho respeto en el momento que se les pierde el respeto vienen los incidentes o accidentes.

  26. Mort Mason
    Mort Mason says:

    I don’t mean to be a pest here, but aren’t pilots required to speak and to understand the English language? Or, if s mtz falld is not a pilot, may I question his expertise in such matters as this one?

  27. Jim Frankenfield
    Jim Frankenfield says:

    Back in the late 50’s a Tri Pacer took off from ABE heading NE toward the Hudson with four souls on board (I knew two of ’em), cold winter day. Plane crashed with no prior radio contact. All four perished and the autopsy found CO 1 poisoning.

    My wife (gone west last year) received a ‘verbal’ check-out in a Mooney Mite from the owner of the FBO at ABE, again late 50’s, and she told me she began to get sick in a hurry and high-tailed for the airport. Upon landing the ‘litnus paper’ stuck to the panel showed the telltale discoloration. She was lucky that day. Old Jim

  28. Nico van Niekerk
    Nico van Niekerk says:

    It was interesting to read about Dick’s observation to “keep the wings level” when a pilot ventures into a thunderstorm. Not wanting to disagree with the author, about 40 years ago I did venture into a squall line trying to get to the other side in a single Comanche. I was alone in the plane, which removed some of the “be responsible” criteria.
    One thing that I always questioned was the rough air maneuvering speed placarded on the instrument panel. It seemed much too fast in situations where the air would be downright hostile, let alone rough. Especially since rough air could have some CAT that could subject the airframe to a serious jolt rivaling the stuff that one finds in a thunderstorm.
    So, before steering the Comanche into the soft belly of the beast I secured all loose objects and set it up at a gut-instinct-speed of about stall-speed plus 20kts. I pegged it at 80 knots believing a stall would be much preferable to chase than a wing going past the windscreen.
    All hell broke loose almost the instant the Comanche disappeared from VFR flight. The VSI would peg at over 6,000 fpm up while I had the nose down at such an angle that I was seriously concerned what would happen when I hit the downdraft again. But the change in vertical air movement just caused the Comanche to flutter, indicating zero airspeed, ending up in a nose up attitude with full power going down again at 6,000 fpm, always keeping the speed around 80 kts. Nothing is exact at this point, trust me.
    The wings were level only on occasions where the violent rolls passed them through the level attitude but there always was a mushy feel to the buffeting and control pressures, which I thought was a good sign; the airframe cannot break when it mushes through turbulence.
    The entire ordeal lasted perhaps 15 minutes or so when Charlie Bravo had enough of my games, realizing he’s not going to have a meal that day, and spat me out at about 11,000′ in the smoothest, silkiest air imaginable — still on the wrong side of the squall line.
    I’ll never know (thankfully) if a thunderstorm could actually spike the plane against the ground in one of these violent downdrafts, or keep the elevator going up until one passes out. If the hammer-head could reach almost into the stratosphere, I guess that is possible. The cause of the accident would be cited as loss of control, I would imagine.
    A couple of years later I inadvertently got sucked up into a thunderstorm while flying in the blackest of nights below cloud (supposedly), in West Africa, where there is NO light at night below an overcast.
    I instantly recognized the Seneca II’s unannounced vertical acceleration as thunderstorm activity, solely because of my experience with the Comanche, and within milliseconds I had the throttles closed and brought the airspeed to under 100 kts and started to ride the bronco.
    My sole passenger kissed the ground Pope-like at our destination swearing on whatever he could find that he would never leave the ground again. (I never knew so much dust could be in a plane’s carpets.)
    I believe it would be very helpful, if it could consistently be done safely, that thunderstorm penetration and flying training should be on all pilots’ curriculum, even if it’s just to make them aware of their mean demeanor.
    I also believe that the rough air maneuvering speed placarded on the instrument panel is a legal statement, not an aeronautical one.
    Nico van Niekerk

  29. Mort Mason
    Mort Mason says:

    The maneuvering airspeed found on that placard, and in the POH, isn’t a legal statement, really, though there is a “safety factor” built into it. The maneuvering speed is an engineer-designed airspeed that allows the wings to momentarily stall before loads exceed the plane’s ability to withstand excessively heavy wing loading and the resuslting structural failure. Handling airspeeds much below maneuvering speeds while in heavy turbulence may lead to a stalled condition that becomes very difficult to overcome, especially while on the gauges if a heavy wing should work to produce a spin.

