C-FBKK, from Aircraft Crashes Records Office.

Eddie Sez:

There is a common theme to these smaller aircraft slow onset hypoxia incidents. These aircraft usually do not have cockpit voice or flight data recorders, their oxygen systems are less than fool proof, and their pilots do not have a lot of high altitude experience. While they are rarely fully investigated, Transport Canada makes a pretty good effort here, but still come up empty. Regardless, there are many lessons to be learned:

  • Fuselage pressure leaks should be addressed immediately and repaired.

  • Oxygen supply and delivery equipment must be pre-flighted.

  • During every climb, part of your 10,000 foot check must be a check of cabin altitude. Most airplanes have a maximum cabin altitude between 6,000 and 8,000 feet. You certainly should not be above that at 10,000 feet aircraft altitude. You should know your normal cabin climb rate, typically around 300 fpm. Even if it takes you ten minutes to get to 10,000 feet aircraft altitude, you should not see more than 3,000 feet cabin altitude at that point. In any case, if it isn't where it should be, level off and investigate.

  • When troubleshooting a pressurization problem, donning oxygen quickly will not only improve your mental capabilities, it can keep you in the game if things go south quickly or insidiously.

  • When in doubt, descend.

What follows are quotes from the sources listed below.

Accident Report


[Aviation Investigation Report A12O0170, pg. 2]

[Aviation Investigation Report A12O0170, pg. 3]


[Aviation Investigation Report A12O0170, pg. 3]

Probable Cause

[Aviation Investigation Report A12O0170, pg. 10]

See Also:

Abnormal Procedures & Techniques / Hypoxia

Abnormal Procedures & Techniques / Slow Onset Hypoxia

Technical / Oxygen


Aircraft Crashes Record Office, Bureau of Aircraft Accidents Archives, (B3A), Geneva, Switzerland

Loss of Control and Collision With Terrain, Socata TBM 700N, C-FBKK, Renfrew, Ontario 10 NM SW, 8 October 2012, Aviation Investigation Report A12O0170, Transportation Safety Board of Canada