SonexBuilders.net

I would appreciate thoughts about different wingspans available to ONEX builders. I already have one opinion stating that possibly the wider span, which is dictated by the length of the wing tips, might be necessary to keep stall speed within LSA requirements. The shorter span, which can be built as much as two feet shorter by the plans, will obviously result in a quicker roll rate which to me is not that important. I prefer stability if I had to trade one for the other. It has also been suggested to me to initially build the wider span as I will then have the future ability to possibly shorten the span as I feel comfortable with after and during flight testing. Your thoughts and experiences please.
Sherm

You could always buy a second set of wing tips.

I'm a 175LB person and will trim my wing tips to the short version. I expect my ONEX stall speed to meet LSA requirements. It is my understanding that the longer wing tips were necessary to keep the stall speed within limits for heavier pilots, up to 250LBs. Correct me if this is in error.

N951X-reserved

My ONEX 350NX was built with the longer wing tips. I weigh 190 and getting around 600 ft a minute climb rate on take off at sea level, the engine not totally broke in yet. It came out at 624 lbs empty. With only 22 hrs on it so far have not rolled it yet but have done some high angle wing overs. Even with the longer wing tips it has an impressive roll rate and will not disappoint. At cruise 3000 rpm,4000 ft I'm seeing
135 mph ias , The only reason I can see to put short wings on it is if you need to keep it in a standard garage since the longer wings folded wont fit.The longer wings you get better climb rate lower stall speed
without much loss of roll response.Anyway those are my thoughts IMHO ;)

I wonder about this as well. Longer wings gives lower stall speed and and higher climb rate. Shorter wings gives higher cruise speed and faster roll rates. But, a longer wing will also decrease Va. Given the longer wing tips simply add length, there is no aerodynamics there, no taper or winglets or anything, I think I will go with the shorter tip. Then if someone makes a "cooler" tip, maybe I'l change? I think though, this is one of those things that is not likely to get changed once it is set, since the difference is minimal.

I'm about at this point in my Onex build too. I'm only about 150 lbs, but still going with the long wingtips for now for the same reasons (better climb, glide ratio & slower stall speed) and the option of cutting them shorter later if I want to for speed, aerobatic handling or higher G's. Good luck, both options have their merits.

Peter

Just another data point, I had some email correspondence with someone who built not one but two Onexes, one with short wings and one with long, and he felt the Onex flew better with the long wingtips.

I thank everyone for their input.
Sherm

gcm52 wrote: he felt the Onex flew better with the long wingtips.

This could mean lots of different things. We all know it fly "fly better" with longer wings, because it has more lifting area per weight unit. That is the whole reason for making them longer. In "kitplanes" (I think, there are links to two magazines reprints on the sonex web page), the person testing both said the short wing felt better (you have to read between the lines, those magazine writers never write negative stuff).

Could you ask your friend to be more detailed?

One other thing about wingspan, the shorter wing will have higher wing loading which will result in it being a somewhat smoother ride in rough air.

Thanks,

Jake