    • Nico van Niekerk
      Nico van Niekerk says:

      Of course, Mort, you are right. I made the statement more flippantly than scientifically, because many folks landed before their wings did after flying in thunderstorms. At the placarded rough air maneuvering speed a turbulence jolt can still deliver quite a blow to the airframe and when that is repeatedly followed up by another one in the opposite direction, it becomes evident that the term “rough air” on the placard has absolutely no reference to the airframe in a thunderstorm.
      I found dealing with a constant incipient spin, recovering just to fall into another one, while on instruments, still more acceptable than wondering what the hell was that flying by.
      On the point of spins in a thunderstorm. I don’t know, I’m just asking. While fighting violent turbulence and vicious up- and downdrafts, I never had a spin develop beyond a half-a-turn before it was blown off the wings, so to speak. I am sure that what I perceived as incipient spins may never have been spins at all and what I believed to be just hell-at-large might have been spins. I never gave that any serious afterthought, you know.
      Thanks for the response.

  30. Jim Frankenfield
    Jim Frankenfield says:

    Hi Mort, Nico, guys and gals… It’s old Jim again, typing one-handed still, with a tale of a flt. in “Henry the mortician’s” Chero. 6 IFR PHL to Bluefield, W VA, back in the late 60s, to deliver human remains (no casket today, just a body bag). Henry, pvt pilot, working toward his instrument ticket was left seat, me working the radio, ‘passenger’ behind me.

    Center advised “Cherokee —–, beginning 20 miles your 12 o’clock and continuing to destination, a line of thunderstorms, what are your intentions? I asked if he could ‘jog’ us east of the line and turn us west through a ‘soft spot’ in the line. He agreed and did give us the anticipated turn to parallel the line and later, the turn to the west for penetrstion. Heavy rain, no lightening, moderate turbulance…then the updraft began. We were assigned 7K but vertical speed UP, was 5K/min. At idle power, now at 7,800 I inquired if there was anybody else in the vacinity and got a negative to that, and he asked us to give him a call when we reached 7K. Five minutes later he called us and asked if we were near 7000. Nope, 7,800, still at idle power, holding V-A. He asked for a call at 7K, which we ‘finally’ did, happy that they were “updrafts” and not “downdrafts”!

    The VOR appr. went well and we met the local mortician on the ramp to exchange body bags. Not a peep out of our ‘passenger’ the entire trip. I handled the “feet’ end, and, yes, they are ‘stiff’! Flt. home was much better, although this flt. took some of the ‘glammor’ away from the vocation.

    CAVU and tailwinds to all. Jim PS, Many thanks to the Patriots throughout our history, who gave their blood and fortune to give us a Free Nation, and personal freedom. Let us not ‘give’ it away. Freedom is not ‘free’. Amen

  31. Mort Mason
    Mort Mason says:

    ONce made a night flight with a friend’s body in a C-180 from ILI to ANC in Alaska. Dead of winter, too. No body bag, just laid out to freeze flat after crashing his C-180 with a load of dynamite at Big Mountain, near Lake Iliamna. His Cessna hadn’t exploded, of course, since the caps were not aboard. 6′-4″ and 245-lbs, he was laid out in order to freeze flat. Placed his head on the battery and secured him to the seat rails. I was concerned about his possibly thawing out in the 2.5-hour flight, so flew without heat and with the windows and ventilators open. No turbulence, but thought I might freeze, too, which I suppose could be considered as a “silent killer” of sorts . . . . .

    • Jim Frankenfield
      Jim Frankenfield says:

      Mort: Good morning: If that tidbit above is any indication of the content of your book, I’m more anxious for it’s arrival now than before. Ole’ Jim.

      • Jim Frankenfield
        Jim Frankenfield says:

        Mort…..I spent a year at Sondrestrom Fjord, (BW-8, 1953-54, army) Greenland so I have had ‘some’ experience in cold climates.(picture outdoor toilet shack..no heat). Walked 2 miles to Air Force KP one morning…40 below , (F and C, where they both aggree.) Sargeant cautioned “don’t run”. (freeze the lungs!) Jim

    • Ronald Usher
      Ronald Usher says:

      Is this what is called “having a dead stick”???? (No disrespect to the passed person)

  32. Mort Mason
    Mort Mason says:

    I remember passing through Whitehorse, YT, on my way south in November of 1985. After fifteen minutes of installing wing, tail, and engine covers, and plugging in the heaters, I was colder than I had ever been after 35-years of the Alaska bush. When I asked the weather guy how cold it really was, he looked at the anemometer, the thermometer, and then ran his fingers down a wind chill chart. His reply? Minus 155-degrees Fahrenheit… Chilly by any standard.

