B738 ONE PACK INOP dispatch - why engine bleeds off?
Hi all,
Recently I had to dispatch with the right PACK inop. The D.D.P.G. in my company states the following:
1) Limit altitude to FL250
2) ER operations not allowed
3) Position associated PACK switch to OFF. To maintain isolation bleed sources, position the isolation valve switch to CLOSED
4) For increased air flow when flaps are extended (takeoff and landing) use APU to supply bleed air to the operating pack;
A: Right PACK inop:
Use the Boeing "No engine bleed takeoff and landing procedure"
B: ....
My question is: Why does a pack inop dispatch require one to depart with engine bleeds off??? I thought this only added complexity to a relatively simple issue - in particular when we did not require the extra performance that the engine bleeds off procedure provides...
Thank you for clarifying!