American 763 takeoff incident, ORD
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Is this really true that the 747 upper deck and 737-800/900 have non-plug type emergency exit doors?
That seems surprising. Plug type is such a nice engineering solution: open-able exactly when you want it to be, not when you don't.
Ok, maybe with the exception of not-depressurizing on the ground, a la Saudi. But still, the best engineering designs are those that passively give the results. Anything that needs active operation/sensors/logic always has extra failure modes.
I guess the plug door has issues in a next-to-seat exit, however I recall old safety cards that showed the over-wing door coming inside the plane and the passenger having to throw it out the window or the like. That looked like plug type operation.
That seems surprising. Plug type is such a nice engineering solution: open-able exactly when you want it to be, not when you don't.
Ok, maybe with the exception of not-depressurizing on the ground, a la Saudi. But still, the best engineering designs are those that passively give the results. Anything that needs active operation/sensors/logic always has extra failure modes.
I guess the plug door has issues in a next-to-seat exit, however I recall old safety cards that showed the over-wing door coming inside the plane and the passenger having to throw it out the window or the like. That looked like plug type operation.
Just for info. On the B777 and B787 the door flight locks engage at or above IAS of 80knots and disengage at IAS below 80knots.
I think. It could be TAS or CAS I forget.
Not sure about B767.
I think. It could be TAS or CAS I forget.
Not sure about B767.
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Is this really true that the 747 upper deck and 737-800/900 have non-plug type emergency exit doors?
That seems surprising. Plug type is such a nice engineering solution: open-able exactly when you want it to be, not when you don't.
Ok, maybe with the exception of not-depressurizing on the ground, a la Saudi. But still, the best engineering designs are those that passively give the results. Anything that needs active operation/sensors/logic always has extra failure modes.
I guess the plug door has issues in a next-to-seat exit, however I recall old safety cards that showed the over-wing door coming inside the plane and the passenger having to throw it out the window or the like. That looked like plug type operation.
That seems surprising. Plug type is such a nice engineering solution: open-able exactly when you want it to be, not when you don't.
Ok, maybe with the exception of not-depressurizing on the ground, a la Saudi. But still, the best engineering designs are those that passively give the results. Anything that needs active operation/sensors/logic always has extra failure modes.
I guess the plug door has issues in a next-to-seat exit, however I recall old safety cards that showed the over-wing door coming inside the plane and the passenger having to throw it out the window or the like. That looked like plug type operation.
On the 737-800 the wing exit change was required by the FAA to approve the increase in passenger capacity to ensure that evacuation could be fast enough, that's why it's a (gas, I presume) powered door and not a manually-removed plug door.
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Aircraft Exit profiles, a bit dated, but hey, its Canada! https://www.tc.gc.ca/eng/civilaviati...tion2-5545.htm
It can clearly make a big difference to the outcome depending on whether the aircraft comes to a stop with the fire upwind or downwind of the fuselage.
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As currently designed the door is large, bigger than the other doors in fact, because of the fuselage curvatures.Here's an example picture.
I don't know if a smaller door could be designed and still attach to the airframe structural members in a reasonable way (maybe tdracer knows). However certainly a door for the the current aperture for that doorway can't be anything the passenger could try to hold, I might guess it weighs over 80kg!
There has also got to be a (large, long) slide somewhere, at the moment it is on the inside in a bustle on the door and while it could be in the fuselage somewhere like the 767, there might not be that much space for it.
I don't know if a smaller door could be designed and still attach to the airframe structural members in a reasonable way (maybe tdracer knows). However certainly a door for the the current aperture for that doorway can't be anything the passenger could try to hold, I might guess it weighs over 80kg!
There has also got to be a (large, long) slide somewhere, at the moment it is on the inside in a bustle on the door and while it could be in the fuselage somewhere like the 767, there might not be that much space for it.
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On the 747-400 it's in the lower part of the door (plenty of space thanks to curvature):
http://www.simtechmanufacturing.com/.../747upper6.jpg
Compare with video of inflation where you can see that portion of the door being left behind when the door opens:
https://www.youtube.com/watch?v=ZSQ8x2LeP18
(747-8 has by far the coolest slides though: The Upper Deck : Photo )
http://www.simtechmanufacturing.com/.../747upper6.jpg
Compare with video of inflation where you can see that portion of the door being left behind when the door opens:
https://www.youtube.com/watch?v=ZSQ8x2LeP18
(747-8 has by far the coolest slides though: The Upper Deck : Photo )
Drain Bamaged
Sorry, I'm an engine guy - things like exit doors are pretty far removed from my area of expertise...
