Bob Jacobsen wrote:
>The factory Tri-Gear Europa was damaged in a landing
>at Lakeland before
>Arlington and did not fly out. It had nothing to do with the
>engine - the
>nose gear had a weld fail. It does have a Whirlwind prop that
>was undamaged
>in the incident (one advantage of 2 blade props!)and the plane will
>be at
>Oshkosh.
>The Airmaster and some of the other electric VP props do fully feather.
>Currently the Whirlwind does not offer this although Bob from Europa
>Lakeland said there has been some talk of it - maybe in the future?
>The
>Rotax is easy to stop the prop turning and won't start windmilling
>again -
>that is what saved the prop on the factory tri-gear. They were
>able to stop
>it before landing when they knew the gear had a problem. Remember
>though
>that even a two blade prop presents a lot of drag if it's not fully
>feathered.
>Bob Jacobsen
>A131
><http://www.hotmail.com";>
We chose the Whirlwind prop because it has
the lightest weight (and the weight is further back),
has very good performance (two blades are more
efficient than three), and is hydraulic. I had
some concern that the electric props would not keep
up with the speed changes during aerobatics
(if you can't do some occasional acro you might
as well take the bus).
The early reports from the factory say that the
difference in glide ratio between feathered to
non-feathered is estimated to be 27:1 vs 25:1.
If true, I don't consider the lack of feathering a
show stopper.
There is no doubt that the prop will stop at some
low speed, the important question is; at what speed
does it begin windmilling again ? 80 kts would be
great, that would allow you to slow down to optimum
gliding speed to stop the prop, and allow air restarts
by diving to 80+ kts. 45 kts on the other hand would
be a real problem, with the engine turning over most
of the time.
Terry Seaver
A135
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