Sport ailerons
Posted: Sun Feb 18, 2018 2:09 pm
by Marrahm
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
Re: Sport ailerons
Posted: Sun Feb 18, 2018 7:53 pm
by fastj22
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.
Re: Sport ailerons
Posted: Sun Feb 18, 2018 9:43 pm
by Fastcapy
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.
Sport ailerons
Posted: Sun Feb 18, 2018 10:14 pm
by Marrahm
Perfect. Thank you both.
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Re: Sport ailerons
Posted: Sun Feb 18, 2018 11:11 pm
by fastj22
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.
Re: Sport ailerons
Posted: Mon Feb 19, 2018 12:04 am
by daleandee
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
Re: Sport ailerons
Posted: Mon Feb 19, 2018 1:24 am
by Corby202
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.
Re: Sport ailerons
Posted: Mon Feb 19, 2018 8:32 am
by peter anson
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
Re: Sport ailerons
Posted: Mon Feb 19, 2018 9:47 am
by DCASonex
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.
Re: Sport ailerons
Posted: Mon Feb 19, 2018 9:25 pm
by fastj22
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?
Re: Sport ailerons
Posted: Mon Feb 19, 2018 9:35 pm
by fastj22
peter anson wrote: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
At normal/pattern speeds, the aileron stick loads are very similar. At full throw aerobatic movements, the sport ailerons are much heavier, but give you a great roll rate. Often, when I do aerobatics, I find myself grabbing the stick with both hands if doing an aggressive roll. Its logarithmic, the farther you throw the control, the more force it will take. But for normal flying, its not even noticable.
Re: Sport ailerons
Posted: Mon Feb 19, 2018 10:29 pm
by daleandee
fastj22 wrote: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?
As Curly Howard would say: https://www.youtube.com/watch?v=g5j8Jioan1w
I took my nine year old grandson for his first flight today. I was quite hazy & bumpy but he really seemed to enjoy it … more than I did. I landed with 20º flaps. I have practiced landings with all flap settings and even no flap landings. Not an issue as the difference is a bit higher approach speed and a flatter approach angle without flaps. Good stuff to practice.
I also made a clean take-off (zero flaps) and like them much better. I’ll sometimes use 10º if I’m trying to get up and gone in a hurry but with my grandson and 14 gallons of fuel we were off and climbing in 500’ or less. I don’t fly aerobatics so I don’t have a need for the big ailerons … so I’m glad I have the barn doors to hang out when I need them.
Dale Williams
N319WF @ 6J2
Myunn - “daughter of Cleanex”
120 HP - 3.0 Corvair
Tail Wheel - Center Stick
Signature Finish 2200 Paint Job
170.5 hours / Status - Flying
Member # 109 - Florida Sonex Association
Latest video: https://www.youtube.com/watch?v=1VP7UYEqQ-g
Re: Sport ailerons
Posted: Tue Feb 20, 2018 8:27 am
by avee8r
I built my Sonex with the Aerobatic Ailerons. The technical data supplied by Sonex says the stall speed is 42 vs. 40 for the standard aileron / flap combination. During flight test, my plane stalled right at 42, very predictably. I use full flaps for landings and they do a great job.
I also happen to like the balanced look of the shorter flaps with longer ailerons.
Happy Landings
John
N50NX
Re: Sport ailerons
Posted: Tue Feb 20, 2018 6:27 pm
by daleandee
avee8r wrote:I built my Sonex with the Aerobatic Ailerons. The technical data supplied by Sonex says the stall speed is 42 vs. 40 for the standard aileron / flap combination. During flight test, my plane stalled right at 42, very predictably. I use full flaps for landings and they do a great job.
I also happen to like the balanced look of the shorter flaps with longer ailerons.
No one has mentioned it but it crossed my mind that the longer ailerons, by design, would cause more adverse yaw as there is more drag being made by the larger surfaces moving. This would no doubt be more noticeable at lower speeds. I’ve never flown the longer ailerons so I have no experience to frame this with. The air frame doesn’t have much if any adverse yaw with the shorter ailerons so if there is an increase it may not be very noticeable.
As far as the look of the aircraft … I noted in another post that I prefer the look of the Legacy model A over the model B. I also prefer the look of the barn door flaps … especially when they are deployed fully on final as they work well! My stall speeds are a bit higher with the increased gross weight of 1250 lbs. I recorded Vs @ 48 & Vs0 @ 45. Full flap three point touch down (wheel chirp) happens at 37 IAS as seen in this video:
https://www.youtube.com/watch?v=WjA7JDJVKeQ
Dale Williams
N319WF @ 6J2
Myunn - “daughter of Cleanex”
120 HP - 3.0 Corvair
Tail Wheel - Center Stick
Signature Finish 2200 Paint Job
170.5 hours / Status - Flying
Member # 109 - Florida Sonex Association
Latest video: https://www.youtube.com/watch?v=1VP7UYEqQ-g
Re: Sport ailerons
Posted: Tue Feb 20, 2018 8:11 pm
by lutorm
daleandee wrote:it crossed my mind that the longer ailerons, by design, would cause more adverse yaw as there is more drag being made by the larger surfaces moving.
