Non functioning APU
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On the 727 if the APU is out, you're dead in the water, so to speak. You cannot start the engines or refuel the aircraft unless ground power, GPU, is available and you have an ground air source to start at least one engine.
In fact, unless modified, if you leave an engine running after landing, you still cannot refuel with out a GPU on the 727.
Oh, the APU on the 727 cannot be used in flight, ground operations only.
In fact, unless modified, if you leave an engine running after landing, you still cannot refuel with out a GPU on the 727.
Oh, the APU on the 727 cannot be used in flight, ground operations only.
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... or did you mean an airport?
This restriction was so that the airplane would have adequate electrical and pneumatic sources available in the event of a double engine failed situation...IE: same electrical/pneumatic redundancy as a four engine type, where an APU would not be approved for airbourne use (ala---B747).
The L1011 APU can be used (and is fully approved) , for both electrical and pneumatic sources, up to FL 310.
So, four engine redundancy, with a three engine airplane, with regard to electrics/pneumatics.
One should also remember...no L1011 has ever crashed due to an aircraft/engine design defect...quite unlike the B747 or the DC10.
Lockheed TriStar, simply a superior design...make no mistake.
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Boarded a CRJ700 in Aspen, CO a few days ago. It was no warmer than -10C outside and that hair dryer of a APU was struggling to keep it colder than 30C in the cabin.
Ended up leaving 10 people behind due to weight restrictions.... They shoulda kept those BAe146's.....
Ended up leaving 10 people behind due to weight restrictions.... They shoulda kept those BAe146's.....
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Thanks for the update 411A, but I don't see how
can be claimed. In a B747-400, dispatching with 1 u/s engine generator does not restrict one to 400 miles from an airport
So, four engine redundancy, with a three engine airplane, with regard to electrics/pneumatics.
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In a B747-400...
In addition, the L1011 can also be dispatched with one engine IDG inop, with minor restriction, so long as the APU is functional.
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Could the 747 Classic use the APU for electrics when airborne?
Did the Classic parallel the engine gennerators?
Did the L1011 parallel the engine generators?
Did the Classic parallel the engine gennerators?
Did the L1011 parallel the engine generators?
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Did the L1011 parallel the engine generators?
IE: no Flight Engineer input necessary.
One should remember that the L1011 was the first truly automatic jet airliner...others followed.
Refer to the thread on CATIIIC capability to see why it works so well.
Except, it appears for the RAF, who has continuing major difficulties.
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As SLF, I flew from LHR to IAD on a BA 744 with an inop APU. It was not comfortable on the upper deck until they got the engines going. Took two huffers to blow start the thing. Had to divert from IAD to PHL and spent an hour at the gate at PHL, again with no APU before they got customs spun up and let us off. For being loyal BA passengers, we all received a complimentary hour's worth of sauna at each end of the flight.
I vote for the APU working even on the 744.
-Old Ag
I vote for the APU working even on the 744.
-Old Ag
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Could the 747 Classic use the APU for electrics when airborne?
Did the Classic parallel the engine gennerators?
Did the Classic parallel the engine gennerators?
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Engine generators sync, but will not sync with the APU generators.
Having said this, the -400 model seems to be a vast improvement over the 'classic' design.
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"On the 727 if the APU is out, you're dead in the water..."
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On the 727 if the APU is out, you're dead in the water, so to speak. You cannot start the engines or refuel the aircraft unless ground power, GPU, is available and you have an ground air source to start at least one engine.
In fact, unless modified, if you leave an engine running after landing, you still cannot refuel with out a GPU on the 727.
Oh, the APU on the 727 cannot be used in flight, ground operations only.
In fact, unless modified, if you leave an engine running after landing, you still cannot refuel with out a GPU on the 727.
Oh, the APU on the 727 cannot be used in flight, ground operations only.
