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Unread 03-22-20, 11:01 AM
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n86121 n86121 is offline
bigcheese
 
Join Date: Nov 2003
Location: Potomac Airfield~!
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Exclamation Possible explanation - squirt your uplocks

It has been decades, but....

The doors will not close until all the uplock micro switches are all closed (wired in series),
which also turns the UPLOCK light ON.

This makes sure everything cycles in sequence correctly
and prevents doors from closing while gear still in transit (or not all the way up).

As I recall,
that uplock light circuit also allows the system to pressurize to 1200-1500 PSI.
When it hits that pressure limit it pops the gear handle down.
The handle goes down, the system at rest,
and all is well in the land....

In your case
the the gear comes up,
the uplocks close UNDER PRESSURE (but not solidly!!!),
the microswitches are closed (under UP CYCLE pressure)
the uplock light comes on (briefly),
your doors close,
then the light goes off
but the down handle never occurs.

I would bet a nice doughnut against a dollar your uplocks not solidly going 'CLICK'

So under UP-CYCLE pressure they the uplocks in position
CAN AND DO close the microswitches,
but wont keep the switches closed without the UP CYCLE pressure.

So the final pressurization needed to pop the handle never occurs.

-------

ANSWER #1: Check /squirt get to know your uplocks.

ANSWER #2: If the system cannot hit the 1200-1500 PSI to shut off,
it wont lock the system UP correctly.

Yes, a leak or air will do this.
ON THE GROUND, try cycling the gear DOWN CYCLE position.
If system can hold pressure it will pop the gear handle 'up'
from DOWN-CYCLE to the DOWN LOCKED position.
No leaks.

The system is 'self-burping' so a bunch of cycles will burp out the air.

I will accept any decent chocolate-covered doughnut as reward.

EXTRA CREDIT

I have replaced those little beasts with tiny screw in 24 volts LEDs
Nice, cool, will never burn out (again).

D
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David Wartofsky
Potomac Airfield
10300 Glen Way
Fort Washington, MD 20744
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