Field Guide to Shortwing Wingtip STC's

[stevesaircraft(Bri)]

Looking for a consensus. Have a customer that is trying to decide which tip to go with on his Pacer. Anyone here fly both? What are the pros and cons of both tips?

Thanks.

Brian.

Some information collected by Marc Davis also loacted on page 12 or 13 of this thread.

I was researching the various wing tips found on shortwings and thought it might be useful to gather the info in one place.
Please correct me if I got something wrong, add info about other tips if I missed some, or provide better pictures.

Madras/Deamer
Cut spar caps (shorter wing than most tips)
Replace last rib with full size plywood or stamped rib.
Install tip on last rib.
Note distance between aileron and last rib



Fergusson / Plane Booster
Bend cap strips straight (adds wing length)
Replace second to last rib with full size
Replace last rib with plywood or stamped rib.
Install tip on last rib.
Note distance between aileron and last rib






Crosswinds STOL
Not very common
Like a Sullivan with stall fence on top




Sullivan / Hendricks
Bend cap strips straight (adds wing length)
Replace second to last rib with full size
Replace last rib with stamped rib.
Install tip on last rib.



Stewarts
Bend cap strips straight (adds wing length)
Replace last rib with full size ribFabric over a bow like stock
Install bow similar to stock
Cover with fabric




Svenn's Aviation / Dakota Cub
STC to install Dakota tip.

[Mr_Boondoggle]

Allow me to answer the question you did not ask.

I have flown Pacers and Tri-Pacers with 125hp, 135hp, 150hp, and 160hp. I have flown standard wings, Madras Booster Tips and Crosswind Stol wings.

Of all the above combinations, the Pacer with a 160hp engine and a Crosswind Stol kit made the shortest take off run and made the Pacer easer to fly.

The Madras Booster Tips help a little.

If I re-build my Pacer again, I'll go with the Crosswind stol kit including wing tips, stall fence, leading edge and gap seals.

Of course, A stock Pacer operations safely out of 1200 foot landing strips.....what more do you need?

[Stephen]

Pat's observations are correct and the main reason that X-Winds STOL kit works best is that it has a variety of mods beyond the tips. It increases wing area, adds flap area, has a cuff and wing fence. I think the increased wing area is most important. This set-up does increase STOL performance.

The Demer (Madras tips) do a good job decreasing the induced drag (maybe better that the X-Winds tips), BUT, they cut off too much wing. My wings with this installation (done according to the STC) has a 28 foot wing span. Advantages are reduced induced drag and increased roll rate, disadvantages are loss of lifting surface and may lose cruise speed, on balance....little to some improvement in STOL.

Stewart's tip increases the wing area over the original wing and should reduce the induced drag some. This set-up may increase STOL, but it is consistently reported to increase cruise speed.

Both, Sullivan and Stewart systems should decrease the roll rate, which is difficult to quantify.

The Sullivan and Demer system has been carefully varified on Cubs, which can only be generalized to our short wing planes.

"A stock Pacer operations safely out of 1200 foot landing strips.....what more do you need?"



600 feet

[Glen Geller]

Brian, I suggest you have your client clarify what his typical mission is going to be, and what acceptable trade-offs will work for him.
And you need to define budget, all the flap and fence and other mods sound pretty spendy to me.
I have the Madras (Droop) tips on my PA22-150 and I would (subjectivly) say it climbs a bit better and stalls a bit slower and rolls quite a bit better than the other three stock PA22-150s in our Bravo Three stable, but it's about 3-5 mph slower in cruise. And they are in my opinion not super pretty, they block side view (OK, just lift the wing but really....) and folks tend to bonk into them a lot. Stand up once into a droop tip and you will see stars for sure.
My personal chhoice would be the Stewart tips (very nice looking and I have heard no bad reports, just praise,) plus I might add VGs. That is said to be a winning combination.
Glen

[stevesaircraft(Bri)]

His mission is twofold.
1: a little better stol performance and
2: better slow speed aileron control.
In my opinion the best setup is Demer/Madras or Plane Booster tips with VG's. This is How our pacer is set up. Unfortunately, the Demer tips are no longer in production therefore not available. Cub Crafters bought out Plane Boosters and changed the tip profile. The new tip has not been certified on the Pacers therefore are unavailable. Crosswinds are too ugly, sorry but they just are. So that leaves us with either Hedrick's or Hanger21. VG's are on order and will be installed probably before we even do the wingtip conversion. Eddie Trimmer put him on to the Hendricks tip. I have never installed one. I have installed the Stewart tip and like thier looks. There is a Cub on the field with the Hendricks tip and it is OK. The question is, which gives the PACER better control and performance?

Alaska guys can chime in at any time here

Brian.

[Homer Landreth]

Brian; I am a week or so of good work days from finishing my Pacer which has Hendrick wing tips and no VGs. I would be extremely interested in seeing some data from your Pacer that you feel will fly with VGs before getting wing tips modifications. Certainly we have a good chance for some head to head data Pacer wise if we keep in touch. I will soon be able to get you some Pacer performance with Hendricks tips only, as I have been holding off on a VG decision and if you would reciprocate with data on a Pacer with only VGs on stock tips we would have some good test cases to sink our teeth into for evaluation. I can also get a "two for the price of one" evaluation in that my Tripacer has Madras tips. The Madras tips give me two specific things that i can hang my hat on. First, lower stall speed. I can't really cleanly stall my Tripacer. It just kind of floats around and rumbles a bit, but stays largely wings level and will lose a couple hundred feet, but then a heat thermal from the desert will come along and I get it all back and the process repeats until you get bored with it all. Second, more positive aileron control in the rotate to flare zone and bleed off of airspeed prior to touchdown. If I rotate to flare from around 65 Mph, and manipulate power using a sea plane Glassy Water technique, I end up touching down and roll out begin at around 50 Mph. Anyway, please keep in touch, i will appreciate it.

[JohnW]

Homer, was there a typo in there? Did you mean to say "...to HANG your hat on..." or did you mean "... to BANG your hat on..."? :mrgreen:

[Stephen]

The Cub data showed that the Demer tip was slightly better for slower speed than the Sullivan, but not by much.

It would be great to get some good data on different wing mods. Unfortunately, I've only seen data on the Stewart tips to was nearly useless.

[d.grimm]

I have added VG's to two Pacers. The first was a really light 135 Pacer (1050 empty) and a heavy PA22/20 heavy Pacer. (1215 empty) Having flown both extensively, and the 135 prior to VG's, my experience was a 9 mph reduction in stall speed on the 135 with two people and full tanks. (1665 lbs) The PA22/20 in the same condition showed a 7 mph reduction in stall speed (1830 lbs)
These are what I would expect, considering the wing area is the same between both. These tests were done at 3000 ft msl at 65-70 degree temperature. The 135 flown solo with 1/2 tanks and a climb prop is quite the performer. (for a Pacer).
The added aileron responsiveness was worth the price with no other benefits. I don't think you can improve on the stock tips for looks.
Dave

[Stephen]

Dave, thanks for the info on VG's. What type of stall (rpm setting and flap position) are you using for comparism.

I agree with you on the looks of the stock tips. I just wish that last foot of stock wing did more for the aircraft's lift.