Piper Cherokee Archer II Pilot Operating Handbook page 168

SECTION 9
SUPPLEMENTS
SECTION 4· NORMAL PROCEDURES
PIPER AIRCRAFT CORPORATION
PA·28-181, CHEROKEE ARCHER U
Prior to takeoff, the air conditioner should be checked for proper operation as follows:
(a) Check aircraft master switch "ON."
(b) Turn the air conditioner control switch to "ON" and the fan switch to one of the operating
positions· the "AIR COND DOOR OPEN" warning light will turn on, thereby indicating proper
air conditioner condenser door actuation.
(c) Turn the air conditioner control switch to "OFF" . the "AIR COND DOOR OPEN" warning
light will go out, thereby indicating the air conditioner condenser door is in the up position.
(d) If the "AIR COND DOOR OPEN" light does not respond as specified above, an air conditioner
system or indicator bulb malfunction is indicated and further investigation should be conducted
prior to flight.
The above operational check may be performed during flight if an in flight failure is suspected.
The condenser door light is located to the right of the engine instrument cluster in front of the pilot.
The door light illuminates when the door is open and is off when the door is closed.
SECTION 5 . PERFORMANCE
Operation of the air conditioner will cause slight decreases in cruise speed and range. Power from the.
engine is required to run the compressor, and the condenser door, when extended, causes a slight increase in
drag. When the air conditioner is turned off there is normally no measurable difference in climb, cruise or
range performance of the airplane.
NOTE
To insure maximum climb performance the air conditioner must
be turned off manually before takeoff to disengage the compressor
and retract the condenser door. Also the air conditioner must be
turned off manually before the landing approach in preparation
for a possible go-around.
Although the cruise speed and range are only slightly affected by the air conditioner operation, these
changes should be considered in preflight planning. To be conservative, the following figures assume that
the compressor is operating con tinuously while the airplane is airborne. This will be the case only in
extremely hot weather. .
,
(a) The decrease in true airspeed is approximately 4 KTS at all power settings.
(b) The decrease in range may be as much as 32 nautical miles for the 48 gallon capacity.
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REPORT: VB-790
94
ISSUED: JUNE 18, 1976
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