I’m not so sure. For a given roll rate, the longer ailerons also need to deflect less, so it’s a matter of the lift/drag at the two different deflections. My guess would be that the airfoil with lower angle of attack, ie the one with less deflection, would operate at a better lift/drag point.
Re: Sport ailerons
Posted: Tue Feb 20, 2018 8:50 pm
by daleandee
lutorm wrote:I’m not so sure. For a given roll rate, the longer ailerons also need to deflect less, so it’s a matter of the lift/drag at the two different deflections. My guess would be that the airfoil with lower angle of attack, ie the one with less deflection, would operate at a better lift/drag point.
I’m not an engineer & couldn’t afford a night at Holiday Inn but what you’re saying makes sense to me. I was just thinking that the further inboard the ailerons come the larger the surface to increase drag. But as I mentioned earlier the adverse yaw in the design is not a concern … in fact there’s a lot to like about it.
Dale
N319WF
Re: Sport ailerons
Posted: Wed Feb 21, 2018 1:54 am
by peter anson
OK, this is only a guess, but I think the reason that the Sonex doesn’t exhibit much adverse yaw is because when an aileron goes up, the gap on the underside of the wing widens causing extra drag, matching the drag of the down-going aileron. If that is correct, longer ailerons shouldn’t produce any extra adverse yaw. It has also occurred to me that fitting a trim strip to fill that gap on the lower wing, as was discussed in several other threads, might drastically change the handling characteristics of the aircraft by increasing adverse yaw.
So, it looks like the owners with the short ailerons are happy with them and the owners with the longer ailerons are happy with them, so do what you like.
Peter
352 hours of happy flying with short ailerons!
Re: Sport ailerons
Posted: Wed Feb 21, 2018 11:14 am
by Rynoth
Adverse yaw… that’s what the rudder pedals are for!
Re: Sport ailerons
Posted: Wed Feb 21, 2018 11:43 am
by Bryan Cotton
If you have never flown a Grob G103, you don’t really know what adverse yaw is! I used to turn it with the rudders and use a little aileron to coordinate it.
Re: Sport ailerons
Posted: Wed Feb 21, 2018 12:18 pm
by sonex1374
peter anson wrote:OK, this is only a guess, but I think the reason that the Sonex doesn’t exhibit much adverse yaw is because when an aileron goes up, the gap on the underside of the wing widens causing extra drag, matching the drag of the down-going aileron. If that is correct, longer ailerons shouldn’t produce any extra adverse yaw. It has also occurred to me that fitting a trim strip to fill that gap on the lower wing, as was discussed in several other threads, might drastically change the handling characteristics of the aircraft by increasing adverse yaw.
Peter,
You are correct that the shape of the hinge line is largely responsible for the canceling of adverse yaw. The NACA did a study on different hinge designs, and the shape used by Sonex (hinge on one side with a triangular opening on the other) was tested along with many other styles. It turns out that the effect is very similar to a frise aileron, and has the added benefit of being easy to manufacture and very strong (sound like standard Sonex qualities?). I’ve had the same discussion with others about covering the hinge gaps. I’d expect the feel of the surface to change somewhat if gap seals were installed, but the changes would only really be noticeable at larger control deflections.
Jeff
Re: Sport ailerons
Posted: Wed Feb 21, 2018 6:26 pm
by daleandee
Rynoth wrote:Adverse yaw… that’s what the rudder pedals are for!
Oh yeah! After owning and flying those “lead with the rudder” Challengers for a good numbers of years and then the Aeronca Champ I know a little about adverse yaw. In fact when I went to get my tail wheel endorsement my instructor noted that it was probably the ultralight experience that helped me to realize early that when I was in an airplane my feet still had something to do.
The real fun with my Cleanex is that there isn’t much, if any, noticeable adverse yaw so the rudder doesn’t get too much to do unless I’m taking off. It takes a boot full of left rudder on take-off with that fire breathing 3.0 Corvair up front!
BTW … it appears that better weather is sneaking up for the weekend!
