Certified Flyers II
Duchess Multi-Engine Study Guide
12
When flaps are positioned below 16 degrees the landing gear horn will sound if the gear is not
down and locked (regardless of throttle position).
ELECTRICAL SYSTEM
Certified Flyers’ BE76 Duchess is equipped with a 12-volt, 35 ampere-hour lead-acid battery
installed in a battery box in the aft fuselage compartment. Two 60 ampere, 14-volt, belt-driven
alternators provide charging. The output of each alternator is controlled by a separate voltage
regulator. The alternator systems are completely separate, except for the BUS TIE FUSE, the
mutual tie to the battery bus through two bus isolation circuit breakers, and the paralleling circuit
between regulators. The
aircraft uses a split bus
system with each
alternator powering its
respective bus. The
battery is used for engine
start and emergency
power. Overvoltage
protection is provided.
There are two loadmeters,
alternator out
annunciators, and
under/overvoltage
annunciators. The
alternator out
annunciatior light and
zero indication on the
ammeter indicate an
alternator failure. If one
alternator fails the other
alternator will provide
adequate electrical power.
LANDING GEAR
The Duchess is equipped
with a tricycle gear,
hydraulically actuated,
fully retractable landing
gear. Hydraulic pressure
is provided by an electrically driven reversible hydraulic pump. There are two circuit breakers:
one for the hydraulic pump, one for the control circuit. The gear is held up using hydraulic
pressure and remains locked in the down position using over-center brace and spring. There is a
time delay which will disengage the hydraulic pump after 30 seconds of continuous operation.