FLAPS
The wing flaps are operated from the landing
gear hydraulic system. The Flaps are actuated with the
flap handle on the center instrument panel below the
mixture control. They can be set to any position desired
by simply moving the handle up or down and then re
-
turning the handle to neutral once they are set to where
you want them.
SPEED BRAKES
Optional wing mounted speed brakes manufac-
tured by “Precise Flight Inc.” are flush mounted in the
top of each wing. Actuation can be either manual or
electric. The speed brakes have been tested to redline
(274 kts.) and landings have been made with full flaps
and speed brakes deployed.
LANDING GEAR
The Lancair IV main landing gear is constructed
of gun drilled tubular steel. The main gear is retracted
into the fuselage via full rack and pinion gears driven
by the hydraulic system.
The nose gear is a conventional air/oil oleo strut
with internal viscous shimmy dampening. Retraction
is accomplished with a separate hydraulic cylinder and
operated through the normal hydraulic system. A dedi
-
cated gas strut is used for emergency extension..
WARNING
The nosewheel shimmy dampener must be
checked on a regular basis. This can be accom-
plished by holding the nose wheel off the ground and
measure the rotational resistance of the assembly.
Air/oil struts should have from 20-50 ft. pounds of
torque. Also check the rotational resistance of the
wheel. If more than one free revolution of the wheel
occurs upon firmly spinning the tire, the split nose
gear doors are operated through the retract linkage,
and are held open by a spring in the same linkage.
The main gear outer doors are opened by springs in
their mechanical linkage, the inner doors are opened
by the main gear strut riding on a nylon track on
the individual door, they are spring loaded toward
the closed position and held in the positive closed
position in flight by a cable mechanism for the inner
door and through mechanical linkage for the smaller
outer door
.
GEAR OPERATION
In the down position the nose gear linkage is
“over centered” and the combination of the gas strut
and normal hydraulic pressure help hold it there. The
main gear is held in the down position by a mechanical
down lock pin located in each hydraulic actuation cylin-
der.
Retraction of the gear is accomplished by moving the
gear handle to the up position which unlocks the main
gear down lock pins, then retracts all three landing
gear. As the gear becomes fully retracted the hydraulic
system reaches its maximum pressure and a pressure
switch shuts off the pump. The gear is held in the up
position by hydraulic pressure.
