21A Air Supply
TTP B1-L3 ATA 21A Beech 90 Series B2-L2 Air Supply Air for pressurizing the cabin, heating the cabin and cockpit, and operating the aircraft pneumatic system is obtained b y b leeding P3 compressor air from each engine (refer to the MSM ). This engine b leed air is ducted from the engine to the fl o w control unit on the l o w er engine mount t r usses. A pressure supp l y line, to operate the pneumatic system, tees off the b leed-air line just aft of the first fire seal for w ard of the fir ew all. The b leed air from either fl o w control unit pr o vides adequate air for pressurization, heating, and the pneumatic system should the opposite engine f ail. The b leed air and ambient air from the c o wling inta k e are mi x ed t o gether b y the fl o w control units to produce a total airfl o w of 14 pounds per mi...