Beechcraft Duchess 76 - Alternate Static Air Source

Section III
Emergency Procedures
BEECHCRAFT
Duchess 76
1. Emergency Extension Valve - CLOSE (Use Emergency
Extension Wrench - Turn Clockwise)
2. Landing GEAR MOTOR Circuit Breaker - ON (push in)
3. Landing Gear Switch Handle - UP
ALTERNATE STATIC AIR SOURCE
THE ALTERNATE STATIC AIR SOURCE SHOULD BE
USED FOR CONDITIONS WHERE THE NORMAL STATIC
SOURCE HAS BEEN OBSTRUCTED. When the airplane
has been exposed to moisture and/or icing conditions (espe-
cially on the ground), the possibility of obstructed static
ports.
should be considered. Partial obstruction will result in the
rate-at-climb indication being sluggish during a climb
or de-
scent. Verification
ot suspected obstruction is possible by
switching to the alternate system and noting a sudden sus-
tained change
in rate ot climb. This may be accompanied by
abnormal indicated airspeed and altitude changes beyond
normal calibration differences.
Whenever any obstruction exists in the Normal Static Air
System, or the Alternate Static Air System is desired for use:
1. Pilot's Alternate Static Air Source - Switch to ON AL-
TERNATE (lower sidewall adjacent to pilot)
2. For Airspeed Calibration and Altimeter Correction, refer
to PERFORMANCE section.
NOTE
The alternate static air valve should remain in the
OFF NORMAL position when system is not
needed.
3-14
January 1978