How far are the gear supposed to retract?

[Edward Rognerud]

I had our PA 39 up on jacks. I cycled the gear a few times, and noticed that the mains do not retract all of the way into the well. The gear doors line up flush with the wings, but the tires hang out at a slight angle with just over an inch of rubber hanging below the wing at the inboard side of the well. Is this normal???

Ed Rognerud
Rosemount MN

[N3322G]

Ed,

Wish you'd been at the CTPT, Inc. Maintenance education last week and had your plane's condition assessed - they talked all about this. The specs are in the service manual on this website or at comanchegear.com

IIRC a 9 pound weight hanging on the gear doors should bring the door down either 1/8 or 1/4 inch. Up limit switch should be adjusted so there is a slight gear motor strain at the end of the cycle as the tires touch the wheel well pads and ... then there's the proper adjustment of the micro-switches and the pre-load.

My recommendation would be to adjust the gear from soup to nuts based entirely on the service manual rather than how it appears. That being said, my 39 tires are visible - couldn't say how much but it is why LoPresti made the gear lobe fairings.

BTW don't forget to look very carefully at the mains swivel attach point where other twin doors have been cracking at the base.

[Kristin Winter]

The gear will show a bit below the wing. Check and see if the fork is snug against the bumper in the well. If you can push the gear up further, they it is not retracted fully.

[md11flyer]

Ditto the above posts and .... very important..... make sure that if you adjust the gear
up limit switch to draw the gear further in the wells , make sure that you can do a manual release without
having to use brute force to move the red lever to release the gear. If the gear is too tight you can get into a situation where if you
try to release the gear transmission during an emergency extension of bending the mechanism and not disconnecting the gear transmission.
Not nice to find out when needed, do the release in the hangar on jacks to be sure.

Gary

[MULEFLY]

Ed -- suggest that you go to www.comanchegear.com .... Matt Kurke is one of the most knowledgeable folks on the planet about the Comanche Gear system. He has quite a bit of information there regarding the gear. The Service Manual outlines a detailed procedure on how to adjust it. Matt adjusted mine so far up that I think the airplane "coughs" when it reaches the up-limit. Actually the gear should just make contact with a pad up in the wheel well. Matt put a thinner pad on my airplane.

Pat is correct that there should be minimal deflection of the door with a 9 pound weight.

The tire will not be totally enclosed. Pat references the LoPresti fairing. Some feel that the Knots-2-U fairing is slightly superior.

Mine is also a PA39.
All the best!
Jim

[Steve Marcozzi]

This comment is probably a little late but....

When you pull the red release lever with the gear all the way up, make sure you have a firm grip on the manual extension handle, ......or one or two trusting souls underneath on creepers to catch the mains (insert stupid human story here).

If not, your gear will fall "like a ton of bricks" since there's no airload against it.

Steve

[Edward Rognerud]

Thanks for the input. The gear does retract all of the way up to the rubber bumpers. It is has a fresh 1000 hr AD, and is adjusted properly to the best of my knowledge. I was just surprised that the rubber would hang down below the wing on an airplane built to be fairly fast. I will put the gear speed mods on my to do list.

Thanks again,

Ed Rognerud
Rosemount MN

[9089P]

The hanging rubber is the cost of having that thin laminar flow wing. The wing is not fat enough to hold the tires.

Don