Narrative:

I believe a design defect exists in the oxygen masks installed in cockpits. I estimate that approximately 5-10% of the time when the pilot/copilot masks are removed from their storage boxes they come out in separate pieces. The gray cup (fits over nose/mouth) separates from the distribution block and renders the mask unusable. The mask will test properly while in its storage box in this useless condition. I recommend an informal inspection to see if my observations confirm an industry wide potentially serious defect. Callback conversation with reporter revealed the following: company tells me that logbook write-ups cause basks to be returned to the vendor. The cup seems to be fitted into the distribution block with a small clip that is inadequate. In event of emergency need of oxygen it would take a person expecting to have to reassemble the mask at least 10-15 seconds to get it out of the box, reassemble it and get on his face with oxygen flowing -- if he had both hands free to accomplish this. If this is the condition of these masks on my airline I suspect the same condition exists on all airlines that use this mask.

Google
 

Original NASA ASRS Text

Title: OXYGEN MASKS FOR FLT CREW ALLEGEDLY COME OUT OF CONTAINER IN SEPARATE PIECES UNUSABLE FOR EMERGENCY OXYGEN.

Narrative: I BELIEVE A DESIGN DEFECT EXISTS IN THE OXYGEN MASKS INSTALLED IN COCKPITS. I ESTIMATE THAT APPROX 5-10% OF THE TIME WHEN THE PLT/COPLT MASKS ARE REMOVED FROM THEIR STORAGE BOXES THEY COME OUT IN SEPARATE PIECES. THE GRAY CUP (FITS OVER NOSE/MOUTH) SEPARATES FROM THE DISTRIBUTION BLOCK AND RENDERS THE MASK UNUSABLE. THE MASK WILL TEST PROPERLY WHILE IN ITS STORAGE BOX IN THIS USELESS CONDITION. I RECOMMEND AN INFORMAL INSPECTION TO SEE IF MY OBSERVATIONS CONFIRM AN INDUSTRY WIDE POTENTIALLY SERIOUS DEFECT. CALLBACK CONVERSATION WITH REPORTER REVEALED THE FOLLOWING: COMPANY TELLS ME THAT LOGBOOK WRITE-UPS CAUSE BASKS TO BE RETURNED TO THE VENDOR. THE CUP SEEMS TO BE FITTED INTO THE DISTRIBUTION BLOCK WITH A SMALL CLIP THAT IS INADEQUATE. IN EVENT OF EMER NEED OF OXYGEN IT WOULD TAKE A PERSON EXPECTING TO HAVE TO REASSEMBLE THE MASK AT LEAST 10-15 SECONDS TO GET IT OUT OF THE BOX, REASSEMBLE IT AND GET ON HIS FACE WITH OXYGEN FLOWING -- IF HE HAD BOTH HANDS FREE TO ACCOMPLISH THIS. IF THIS IS THE CONDITION OF THESE MASKS ON MY AIRLINE I SUSPECT THE SAME CONDITION EXISTS ON ALL AIRLINES THAT USE THIS MASK.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.