The Cessna wing seems like a standout among wing designs throughout aircraft design history, and I was thinking about most of the kitplanes available these days, and they're all straight chord designs.

Is this simply due to simplicity of building? Is the speed gain of the tapered design not enough to justify the complexity of the build? Tough to do with a rag&tube construction?

An excellent design by Dean Wilson designer of the Avid Flyer (the father of the Kitfox, Just Aircraft, Ridge Runner and many more).

Too complicated to build to be a success.

Dean is a great guy. I Knew and work just a little bit with him when he was in Caldwell in the early 80s. The guy has a vision and made great stuff.

The two metal wing homebuilt aircraft I have had both try to keep construction simple for the one off or first time builder. Having the ribs progressively shorter in the taper and the increased difficulty that comes with that would cause most to pass on the design since the wing is already the most difficult and time consuming part of building.

Treefeller wrote:The Cessna wing seems like a standout among wing designs throughout aircraft design history, and I was thinking about most of the kitplanes available these days, and they're all straight chord designs.

Is this simply due to simplicity of building? Is the speed gain of the tapered design not enough to justify the complexity of the build? Tough to do with a rag&tube construction?

its gotta be about simplicity. It's certainly not about the elegant shape of a hershey bar.

An eliptical wing may look a little out of place on a high wing, bush capable plane like the SC, Husky etc., this mostly due to that's what we are used to seeing.

That said, I used to own a little SA-100 Starduster biplane. It, and it's 2-place big brother the SA-300 are the only little sport bipes I'm aware of that have an eliptical wing - so you can always ID them on a ramp. These were mostly all plans built, more work of course, but good asthetics can be its own reward.

Supermarine Spitfire.

bumper

late model cherokees have the semi tapered shape too.

An aircraft with an elliptical wing planform MAY not have the most desireable stall characteristics for a STOL airplane type. Great maneuverability, perhaps, but slow speed characteristics may not be the best.

Tapered or semi tapered wing planforms are more complex to build and constitute a higher individual parts count.

MTV

c170pete wrote:.......
It's certainly not about the elegant shape of a hershey bar.

To paraphrase Forest Gump: "handsome is as handsome does". There's a certain beauty to a straight-cord, square-tipped wing.

The Bush Hawk has a partial tapered metal wing.

With composite technology, it is about as easy to build a wing with variable taper, discontinuous leading edge, curved leading edge or elliptical planform, as it is to build a constant chord wing with a little washout. Once you have made the mold, features in the molds and assembly jigs are actually quite handy as spatial references for wing structure closeout. With cored wing skins, there is no need for ribs other than fuel baffling, so you can keep your part count down.

There are definitely optimizations that can be made from non-prismatic wings for any flying machine. Stall, pitching moment and drag characteristics can be finely tuned for specific flight profiles, but the need for tighter manufacturing tolerances is also necessary. The aerodynamic analysis is trickier with variable section wings, but if you have accurately developed characteristic curves for all of the airfoil sections it's completely manageable.

Scolopax wrote:... Once you have made the mold...

important little caveat there...

Making molds is actually not too challenging c170pete. There are several outfits that have expertise with this technology in the PNW.

You military history buffs can compare the mass production design of the ME109 wing to the graceful but complicated Spitfire. In the air both did the job. I want a ME109, cheap, quick, easy, does the job.

soaringhiggy wrote:Dean is a great guy. I Knew and work just a little bit with him when he was in Caldwell in the early 80s. The guy has a vision and made great stuff.

Here are some other Dean Wilson designs. The Private Explorer single engine nicknamed the Wingabago, and a twin version. I believe the twin crashed somewhere in Canada. The Wingabago was equipped with a double bed, stove, counter and sink. Imagine pulling up to your favorite flyins in one of these. No setting up a tent and stuff. Just pull out the lawn chair and crack a beer.

^^^^Functionally it sounds good,
but visually it looks like it needs a...... crash diet....

I know. No points-low hanging fruit!
lc

I believe the twin (Gobal Explorer) crashed somewhere in Canada.

The first one built in 1991, N376DT crashed on the BC coast, some say taking off from a strip, others say a lake. The "locals" stripped it before it could be recovered (why we always carried a full-sized spare tire driving in the backwoods). I remember seeing it before it crashed and having a good look inside somewhere on North Vancouver Island, maybe on the Port McNeill strip. Anybody know exactly the crash location? Maybe Dean Wilson in Idaho would remember?

The second one built in 1994 was the yellow one. N376LC. I think it eventually crashed too, both were pilot error.

I don't know why, but when I see that plane my brain recalls Buckminster Fuller's car the Dymaxion



BTW, I was engaged, back at UCLA, to an Ex-Luftwaffe pilot's daughter, another story. He flew the ME109 and the FW190. He hated the ME109 and loved the FW190, which he ultimately got shot down in shortly after Normandy. The FW190 was a delight with switches to control everything. The ME109 was a coffin, very hard to bail out of as the canopy mechanism as daft and really heavy. After he was in the American hospital recovering from his injuries; he had, as he described, the first good meal in two years. He went on to become the head of Volkswagen USA. Great stories after you got a few beers in him. Ironically, he had completed the ground school for the ME262 and was going to transfer when the invasion called him to the front.

If I remember correctly from decades old experience in a glider that a tapered wing can more easily suffer a stall at the wing tip. Whose up on this?

Yep, elliptical wings are the cats meow of aerodynamics. They have the perfect lift distribution and downwash characteristics. However, those desirable characteristics translate into a problem with stall progression over the wing. They can stall all along the trailing edge (where your ailerons are...) and give you a nasty surprise.

The good old Hersey Bar wing, besides being simple to build, stalls at the wing roots first and progresses outboard and forward as we become more stupid and ignore the buffet. It can fly with the whole center section of the wing stalled and still have the ailerons doing their job.

Tapered wings are rough approximations of elliptical wings; the more tapered sections you have, the closer you come to the elliptical planform.

YB

Yellowbelly wrote:The good old Hersey Bar wing, besides being simple to build, stalls at the wing roots first and progresses outboard and forward as we become more stupid and ignore the buffet. It can fly with the whole center section of the wing stalled and still have the ailerons doing their job.

Is that a function of the chord though? Or the washout that's built into the wing? I think you can build washout into any wing chord profile and achieve the desirable effect of root stalling first, tip stalling later to retain aileron effectiveness. Will the hershey bar have that characteristic on its own without washout?

My original question was mostly in regard to the type of flying we enjoy-- bushplanes. I'd forgotten about the Bushhawk.

I wonder what the actual measurable speed envelope difference is between 3 wings of equivalent span, but each having a different chord profile-- straight, semi tapered, and fully tapered.