Drop down oxygen masks

[flystarboy]

Not sure if this is the right arena to ask but I will anyway.

Are the pax drop down masks specified in quantity by the operating airline or are they a standard fit by aircraft manufacturers?

How many masks are there per drop down psu?

Would it be safe to presume that there would be 3 masks above a double seat, 4 above a triple seat and 5 or 6 above a quad seat depending if it was at a bulkhead/ bassinet position?

Many thanks in advance

[grounded27]

The CAA/airline. It is common to adjust the "Pitch" of the masks to meet seat location/QTY as cabin interiors often change with acquired aircraft or a new marketing plan.

[Tinwacker]

Will require one oxygen mask per pax seat, per cabin crew seat and toilet cubicles, extra connections in the system are avilable for changing the configaration to all economy high density layout for example.

There is a set quantity of portable oxygen cylinders for sick paxs or for crew to walk a round during an emergency depressurisation.

TW