NTSB · Safety Recommendation
Safety Recommendation A-76-022
Recommendation
ISSUE AN AIRWORTHINESS DIRECTIVE, REQUIRING INSTALLATION OF ADJUSTMENT TABS ON IN-SERVICE AND IN-STOCK PASSENGERS SUPPLEMENTAL OXYGEN MASK HEADBANDS.
Safety Issue and Context
SEVERAL RAPID DECOMPRESSION MISHAPS INVOLVING DC-10 AND L-1011 AIRCRAFT HAVE DISCLOSED PROBLEMS WITH CHEMICALLY GENERATED PASSENGER SUPPLEMENTAL OXYGEN SYSTEMS. THE NATIONAL TRANSPORTATION SAFETY BOARD'S SPECIAL STUDY, "CHEMICALLY GENERATED SUPPLEMENTAL OXYGEN SYSTEMS IN DC-10 AND L-1011 AIRCRAFT"1/INDICATES THAT THESE PROBLEMS ARE PRIMARILY THE RESULT OF A LACK OF UNDERSTANDING OF THE SYSTEM BY BOTH PASSENGERS AND FLIGHT ATTENDANTS.
Response History
June 22, 1978 · NTSB Correspondence · FAA
Closed-unacceptable action.
February 11, 1977 · Recipient Response · FAA
We do not propose to retrofit the presently installed passenger masks with masks equipped with adjustable tabs. In our judgement, we do not have sufficient justification to require such a retrofit of the entire air carrier fleet, irrespective of cost. As new masks are installed in accordance with the revised tso standards, masks with adjust- able tabs will begine to be installed in place of the present masks.
December 29, 1976 · NTSB Correspondence · FAA
We recommend reconsideration of this recommendation.
August 2, 1976 · Recipient Response · FAA
WE DO NOT CONCUR THAT THE ABSENCE OF HEADBAND ADJUSTMENT TABS IS A HAZARDOUS CONDITION. THE PROPER PROCEDURE FOR MASK USE IS TO FIRST, HANDHOLD THE MASK OVER THE NOSE AND MOUTH; THEN, FOR COMFORT, PLACE THE HEADBAND OVER YOUR HEAD AND ADJUST. WE DO NOT FEEL THAT THE PROPOSAL TO AD ALL MASKS WITH ADJUSTABLE TABS, NOW IN SERVICE AND INSTOCK, IS ESSENTIAL TO SAFETY FOR THE ABOVE MENTIONED REASONS. RESPONSE DATED 2/11/77 "WE DO NOT PROPOSE TO RETROFIT THE PRESENTLY INSTALLED PASSENGER MASKS WITH MASKS EQUIPPED WITH ADJUSTABLE TABS. IN OUR JUDGEMENT, WE DO NOT HAVE SUFFICIENT JUSTIFICATION TO REQUIRE SUCH A RETROFIT OF THE ENTIRE AIR CARRIER FLEET, IRRESPECTIVE OF COST.
AS NEW MASKSARE INSTALLED IN ACCORDANCE WITH THE REVISED TSO STANDARDS,MASKS WITH ADJUSTABLE TABS WILL BEGIN TO BE INSTALLED INPLACE OF THE PRESENT MASKS."