Dale Williams
N319WF @ 6J2
Myunn - “daughter of Cleanex”
120 HP - 3.0 Corvair
Tail Wheel - Center Stick
Signature Finish 2200 Paint Job
170.5 hours / Status - Flying
Member # 109 - Florida Sonex Association
Latest video: https://www.youtube.com/watch?v=1VP7UYEqQ-g
Re: Sport ailerons
Posted: Thu Feb 22, 2018 9:53 am
by Onex107
sonex1374 wrote:
peter anson wrote:OK, this is only a guess, but I think the reason that the Sonex doesn’t exhibit much adverse yaw is because when an aileron goes up, the gap on the underside of the wing widens causing extra drag, matching the drag of the down-going aileron. If that is correct, longer ailerons shouldn’t produce any extra adverse yaw. It has also occurred to me that fitting a trim strip to fill that gap on the lower wing, as was discussed in several other threads, might drastically change the handling characteristics of the aircraft by increasing adverse yaw.
Peter,
You are correct that the shape of the hinge line is largely responsible for the canceling of adverse yaw. The NACA did a study on different hinge designs, and the shape used by Sonex (hinge on one side with a triangular opening on the other) was tested along with many other styles. It turns out that the effect is very similar to a frise aileron, and has the added benefit of being easy to manufacture and very strong (sound like standard Sonex qualities?). I’ve had the same discussion with others about covering the hinge gaps. I’d expect the feel of the surface to change somewhat if gap seals were installed, but the changes would only really be noticeable at larger control deflections.
Jeff
I agree with the aileron yaw canceling, but, on my Onex I have installed a rudder gap seal and it definetly made a difference in taming the tail, which could be construed as yaw.
Re: Sport ailerons
Posted: Fri Feb 23, 2018 10:44 am
by sonex1374
Onex107 wrote:I agree with the aileron yaw canceling, but, on my Onex I have installed a rudder gap seal and it definetly made a difference in taming the tail, which could be construed as yaw.
The tail is a bit different than the wing, and feels the effect of adverse yaw a bit differently. The drag created by deflecting the rudder shows itself as a slight decrease in control power. Essentially, the rudder deflects causing lift to be generated by the tail to the side (i.e. yawing the airplane). Deflecting the rudder also has the negative effect of increasing the drag (i.e. increasing induced drag), which pulls the surface backward. This backward pull serves to cancel a small amount of the yawing motion created by the rudder. Effectively, the drag reduces the effectiveness of the yaw.
This effect is not symmetrical. Deflecting the surface in such a way as to open the hinge gap will increase the drag of that gap, and closing the gap decreases it. Although this is the exact effect you want on the ailerons to cancel the unwanted (adverse) yawing motion caused by rolling, it doesn’t really work the same on the rudder. Rudder one way (say left rudder that opens the hinge gap) vs the other (e.g. right rudder that closes the hinge gap) simply creates a bit more drag one way than the other. You’ll notice this as a more effective rudder in one direction (in this case, right rudder is slightly more effective than left rudder).
Sealing the hinge gap eliminates the drag-creating asymmetry caused by increasing or decreasing the hinge gap, and perhaps reduces the overall drag of the tail itself. These are not bad things for the tail, and would almost certainly provide a better tail. Why doesn’t Sonex do this in the first place? Well, my opinion is that the beneficial changes from adding the gap seals are not all that significant, and they feel it doesn’t really justify the effort/weight/complexity of gap seals. Plus, using the triangular hinge is just so darn convenient!
So I guess the bottom line is that the Sonex hinge design works amazingly well on the ailerons, and is simple and effective (enough) for the tail surfaces. Is there room for improvement, probably. Is it worth it, perhaps…
Jeff
Re: Sport ailerons
Posted: Sat Feb 24, 2018 11:36 am
by avee8r
This is why I put a Waiex ventral fin on the bottom of my Sonex.
…not really, I just liked how it looks so I added it. Someday I’ll see if there’s any performance difference without it. It’s just screwed on so its easily removed.
Happy Landings
John
N50NX
Re: Sport ailerons
Posted: Wed Jun 19, 2019 11:07 am
by N418SX
fastj22 wrote: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?
Since nobody answered, I’ll bite. Flaps are nice, but not a necessity. Nothing more fun than leaving the flaps up to practice slips in the case of of a failure. Many of the older taildraggers I’ve flown had no flaps. Piloting skills are learned by practicing for emergencies. Fun stuff.
Re: Sport ailerons
Posted: Wed Jun 19, 2019 11:57 am
by Rynoth
As someone who just completed my first flight with sport acro ailerons, I can say that full flaps (30 degrees) on the shorter flaps gave me a very nice descent rate and were quite effective, I certainly didn’t feel that they were lacking in comparison to other planes I’ve flown.
Sport ailerons
Posted: Wed Jun 19, 2019 12:31 pm
by caveman370
I have the standard ailerons but have flown the acro also. The landing speed is close to the same. You just have a faster roll rate
Sent from my iPhone using Tapatalk
Re: Sport ailerons
Posted: Thu Jun 20, 2019 8:30 am
by DCASonex
How much flap you need depends on how short your landing strip is, and how high the trees at the approach end are.
David A.