Bunga777 From United States of America, joined Oct 1999, 46 posts, RR: 0 Posted (11 years 3 weeks 1 day 2 hours ago) and read 1563 times:
Why are all of the doors on this 757-300 different, with the exception of the two overwing emergency exits? Isn't this more expensive than standardizing on door type?
Gr8SlvrFlt From United States of America, joined Jan 2002, 1583 posts, RR: 16 Reply 2, posted (11 years 3 weeks 1 day 2 hours ago) and read 1496 times:
I believe the 1, 2 and 4 doors are identical and can be used for boarding. The 3 doors are for emergency use only, as are the overwing exits, which, I imagine, are the same as those on the 737NG.
Aq737 From United States of America, joined Nov 2000, 612 posts, RR: 0 Reply 3, posted (11 years 3 weeks 1 day ago) and read 1469 times:
Indeed, the two window hatches are the same and are like the 737NG ones. (They flip out and up instead of you taking it out). As for the #1, #2, #5(last) doors, they are the same. The #2 door is usually used for boarding. As for the small door exit, aft of the wing, it is identical to some of the 752 #3 exits.
The original design for the 753 was for 2 hatches and 3 main doors, but the FAA asked for more. So, they added a 752 style one (not the hatches) to meet the FAA requirement. This also meant that no other manufacturer would have to be involved because all 3 types of doors were already used for the 752.
Bunga777 From United States of America, joined Oct 1999, 46 posts, RR: 0 Reply 4, posted (11 years 3 weeks 21 hours ago) and read 1427 times:
My main question is about the main doors and not the emergency exit hatches over the wing. I thought that 1, 2, and 4 should be the same (like in the Condor 753 pic), but in the CO pic the #4 door looks thinner than the #2 door, which looks like the standard 757 door, and the #1 door is smaller than #2.
Are there plans to incorporate the flip-up emergency exits over the door been incorporated into additional models outside the 753 and the 737NG? Is it an option for other models?
Larspl From Netherlands, joined Apr 2002, 466 posts, RR: 0 Reply 5, posted (11 years 3 weeks 20 hours ago) and read 1423 times:
on many aircraft types there is a difference between the doors on the left side and right side.
the left side is mainly used for boarding while the right is used for catering cleaning and maintenance,.
a door is a small problem in the structual integrity of the plane so when you can make a door smaller cause it will only be used for catering why don't you?
Nwa757300 From United States of America, joined Oct 2001, 298 posts, RR: 2 Reply 6, posted (11 years 3 weeks 13 hours ago) and read 1365 times:
There are some small differences in the 757 doors. I do believe that doors 4L/R are thinner than 2L/R. Also door 1R is smaller because it it used only for catering. I don't think the overwing exits are the flip up kind. At least NW didn't get that kind. If they did they would have to requalify the flight attendants on the exit.
Duncan From United States of America, joined Apr 2002, 131 posts, RR: 0 Reply 7, posted (11 years 3 weeks 10 hours ago) and read 1287 times:
OK OK, I can't stand it. the 757-300 DOES NOT have the 'flip up' over wing exits like the 737NG. Trust me, I helped build the first 10 or so that went out of the door.
The #1, #2 and #4 doors are all different. #1 L and #2L are slightly larger as these are mainly used for boarding. #1R is shorter than #1 L as this is used for catering. #2R is about the same as #2L except opposite. and #4L & R are the about same except opposite (and narrower than #1 and #2).
The #3 Emergency door is located in an area of high fuselage skin loads. I like my little science experiments so here goes:-
Example:- Place a ruler hanging over the edge of your desk and apply load to the free end. It will break the ruler at the desk, not mid way along the ruler. This is the same configuration that occurs in the tail section of an aircraft. Add to that torsion induced by the vertical tail loads and hey presto, high stresses!.
Based on this, the bigger the door at that location, the more beefing up of the structure would be required to accomodate the fuselage skin cutout (thicker skins and extra doublers = more weight and more complex structure).
Also to quote from above: "This also meant that no other manufacturer would have to be involved because all 3 types of doors were already used for the 752." (Aq737)
Boeing manufactures the doors for the 737 and 757 (unless it's changed in the past 3 yrs). Some at Witchita and they used to do some at Renton, though this may have changed. Supplier of doors is not a consideration when determining how many and where to install them.
RE: Flip up doors.
I doubt any operator would willingly update their fleet to incorporate flip up emergency exits. The only reason the 737NG has them is because the CAA mandated it in a revision to their regulations (after the Manchester runway fire accident). The 757-300 has a different passenger to door ratio and therefore does not need to comply with this regulation. This would be very labour intensive to incorporate in the field. We had to scramble at Boeing to get the first 20 something aircraft modified before delivery to accomodate this new requirement, loads of overtime though!
Sponsor Message: 
From United States of America, joined Oct 1999, 46 posts, 
From France, joined Sep 2006, 0 posts, 
From Netherlands, joined Apr 2002, 466 posts, 
From , joined Dec 1969, posts, 
Printer friendly format 
