Hey everyone,

 

Quick question regarding the APU. What is the normal procedure regarding APU prior to departure assuming that ground power and external air are already connected. I've read that generally the APU is turned on 10 min prior to pushback but are the APU generators and APU bleed turned on as soon as the unit powers up or does the aircraft continue to remain on ground power and external air until pushback begins?

 

Thanks!

 

-Jaison Diaz

APU gen can be connected right away after APU start.

But it's recommended to wait at least one minute before open APU bleed valve (FCOM vol.2, page7.30.3). And APU bleed must be closed when ground air connected and isolation valve opened (FCOM vol1, page L.10.8).