View Single Post
Old 5th Apr 2021, 01:34
  #11 (permalink)  
tcasblue
 
Join Date: Nov 2019
Location: unknown
Posts: 198
Intruder

That's new to me, I have flown pax, straight and converted combi, Boeing freighter with nose door and IAI Special Freighter 747-400's. As far as I can remember, APU to Pack and Packs Off is allowed on all of them. All available as an option in the OPT for performance calculations.

APU-to-Pack Takeoff
After engine start:
LEFT and RIGHT ISOLATION valve switches - OFF
Leave APU running to supply air to pack 2.
Before takeoff:
PACKS 1 and 3 control selectors - OFF
After takeoff:
PACK control selector (One only) - NORM
After engine thrust is reduced from takeoff to climb, position one Pack Control selector to NORM.
PACK control selector (Remaining pack) - NORM
When cabin pressurization stabilizes, position remaining Pack Control selector to NORM.
LEFT and RIGHT ISOLATION valve switches - ON
APU selector - OFF


Packs Off Takeoff
Before takeoff:
PACK Control selectors - OFF
After takeoff:
PACK Control selector (One only) - NORM
After engine thrust is reduced from takeoff to climb and prior to reaching 3,000 feet above field elevation, position one Pack Control selector to NORM.
PACK control selectors (Remaining packs) - NORM
When cabin pressurization stabilizes, position remaining
Pack Control selectors to NORM.


As for a bleeds off takeoff in an aircraft, I seem to remember most of our takeoffs in the 737-200 were with bleeds off as the call during climb was "Climb Thrust Bleeds On".
tcasblue is offline