Double ENG failure 733 what would you do?
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Double ENG failure 733 what would you do?
Scenario: TOC you get fuel filter cautions - both engines, followed by simultaneous eng shutdown.
Actions: Action the QRH, get the APU started and on bus. You are unable to restart the engines so you head for the nearest longest airfield, join the overhead and continue to descend at best glide speed. You have approx 12k feet to loose in the overhead.
My question is:
Can you use your APU to assist in dropping the gear and flap operation? If so how????
Many thanks in advance
Actions: Action the QRH, get the APU started and on bus. You are unable to restart the engines so you head for the nearest longest airfield, join the overhead and continue to descend at best glide speed. You have approx 12k feet to loose in the overhead.
My question is:
Can you use your APU to assist in dropping the gear and flap operation? If so how????
Many thanks in advance
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Yes but since you can only put it on one bus at a time whilst airborne, i suggest you fly a 'high' profile to runway at 210kts, drop the gear when you KNOW you're going to make it (500'?), swap the APU onto the other bus, select Flap 40 and just land with whatever flap you have by the time you touch down. Works quite well in the sim!
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Thanks GL,
I knew you could do this, ie one bus at a time, but just wanted clarification and best technique.....
Forgive my laziness here ( not got my tech manual to hand), but which bus for gear and which bus for flap?
Thanks
I knew you could do this, ie one bus at a time, but just wanted clarification and best technique.....
Forgive my laziness here ( not got my tech manual to hand), but which bus for gear and which bus for flap?
Thanks
ECON cruise, LR cruise...
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Depends on altitude... If at 500 ft after T/O, I'd just drop the nose, call for gear and flaps (hope that a bit of windmilling might assist), then call for manual gear extension and hope for a decent site to put her down.
Above FL100, again, memory items for hot relight, trim to green dot speed while calling for the APU and calling for masks on, deciding where we're going in and then attempting relight once APU was up and running.
Higher up, I'd start the stopwatch (12 min O2 in the PSUs) and might consider trying a windmill relight after deciding where we're heading and being happy that we have the altitude to do it. Then cranck the APU when lower etc etc.
If on approach - well, depends on altitude, speed and distance to go :-/
Above FL100, again, memory items for hot relight, trim to green dot speed while calling for the APU and calling for masks on, deciding where we're going in and then attempting relight once APU was up and running.
Higher up, I'd start the stopwatch (12 min O2 in the PSUs) and might consider trying a windmill relight after deciding where we're heading and being happy that we have the altitude to do it. Then cranck the APU when lower etc etc.
If on approach - well, depends on altitude, speed and distance to go :-/
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Endofeng, I am confused , we have reached the TOC and now have a pressurisation issue and a power issue. We assume you have:
Declared a MAY DAY.
Completed the recall items for Loss of Thrust on Both Engines
Established the appropriate speed for a immediate windmill restart attempt,
( higher probability of start due to higher engine RPM), but drift down may be required to below FL30 to improve windmilling capability if unsuccessful.
Started the APU when available ( relight not guaranteed above FL250).
Initiated the Rapid Relight Recall items before attempting APU start.
Do not confuse the establishment of APU power with engine driven gen power at idle rpm.
Turned towards the landing airport and started the drift down.
Of course, at lower levels, you are trading altitude for speed and in reality you will have to decide when to abandon the relight attempt and " Fly the airplane" as 12K feet only gives you about 36 track miles to configure and land.
As one comment states you can only Power one Bus from the APU and thus you would need to prioritise and switching buses at a critical phase of flight may not be a good idea. You would subsequently get more master cautions and distractions as well as load shedding, dont create your own chaos.
Gear is dropped using alternate method, flaps use alternate method if system B pressure is low. I would tend to put the APU on Gen bus 1 and leave it there. You have 30 mins battery power at least and only 10 mins in the air
Straight in final, configure early to allow for incresed flap time, drop gear as late as possible.
In FCTM there is a good section on Non Normals outside of the scope of the checklist.. worth a look
Declared a MAY DAY.
Completed the recall items for Loss of Thrust on Both Engines
Established the appropriate speed for a immediate windmill restart attempt,
( higher probability of start due to higher engine RPM), but drift down may be required to below FL30 to improve windmilling capability if unsuccessful.
Started the APU when available ( relight not guaranteed above FL250).
Initiated the Rapid Relight Recall items before attempting APU start.
Do not confuse the establishment of APU power with engine driven gen power at idle rpm.
Turned towards the landing airport and started the drift down.
Of course, at lower levels, you are trading altitude for speed and in reality you will have to decide when to abandon the relight attempt and " Fly the airplane" as 12K feet only gives you about 36 track miles to configure and land.
As one comment states you can only Power one Bus from the APU and thus you would need to prioritise and switching buses at a critical phase of flight may not be a good idea. You would subsequently get more master cautions and distractions as well as load shedding, dont create your own chaos.
Gear is dropped using alternate method, flaps use alternate method if system B pressure is low. I would tend to put the APU on Gen bus 1 and leave it there. You have 30 mins battery power at least and only 10 mins in the air
Straight in final, configure early to allow for incresed flap time, drop gear as late as possible.
