"Brian Whatcott" skrev i en
meddelelse
...
On 6 Jun 2005 09:48:03 -0500, Dave
wrote:

On Mon, 06 Jun 2005 08:01:55 -0400, Gogarty
said:

A freewheeling propeller creates more drag than a locked
on.. Just
consider a helicopter. Engine out and rotors
freewheeling, the aircraft
will go down safely. Rotors locked and it drops like a
stone.

Bad analogy. In a helicopter when the rotors are
freewheeling after the
engine dies they're still rotating in a direction that
generates lift.


Hmmmm, so Dave feels that a boat prop will reverse
direction if the
drive is placed in neutral from forward, while under way?

Brian Whatcott Altus, OK

Being a sailor with no experience with aviation, I do not
understand the helicopter analogy.
In my opinion, a helicopter driven by the engine corresponds
in my understanding to a sailboat, where the propeller is
set to drive the boat *backwards* ..... When the propeller
on the boat 'gets the chance' to run without the force of
the motor, that is just sailing forward by sail, I expect
the propeller to turn in the opposite direction ... that is
'forward' ... If that happens in a helicopter, I would
expect the helicopter to hit the ground very fast ... don't
you? I do not assume, that there is a lot of inertia in a
propeller or shaft en a sailboat - may be that is the case
in a helicopter, and that could explain the smooth landing
without the assistance from the motor - or I'm I completely
wrong here? ...

--
Flemming Torp