Hypoxia on Kalitta 66

26 Sep 14 21 Comments

This video is making the rounds again and it chills me as much to listen to it now as it did the first time I heard it.

The video features actual audio from Air Traffic Control dealing with a hypoxic pilot. Here are the details of what happened.

Kalitta flight KFS-66 was a cargo flight flying from Manassas, Virginia to Ypsilanti Airport, Michigan.

Kalitta Air is a cargo airline headquartered in Ypsilanti. Conrad Kalitta started carrying car parts in his twin-engine Cessna 310 in 1967. His business, originally called American International Airways. Kalitta retired in 1997 but in 2000, the company ceased operations and Kalitta came out of retirement to rescue it. He called the new airline Kalitta Air. In 2007 Kalitta received the FAA’s Diamond Award – the highest honor for maintenance training. Kalitta Air is still owned by Conrad Kalitta.

Kalitta flight KFS-66 departed Manassas normally and was en-route flying at FL320: 32,000 feet over the sea. The flight crew had just been handed off to Cleveland’s Air Route Traffic Control Center when air traffic controller Jay McCombs noticed that the aircraft had a “stuck mike” – that is, the Push-to-talk microphone was being pressed , keeping the transmission open.

What was actually happening was that the First Officer was already unconscious and his arm was flailing violently and uncontrollably, disengaging the autopilot and forcing the Captain was trying to hand-fly the aircraft. The air traffic controller can’t understand the Captain and a second pilot in a different plane helps to get the message across.

This transcript is from the National Air Traffic Controllers Association.

Controller Jay McCombs: Kalitta sixty six how do you hear?
Captain: Kalitta six six … (unintelligible)
McCombs: Kalitta sixty six roger. You’re keying your mike and it’s staying on there frequently so please be careful.
Captain: Kalitta six six, declaring emergency.
Second Pilot (in another aircraft): Sir, he’s declaring an emergency with his flight controls.
Captain: Affirmative!
Second Pilot: Yes, sir, he said affirmative on that.
McCombs: All right Kalitta sixty six, roger. What are your intentions?
Captain: Request vectors Ypsilanti.
Second Pilot: Sir, he’s looking for vectors.
McCombs: Alright, Kalitta sixty six, I understand an emergency, you want a vector to
Cincinnati. Is that correct?
Captain: Negative. Vectors Ypsilanti.
Second Pilot: Ypsilanti.
McCombs: Ah, Kalitta sixty six are you able to maintain altitude. What assistance can I give you other than that vector?
Captain: Unable to control altitude. Unable to control airspeed. Unable to control heading. Kalitta six six. Other than that, everything A-OK.
McCombs: OK, Kalitta sixty six understand you’re not able to control the aircraft. Is that correct?
Captain: That is correct.
McCombs: Kalitta sixty six are you able to land at an airport that is closer to your position? Pittsburgh approximately five zero miles southwest of your position, Cleveland about eight zero miles northwest of your position.
Captain: Prefer to land aircraft at destination airport as the aircraft is (unintelligible). No possible damage to any part of the aircraft (unintelligible). So we’re slowly, ever so slowly, regaining control the airspeed and the aircraft if we are given the time to slowly reengage.

Meanwhile, fellow controller Stephanie Bevins tunes into the frequency so she can hear the pilot. She concludes that he must be suffering from hypoxia. Hypoxia is where effectively your body is starved of oxygen. The onset of hypoxia is often masked by the euphoria – you have a general sense of well-being and can be apathetic to the fact that something has gone wrong. You will feel confused and disoriented. Your time of useful consciousness is limited – the time in which you remain capable of making sensible decisions and correcting the issue.

Bevins knows that they need to get the aircraft down from FL32 to a level where the oxygen is sufficient for the pilots, and quickly before the Captain loses consciousness. At this stage, the Captain appears to only be able to respond to direct commands. McCombs tells Kalitta to descend.

McCombs: Kalitta sixty six if able descend and maintain flight level two six zero.
Captain: Descending now to flight level two six zero, Kalitta six six.
McCombs: Ah, Kalitta sixty six, are you still requesting a vector for Ypsilanti?
Captain: Affirmative. We sure are. Got the aircraft back under control.

The Captain couldn’t turn on the autopilot as his First Officer kept switching it off, which probably saved his life. His focus on hand-flying the aircraft kept him conscious through-out; otherwise they almost certainly would have continued on autopilot at 32,000 feet until the aircraft ran out of fuel and fell out of the sky.

As Kalitta 66 descends, the Captain’s voice changes. Slowly, his words become more understandable and his reactions more professional. By 11,000 feet, he and his First Officer have recovered.

