B737 gear manual extension cover

[RAT 5]

Searched & searched. No success. Wanted: learned opinions or facts. On the NG there is a cover for the manual gear extension handles. (if I remember this was not on the 732 or classics). Inside there is a micro-switch. If the door is open even only a fraction the gear can not be raised. For a pilot the only reason to open this door is to lower the gear manually. The QRH does not tell you to close it again, but common sense means you do; to avoid tripping over it on exit.
Nowhere can I find any procedure for a pilot to open the door AND leave it open. So why is the protection there? Is this for some maintenace procedure to avoid having to descend and put the pins in?

[IFixPlanes]

Even the 737 Jurassic have this door. But only the NG have the micro-switch.
When you want to lower the L/G on the 737-100 to 500 manuell the L/G lever must be in the OFF-position to connect the UP and DOWN side of the actuators with the return line. If you donīt do this, the trapped hydraulic fluid prevent the correct lowering.
In the NG it does not matter in which position the lever is because the opening of the manual extension door actuate the micro-switch.
Now you have the manual extend solenoid valve in the landing gear selector valve powered and the L/G goes down as if lever is in OFF.
With this in mind you can do a little trouble shooting if L/G did not go Up after lift off:
If you pull the CB D6 (LANDING GEAR ALTN EXTEND SOL) and then retraction is possible, you have a faulty activated micro-switch.
Or simply the access door is open

[RAT 5]

Ah Hah. Many thanks. You are correct about the door; I meant the micro switch. The only info to us was that the gear could not be raised thus implying that it was a retraction protection. From your explanation the micro switch is in fact to aid the extension. How easy it is to fool people with incomplete imformation leading to wrong assumptions.