A connection rod transmits the movement of the safety shaft to the drive shaft of the gear box. The output shaft of the gear box operates the drawbar which opens or closes the vent door.
 (4) Drift Pin Mechanism
 The drift pin mechanism is installed in the middle of the cargo door. It decreases the contour off-set between the fuselage and the door. The drift pin mechanism includes the teleflex controls and the drift pins with the related bellcranks and the connection links.
 The teleflex controls transmit the movement of the safety shaft to the bellcranks. They operate the connection links which retract or extent the drift pins. When the cargo door is correctly locked, the extended drift pins engage with the pockets of the fuselage frame.
R **ON A/C 106-149, 221-299, 301-399, 401-499,
 (3) Locking Mechanism
 The locking mechanism is installed parallel to and below the latching mechanism in the lower part of the cargo door. The primary task of this mechanism is to tell the operator that the latching mechanism is correctly latched. The locking mechanism includes the subsequent components:
 -
the locking shaft, which has a link rod, six lock cams with a red and green mark, a vent door lever, a connection rod and a sequence shaft.

 -
the linkage mechanism which includes the control rod, the serrated shaft and the gas spring.

 The control rod transmits the movement of the door handle (from 0 degrees to 65 degrees) through the maltese-cross lock to the locking shaft. The lock cams then engage with, or disengage from, the recess of the latching hooks. The engaged lock cams prevent the operation of the latching hooks. Then, the operator can see the green mark on each safety cam through the indication windows of the access panel. When the operator can see a red mark in the indication windows, then the lock cams are disengaged from the latching hook.
R 1EFF : 051-052, 106-149, 221-299, 301-399, 1 52-31-00Page 35 1401-499, 1Aug 01/05 1 1 1CES 1 The vent door lever transmits the movement of the locking shaft through the sequence shaft to the input bellcrank. The connection rod operates the linkage of the drift pins and the vent door.

 (4) Drift Pin Mechanism with Vent Door Mechanism
 The drift pin mechanism is installed in the middle of the cargo door. It decreases the contour off-set between the fuselage and the door. The drift pin mechanism has a drift pin assy and a linkage mechanism which includes the connection rods, the control rods, the drift pin bellcrank and the input bellcrank.
 The linkage mechanism transmits the movement of the locking shaft to the drift pins which retract or extend them. When the cargo door is correctly locked, the extended drift pins engage with the pockets of the fuselage frame.
 The vent door mechanism causes the vent door to open or close in accordance to the position of the drift pins.
 **ON A/C ALL
 (5) Switch Mechanism
 The switch mechanism is installed in the lower part of the cargo doors at FR25. This mechanism includes the target lever with the related target and the link assy.
 The target lever is attached on the support fitting which is riveted on the frame structure. The upper fork end of the link assy is installed on the lever of the drive shaft and its lower fork end on the target lever.
 The link assy transmits the movement of the drive shaft to the target lever. The target moves to or away from the proximity sensor 30WV which is installed below the door sill of the fuselage.
R 5. Operation
_________
R **ON A/C 001-049, 053-099, 101-105, 151-199, 201-220,
 (Ref. Fig. 007)
 1EFF : ALL 1 52-31-00Page 36 1 1 May 01/05 1 1 1CES 1 **ON A/C 051-052,

 (Ref. Fig. 007A)
R **ON A/C 106-149, 221-299, 301-399, 401-499,
 (Ref. Fig. 007B)
 **ON A/C ALL
 (Ref. Fig. 008)
 **ON A/C 001-049, 053-099, 101-105, 151-199, 201-220,
 A. Release Mode
 To release the cargo door mechanism, pull the door handle away from the cargo door. To get access to the door handle, the operator pushes the spring-loaded handle flap automatically inboard. This releases the door handle from the catch hook of the door structure.
 When the door handle is pulled up to the 65 degree position, the subsequent occurs:
 -
the door handle engages with the Maltese-cross lock to operate the linkage mechanism. Its control rod then turns the locking shaft so that the lock cams move away from the recess of the latching hooks,

 -
the drift pin lever moves up and operates the linkage mechanism. The control rods transmit the movement through the housing assy and the bearing assy to the connection rods. They move the drift pins which retract from the pockets of the fuselage frames.