Originally Posted by
Analise
Most? So there are no federal requirements or some kind of int'l requirements mandating an extra mask per row? I'm surprised by that. How do you find out which airlines DO have that extra mask aside from calling the airline?
There are certification requirements for pressurized aircraft designed to be operated above 25,000 feet. One of thse requirements is as follows:
If certification for operation above 25,000 feet is requested, there must be oxygen dispensing equipment meeting the following requirements:
(1) There must be an oxygen dispensing unit connected to oxygen supply terminals immediately available to each occupant, wherever seated, and at least two oxygen dispensing units connected to oxygen terminals in each lavatory. The total number of dispensing units and outlets in the cabin must exceed the number of seats by at least 10 percent. The extra units must be as uniformly distributed throughout the cabin as practicable. If certification for operation above 30,000 feet is requested, the dispensing units providing the required oxygen flow must be automatically presented to the occupants before the cabin pressure altitude exceeds 15,000 feet. The crew must be provided with a manual means of making the dispensing units immediately available in the event of failure of the automatic system.
These masks making up the additional 10 percent (a minimum number) might not be at each row of seats but must be evenly distributed throughout the cabin. This is why not every seat row may have additional masks.