"Andrew Gideon" wrote in message
online.com...
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.

I'm not sure there's enough standardization in gear retraction/extension
systems to say what's "normal". However, certainly the lack of redundancy
is common enough on light planes. In fact, not only is the gear on my
airplane designed similarly, the flaps and elevator trim use the same
hydraulic system. A failure in the hydraulic system that takes out certain
lines, and/or results in a loss of fluid would affect all three systems
simultaneously.

Occasionally you might find a "fail safe" system like the one on the Lance
that Paul mentions, but as he even points out, those systems come with their
own issues. Aircraft designers often come to the conclusion that the extra
complexity, cost, and weight isn't worth the marginal increase in safety.

Especially when one considers just how dangerous a gear-up landing *isn't*,
it's not hard to see why that conclusion is reached so often. As far as I
know, such "insufficiently redundant" systems are more common than
"sufficiently redundant" ones.

Pete