McCombs (to someone else inside Cleveland Center) Kalitta sixty six can I vector him to the right? Try and hold on, we think he has hypoxia.
Unidentified voice: All right, to the right is approved.
McCombs: All right thank you.
McCombs: Kalitta sixty six if able fly heading of three three zero.
Captain: Three three zero.
McCombs: Kalitta sixty six, area of precipitation 11 o’clock and one five miles extends approximately three zero miles along the route of flight.
Captain: OK, we see that. Looks like it’s (unintelligible).
First Officer: And roger, at eleven thousand Kalitta sixty six.
McCombs: Kalitta sixty six roger say intentions.
First Officer: And Kalitta sixty six. Destination Ypsilanti.
McCombs: Kalitta sixty six roger. Cleared to Ypsilanti via direct. Maintain one one
Captain: OK … proceed direct Ypsilanti, Kalitta six six.
First Officer: And Kalitta sixty six, the aircraft is stable at this time.
McCombs: Kalitta sixty six roger. Again, maintain one one thousand. You are cleared direct Ypsilanti. Contact Cleveland Center one two zero, point seven seven.
First Officer: Twenty seven seven direct. Yip, Kalitta sixty six.

Stephanie Bevins and Marvin McCombs were awarded the Archie for the Great Lakes region, the National Air Traffic Controllers Association annual safety award.

Great Lakes Region Award Winner

Without Bevins and McCombs, there is no telling what would have happened. Bevins’ diagnosis made all the difference to the fate of the passengers, and without McCombs, the necessary actions to solve the problem would not have been taken to get the aircraft down safely. Various individuals were involved in the assistance of KFS66, clearly stated by McCombs who says that “the entire area (Area 5) worked extremely well as a team.”

I agree with NATCA that this is an amazing story which really shows off air traffic controllers at their best. It’s also well worth a listen for all pilots to remind them just how insidious and deadly hypoxia can be.

Category: Accident Reports,


  • I had forgotten about this incident. It looks certain that without the quick thinking of ATC controllers and other pilots this would not have had the “happy” ending.
    There still is the question about what caused the hypoxia. Yes, lack of oxygen. So to re-phrase: what was the sequence of events that led to this incident ?
    I myself have been involved in two rapid decompressions in a Cessna Citation. The first time we were at FL370, even 5000 ft higher than the Kalitta flight.
    The cause was the sudden failure of the inflatable door seal.
    The second time it happened at FL 390. the new seal had been improperly fitted and blew out – again.
    Our destination was Geneva, Switzerland. We had just been cleared to descend to 7000 ft.
    The previous time we were going to Prestwick, Scotland. We declared an emergency and made a textbook emergency descend. Once we were below FL 150 we told ATC that we wanted to cancel the emergency, everything was under control and we were already entering their airspace. We had enough fuel and decided to continue at FL 110 to our destination.
    But when we landed, the runway was lined with fire fighting engines. They followed us to the parking and surrounded us, nozzles aimed at our airplane.
    This was the scariest part of the incident and so the second time, already cleared to 7000 ft anyway, we decided to make the descent a bit more rapidly than otherwise. This time, we did not declare an emergency. The Air Traffic controllers must have been a bit surprised to see us come down like the proverbial “ton of bricks” but said nothing.
    The new door seal, still intact, was re-attached and the aircraft was serviceable again the next day.
    But what I cannot understand is:
    When the cabin depressurizes to the equivalent of 10.500 feet, a warning, both aural and visual goes off accompanied by a large, bright red master warning.
    It is impossible to ignore. Or so I thought.
    So, did the warnings fail in the Kalitta flight or did the crew not heed them ?

  • Rudy, I would love to know the answer to this. There was no formal report of the incident, unfortunately, so the only information is from the point of view of the ATC handling.

    I saw a comment about a pressure seal failure but I have no idea if the commenter was speaking from a position of knowledge or even if he had the right incident (Kalitta have had two hypoxia events, one is documented on the NTSB site).

  • You know it’s such a good recording for demonstrating Hypoxia, we use it on some of our courses.
    You’re totally right. Listening to the Hypoxic pilot is totally chilling. Your description is 100% correct.
    (Great site by the way!)

    • Sorry that it took me so long to approve your comment; I was out of town but any further ones will go straight through. And thank you!

