A. Put the aircraft back to its initial configuration.
(1)
Lower the aircraft on its wheels (Ref. TASK 07-11-00-586-001).
(2)
Remove the safety barriers.
(3)
Remove the warning notice(s).
(4)
Make sure that the work area is clean and clear of tool(s) and other items.
1EFF : ALL 1 32-22-16Page 409 1 1 Feb 01/01 1 1 1CES 1 EXTENSION AND RETRACTION - DESCRIPTION AND OPERATION
____________________________________________________
1. General
_______
R **ON A/C 001-049, 051-099, 101-149, 151-199, 201-299, 401-499,
(Ref. Fig. 001)
**ON A/C 301-399,
(Ref. Fig. 001A)
**ON A/C ALL
The extension and retraction system extends and retracts the landing gear (L/G). The system is divided into two sub-systems:
-
the Normal Extension and Retraction System (Ref. 32-31-00)
-
the Free Fall Extension System (Ref. 32-33-00).
A.
Normal Extension and Retraction
The L/G control lever (6GA) is on the First Officers side of the center instrument panel. It operates the extension and retraction of the landing gear.
The normal extension and retraction system is used to extend and retract the L/G. The system is electrically controlled and hydraulically operated. The hydraulic supply is from the Green hydraulic power system (Ref. 29-11-00). A Landing Gear Control and Interface Unit (LGCIU) controls the sequence of operations.
The two control and position-sensing systems each have a LGCIU, proximity sensors and targets.
B. Free Fall Extension
The free-fall extension control-handle is on the rear of the center
pedestal and operates the L/G mechanically.
If the normal extension and retraction system is not servicable, you can operate the free-fall extension system. It extends the nose landing gear (NLG) and the main landing gear (MLG) by gravity. The system is mechanically operated by cables, rods, and levers, used to make the necessary extend selections.
1EFF : ALL 1 32-30-00Page 1 1 1 Aug 01/05 1 1 1CES 1
Extension and Retraction - Schematic
Figure 001
R 1EFF : 001-049, 051-099, 101-149, 151-199, 1 32-30-00Page 2 1201-299, 401-499, 1Aug 01/05 1 1 1CES 1
R Extension and Retraction - Schematic
R Figure 001A
R 1EFF : 301-399, 1 32-30-00 Page 3
1 1 May 01/04
1 1
1CES 1
When you operate the free-fall extension control-handle, it releases the uplocks on:
-
the MLG door
-
the NLG door
-
the MLG gear
-
the NLG gear.
A mechanically-operated valve isolates the hydraulic supply. To prevent cavitation and hydraulic locks, other mechanically-operated valves let fluid move in the hydraulic components of the normal extension and retraction system. When the uplocks release, gravity extends the L/G doors and the L/G. Springs pull the downlock-links of the L/G into the locked position and the L/G doors stay open.
When you put the free-fall extension control-handle to the NORMAL position and set the L/G control handle to DOWN:
-
the main doors close
-
the system is set to the normal extension and retraction mode.
2. Component Location__________________
Not applicable
3. System Description__________________
A. Normal Extension and Retraction
The normal extension and retraction system has two independently wired electrical circuits, SYSTEM 1 and SYSTEM 2. Each system contains a LGCIU, and proximity sensors to show the position of the L/G components. Only one LGCIU controls the System at one time. The LGCIU in control is the active unit and the other is the standby unit. Each circuit connects to the L/G control lever, a L/G and a L/G door selector valve. A safety valve connected to the ADIRS (Ref. 34-10-00) isolates the system from the Green hydraulic supply when the aircraft flies faster than 264 knots. This prevents the extension of the L/G. The L/G and the L/G door selector valves control the flow of the hydraulic fluid to and from the system hydraulic components.
The L/G hydraulic system includes:
-
the actuators that move the mechanical L/G and L/G door components
-
the mechanically operated valves that let the doors open on the ground.
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