Unless Boeing went the several versions of the fueling valves and manifolds (which they didn't) the 727 can be refueled without even the battery being on. The only part you got right is that the 727 APU shouldn't be used in flight (it can't be started anyway, but can be left on accidentally after takeoff, and will flame out around 25000 feet), some operators had the T/O Warning horn attached to the APU in addition to the Flaps, Trim and Speedbrakes to prevent inadvertant takeoff with the APU on.
Bar none it's one of the best remote operations jets in the world.
Last edited by aviatorhi; 14th Jan 2011 at 06:33.
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Normally quite OK, however...MEL restrictions might apply.
For example, with the L1011, flights more than 400 NM offshore are not allowed.
In addition, there is normally an MEL time limit on APU unserviceability...ten calendar days in the case of our aircraft.
For example, with the L1011, flights more than 400 NM offshore are not allowed.
In addition, there is normally an MEL time limit on APU unserviceability...ten calendar days in the case of our aircraft.
The L-1011 MMEL has no such restriction.
411A's airline may have added it to their MEL, which is allowed. The airlines MEL can always be more restrictive (never less restrictive) that the MMEL.
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Now that I got to thinking about it, in a pinch you could start a 727 without even the battery being on, that's right, no power at all. All you need is air (however this is a long drawn out procedure I've had explained to me by PFEs who flew in war zones). Realistically though, you could start without aircraft electrics but you would need ground electrics.
Last edited by aviatorhi; 17th Jan 2011 at 05:26.
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That's the furthest thing from the truth I've heard in a while. Sentence by sentence: You can start the engines off Battery Power only,
I do agree with this.
Bar none it's one of the best remote operations jets in the world.
How are you going to start the engines?
One more point we differ.
but can be left on accidentally after takeoff, and will flame out around 25000 feet)
Also on both occasions, there was a pilot/FE, not a professional FE riding side saddle.
By the way, I do have over 7,000 hours flying the 727.
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I did say the only thing you need is air, so no APU=not dead in the water.
I've left it on once and noticed it at 1000 MSL and switched it off... I've heard leaving the APU on results in everything from it just flaming out to blowing up the tires to fire bells to compressor stalls (when switching onto #2 bleed in flight) etc. etc. I've never let it get that far and the most common one I hear is a flamout.
I'm not sure how much they taught you at EA, but I've had to climb under the LE flap more than once to override a premature VTO shutoff.
I've left it on once and noticed it at 1000 MSL and switched it off... I've heard leaving the APU on results in everything from it just flaming out to blowing up the tires to fire bells to compressor stalls (when switching onto #2 bleed in flight) etc. etc. I've never let it get that far and the most common one I hear is a flamout.
I'm not sure how much they taught you at EA, but I've had to climb under the LE flap more than once to override a premature VTO shutoff.
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I've left it on once and noticed it at 1000 MSL and switched it off... I've heard leaving the APU on results in everything from it just flaming out to blowing up the tires to fire bells to compressor stalls (when switching onto #2 bleed in flight) etc. etc. I've never let it get that far and the most common one I hear is a flamout.
I remarked to the co-pilot that I kind of wished he had not done that, silence the bell, as we had an overheat/fire condition indicated somewhere. So trouble shooting was now rather limited. So I told him to recheck the lights, there was a chance that two bulbs had gone out at the same time, but not very likely. Just about then I started to think on just what could set off an fire alarm, but not light up anything on the instrument panel. Then it hit me, the APU.
So I kind of stood up in my seat, craned my head around so I could see the APU panel and sure enough, the APU fire light was on. So I told the FE to shut down the APU, so he grabed the start/stop switch and moved it to off. Of course the switch is disabled while airborne, so I had to tell him to pull the APU fire handle. He did and the light went out immediately.
Then he started arguing with me, he claimed that he did shut down the APU before takeoff and that the APU must have self-generated a start.
Besides being a terrible FE, he wasn't much of a pilot either as it turned out.
Give me a professional Flight Engineer any day.