User manual

Page 41

Aircraft Operation Manual

Piper Cheyenne I, IA, II, IIXL

For ight simulation use only

Inverter & Bus Tie Switches

1: Inverter 1/OFF/2 Selector

2: GYRO/INV Bus Tie Switch

Inverters convert 28V DC power from the generators to 115/26

VAC 400Hz AC power. The GYRO/INV Bus Tie Switch (2) selects

either the left or right Main Bus as the power source for DC po-

wer. The Inverter 1/OFF/2 Selector (1) selects either Inverter 1 or

2 as active.

Left/Right HTG Test Switches

These two center-locking switches (1 and 2) are used to test the

hydraulic topping governors prior to ight. When operating pro-

perly, with the propeller lever fully forward and Np set at 1625

RPM (IIXL: 1450RPM), holding the appropriate switch in the up-

per „H.T.G. RESET“ position will result in a 85 RPM reduction in

Np. Returning the switch to the center position will return the Np

to 1625 RPM (IXL: 1450 RPM).

Oxygen Control Knob

The oxygen control knob controls the cable-operated manual

shutoff valve. When pulled out, oxygen is supplied to the cockpit

and cabin outlets. A 22 or 48 cubic foot oxygen supply bottle is

installed aft of the baggage compartment. The oxygen system is

designed to provide emergency oxygen for the crew and passen-

gers for ight at altitudes above 10.000 feet.

Garret or Dukes Pressurization Controller

See section PRESSURIZATION (page 82) for a detailed description

of the cabin pressurization system and the operation of the Gar-

ret or Dukes Pressurization Controller.