Would you cycle the gear?

In article ,
Roy Smith wrote:
The nose green light was flashing, as was the yellow "gear in transit"

There were two options: Cycle the gear, and try an emergency extension.
There are so many different gear systems out there it's hard to say what
would help.

I'd say a bad limit switch is a reasonable guess, but I wouldn't be so
quick to rule out an actual failure to lock. Some tiny last bit of
travel to get a cam overcenter or a lock in place.

Hydraulic and combination electric/hydraulic runs the risk of running
out of fluid if there's a leak. That's the case in the Arrow, right?
On the other hand, isn't the fluid just there to hold the gear *up*? In
theory it should just fall down (spring assist?). Some of the big Cessnas
can 'blow' the gear down with compressed gas if the hydraulics run out.

My Comanche's gear is all mechanically interconnected, and there is only
one down light. If it didn't light my first thought would be to slow way
down and try again (slowing down is part of the emergency extension anyway),
and follow through on the manual extension lever to help the electric motor.
If I felt the downlock through the lever I'd be tempted to leave the motor
engaged, since it helps hold the gear in place, and there's likely not much
more I could do with the lever alone. You can't re-engage the motor in
the air, you have to jack it up. After the flight you probably install one
of those little parabolic mirrors on the left wingtip for checking the
gear (every PA-24 I've flown but my own has had one

The Mooney is similar to the Comanche (ie I see no harm in cycling it,
other than the battery drain, since those big motors draw more than the
alternator can continuously supply). My brief Mooney gear training did
not include any caveats about the manual extension being "weaker" than
electric extension, so I'd be tempted to try it. It's a cable you pull
sort of like starting a lawnmower, and you get a gear down indication
through a little window. You *can* go back to electric gear in the air
if you change your mind.

--
Ben Jackson

http://www.ben.com/

(Ben Jackson) wrote in news:Wljac.38295$JO3.30797@attbi_s04:

Hydraulic and combination electric/hydraulic runs the risk of running
out of fluid if there's a leak. That's the case in the Arrow, right?
On the other hand, isn't the fluid just there to hold the gear *up*?

Right. It's held up by hydraulic pressure, falls down by gravity and
spring assist (if the pump isn't working).

The nose gear is the most problematic, because it has less "free fall"
weight and more air resistance. Personally, I would have gone out of the
pattern and "played with it" a bit. Retract it, then drop it again at low
airspeed with a small pull-up right at the end. Unlike a Cessna 210 (for
example) if the pump is dying or the the fluid is leaking out, it's not
really going to get any worse.

But there *is* a small chance of mechanical damage that is limiting
transit, and it might jam. Of course, in that case, the nose gear probably
isn't locked now anyway.

NONE of that is to say that you decision was in any way incorrect. Any
such decision is a guess based on limited information and I believe either
choice is justified.

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James M. Knox
TriSoft ph 512-385-0316
1109-A Shady Lane fax 512-366-4331
Austin, Tx 78721
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