Number of oxygen masks per row

[Rwy in Sight]

A quick question regarding how many masks are installed over each row of seats. I thought each row of three seats has four masks over it, a spare one for a kid or someone standing on the aisle but a well travelled friend told me some rows (of three seats) have only just three masks. Any ideas what is the numbers of masks per row?

[Johnny F@rt Pants]

Your friend is correct.

Some rows have an extra mask for infants, some don’t.

[WHBM]

Commonly done alternate rows, and alternate sides. Lap infants will only be assigned to such rows by the check-in system.

[TCU]

I experienced a mask deployment in a BA 747 (G-CIVD) in early 2016 about 3hrs out of CPT. I was sat upstairs in 60A. Just checked the pictures I took and four masks popped down, so 2 per seat.

[Hartington]

Upstairs on a 747 can be configured for economy 3-3 hence the need for 4 masks. Air NZ did that.

[Plane Speaker]

The certification rule is an additional 10% of masks in the cabin. ie 180 pax requires 198 02 masks. Every PSU having an additional 02 mask makes positioning parents with infants much easier in the cabin. Each lav has 2 masks.