Certified Flyers II
Duchess Multi-Engine Study Guide
13
The aircraft is equipped with a gear warning system which will activate under the following
conditions:
1.
Gear is not in the down and locked position below apx. 16” of MP on either engine
2.
Gear is not in the down and locked position with flaps extended below 16 degrees
3.
Gear handle is in the up position on the ground
Gear retraction on the ground is prevented by the ground pressure safety switch located in the
pitot system to deactivate the pump circuit when airspeed is below 59-63 KIAS.
(It should be noted that gear warning systems are no replacement for proper checklist usage and
should not be relied on to prevent an inadvertent gear up.)
The gear system is equipped with a hydraulic bypass valve for manual gear extension in the
event of an emergency. The valve is located beneath the floor panel in front of the pilot, by
rotating 90 degrees hydraulic pressure is released and the gear is lowered manually. This can
only be accomplished below 100 KIAS and the emergency checklist should be followed. In the
event that hydraulic pressure is lost with gear retracted, gear will free fall to the down position.
ENVIRONMENTAL
The BE76 Duchess is equipped with a 45,000 btu Janitrol gas heater located on the right side in
the nose compartment. This provides heated air for cabin warming and windshield defrosting.
Fuel consumption of the heater is approximately 2/3 gal per hour from the right fuel tank and
should be considered during flight planning. Operation of the heater is controlled by a three
position switch on the pilots subpanel labeled “HEATER-ON, BLOWER ONLY, OFF.” The
“BLOWER ONLY” position is only for ground operations. Another switch labeled “CABIN
AIR- PULL OFF” controls the amount of air entering the cabin from the heater. Pulling the knob
more than half closed will deactivate the heater in order to prevent overtemp. The push-pull knob
labeled “CABIN TEMP- PULL TO INCREASE” controls the temperature of air entering the
cabin.
BRAKES
The Duchess has hydraulically actuated disk brakes on the main landing gear. The hydraulic
system for the brakes is independent from the landing gear. The brakes are actuated by
depressing the top of each respective rudder peddle. To set the parking brake, pressure must be
applied to the top of the rudder pedal. The brake reservoir is located on the left side of the nose
compartment.
PITOT-STATIC
The pitot tube is located on the left wing. There are two static ports on each side of the aft
fuselage. There is an alternate static source located inside of the cockpit. The pitot tube is also
equipped with a pitot heat system. The pitot-static system provides air pressure used for
indications on the airspeed indicator, vertical speed indicator, and altimeter.
VACUUM SYSTEM