Sonic99 From , joined Dec 1969, posts, RR: Posted (14 years 1 month 12 hours ago) and read 4250 times:
On my recent forray to the airport, watching aircraft being serviced at the gates, I again noticed an open "vent" (not really sure what it is?) at the rear of the fuselage on the A320 which sparked my curiosity. I've seen this before but never quite paid attention to it. At first I dismissed this open "vent" as perhaps something the ground crew overlooked. But as the aircraft taxied away I realized it must be controlled by the pilots.
The "vent" in question is clearly seen in these two photos at the rear of the fuselage just below the door. It only appears on the right (starboard) side of the aircraft.
Rmm From Australia, joined Feb 2001, 527 posts, RR: 1
Reply 1, posted (14 years 1 month 11 hours ago) and read 4218 times:
It's the outflow valve. It regulates the flow of air leaving the cabin so it can be pressurised. It can be controlled in an automatic or manual way but mostly, if not all, automatic. It will start to close just after take off.
Yes, all other pressurised aircraft will have a similar door/doors or system.
Shaun3000 From United States of America, joined Mar 2002, 445 posts, RR: 0
Reply 2, posted (14 years 1 month 7 hours ago) and read 4189 times:
Most planes have a butterfly valve instead of a vent. This is a hole with a round cover, which is connected and pivots about the middle. It can be easily seen on MD-80s.
Also, many planes have a second vent, usually in the tail section, which is for hte APU. however, these point foward so as to scoop are in if it is used in flight. Some are a scoop, such as on the 767, and others are a vent style, like on the 737.