Old Jul 17, 19, 11:09 am
  #23  
commuterpilot
 
Join Date: Dec 2011
Posts: 12
Originally Posted by grapkoski View Post
This has been an issue at DCA for a few summers now. I think its a mix of ground crews not having a checklist (or not following), the ground AC units being broken (aka MWAA's problem), and obviously, not wanting to run the APUs... although all airlines do this. Can't recall exactly, but pretty sure Delta has a reminder on the exterior Gate signs at ATL, 'HOOK UP, TURN OFF APU.'

Do Pilots need to flip any switches in the cockpit in order for the plane to use ground AC?
No, once plugged in it supplies air. Sorta.

So there are straight low pressure conditioning units at jetways and towed around by tug. You can also use the air start carts that normally supply high pressure air to start the engines, and they will run the packs as well, which would require turning the packs on.

However you are fighting ground grew hooking it up incorrectly and equipment issues that normally result in massive kinks in the line. Most of the conditioned air coming out of the units doesn't even get to the airplane. AA invested in ground start carts that actually run off an APU instead of diesel engines and they do an outstanding job, but they only have a handful at each hub.
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