In FCTM there is a good section on Non Normals outside of the scope of the checklist.. worth a look
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KG,
Thanks for your thoughts. I was thinking more on terms of a short hop so cruise 180 or the likes. Yes I agree - prioritise ie pressurisation, ANC, recalls etc but relight unsuccesful, committed to double eng failure landing scenario sort of thing, highly unlikely, but possible!
I'm more interested in peoples thought processes and as already mentioned the use of the APU gen for gear/flap extension. I think I'd be inclined to head for the nearest suitable available airfields' overhead, better to crash on a runway than 2 miles short, fly the green dot and configure as late as possible. My priority for landing would of course be gear over flaps, especially on a long R/W, but as I've asked would using the APU gen ( which gen?) be beneficial over the alternate gear extension?, as the alternate gear extension is gravity drop and at a moment of high workload would it be worth swapping gens etc over pulling the altn gear?
Thanks guys
Thanks for your thoughts. I was thinking more on terms of a short hop so cruise 180 or the likes. Yes I agree - prioritise ie pressurisation, ANC, recalls etc but relight unsuccesful, committed to double eng failure landing scenario sort of thing, highly unlikely, but possible!
I'm more interested in peoples thought processes and as already mentioned the use of the APU gen for gear/flap extension. I think I'd be inclined to head for the nearest suitable available airfields' overhead, better to crash on a runway than 2 miles short, fly the green dot and configure as late as possible. My priority for landing would of course be gear over flaps, especially on a long R/W, but as I've asked would using the APU gen ( which gen?) be beneficial over the alternate gear extension?, as the alternate gear extension is gravity drop and at a moment of high workload would it be worth swapping gens etc over pulling the altn gear?
Thanks guys
TOC you get fuel filter cautions - both engines, followed by simultaneous eng shutdown.
12,000 feet in the overhead, 4,000' per orbit, two orbits, then position so that you are over the outermarker at twice the chart height AGL. (typically this will be about 3,000' AGL), gear up, flap 5 and inbound. If you make that point, gear down flap 15 and landing isn't a problem.
Manual gear extension, and windmilling engines for enough hydraulic power to get the flaps out.
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Hi Friends
Fortunately loss of thrust on both engines or double engine failure is an exceptionally rare occurrence. So rare that I have never, let me say again, I have never heard about a real case of Loss of thrust on both engines that has happened in the Boeing 737 history with a happy end. Not at all. So, why worry ???
I do believe that everybody here understand what does "exceptionally rare" mean!!!
NEVERRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRR !!!!!!!
Thanks:
Fortunately loss of thrust on both engines or double engine failure is an exceptionally rare occurrence. So rare that I have never, let me say again, I have never heard about a real case of Loss of thrust on both engines that has happened in the Boeing 737 history with a happy end. Not at all. So, why worry ???
I do believe that everybody here understand what does "exceptionally rare" mean!!!
NEVERRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRR !!!!!!!
Thanks:
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"mvsb1863 Hi Friends
Fortunately loss of thrust on both engines or double engine failure is an exceptionally rare occurrence. So rare that I have never, let me say again, I have never heard about a real case of Loss of thrust on both engines that has happened in the Boeing 737 history with a happy end. Not at all. So, why worry ???
I do believe that everybody here understand what does "exceptionally rare" mean!!!
NEVERRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRR !!!!!!!"
Seem to remember a classic that had a double failure as a result of rain ingestion and landed on a levee. Ryanair had one too last year, too many birds. A/C written off but no px dead. Rare yes, never happened no.
Fortunately loss of thrust on both engines or double engine failure is an exceptionally rare occurrence. So rare that I have never, let me say again, I have never heard about a real case of Loss of thrust on both engines that has happened in the Boeing 737 history with a happy end. Not at all. So, why worry ???
I do believe that everybody here understand what does "exceptionally rare" mean!!!
NEVERRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRR !!!!!!!"
Seem to remember a classic that had a double failure as a result of rain ingestion and landed on a levee. Ryanair had one too last year, too many birds. A/C written off but no px dead. Rare yes, never happened no.
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Engine Failure or Engine Flame out? because Both Engine Flame out exists, and happened on the A330 GE engines and not only once , forcing GE to provide a software "Patch" to work around the problem, which means that the problem is not solved yet
Engine Failure or Engine Flame out? because Both Engine Flame out exists, and happened on the A330 GE engines and not only once , forcing GE to provide a software "Patch" to work around the problem, which means that the problem is not solved yet
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BOAC I've edited the text, the intention was to state that at a lower speed the required ROD would be less and the time to landing more, allowing for alternate systems to extend flaps etc. You are quite right.. it didn't make sense in the previous format.. thanks
Not sure you can even count this as a double failure as I thought both engiens were producing a little thrust, not enough to fly but enough to power systems. I believe the aircraft was in normal law when it hit the river. The only total power loss landing in any modern jet airliner that I can think of was the Air Transat A330 deadstick in the Azores and the AirCanada B767 incident at Gimli. So far we are batting 1000 on deadstick landings