Understanting bleeds-off takeoff.

[JMEppright 2]

I have quite a few take offs in the NG and never had to use bleeds off take off yet. I have used flaps 25 and bump thrust but never the need yet for bleeds off. Its the last resort dispatch will use to get you off the ground. In fact I havent had any of my friends at our company use bleeds off yet. But I am sure there are some runways out there that require them.

Usually high and hot such as Denver at 95 degrees.

[ronzie 21]

Isn't it done in certain situations to enable one pack on bleed instead of both to preserve thrust?

I have quite a few take offs in the NG and never had to use bleeds off take off yet. I have used flaps 25 and bump thrust but never the need yet for bleeds off. Its the last resort dispatch will use to get you off the ground. In fact I havent had any of my friends at our company use bleeds off yet. But I am sure there are some runways out there that require them.

[Spin737 102]

Isn't it done in certain situations to enable one pack on bleed instead of both to preserve thrust?

The APU provides pressurization/air conditioning in this case and to the left pack only.

[Jack C 8]

Isn't it done in certain situations to enable one pack on bleed instead of both to preserve thrust?

Don't get a "bleeds off" take off confused with "packs off". Packs off take off don't really exist. Engine bleeds take off do.

[victorlima01 4]

Actually packs off takeoff do exist, however not in 737s so you are correct. I have seen however packs off takeoffs being done in a 777-200ER in MMMX.

[Jack C 8]

Actually packs off takeoff do exist, however not in 737s so you are correct. I have seen however packs off takeoffs being done in a 777-200ER in MMMX.

That's why we are in the 737 forum!!