American 763 takeoff incident, ORD
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RatherBeFlying Going back a few decades shows a less benign record. Some of the reduced fatality count can be credited to improved design of fuel systems and structures. But some day there will be another major fuel system breach with the wind blowing the wrong way.
In that case the fatality count will be a function of delay in beginning evacuation.
In that case the fatality count will be a function of delay in beginning evacuation.
This a complex area. For example wind speed has a significant impact on heat flux and heat location. Winds increase mixing and therefore increase the heat. Interestingly research has shown that in low to moderate winds heat is greatest on the windward side of the aircraft, in high winds heat is greater on the leeward side.
When you keep the doors closed, the increased cabin pressure actually assists in keeping combustion products out.
The important barriers are time to extinguish and heat resistant materials. Evacuation will not always be safer.
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Just to clarify, fuselage skin part of the door rotates outwards/upwards. Only the slide assembly falls outside (like the main cabin doors).
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).
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).
No it's a function of evacuating safely being fully informed of the outside conditions. The last thing you want to do is open the exits when that allows ingress of smoke and fire into the cabin, or if the passengers will exit into the pool fire. Those things will kill passengers more quickly.
This a complex area. For example wind speed has a significant impact on heat flux and heat location. Winds increase mixing and therefore increase the heat. Interestingly research has shown that in low to moderate winds heat is greatest on the windward side of the aircraft, in high winds heat is greater on the leeward side.
When you keep the doors closed, the increased cabin pressure actually assists in keeping combustion products out.
The important barriers are time to extinguish and heat resistant materials. Evacuation will not always be safer.
This a complex area. For example wind speed has a significant impact on heat flux and heat location. Winds increase mixing and therefore increase the heat. Interestingly research has shown that in low to moderate winds heat is greatest on the windward side of the aircraft, in high winds heat is greater on the leeward side.
When you keep the doors closed, the increased cabin pressure actually assists in keeping combustion products out.
The important barriers are time to extinguish and heat resistant materials. Evacuation will not always be safer.
I was in an older building where a minor basement fire reached an electrical supply shaft. The fourth floor was rapidly engulfed. Most fortunately the people in these units had self evacuated at the first sign of smoke.
A classic uncontained structural failure of an HP turbine disk:
http://http://news.aviation-safety.net/2016/11/04/5528/
This is bound to cause problems in the fleet.
http://http://news.aviation-safety.net/2016/11/04/5528/
This is bound to cause problems in the fleet.
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This link will work better:
ASN NewsNTSB: Engine fragments in Chicago Boeing 767 takeoff accident found 900 m away - ASN News
ASN NewsNTSB: Engine fragments in Chicago Boeing 767 takeoff accident found 900 m away - ASN News
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Interesting, thanks! Does that make it easier to close and reset the mechanism if the door is opened without need, or for access to the wing surface?
Is this design common to a lot of doors? Certainly A320-series main doors I've seen seem similar, the door moves inwards then down to align pins in slots as you describe. Therefore it's an outward opening door with most of the inherent safety benefits of a plug door.
Is this design common to a lot of doors? Certainly A320-series main doors I've seen seem similar, the door moves inwards then down to align pins in slots as you describe. Therefore it's an outward opening door with most of the inherent safety benefits of a plug door.
Last edited by Maxmotor; 20th Nov 2016 at 09:25.
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As always, some good reading in the accident docket.
From the CVR, sounds like the FO maybe pushed the override button to unlatch the right fire handle a couple of times but didn't immediately twist the handle after pulling it. The handle would have been unlatched anyway in this situation since they had a fire warning. The captain caught the error, good crosscheck.
They never got to the first item on the Engine Fire, Severe Damage or Separation checklist but on the ground the fire handles and fuel cutoffs are all that mattered in this case and they are on the evac checklist. Still, I'm sure the feds will gig them for not following the challenge and response cadence of the emergency checklists more closely while on fire.
Over the years the number of memory items on the engine fire and evac checklists has dropped to zero on the Boeing twins. Will some of the memory items come back for a more rapid shutdown and evac perhaps? Would it have made a difference in this case?
The flight attendant interviews seem to repeatedly ask why they didn't bring their flashlight off the aircraft for a daytime fire evac.
A couple of questions involved the service dog, er, I meant to say the emotional support animal that apparently was evacuated successfully.
From the CVR, sounds like the FO maybe pushed the override button to unlatch the right fire handle a couple of times but didn't immediately twist the handle after pulling it. The handle would have been unlatched anyway in this situation since they had a fire warning. The captain caught the error, good crosscheck.
They never got to the first item on the Engine Fire, Severe Damage or Separation checklist but on the ground the fire handles and fuel cutoffs are all that mattered in this case and they are on the evac checklist. Still, I'm sure the feds will gig them for not following the challenge and response cadence of the emergency checklists more closely while on fire.
Over the years the number of memory items on the engine fire and evac checklists has dropped to zero on the Boeing twins. Will some of the memory items come back for a more rapid shutdown and evac perhaps? Would it have made a difference in this case?
The flight attendant interviews seem to repeatedly ask why they didn't bring their flashlight off the aircraft for a daytime fire evac.
A couple of questions involved the service dog, er, I meant to say the emotional support animal that apparently was evacuated successfully.
