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Anyone have data on change in stall speed with sport mod and shorter flaps? Or recommendations generally on the sport aileron modification? As a new pilot starting on my wing build this week, I suspect i dont *need* more sport in my new toy, but if there really is no material increase in stall speed, it seems like a fair trade.

This report is the only one i’ve been able to find so far and it does not have any numbers other than “a few knots” on stall changes. http://www.sonexaircraft.com/aircraft/sa_test.html


Thanks,
Mike, 1713B

Marrahm wrote:Anyone have data on change in stall speed with sport mod and shorter flaps? Or recommendations generally on the sport aileron modification? As a new pilot starting on my wing build this week, I suspect i dont *need* more sport in my new toy, but if there really is no material increase in stall speed, it seems like a fair trade.

This report is the only one i’ve been able to find so far and it does not have any numbers other than “a few knots” on stall changes. http://www.sonexaircraft.com/aircraft/sa_test.html


Thanks,
Mike, 1713B

Go with the sport. I've flown both. The barn door flaps of the standard are way to big and I doubt you'd ever use full flaps that much. Most guys I know with them only use 20 degrees unless going into something really tight. With the sport flaps, you just use more. I typically will put in full flaps if I want to land short.

Mine has the sport ailerons and I have flown 3 others without. I really do not notice the difference other than the larger ailerons require more force for full deflection.

I honestly don't feel like they are "aerobatic ailerons" because I feel they don't increase the roll rate substantially, at least not enough to call them acro ailerons. I actually find them cumbersome for acro due to their large chord... I have thought about trying to add spades but decided it isn't worth the effort.

Slow speed aileron authority is where I feel they shine.

Even with the shortened flaps the stall speeds are still low. With mine I see VS0 stall speeds around 41mph at gross.

Perfect. Thank you both.


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Fastcapy wrote:Mine has the sport ailerons and I have flown 3 others without. I really do not notice the difference other than the larger ailerons require more force for full deflection.

I honestly don't feel like they are "aerobatic ailerons" because I feel they don't increase the roll rate substantially, at least not enough to call them acro ailerons. I actually find them cumbersome for acro due to their large chord... I have thought about trying to add spades but decided it isn't worth the effort.

Slow speed aileron authority is where I feel they shine.

Even with the shortened flaps the stall speeds are still low. With mine I see VS0 stall speeds around 41mph at gross.

I have measured the roll rate. Standard is 90 deg per sec. so 4 sec to do a full aileron roll. sport is 120, or 3 sec to do the roll. The full deflection force is much greater.

fastj22 wrote:The barn door flaps of the standard are way to big and I doubt you'd ever use full flaps that much. Most guys I know with them only use 20 degrees unless going into something really tight.

I might be the odd man out but I use full flaps on nearly every landing. Most all my landings are three point and attempting to get the airplane as slow as I can before touchdown. To me a great advantage of full flaps is to come in high and tight and then use full flaps on final with idle power and maybe even a slip thrown in to help get it down.

Admittedly the approach can be quite steep and has a touch of the flavor of a space shuttle approach where, as you can see in the video, it glides like a refrigerator: https://www.youtube.com/watch?v=kkjDr5-I5-s

Dale Williams
N319WF @ 6J2
Myunn - "daughter of Cleanex"
120 HP - 3.0 Corvair
Tail Wheel - Center Stick
Signature Finish 2200 Paint Job
169.4 hours / Status - Flying
Member # 109 - Florida Sonex Association
Latest video: https://www.youtube.com/watch?v=1VP7UYEqQ-g

I also use full flap on nearly every landing (standard flaps). With a passenger however I do not because of the effort required to engage the lever is to high. Disengageing full flaps on a go around requires a lot of effort.

I have only had a very brief turn on the controls of a Sonex with the larger ailerons but my main impression was that they felt very heavy. With the standard ailerons the control balance feels pretty good at low speed, but at higher speeds the ailerons become fairly heavy whereas the elevator seems to become more sensitive, a difference which I think would be exacerbated by the larger ailerons.

Peter

Yet one more that uses full flaps on landing, most always three point. I do have slight advantage in that I have an electric operator and can add flaps as appropriate in any stage of landing without moving hands from stick or throttle.

The big barn door flaps really do allow for a steep approach angle. Necessary at one airport when landing over trees, and saved my backside at home airport few years ago when engine quit (Particle in needle valve of float bowl) while in the pattern and I turned toward runway too soon and found myself way high. Point nose up to slow it down to about 65 MPH lower full flaps and it has the glide angle of a brick. Was safely down and stopped just past mid field.

David A. Sonex TD, CAMit 3300.

Ok, I've got to ask you barn door flappers. If you only had 20 degrees of flaps available, could you land your aircraft safely? That's basically what 30 degrees of sport flaps gives you. Or do you need that extra 10 degrees to make a safe landing?