Backup for dropping the gear

"Paul Tomblin" wrote in message
...
The POH for the Lance isn't 100% clear on this, but my understanding is
that with the emergency gear extension, the gear will come down if you go
below a certain manifold pressure at one speed, or will come down
regardless of the manifold pressure at a lower speed.

Well, if it's manifold pressure based, then an engine failure would only
cause the gear to come down if the failure was caused by a blocked air
intake, or if the pilot later pulled the throttle to idle. Again, an engine
failure would not, in and of itself, necessarily cause the gear to extend.

[...]
Actually, reading that again, it's possible that what is happening isn't
that it comes on at a lower speed if you have power on, but that the
propellor slipstream holds the gear up against the springs if you have
power on.

I don't know how the "propeller slipstream" could hold the gear up. The
only "propeller slipstream" I'm aware of is the helical movement of the air
around the fuselage, and compared to the other forces involved I doubt it's
all that strong.

I think it's interesting that the POH puts "propeller slipstream" in
parentheses after "engine power", because to me it's not at all clear what
they mean. The two aren't exactly equivalent, so it's odd they would use
them as if they were. The parenthetical comment ought to add information,
but to me it just confuses things.

Pete