Different wings, bad idea?

[nogoodusernames]

Has anyone tried to put a different wing on a Pacer or derivative fuselage to try to speed it up a little bit?

I've seen a Cessna wing on a Super Cub (at least generically Super Cub ish). I think that's probably a little long for a Pacer derived fuselage, but that's neither here nor there.

Has anyone tried putting something like a Bearhawk or Maule wing (or slightly shorter version of one) on one?

I've heard rumors of people putting Taylorcraft ribs on Piper wings, but I'm not sure if those are just copies of the T-Craft airfoil built for the Piper spars or if the spar spacing is the same between the T-Craft and Piper.

It would seem that loads of different ribs with different airfoils could be built up for a Piper-pattern fuselage, but I don't know what changing to an aluminum wing with one strut would require as far as fuselage structure.

Anyway, let me know if this is a horrible idea or if you've tried it! If you have Bearhawk wing drawings and can tell me that the distance between the fuselage/wing attachment points is nine inches different than the Piper, that would qualify as "that's a horrible idea". If you are one of those folks with a Cessna wing on a Piper-pattern fuselage, please let me know if the wing/fuselage attachment points just perfectly lined up when you were building it or if you had to rebuild the top of the fuselage to fit the wing.

Thanks for any ideas (or shooting down my horrible ideas)!

 

[Steve Pierce]

Cessna wings and rag and tube Piper wings have the same distance between spars 30".

A Maule wing is pretty much the evolution of a Pacer wing. Same airfoil.

Taylorcraft wings on a Cub fuselage was done by the aerobatic guys (Charlie Hillard, Jim Swick, Duane Cole) so the could go upside down.

I fly with two of Badland Travelers built by [FONT=&quot]Clint Busentiz[/FONT] both on the Brazos River and at STOL contest. They perform quite well, fast and slow. Clint has built his own wing and is flying it on one now. Reports are good but don't know much detail.

I take it your goal is to take a Pacer fuselage, re-wing it and go faster?

 

[nogoodusernames]

My goal? At this point, I don't know what my goal really is! I'm stuck inside due to bad weather, so all I can do is dream about airplanes, which may end up with me having another project. I'm not sure if that's good or bad at this point.

My 22/20 Pacer performs pretty well (I think) on an o-320. I've got the Sullivan tips (haven't installed them yet, because I'm afraid of not having a flying airplane for too long), but the performance should only get better. I'm smaller than the FAA "standard" male, so I can fit a full-size guy in the front seat with me, which I would not be able to do with the Sportsman 2+2 from Wag-Aero. I think it's 4" narrower. I can stick all the bags I need in the Pacer, full fuel, wife, and child. There's not a ton of legroom in the back, but my child doesn't care at this point. If I'm on an afternoon joy ride, I can stick a full-size guy in the front, full-size guy in the back, and with no bags, still perform decently enough and comfortably enough for a joy ride. Every time I think about what kind of airplane I want to build, I come up with a Bearhawk. It's got four seats, fast enough, takes off/lands short enough. The downsides are that it takes more fuel, and it's got a longer snout (and it can't be shorter, due to W/B) so I can't see any better than the Pacer. I also don't really need four real seats, just four seat belts.

The Pacer really fulfills the mission that I want. The fuselage is really exactly the right size. Small enough to be light enough for 150 horses. Wide enough for two people, as long as one of them (me, for now) is fairly narrow (it could be a little longer, but the fuselage stretch adds weight, and adds it aft of the CG). Plus, there are gobs of derelict fuselages out there. If I'm going to build an airplane, I'm going to try to get the best performance possible. If I can get a Bearhawk wing to fit, I can get the 51% if I only salvage the fuselage. If not, I can scratch build a Pacer-like fuselage and put (shortened?) Cessna wings on it. I can't weld as well as Clint can though, so that's going to be a challenge, but not impossible.

Jim Younkin showed with his Mystery Pacer that the airfoil is capable of going pretty fast, but if I can get any improvement, why not try? One strut seems like it should be faster as well.

Of course, if this doesn't work, I can always build a Bearhawk Companion, and figure out how to get a rear seat for children in there. But it's more than two feet longer than the Pacer, which means it surely could be lighter, and 150 horses is at the bottom end of what is written as recommended on the posted drawings.

 

[dgapilot]

Jim was able to cruise right around 160 mph with the Mystery Pacer. 160 hp with fixed pitch prop. The prop is really the limiting factor, not the airfoil. Simple aerodynamics of the prop, as airspeed increases, the angle of attack of the prop reduces to negligible thrust right around 150 mph. Increase the pitch for faster cruise speed, you are greater than critical AoA static and the prop is stalled.

