A possible method of reducing drag

[sonex1374]

The advise to test carefully is always good advice. One thing that might shed some light on the situation before going to the trouble of testing gap seals is to get a better understanding of the airflow patterns around the aileron/rudder/elevator gaps. Tufting the surfaces both ahead of and behind the gap will show what the airflow is doing, and can be accomplished easily with a gopro. You might find that the airflow is actually fairly smooth going over that control surface gap, and that a seal may not actually improve things much. Likewise, a strip of tape applied over the piano hinge would seal the hinge line and help you determine if air leakage past the hinge is really a concern. You could even tape over the flap on both top and bottom surfaces to see if there is any improvement.

I suspect that none of these things will prove to make that much difference, but the fun is in the testing!

Jeff

[Doron]

I believe that significantly drag reducing will be achieved by new wing tip design. all new aircraft are using "Winglet" this vertical tips reduce wing tip vortex = less drag = lass fuel
Doron

[NWade]

I believe that significantly drag reducing will be achieved by new wing tip design. all new aircraft are using "Winglet" this vertical tips reduce wing tip vortex = less drag = lass fuel
Doron

The aspect ratio of the Sonex and the large chord at the tip are not conducive to improvement through winglets. And while winglets can help roll authority (by reducing spanwise flow) in some wing designs, and they can improve performance in high-aspect-ratio wings where you cannot extend the wingspan any further, they are not a panacea or a guarantee of improved performance. Note that the new Boeing 787 doesn't use winglets, for example.

--Noel
Sonex #1339
(...and Sailplane pilot, owner of an ASG-29 with winglets) ;)

[builderflyer]

Two things to ponder........

1. Especially with the larger engines, it wouldn't take too many successful modifications to take the Sonex out of the light sport arena. If that is a concern regarding a need for a medical certificate for the pilot, then modifier/pilot beware. A simple mod such as a propeller change can do this as well. The FAA may not be so observant to notice, but I'll bet John M. would be.

2. Your insurance company may very well want to know if you've made any modifications to your airplane that have not been approved by Sonex LLC. If you have done any significant mods to your airplane and haven't told the underwriter, they possibly may use that to attempt to deny any claim.......

My thoughts...........

Art,,,,,,,,,,,,,,,,,,,Sonex taildragger #95,,,,,,,,,,,,,,,,,,,Jab3300 #261