B737-700 Manual Gear Release Hatch

[regor]

According to the OPS manual, once the manual gear release hatch has been opened, "landing gear retraction is disabled".

Can anyone enlighten me as to whether the 'disabling' is done mechanically; by activating the solenoid for the gear lever lock, or hydraulically; by keeping a valve shut.

[Flight Detent]

Regor,

My understanding of the floor mounted manual gear release hatch is simply:
When the hatch is opened an access door position switch sends a signal to the landing gear selector valve to prevent a hydraulic lock which may not permit manual extension of the landing gear.

If this access door is not properly closed during normal operations, the landing gear will not retract!

That is, the up side is depressurized to allow the free-fall of the gear!

Cheers,



:D

[IFixPlanes]

If you dont get the gear up after TO, check the access door of alternate gear extend. When you find it in close position, pull the CB "ALTN EXTEND SOL". If you get the gear up now, you have a faulty access door position switch. :hmm:

http://img341.imageshack.us/img341/6218/manualextend019ct.th.jpg (http://img341.imageshack.us/my.php?image=manualextend019ct.jpg)
http://img341.imageshack.us/img341/6410/manualextend028vl.th.jpg (http://img341.imageshack.us/my.php?image=manualextend028vl.jpg)