Programs: Duke of Bombay, Delta Ham Sandwich tm, Delta's Glitch
Posts: 3,827
Flying without working APUs
Is it just an anomaly or is this happening more often.... especially on RJ flights?
If they send out a plane without an operating APU, is it protocol to make sure the airport they are heading to has an APU and people on the ground who know how to use it?
If something were to cause a very unlikely double engine failure whilst in flight, would they be able to restart the engines if the APU was non operable?
I can understand when stuff breaks, but this just seems like poor planning.
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Had a 3+ hour Mx delay on ZRH-ATL a few weeks ago due to fuel pump not shutting down after APU started engines while lined up on runway. 3 Trips back to gate and they finally had to shut whole thing down and manually start engines. This was on a 767-300, not an RJ - but glad to have the problem addressed before going TATL.
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Programs: DL Diamond MM, SPG Platinum, Skywards Silver
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Happened to me Sunday
ATL-MCO on a 753...had to bring a "cart" over to start Engine 1 while at the gate...cart failed...waited for new cart to come over to start engine. Captain said they were using a cart because they "weren't using the APU". I don't know if that's French for "It's broken"
Programs: Duke of Bombay, Delta Ham Sandwich tm, Delta's Glitch
Posts: 3,827
Quote:
Originally Posted by FlyingDL4Fun
ATL-MCO on a 753...had to bring a "cart" over to start Engine 1 while at the gate...cart failed...waited for new cart to come over to start engine. Captain said they were using a cart because they "weren't using the APU". I don't know if that's French for "It's broken"
Are they turning APU's off to save fuel?
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Programs: DL - Diamond (NW - Plat), AA - Gold, Marriott - Plat, SPG - Plat, Omni - Black, Avis - First
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I'm not going to do into all the details...
1. Yes an aircraft can be operated without an operating APU - it can be a maintenance-deffered item for a certain period of time
2. Yes, the airport needs to have the following in the event on an inop APTIU
a) Ground Power Unit (GPU) or landside power connection - to power the aircraft while the engines are off
b) Air Start Cart - provides pressurized air to start the engine without the APU
3. Yes, engines can be restarted in flight without an APU
4. Yes, the APU is usually turned-off on the ground when the aircraft is connected to ground power and it is also turned-off in-flight
5. Yes, RJs are somewhat more prone to APU issues
Yeah, its annoying because if its warm outside, then the plane will end up getting hotter due to lower air flow. Also means you get to start the plane with the fun air cart that they wheel over, and it takes longer to do the whole process.
Yeah they can restart engines while in flight using a 'windmill' start as long as the aircraft is traveling at sufficient speed to spin the turbine enough.
On Thanksgiving, my daughter's plane, a 16 day old AA 738 had a malfunctioning APU at RDU. The next evening, my delay for a bad APU was on a WN 73G at BWI.
Programs: DL Diam MM, former NW Plat, HH Gold, PC Gold, Marriott Gold, Hyatt Plat
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Many many years ago I was flying NW MSY-MSP with a connection in MEM. The MSY-MEM flight was on a 757 and the APU wasn't operable. They couldn't start the engines at MSY with the available ground unit, at least not at first. Ended up having to bring a second unit over from AA and use them in tandem to get enough air pressure to eventually start the 757 engines (at least that is how it was explained). Ended up very late to MEM and spent the night at NW's expense.
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I believe the aircraft has to be doing around 230+ Knots to re-start the engines without an APU.
An aircraft usually lands at 130 - 140 Knots (depending on how heavy it is) so it could be going too slow to re-start the engines without APU.
Yeah, I know during approach and landing its far too slow to restart, however if you had a double engine failure then you're probably screwed even with a functioning APU
Yes! The summer sauna that was just about every DL aircraft was explained to me as that reason. The APU wasn't started until it became "too hot" in the cabin.
Nope. Was on BA2036 a 777-200ER from MCO-LGW, APU wasn't working so the number 2 engine was started at the gate before departure and then not shut down until ground power was available upon arrival. The captain notified the aircraft that the APU was inop.
Programs: Duke of Bombay, Delta Ham Sandwich tm, Delta's Glitch
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If something happens to a plane or there is WX issues, I can roll with the punches.
When they send a plane away from ATL or another hub with an APU that does not work to an airport that does not have a working cart.... that is just total crap and perhaps I have had a bad run of luck, but it has popped up a a number of times of late. Seems like something someone in Ops should be asking about.
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