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The NTSB report is published here:
https://www.ntsb.gov/investigations/...ts/AAR1801.pdf
Looks like American did still have memory items on the Engine Fire/Severe Damage checklist after all. The NTSB wants to see a separate checklist for engine fires on the ground as with Airbus and Embraer aircraft.
https://www.ntsb.gov/investigations/...ts/AAR1801.pdf
Looks like American did still have memory items on the Engine Fire/Severe Damage checklist after all. The NTSB wants to see a separate checklist for engine fires on the ground as with Airbus and Embraer aircraft.
I too frequently occupy a 737 exit row. As said several times above cabin crew usually any stress opening the door and nobody will be here to help. Partly because I am a PPL smartarse and partly because I think it is relevant I sometimes say out loud for others to hear - don't open the door if there is fire outside.
The point about waiting because the engines might still be running I had not really thought about but I am sure it is something that should be on the card and which most people would easily grasp. Probably would not make much difference in a panic situation but might give some cause to think twice in a lesser emergency.
The point about waiting because the engines might still be running I had not really thought about but I am sure it is something that should be on the card and which most people would easily grasp. Probably would not make much difference in a panic situation but might give some cause to think twice in a lesser emergency.
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Looks like American did still have memory items on the Engine Fire/Severe Damage checklist after all. The NTSB wants to see a separate checklist for engine fires on the ground as with Airbus and Embraer aircraft.
SLF here. The report says that at the time the autobrakes activated, "the airplane’s airspeed was 134 knots, which was also the calculated takeoff decision speed (V1)".
My understanding is (after a quick internet search) that "V1 is the speed by which a pilot must have decided to abort if they are going to stop on the runway". The report states that there was about 3775 feet of runway remaining from the point at which the airplane finally stopped. Does that suggest that V1 could have been higher and the plane still stop on the runway?
My understanding is (after a quick internet search) that "V1 is the speed by which a pilot must have decided to abort if they are going to stop on the runway". The report states that there was about 3775 feet of runway remaining from the point at which the airplane finally stopped. Does that suggest that V1 could have been higher and the plane still stop on the runway?
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topgas, in simple terms V1 is "decision speed", when take off performance is "balanced field" the distance from brake released to decision to stop, including approx 2 secs decision making is the same as the distance from decision to go until lift off. In non tech terms Accelerate stop distance = Accelerate go distance. In the real world, the trust available for a given weight usually results in an additional "stop margin" and thus we reduce the thrust to save engine life and in certain conditions, potential control problems if an engine fails ( wet/ contaminated runways etc). The answer to your question is that in performance terms if you can go, you can stop, thus if V1 was higher there would be no issues provided the crew acted in a timely manner. The auto brakes automatically activate after the thrust levers are retarded and reverse selected, but this time for "essential actions" is built into the performance tools.
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I too frequently occupy a 737 exit row. As said several times above cabin crew usually any stress opening the door and nobody will be here to help. Partly because I am a PPL smartarse and partly because I think it is relevant I sometimes say out loud for others to hear - don't open the door if there is fire outside.
In consequence it is almost always like riding in a freighter with no view out at all. In an emergency, especially one where the aircraft hit something and is distorted so blinds are jammed it may not be possible to see if there is a hazard that side of the aircraft.
BY all means as soon as the aircraft is airborne close the blinds but it seems to be that the pax are less safe if they and the FAs have no idea what is going on outside the aircraft.
Last edited by Ian W; 8th Feb 2018 at 09:23.
2.3.2.2 Recurring Evacuation-Related Issues
A long quote from the NTSB report was removed discussing the many RTO accidents where miscommunication between flight and cabin crew impeded evacuation and/or resulted in chutes coming down while one or more engines were still running.
The NTSB remains concerned that: Lessons are not being learned.
Give section 2.3.2.2 a careful read.
So far we have been lucky.
The common theme is that after a reject, flight crews remain unaware of serious fire and smoke situations for an unacceptable period.
Interphones get fumbled. Door Open annunciations on the EICAS roll off the display.
Admittedly there are some high priority messages in a reject situation, but Door Open needs to be prominently displayed as: EVACUATE IN PROGRESS.
A software update could fix that.
The NTSB remains concerned that: Lessons are not being learned.
Give section 2.3.2.2 a careful read.
So far we have been lucky.
The common theme is that after a reject, flight crews remain unaware of serious fire and smoke situations for an unacceptable period.
Interphones get fumbled. Door Open annunciations on the EICAS roll off the display.
Admittedly there are some high priority messages in a reject situation, but Door Open needs to be prominently displayed as: EVACUATE IN PROGRESS.
A software update could fix that.
Last edited by RatherBeFlying; 8th Feb 2018 at 03:07. Reason: Edit to involuntary edit
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At least one FA (lead FA) should wear a portable intercom, much like the units police and fire wear. They would not have to make their way back to a attendant intercom to advise cockpit of fire or such. Could be outside and still talk to the pilots.
Last edited by jack11111; 7th Feb 2018 at 23:33.
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I find section 2.3.4, regarding passengers bringing their luggage, shameful. I quote:
If these incidents do not warrant criminal charges for interfering with flight crew, then I don't know what does.
In one case, a flight attendant tried to take a bag away from a passenger who did not follow the instruction to evacuate without baggage, but the flight attendant realized that the struggle over the bag was prolonging the evacuation and allowed the passenger to take the bag. In another case, a passenger came to the left overwing exit with a bag and evacuated with it despite being instructed to leave the bag behind.
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