Pitot-Static System - Arrow PA-28R-201 Pilot's Operating Handbook And Faa Approved Airplane Flight Manual

SECTION 7
DESCR/OPERATION
7.19 VACUUM SYSTEM (continued)
A vacuum regulator is provided in the system to protect the gyros. The
valve is set so the normal vacuum reads 4.8 to 5.2 inches of mercury, a setting
which provides sufficient vacuum to operate all the gyros at their rated rpm.
Higher settings will damage the gyros and with a low setting the gyros will be
unreliable. The regulator is located behind the instrument panel.
If equipped with the optional auxiliary vacuum system, refer to Section
9, Supplement 3, for operation procedures.

7.21 PITOT-STATIC SYSTEM

The system supplies both pitot and static pressure for the airspeed
indicator, altimeter and vertical speed indicator (when installed).
Pitot pressure is picked up by the pitot head on the bottom of the left
wing. An optional heated pitot head, which alleviates problems with icing or
heavy rain, is available. The switch for pitot heat is located on the switch
panel. Static pressure is sensed by button type vents on each side of the aft
fuselage. Push-button type pitot and static drains are located on the lower
left sidewall of the cockpit.
An alternate static source is available as optional equipment. The
control valve is located below the left side of the instrument panel. When the
valve is set in the alternate position, the altimeter, vertical speed indicator
and airspeed indicator will be using cabin air for static pressure. The storm
window and cabin vents must be closed and the cabin heater and defroster
must be on during alternate static source operation. The altimeter error is
less than 50 feet unless otherwise placarded.
To prevent bugs and water from entering the pitot pressure hole when the
airplane is parked, a cover should be placed over the pitot head. A partially
or completely blocked pitot head will give erratic or zero readings on the
instruments.
During preflight, check to make sure the pitot
cover is removed.
REPORT: VB-1365
7-18
PIPER AIRCRAFT CORPORATION
NOTE
ISSUED: SEPTEMBER 15, 1988
REVISED: MAY 10, 2009
PA-28R-201, ARROW