An American Airlines 777-200 had a small fire in an onboard electrical system and made an emergency landing. I arrived at the airport in time to take a few pictures of the first passengers coming off to disembark in wait for a replacement aircraft.The following video was made by a local blogger that caught some of the action.http://www.youtube.com/watch?feature=player_embedded&v=wWdWQsvmikg#at=18Anyway, nothing much exciting usually happens around here, so it stirred up a bit of local interest.Kind regards,

When the emergency fella opens the rear door from the outside (at 0:18) a small window on top of the door handle goes from white to black: Is something opening to equalise cabin pressure? (Never seen this before).Cheers,- jahman.

Bet you guys don't get many triple sev's out in Moncton, eh? AA had one divert here last summer after an inflight shutdown of the #1 engine. Our company actually got to ground-handle it, so it made for a bit of fun!

When the emergency fella opens the rear door from the outside (at 0:18) a small window on top of the door handle goes from white to black: Is something opening to equalise cabin pressure? (Never seen this before).Cheers,- jahman.

It's just a vent flap. All aircraft have them.

Nevermind. Call me Captain Obvious.

...It's just a vent flap. All aircraft have them.

So why do they need a vent flap if they already have an outflow valve?Or is the vent flap there so emergency crew can open the door in case tha aircraft has a mishap after pressurizing before take-off (or defore de-pressurizing post-landing)?Cheers,- jahman.

So why do they need a vent flap if they already have an outflow valve?Or is the vent flap there so emergency crew can open the door in case tha aircraft has a mishap after pressurizing before take-off (or defore de-pressurizing post-landing)?Cheers,- jahman.

The vent panel is designed to prevent the aircraft from pressurizing to an unsafe level if the door in not completely closed, latched and locked. If you look at the video closely you will see the vent panel opens immediately as the handle is turned from the locked position. So if you reverse the process then you can visualize the vent not closing completely until the door is fully closed and the handle is locked.You can imagine what would happen to a door without this vent if it (the door) is not completely closed and the aircraft starts pressurizing. With this vent panel, the aircraft won't pressurize but at least the door won't blow open or off as the aircraft is climbing. This, of course, assumes the annunciator light in the cockpit isn't telling the pilots the door is still open but we all know that switches fail.Also, the vent panel will fully open at low differential pressures but as the pressure increases the vent will only partially open and a mechanical interlock will not allow the door to be opened until pressure is reduced. At very high differential pressures the vent panel (and, of course, the door) will not open for obvious reasons.And no, I don't fly the 777 but I did sleep at a Holiday Inn Express last night.:( (I'm sorry, I couldn't resist. I know that only the U.S. guys will probably get that.) Seriously, though, I do have access to the 777 manuals so I'm just regurgitating what I read from the manual.