User manual

Page 82

Aircraft Operation Manual

Piper Cheyenne I, IA, II, IIXL

For ight simulation use only

PRESSURIZATION SYSTEM

Dukes Pressurization Controller (Cheyenne I & IA)

Garret Pressurization Controller (Cheyenne II & IIXL)

1: Cabin rate of climb gauge 2: Cabin altitude gauge

3: Cabin rate of change control 4: Cabin altitude controller

Defaults to 500 ft/min cabin change rate 5: Cabin pressure test/dump switch (Garret only)

May be adjusted to a minimum of 100 ft/min

or a maximum of 1000 ft/min (Garret: 2500 ft/min)

Pressurization air for the Piper Cheyenne is obtained by use of high pressure en-

gine compressor bleed air. The high pressure air is routed through an intercooler,

then into a jet pump which mixes bleed air with outside air. The decreases the

amount of high pressure air required from the engine and also lowers the tempe-

rature of the bleed air. The air then proceeds to the main pressure line under the

cabin oor and passes through the pressurized air control box assembly, which

controls the ow of air that is to be routed either to the cabin or overboard.

The cabin air control has three positions marked: PRESSURIZED AIR, RECIRCULA-

TED AIR, and OUTSIDE AIR. When the control is in the PRESSURIZED AIR position,

the air is directed through the air conditioning evaporator to the heater and