  • On the question about the warnings going off on such condition, i would assume that if the plane was configured to give a warning, in the absence of a report, the CVR could have confirmed it. It would be very interesting and educational to know what happened in that aspect. In general, you have a CPAM ( Cabin Pressure Acquisition Module) which monitors the INTERNAL pressure of the vessel, and as we know easily translated to altitude, and the rate of climb or descent of this altitude. Curiously. in my experience i worked on aircraft equiped with only one CPAM, no redundancy. Systematically speaking you could easily produce a warning out of a CPAM reading… any cabin altitude over 14000 could set off an alarm, for example. All this said, my advise to pilots is to integrate the press info as a priority on their panel scans, and do it VERY often. It is not the sudden depress that is a problem, is the ones that happen smoothly. The airplane wont warn you of a rate change unless, maybe, is dramatic enough. If you scanned your press info often enough you could identify loss of pressure (O2) and act before hypoxia even starts. This all seems rather redundant or idiotic, but believe me, do not take it for granted. I came up with this though: If you are high enough to be afraid of hypoxia, airspeed monitoring takes second place.


  • I have a science background and frequently work with liquid nitrogen and other cryogens. We have oxygen concentration sensors in the main rooms, as a major spill/leak of LN2 or LHe can quickly displace most of the oxygen, and without the alarm you never know there is a problem ( you just get stupid and then pass out)

    Historically the sensors had limited life (2-3 years) but over the last decade cheap (<$100) sensors have been developed with virtually unlimited life. It surprises me that these kind of alarms aren't commonly used in aircraft.

  • I hear the alarms going off in the first several transmissions, but those pesky alarms were ruining his hypoxic experience. out of muscle memory he probably silenced them “thinking” he knew what the problem was and how to fix it right away. most airplanes are equipped with co2 sensors, but the presurization is a system all to its own. there was probably plenty of warnings, yet at this altitude its like being at the bar allllllllll day. no rational decisions or thought processes exist.

  • Puzzle: How come “hypoxia” was (implicitly) an “obscure” diagnosis, perhaps even “remarkable”?

    The pilot’s sound of extreme drunkenness, nearly unconscious stupor, led me to that immediate conclusion, within a couple/few seconds of the first radio call.

    (I’m no pilot, just an ordinary in-DUHH-vidual with little more flight training than duct tape.)

  • Hi All,
    Wonder why the controller never mentioned to make sure they had their O2 masks done.
    Any more info on this case?

    • What’s DCS?
      The captain of this flight was your father? He sounded very familiar to me, but the person I thought it sounded like has the initials JWG and flew 20-30 series Learjets his whole life. This ends my (false) idea of who the captain was. Glad he was the iron man who was able to get the thing down!

  • In he circumstances the pilot showed remarkable endurance – the fact the the co-pilot was already unconscious really was a sign that the pilot was focusing able to regain full faculties and land. Wondering what if any sensor’s would/should have been in play to detect decompression on an aircraft that can fly at altitude! Seems in some respects to be one of those “accident waiting to happen”.

    • Yes, that type of aircraft has alarms to warn pilots of high cabin altitudes.
      Oxygen masks have to be put on right away or you will get hypoxia.

    • Yes, that type of aircraft has alarms to warn pilots of high cabin altitudes.
      Oxygen masks have to be put on right away or you will get hypoxia.

    • The incident described in this blog post happened on July 26, 2008; it happened over Ohio and to a Kalitta pilot. The Burse incident similarly happened over Ohio to a pilot employed by the same company, but at a different time, and that pilot was the only crew member affected by hypoxia (decompression sickness, DCS).

      “On March 15, 1994, the plaintiff was assigned to fly cargo for the defendant from Atlanta, Georgia to Charlotte, North Carolina; from Charlotte to Ypsilanti, Michigan; and then from Ypsilanti back to Atlanta. While the plane was on the ground in Michigan, maintenance personnel repaired a burnt-out landing light. When the maintenance personnel left the plane, they failed to reseal the emergency exit door properly. [It later detached and fell inside the cargo hold.] After the plane had taken off and ascended to an altitude of 10,000 feet, the crew discovered that, as a result of the unsealed exit door, the plane could not be pressurized properly. The plaintiff, as the commanding pilot, ordered his crew to don oxygen masks, while the plane continued to ascend. [This was company policy.] Somewhere between the altitude of 20,000 and 25,000 feet, the plaintiff began to feel the effects of decompression sickness. At 30,000 feet, the plaintiff grabbed the throttle and reversed thrust on the engines, which caused the plane to descend rapidly. He then blacked out. The plane, piloted by the rest of the crew, made an emergency landing in Kentucky”. ( https://casetext.com/case/burse-v-american-international-airways ) [My additions are information from the Connecticut WCC case 3986 CRB-02-99-03.]

      That case also states that American International Airways was actually Connie Kalitta Services, Inc. until 1990, so apparently it only was AIA for a decade or so, and “Kalitta” before and after that.

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