Can one start a rotary by hand proping?  If properly done, it's not

dangerous on

a recip, and you sure save dragging a lot of weight around for the

rest

of the

flight.

Even a variable pitch prop remains directly coupled, so once you

have

airborne

momentum, you have an air re-start capability, and like it or not

...

without

power, windmilling is more of a problem than not being able to "turn

the

engine

over".

Any problem feeding hand torque back through the PRSU?  Does it

"catch"

abruptly?  Too much compression, too quickly?  Or "piece of cake"?

Just curious,

Dale Smith

John Gibbons wrote:

 Hey Dale,

       Won't work. Your PSRU is going to cut the speed you can swing

your

engine in at least half. I would also guess that you would then also

have a

futher three fold reduction because of the gearing inside the rotary.

Unless

you were to use magnetos you would still need a  of some sort to
power your ignition. With a Lycosaurus you can just swing it fast enough

for

it to catch so you would have to increase your swing speed by 500 - 600

%.

Cheers,

John Gibbons

I think you have it backwards John. One rev of the prop is 2.17 revs in

the

engine.

I am not sure hand propping engine speed is an issue with electronic

ignition and

fuel injection properly timed for starting. You will need a battery of

course.

Paul Lamar

Whoops, and I thought dislexia only effected reading. But the rotor rotation
would be 1/3 of the shaft, correct ? I was once told you couldn't hand swing
an 80 hp Rotax because of the 2.17 reduction, of course I had to try and
they were right. Someone said they saw someone hand propping, was that a
rotary ? One rotor or two ?

Cheers,

John Gibbons (red faced)

I think it may be a prop rotational inertia issue. The prop perhaps just not 
heavy enough to keep rotating in the face of that 2 to 1 gear up to engine rotation.

Paul Lamar


 
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