Backup for dropping the gear

Mark Astley wrote:
Yet other planes have an emergency
tank for blowing the gear down (beech maybe?).

Bonanza's: 50 turns of the little crank, located behind the little door
on the back of the main spar below the copilot's seat. The crank is
attached to a gear that meshes with another gear on the shaft attached
to the gear motor and landing gear.

"Mark Astley" wrote in message ...
snip
There are
various anecdotes about pilots reaching out the door with the towbar to pull
the gear all the way down.


I read one in a flying mag several years ago. Under the direction
of a ground based A&P, the passnger accessed the empty hydraulic
reservoir from inside the cabin and replenished it with a biologically
manufactured fluid. It was enough to get the gear locked and they
landed safely.

I'll bet the A&P that had to work on that system was ****ed :-)

John Galban=====N4BQ (PA28-180)

There are a lot of things that are not redundant.

The lesson to learn is to know the systems of your plane very, very, well.
This is not an easy task, nor is it common between planes.

You should know all the systems, and the what-if scenarios that go with
them. This includes the mechanical systems. Like how the cables and
pushrods are run through the plane.

For example: What if you pump down the gear but do not get a green
light? Do you cycle the gear? Answer - it depends. You need to give
thought to the possibility that cycling the gear may lose what little
hydraulic fluid you have left. When the hydraulic system runs more
than one thing, you need to worry about what else you might lose.
There is no one pat answer that fits all planes. Reading the emergency
procedures is great - except the emergency procedures have difficulty
determining which combination of failures has happened. You really
need to understand the systems.




In article ne.com, Andrew
Gideon wrote:
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I've been reading the POH for my club's 182RG, and I find myself surprised.
The manual gear extension replies upon the same hydrolic pressure system as
the powered mechanism.

Isn't that insufficiently redundant?

I'm not sure what I expected - perhaps something purely mechanical. But I
didn't expect a lone pressure system to be a single point of failure.

Is this normal?

- Andrew

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"d b" wrote in message
ink.net...

You should know all the systems, and the what-if scenarios that go with
them. This includes the mechanical systems. Like how the cables and
pushrods are run through the plane.

Reminds me of a story about the Aztec, on which I did my inital MEP
training.

The procedures go something like this:

To extend the gear, you move the gear selector lever to "down".

In case of failure of the engine-driven hydraulic pump:
1. move the gear selector lever to "down"
2. Extend handle of manual backup pump
3. Pump mumble times to extend gear
4. Stow handle

In case of failure of the hydraulic system
1. move the gear selector lever to "down"
2. actuate the emergency gear extension system
(AFAIR that releases something and the gear drops under gravity)

Not just one backup, but two! But I've only heard of one undercarriage
incident with the aircraft: As the pilot retracted the gear, the gear
selector lever came off in his hand, detaching at a point behind the
panel...

Julian Scarfe

"Julian Scarfe" writes:

In case of failure of the hydraulic system
1. move the gear selector lever to "down"
2. actuate the emergency gear extension system
(AFAIR that releases something and the gear drops under gravity)

"actuate" here means "reach under the left seat, flip up the door, and
yank the ring(?)". It causes CO2 to be released from a small tank into
the hydraulic system, making a mess and eliminating further worries
about what to do with the gear or flaps. Gravity plays a minor role.

Realize also that the Aztec is somewhat unique in that it can land and
roll out on retracted gear. Sure, you'll be replacing lots of stuff as
a result but at least it'll roll instead of skid.

--kyler

"Julian Scarfe" writes:

In case of failure of the hydraulic system
1. move the gear selector lever to "down"
2. actuate the emergency gear extension system
(AFAIR that releases something and the gear drops under gravity)

"Kyler Laird" wrote in message
...

"actuate" here means "reach under the left seat, flip up the door, and
yank the ring(?)". It causes CO2 to be released from a small tank into
the hydraulic system, making a mess and eliminating further worries
about what to do with the gear or flaps. Gravity plays a minor role.

That's the one. It did sound like a desperation measure.

Julian

The hand pump gives redundancy to the hydrolic system only in the event that
the electric power pack fails. In the event of an electrical failure, the
hydrolic system itself would still be intact, but the hand pump is a one way
pump, only allowing you to pump the gear down, not up. The 182RG's gear
system is a closed hydrolic system, as it only operates the gear. To have a
complete hydrolic system (gear) failure such as a blown hydrolic line or
fitting causing the system to loose it's entire quantity of hydraulic fluid
would be quite rare I would think. I'd much rather have a backup system to
an electrical system malfunction than have a back up to an hydrolic system.

Jim

All this discussion of alternate landing gear extension methods, and not one
person mentioned Fred Flinstone's landing gear.