CHECK OUT THE VIDOES ON THIS THREAD: https://groups.google.com/forum/m/#!...ng/QIeXikPEkaY

I agree 4% is pretty high...but clearly it is not exactly equal performance from an aerodynamic perspective. Seems like an easy thing for the handicap committee to act on. The FES owners are trading some performance for convenience and safety (avoiding land outs, etc). Nobody likes to start with a significant disadvantage in any form of competition.

As a pseudo engineer, there is significant square edged frontal area exposed to the airflow right at the nose. In addition a gap between the spinner and the fuselage in a high pressure area of the nose. Then you have 2 complex curved 18 inch propellers laying against the nose aft. At 80-100mph+, that must be killing the gliders performance. At 70 it surely cannot be helping. It also probably damages the flow over the wing root area, especially at low speed and higher AoA.

I will start some research into getting the study results in detail. I have have already sent a few emails. In the meantime look at the videos I posted last summer in the link above.

I think at least a 1% handicap is warranted. Something! Not a huge amount of these gliders in the market, but there are 20 or so and several new Lak17b FES in the US and Canada. The handicap is affecting the decision to convert gliders in some cases. Not just Laks but the usual suspects.

That said, maybe the aero impact is balanced out by the 60-80 lbs of added weight in batteries, etc? Is that the case? I'm not really sure how handicaps are formulated in terms of modifications, wing loading, etc.

Yes, I am thinking about converting my Lak17a to FES someday....

Flying to Florida as I type.... :-)

Sean