    • Jim Frankenfield
      Jim Frankenfield says:

      Mort…that sounds like the dark side of the moon. HAPPY MEMORIAL DAY EVERYBODY. Ole’ Jim

  33. Jim Frankenfield
    Jim Frankenfield says:

    In the mid 50s a GI Bill student at our little pea-patch of an airport, Larry S., got his comm. cert.; then we lost track of him….until, a piece of mail crossed my desk, from “Weather Engineers”, Inc., Hondruras, …Larry had listed ‘us’ in his resume’, and of course, I responded with a glowing report…and he got the job….’busting up’ the growing CBs with T-6s and T-28s, and the silver-iodide burners. He said it was mostly recovery from unusual attitudes and ‘ducking’ in the cockpit from the hail. The company started each season with a dollar in the ‘kitty’ for each healthy banana tree, and the plantation owner deducted a buck for each tree blown down or otherwise destroyed by the storms. Boss sat in front of the radar scope and when the time was ripe, he’d say “go get ’em”.

    Didn’t hear from Larry for a few years ’till another letter came, from Alaska, might have been Wren, not sure, but he got that job, too, co-pilot on DC 3 I think, later bought his own C-180. Then, one day he came buzzing out of the blue, in his 180,…I was driving the Jeep cuttin grass on our E-W runway, and he buzzed me so close, his rt. wing clipped the rag top of the jeep. No damage, but he was still a wild and crazy guy. Turns out he got caught in IMC, got on top at 15K, ATC vectored him over the ocean for the letdown…broke out at 200 ft. His boss said “you’ll have to go back to the states, get your instrument ticket” and you’ve got your job back. And this he did. Wonder if he’s still around! ole’ Jim

  34. Mort Mason
    Mort Mason says:

    I have to wonder if he might somehow have developed some good sense to go along with his spparent skills and confidence somewhere along the way? His high-wing C-180 had to be pretty close to the groiund to clip the canopy on a golf cart.

    Sort of odd that he could get the second seat on a DC-3 without the instrument rating . . .

    • Jim Frankenfield
      Jim Frankenfield says:

      Mort: I was driving the jeep (not ‘golf cart’) and his wheels were nearly on the deck. I could be wrong re/ co-pilot on the gooney bird. (fuzzy memory..53 yrs ago.) Two more days and I get my book “Alaska Chronicles”…That’ll keep me out of trouble for a couple of days!. Jim

      • Mort Mason
        Mort Mason says:

        Hope you enjoy the book, Jim. I assure you that the typos were the fault of the editing staff. The manuscript didn’t get to them in that casual shape!

  35. Jim Frankenfield
    Jim Frankenfield says:

    I sure did enjoy the book, Mort, as I left “glowing” comments on it at the bottom of the “still runing out of gas” thread. I left the book for LeRoy Rorgen to read after he gets back from his summer as a licensed Alaska Hunting Guide, then It’ll go to the EAA Chapter 1288 library. Best wishes, Jim

    LEN PAGGI says:

    A truly excellent documentary.As a 13500 hour general aviation pilot in West Australia, where in places terrain are difficult to identify and prior to GPS, navigation was purely look and see, single pilot operations at times pushed junior pilots to the limits of their capabilities.Flying in IFR weather should never be attempted unless the pilot is fully qualified, current and familiar with the type of aircrat he is to fly.
    We often witness pilots with low hours, long time since last flight, fly into disastous weather conditions.Flying into IMC without autopilot for a long period, is demanding even to an experienced pilot and we should be fully aware of the possible danger

  37. Mort Mason
    Mort Mason says:

    I can’t argue with that. If you are involved with outback flying, and do it on a daily basis, you are probably safe on the knife edge of performance. Both yours and that of the plane. But if you fly ten hours a week minimum, and much of that in marginal weather, and then lay off for one week, you will find your sharp edge of performance has slipped. Lay off for one month, and you’re back to a level that should tell you to avoid scud running and other marginal VFR flight.

    The same is true for instrument flight. A relatively short layoff can quickly put you behind the power curve. A wise pilot will engage his brain before he puts his flying skills to the test.

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