The Mystery Pacer has significant drag reduction mods on it. I spent many an afternoon with Jim discussing what he had done. Most of it was reducing cooling drag and reducing drag on the fuselage. It has small main wheels with fairings which limit operations to improved runways.

Decide what your mission is and design or build or buy the airplane that meets the mission. You will never get everything you want in a single airplane. Decide the most important things and find the closest thing you can. My stock TriPacer (metalized) with a 160 would cruise all day at 130 mph with a 60” pitch prop but was limited in take off performance (just over 1200’) for what I wanted. Switched the prop for a 53” pitch prop and could get in and out of 700’ strips with room to spare but would only cruise at 105 unless over revving the engine.


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[Gilbert Pierce]

I visited With Jim several times at the Antique Airplane Fly-in. He said he would depart Fayetteville and climb and cruise at full throttle until he past the VOR South of IA27 and the he would pull the throttle back and land. That’s a little over 300 miles at full throttle.
As he was looking my Clipper over he said he really wanted a Clipper but couldn’t find one.
https://www.supercub.org/forum/attachment.php?attachmentid=4202&d=1321337233

 

[nogoodusernames]

Pertinent notes.

I cruise at 101 indicated knots (call that 116 statute) at 2300 rpm (I think! It's been a while since I had a long cross-country trip). I really don't know what I'd get at full throttle. I'm sort of scared about my fuel burn and the damage it would do to my wallet. Like I said, it's been a while since I had a long cross-country trip.

My Pacer is already heavier than Younkin's, even if I take out the back seat. Assuming he was telling the truth. It's not just the Monocoupe guys that read their airspeed indicators with a little, uh, optimism. Plenty of people do the same with the scales.

My mission is a balance of efficiency with the capability of taking off and landing in reasonable distances with four seatbelts and room for me and two realistic adults.

Also in the mission category, I want to get a repairman certificate on something, and it might as well be something shortwing-inspired, since Younkin's Pacer is pretty close to what I want.

I understand that the prop is more limiting than the wing. However, I'm talking about a building project anyway, so if I can get a less-draggy wing, I'm going to do it. I'd especially like a metal wing with only one strut to fair. I understand that changing airfoils isn't a magic bullet, but it would be just a part of my drag-reduction campaign. If, of course, one can be found that fits. Clint Busenitz seemed to decide that the Cessna wing was too much of a hassle, and the Bearhawk is the only other one I can think of (which it seems that nobody here has experience with), since the Maule doesn't seem to offer any benefit. Even if the prop limits me to the same speed, I might be able to get there burning fewer dinosaurs.

I'm curious why Younkin wanted a Clipper rather than the Tripacer. Did he tell you? Is it narrower behind the front seats?

 

[stevesaircraft(Bri)]

The Pacer we used for our 0-360-A1P with constant speed prop STC (basically firewall forward off a Husky with different air box and exhaust system) cruises at 145 MPH at 2400 rpm and 24 inches manifolds pressure burning right at 9 GPH. Wings are stock airfoil with old style plane booster squared off droop tips. Running wheel pants. No other fairings to speak of. That twisty prop up front makes a world of difference.

Brian

 

[Steve Pierce]

I'm curious why Younkin wanted a Clipper rather than the Tripacer. Did he tell you? Is it narrower behind the front seats?

Because of the sticks and the way they fly. Very nice control harmony.

Jim told me he had designed the tunnel in the boot cowl for a cowl flap but never got around to building one.

 

[dgapilot]

Agree about the sticks and control harmony.. also the lighter weight (of course you also get a lighter gross). With the Clipper he wouldn’t have had to lower the structure over the rear seat as it was already lower, and maybe not raise the point where the center stringer intersects the vertical stabilizer.. I don’t know if he would have gotten the 30 gallon tanks in the Clipper given the lower gross weight, and he certainly would not have gotten the extended baggage compartment that he had in the Pacer. With the diagonal tube removed (it had to be installed for flight) he could unroll his sleeping gage and sleep in the back of the Pacer.


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[dgapilot]

Pertinent notes.

I cruise at 101 indicated knots (call that 116 statute) at 2300 rpm (I think! It's been a while since I had a long cross-country trip). I really don't know what I'd get at full throttle. I'm sort of scared about my fuel burn and the damage it would do to my wallet. Like I said, it's been a while since I had a long cross-country trip.

My Pacer is already heavier than Younkin's, even if I take out the back seat. Assuming he was telling the truth. It's not just the Monocoupe guys that read their airspeed indicators with a little, uh, optimism. Plenty of people do the same with the scales.

