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Date: Mon, 26 Feb 2007 20:38:42 -0500
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Subject: 360 gear door closes before gear retracts
From: "bob mackey" <n103md@yahoo.com>
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Greg:
I guess this was the nose gear door that closed, based on the
"possible prop strike" comment. The only failure mode that
makes sense to me is a sticky sequencer valve.

First part of the diagnosis would be to put the airplane on jacks
so that an erroneous diagnosis doesn't lead to dropping the airplane
on its belly or worse - on your head. Then check that sequence valve
to see if it could have stuck in the compressed position while the
gear was up. Then when the gear came down it would have had to shove
the door out of the way. The pressures are low during transit, so this
wouldn't have been much trouble. Then, with the gear down, the door may
have closed. On the way back up, the gear would have collided with the
closed door and fully pressurized. Probably did some damage to the
the gear door, and possibly to the gear and to the hydraulic cylinder
mounting points.

Was the door still closed when you landed? If so, you could
reach inside (carefully!) and tug on the sequencer valve.
when it opens, and the hydraulics are powered into the down position,
the door should open.

ps - "kneaded pleasures"? is that massage therapy or baking?

-bob


> Don't think I caused this problem but I certainly have to deal with
> it - gear door closed before gear retracted in flight - no accident
> but could have been if the gear had strongly jammed into retract such
> that low pressure on extension might not have been sufficient to permit
> extension; possible prop strike.
>
> Didn't know of this condition until I was safely on the ground - didn't
> use the emergency gear extension - nor did I flip the
> gear-pressure-release valve - don't think I changed anything from
> the careful routines that I have used in dozens of previous flights.
> So what might have caused this scenario?  What must be done to prevent
> it in the future (besides "not flying")?
> Thanks for your comments.   Greg Nelson