PPRuNe Forums - Packs OFF for take off?

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Quote:

Originally Posted by stilton (Post 11709868)

Never flown the A320, we had a procedure in the 757 to use APU bleed for the packs on the rare occasions we needed more power out of limiting airports

If there’s no option to supply air for the packs from the APU I understand why they are turned off when necessary for increased power on take off

What I don’t understand is leaving the APU and it’s bleed on with the packs off. What benefit is that ?

On Airbus aircraft this is to allow pressure to get water to flow to the galleys and essential for that "cuppa coffee first thing" !!

Indeed, and some also like to wash their hands after a visit to the vacuum room.

But after leaving the parking stands, there is really no point in running the APU if You need neither its electricity nor its bleed air. Even if You suffer from excessive weight and want to get rid of fuel to get below MLW, there are better methods.

767. Before T/O, packs off. After T/O, packs on, one at a time. No pax so no probs. Hot/high gains about 2T of performance.