My mission is a balance of efficiency with the capability of taking off and landing in reasonable distances with four seatbelts and room for me and two realistic adults.

Also in the mission category, I want to get a repairman certificate on something, and it might as well be something shortwing-inspired, since Younkin's Pacer is pretty close to what I want.

I understand that the prop is more limiting than the wing. However, I'm talking about a building project anyway, so if I can get a less-draggy wing, I'm going to do it. I'd especially like a metal wing with only one strut to fair. I understand that changing airfoils isn't a magic bullet, but it would be just a part of my drag-reduction campaign. If, of course, one can be found that fits. Clint Busenitz seemed to decide that the Cessna wing was too much of a hassle, and the Bearhawk is the only other one I can think of (which it seems that nobody here has experience with), since the Maule doesn't seem to offer any benefit. Even if the prop limits me to the same speed, I might be able to get there burning fewer dinosaurs.

I'm curious why Younkin wanted a Clipper rather than the Tripacer. Did he tell you? Is it narrower behind the front seats?

If you proceed, get a copy of the fabrication and assembly checklist and use that as a guide if you really want to go the E-AB route. Remember that you can’t take any credit for work you do (even modifications) on assemblies salvaged from previously certified aircraft. So if you start with a TriPacer fuselage, you get no credit for anything you do on that fuselage. Same with wings, if you start with Cessna wings, you get no credit for anything done on those wings. I would suggest working with your DAR from the start.


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[Gilbert Pierce]

Pertinent notes.
I'm curious why Younkin wanted a Clipper rather than the Tripacer. Did he tell you? Is it narrower behind the front seats?

The full span ailerons greatly improve the the flying qualities and as Steve noted control harmony.
Aileron control is a light two fingers on the stick.

Same width behind the front seats but shorter baggage compartment.

 

[nogoodusernames]

If you proceed, get a copy of the fabrication and assembly checklist and use that as a guide if you really want to go the E-AB route. Remember that you can’t take any credit for work you do (even modifications) on assemblies salvaged from previously certified aircraft. So if you start with a TriPacer fuselage, you get no credit for anything you do on that fuselage. Same with wings, if you start with Cessna wings, you get no credit for anything done on those wings. I would suggest working with your DAR from the start.

Yeah, that’s what everyone says. When I worked through the list last time, it seemed like I could get enough points if I use a Pacer salvage fuselage, or Cessna salvage wings, but certainly not both. It doesn’t really matter, I have neither a spare fuselage nor a set of Cessna wings and am happy to scratch-build either. Pacer drawings are readily available. I wouldn’t scratch build exact Cessna wings, but could build another wing. I’m not primarily looking for something super-easy to build, I really think the Pacer fuselage fits my “needs” the best. Certainly will talk to the DAR before spending money.

 

[nogoodusernames]

Data point time!

4500 feet MSL
Full throttle, 2575 rpm
132 statute miles per hour indicated.
Best I can tell, 11 gph.

The data is not as good as I would like, but this is what I got. I topped off the tanks, took off and climbed on the left tank, switched to the right and flew for half an hour then switched back. When I landed, I used a 5 gallon jug as my measure. So my fuel burn should be close, but it's not going to be that close. I also forgot to record the temperature. I'd guess it was 40 F at 1200 MSL. I could probably play around with the trim and do better at being consistent with my altitude and get one or two more or less mph. It's tough to be consistent on such a short leg. I didn't fly in a straight line, although my airspeed observations were always on straight sections. Anyway, I did the best I could.

Younkin was 23 statute faster than what I got. He had 160 horses, I've got 150. If I could get to 155 at full throttle, I don't think I would. I'd probably still cruise at 2300 rpm and hope for 138 statute (116 now) and 7.8 gph. If I could get 145 statute at 9 gph, I'd go for that. With the proliferation of at least variable-pitch (if not constant-speed) props on the experimental market, I can't see building something with a fixed-pitch (unless I was really focused on staying super light).

For the Clipper fans, if I do end up building something along these lines, I'd probably use something along the lines of the Clipper's stick. If for no other reason than saving weight. I've not flown in a Clipper, but I'll take y'all's word for the control harmony. Or if someone wants to give me a ride, I'll happily go along.

I did find out that the attachment points on the Bearhawk wing are two inches further apart, so it wouldn't be a plug-and-play option there, and I don't know of any other single-strut plans-built wings available. If you do, please let me know.

 

[Jspey]

I think there was a thread a while ago where people posted their performance stats, and someone was going to graph them. Or maybe it was on SWPC.