This argument started on IRC. Someone I know does not remember ever flying on a plane whose doors opened outwards (tho’ she’s lived in Norway for years now), while I remember nothing BUT planes whose doors open outwards.
She’s wondering why such a design is allowed at all; she says it’s “just begging for a latch failure and explosive decompression. In the case of DC-10’s, the latch mechanism is even faulty, so when the rear cargo door blows out it takes the rear of the plane with it. And usually destroys all the control hydraulics on the way.” She further asks, “How do they prevent it from being opened at altitude?” IOW, doors opening outwards strike her as something that’s incredibly dangerous and stupid.
So what’s the straight dope, all? Is Boeing putting our lives at risk every day with carelessness? Is this an FAA ignorance scandal in the making? Or is it, as I’m sure it is, that my friend and I are missing something here?
The cabin doors have to be pulled into the plane a small amount first, then they pass back through the opening and to the outside of the plane, giving everyone more room while the door is open. So the air pressure difference actually seals the door tighter. I’m not sure about cargo doors, but how often do DC-10s go down due to faulty cargo doors?
They probably operate the same way. Remember, plane doors were all modified after D. B. Cooper got his money and got away, so that they couldn’t be opened while in flight. Didn’t want anyone else hijacking a plane and parachuting to safety.
Just a nitpick, although it has passed into common knowledge that the hijacker’s name was “D. B. Cooper” he only ever identified himself as “Dan Cooper”. The D B came from a person who was investigated but cleared.
Passenger doors vary a great deal between different makes of plane- the DC-10 has a motorized door that slides upwards on a curved track, while an A300 has an outward opening door with a heavy manual latch. Each design probably has its own headaches with respect to risk of explosive decompression.
As for cargo doors, they almost always open outwards on commercial aircraft. An inward opening door takes up space that could be holding freight, so carriers looking to maximize cargo capacity will probably not choose one. The DC-10 problem that Leaper’s friend was referring to has apparently been fixed (or at least mitigated) through retrofitting that was required after some high profile crashes caused by rear cargo door failures. See this link for a more detailed explanation
At least two. One landed safely, and one crashed. The last was after a door refit was done on all DC 10s, but it got missed somehow.
AFAIK, the reason for the door opening outward is that it’s so big that opening inward would mean a large loss of cargo space. I have a book someplace that talks about it. If I find it and it’s enlightening, I’ll post again.
There are quite a lot of commercial aircraft where the cargo doors open inwards. The probably most popular passenger plane Boeing 737 is one example.
When cargo doors open outwards (e.g. Boeing 757, big aircraft in general) it is usually a motorized mechanism. The inwards opening doors are usually operated manually (without help of a motor).