Those over wing exits
Just got off a 737-700. I was seated in the exit row per SOP.
No mention in the brief of when to open the exit, just there would be no crew there.
Over the door, which opens up and out on a hinge, there were pictures of checking for fire etc. Looking at the door, I'd say a a substantial number of passengers would never be able to use it in an efficient manner. They have to step up and then fit through. Not happening for some of the larger or more elderly passengers.
No mention in the brief of when to open the exit, just there would be no crew there.
Over the door, which opens up and out on a hinge, there were pictures of checking for fire etc. Looking at the door, I'd say a a substantial number of passengers would never be able to use it in an efficient manner. They have to step up and then fit through. Not happening for some of the larger or more elderly passengers.
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Originally Posted by YRP
Is this really true that the 747 upper deck and 737-800/900 have non-plug type emergency exit doors?
That seems surprising. Plug type is such a nice engineering solution: open-able exactly when you want it to be, not when you don't.
That seems surprising. Plug type is such a nice engineering solution: open-able exactly when you want it to be, not when you don't.
Originally Posted by triploss
Compare with video of inflation where you can see that portion of the door being left behind when the door opens:
https://www.youtube.com/watch?v=ZSQ8x2LeP18
https://www.youtube.com/watch?v=ZSQ8x2LeP18
The 747-400 upper deck door security relies on large pins sitting in L shaped-slots (plus the electronic system locking the door handle in flight). The locking system can be inoperative for flight as long as the door is guarded by the flight attendant when cabin/external differential pressures are low. With larger differential pressures, the door latching mechanism is loaded up with greater mechanical forces (making it impossible to open the door).
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I think a plug-type door that the passenger had to hold, for the 747, would be impossibly heavy.
On the 737-800 the wing exit change was required by the FAA to approve the increase in passenger capacity to ensure that evacuation could be fast enough, that's why it's a (gas, I presume) powered door and not a manually-removed plug door.
On the 737-800 the wing exit change was required by the FAA to approve the increase in passenger capacity to ensure that evacuation could be fast enough, that's why it's a (gas, I presume) powered door and not a manually-removed plug door.
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FedEx grounds one plane over GE engine part concern
More from: FedEx grounds one plane over GE engine part concern | Reuters
REUTERS - Mon Nov 7, 2016 - FedEx Corp is grounding one of its planes temporarily that has an engine General Electric Co flagged after a passenger jet erupted in flames last month, a spokesman for the cargo airline told Reuters on Monday.
Engine-maker GE on Friday alerted airlines about a small number of parts under investigation following American Airlines Flight 383, which caught fire on Oct. 28. The parts were made from the same lot of alloy as a turbine disk used by American, which GE subsequently discovered had a "material anomaly."
While U.S. investigators have yet to assign blame for the non-fatal incident, they have found what appeared to be fatigue cracking where the disk had an anomaly. Experts have said the disk's corrupted material may indicate a manufacturing defect, either by the parts or metal maker.
In a statement, FedEx spokesman Chris Allen said the company was notified that an engine in one MD11 aircraft was affected.
Engine-maker GE on Friday alerted airlines about a small number of parts under investigation following American Airlines Flight 383, which caught fire on Oct. 28. The parts were made from the same lot of alloy as a turbine disk used by American, which GE subsequently discovered had a "material anomaly."
While U.S. investigators have yet to assign blame for the non-fatal incident, they have found what appeared to be fatigue cracking where the disk had an anomaly. Experts have said the disk's corrupted material may indicate a manufacturing defect, either by the parts or metal maker.
In a statement, FedEx spokesman Chris Allen said the company was notified that an engine in one MD11 aircraft was affected.
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The 747-400 upper deck door security relies on large pins sitting in L shaped-slots (plus the electronic system locking the door handle in flight). The locking system can be inoperative for flight as long as the door is guarded by the flight attendant when cabin/external differential pressures are low. With larger differential pressures, the door latching mechanism is loaded up with greater mechanical forces (making it impossible to open the door).