NORMAL OPERATIONS
The pilot operates the normal retraction and extension of the landing gear
acting on the LGCL which controls the Landing Gear Control Valve (LGCV).
The following figures show the extension and retraction operation
sequenced in phases.
NOTE
Only the LH MLG is shown in the diagram; RH MLG operates in the
same way.
Actuator position microswitches control all the extension/retraction phases.
NORMAL RETRACTION
Normal retraction occurs in two phases:
PHASE 1 – MLG SHORTENING
When the helicopter lifts-off, the WOW release the LGCL locking pin and the
pilot can move the LGCL to UP position. The NOSE, LH and RH amber
lights on the LGCP are illuminated because the LGCL position is UP while
the LG is not.
The retraction procedure starts only if the NLG is locked in the center
position (LOCK illuminated green in the NOSE WHEEL CENTERLOCK
pushbutton).
The VALVE 1 UP solenoid is energized and pressure from the hydraulic
system no.2 is delivered to the MLG Shortening Actuator (MLG SA) to
unlock from DN position and to shorten the MLG. As the SA piston unlocks,
the position microswitch extinguishes the relevant green triangular
annunciator on the LGCP.