Why are some door widths narrower on Boeing 737s than on 747s? Will it affect emergency evacuation speeds?

Question

Boeing 747-100/200 exit door dimensions;
Type I pax. door 1,93 m x 1,07 m
Type I service door 1,93 m x 1,07 m
Type I pax. door 1,93 m x 1,07 m
Type I service door 1,93 m x 1,07 m
Type I pax. door 1,93 m x 1,07 m
Type I service door 1,93 m x 1,07 m
Type I pax. door 1,93 m x 1,07 m
Type I service door 1,93 m x 1,07 m
737-400 overwing exits are less than 1 m wide.

Answer 1

The answer is very obvious when you think about it. The main doors are full height and width and are intended as normal entrances and exits. They are also attached to the aircraft by hinges and lock in from the outside. In an emergency they are swung open and their hinges bear the weight.

The over wing exits are for emergency use only, they are fitted from the inside and detach completely. The hugely important thing is that a single person needs to be able to open that door, pull it off its mounts and then toss it out onto the wing so that it doesn't impede the evacuation. They weigh in the region of 50-60 pounds, compared to several hundred for a regular entrance/exit door. That's why the 737 has two small exits over each wing instead of one big 200lb exit that would end up crushing someone.

Secondary to this is that there isn't enough height above the wing to fit a full door. On the 747 the overwing exits are well above the wing because the main spar is under the cargo hold and the exit is well back on the wing.

Take a look at the images from airliners.net

Answer 2

The exits on the 737 can be smaller because they only carry 1/4 the people of the 747.

Answer 3

The 737 is a lot smaller aircraft. If you had doors the size of 747's it would compromise the airframe. But because of the smaller size there are less people to evacuate (around 110).

Answer 4

No, it makes sense to have a door big enough for one at a time to get through and use the slides. If it were physically possible, a huge doorway with a knot of people struggling in it is going to block up quicker. Who do you know who can't get through a 1 metre door if need be?

Answer 5

the 747 got 4 hundred people going threw two doorways (jet-ways) the 737 a little more then 1 hundred people get annoyed want to get off and on ,,,,THAT new airbus can seat 800 hundred passengers on some seating configures with two Jet-ways pack some patience

Answer 6

That's obvious, a smaller door would lessen the time it would take for a large number people to go through it. As to why, you would have to ask the designers of the airplane why they made the doors smaller, not us.....we didn't make that decision.

Answer 7

Will it affect emergency evac speeds? No.

Emergency evac has to be demonstrated as a condition of certification anyway. How would it affect the evac speeds?

Answer 8

i dont know but before i get on a plane next time im goning to ask probobly not because they make sure ur able to avacuate quickly in planes or they cant use it

Answer 9

Why,where are you going to evacuate to at 30,000 feet?

Answer 10

no beccause you have less passengers scrambling for doors,,,