I was told that my leading edge profile is a standard Robertson STOL and not a Sportsman leading edge. … looking at the pictures I’m not so sure. Perhaps the wingtip is smaller than a stock profile and the difference is throwing me off, if anyone knows for sure by looking at these pictures please let me know.

Sure looks like a Sportsman cuff to me. Any other pictures? Is the plane equipped with a Robertson STOL kit? Do the ailerons droop with flap deployment?

MTV

Thanks, …Yep, here is one showing where it hits the window.

I'd put my money on it being a sportsman.

No fence on top of the wing or the inboard edge of the cuff, should be a Sportsman. The Robertson does have a fence on top of the wing, so I guess you could have both. If the cuff rounds off back into the wing at the fuselage, I would bet it's a Sportsman. Airframe Paperwork should tell definitely.

Based on the looks of the cuff near the windshield I’d say that it isn’t a Sportsman.

robw56 wrote:Based on the looks of the cuff near the windshield I’d say that it isn’t a Sportsman.

It's really hard to tell what the root looks like in that picture. But the Robertson/Horton doesn't have that much cuff on the tip I don't think.

Definitely a Sportsman cuff. See if there are aileron gap seals. That’s part of the Sporstman kit.

MTV

hotrod180 wrote:

shortfielder wrote:.......Airframe Paperwork should tell definitely.

Of course it SHOULD.....perhaps it doesn't, but it's obvious that plane has been modified and the owner is trying to make it legal???

MTV

robw56 wrote:Based on the looks of the cuff near the windshield I’d say that it isn’t a Sportsman.

I'm gonna agree with Rob - that does not look like a Sportsman wing root - it also doesn't look like it has the droop of the sportsman leading edge, but hard to tell with the white paint.

So, AzFlyer, you going to tell us what this is all about?

Is the plane equipped with a Robertson STOL kit (do the ailerons droop?).

Does the plane have aileron gap seals installed? (indicates Sportsman kit)

Or???? Inquiring minds want to know.....

MTV

Our horton on 207's have that end plate where the wing tip profiles don't match up. The plate protrudes much further than the actual leading edge profile. I suspect that the end plate is deceiving you all into thinking it's a sportsman when it could be a robertson or horton or whatever. Maybe?

The sportsman on 185 and 206's we have doesn't have that plate and the wing root fairing looks different.

asa wrote:Our horton on 207's have that end plate where the wing tip profiles don't match up. The plate protrudes much further than the actual leading edge profile. I suspect that the end plate is deceiving you all into thinking it's a sportsman when it could be a robertson or horton or whatever. Maybe?

The sportsman on 185 and 206's we have doesn't have that plate and the wing root fairing looks different.

You are probably right on the end plate being deceiving Asa. I have seen that style of end plate on a Sportsman though. I actually built it. We wanted to retain the super droop Madras tips so had to end the cuff somehow.

Hey everyone, Thanks for the input!

The airplane has the Roberts install kit which has gap seals, drooping ailerons and all that.

The airplane came with uninstalled Vortext generators, i’ve received advice for and against putting them on, Someone also suggested putting sportsman cuff on the wing along with the R STOL would make it a real performer… I was thinking I might try the VGs with some double-sided tape to see how they changed the stall characteristics, then I got to thinking Man if I’m gonna go through all that trouble maybe I should see about putting the sportsman cuff on first. I found the drawings of the profiles of the different stol kits and darned if it didn’t look a little to me, from the wingtip and at least, more like the Sportsman than the Robertson as shown in the above drawing, …Thus my asking for opinions.

The droop on the tip looks too aggressive to be a Robertson cuff to me. The Robertson cuff was very close to the later Cessna “Camber lift” leading edge.

As to the plate at the tip, the Sportsman cuffs we had installed only provided the cuff. If you wanted matching tips, they were extra. Our maintenance folks fabricated a new leading edge for the stock tips from fiberglass, so that the tip matched the cuff, but I’ve seen them just ended like that.

I suppose it’s possible that the cuff is a Horton/Bush or ?

It just seems pretty large compared to RSTOL cuffs I’ve flown.

I REALLY like the Sportsman cuff combined with the RSTOL on a Cessna wing. I flew two of them quite a bit: a 185 and a 206. The RSTOL kits, if flown really slow, can have rather abrupt stall characteristics. The Sportsman mellows all that out, so stalls are a non event, just sink. So you can actually USE the slow flight capability of the RSTOL safely.

MTV

Thank you MTV,

As I am learning where the outside edge of the envelope is with this new to me airplane, I have already run into reduced aileron effectiveness in a strong crosswind with full flaps and low speeds,… It sounds like the VG‘s will not help much with the stall but may help with the aileron effectiveness. … on some wing profiles it seems the VGs create a more abrupt stall which could exasperate The RSTOL stall? A Sportsman leading edge with VGs and RSTOL might be a nice combo, I do know the Sportsman leading edge will significantly improve the engine out glide ratio

Right now the biggest improvement to be made is probably by adjusting the nut aft of the control wheel!

The RSTOL kit does slightly reduce aileron effectiveness in a gusty crosswind. None of the RSTOL equipped airplanes ive flown had aileron gap seals, EXCEPT those two with a Sportsman kit. Aileron gap seals were not a part of the RSTOL kit, to the best of my knowledge. I don’t know if any of the other LE cuff kits included them.

The best solution to limited aileron effectiveness is to restrict flap deflection, which can limit aileron defection. The RSTOL kit droops ailerons more with each additional flap deflection, UNTIL you go from 30 to 40 degrees. There, the aileron deflection actually decreases.

I found the worst situation to be on heavily loaded takeoffs, where you stagger into ground effect to accelerate. On landings, just stack on a LITTLE more speed, get wheels on ground, THEN decelerate.

On crosswind takeoffs or landings, in gusty conditions, just li it flap deflection to no more than 20 degrees. Sometimes, I’ll use 10 degrees, or no flaps….now you have a stock system.

Beyond 20 degrees, Cessna flaps mostly create drag, not lift so much. At 20 you get most of the lift benefit, and a lot less drag.

I LOVE RSTOL systems, and over half my total flight time is with planes with drooping ailerons.

Dirty little secret: The deHavilland airplanes (Beaver, Otter, Twin Otter, Caribou, etc) droop their ailerons with flap deflection.

Ever hear a Beaver pilot complaint about aileron droop?

MTV

MTV, FWIW, the picture he shows of the plane shows it as a 206. No aileron gap seals for the 206/207 with the sportsman kit either.

Paperwork has always confused me. It seems very surprising to me that you could combine a Sportsman cuff with the remains of Robertson STOL kit.

Can someone explain?