Originally Posted by
WB627
I'm surprised that they can fly with an inoperative APU?
...........
Not a MEL item then?
Before go into the meat of this - for those reading this and being
- The Minimum Equipment List (MEL), also commonly known these days as a Despatch Deviation Guide (DDG) is a document that lets a crew know what defects are “No Despatch” and OTOH those which are acceptable to take into flight and also any changes to rules or procedures caused by those defects.
APU inoperative may well be a MEL or DDG “item” but the book, whatever you call it, may well say despatch is allowed without the APU or components of it working as long as certain rules and procedures are followed.
Not having the APU available complicates things on the start ( you need the ground air truck to give you compressed air to spin at least one engine up for start, and you need ground electrical supply plugged in until you have an engine driven generator available) but after that, on many types, as long as there are no other problems with other elements of the engine driven electrical and air systems it’s usually “operations normal” until you get to destination.
FWIW on many of the “big twins” you can still do the likes of ETOPS without a serviceable APU, so I can’t see lack of an APU stopping a minibus from doing shorthaul sectors...but I suspect it adds more hassle to the crew’s working day.