# Wittman Tailwind modified to meet E-LSA?

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#### TFF

##### Well-Known Member
CAFE did the same thing, prop off gliding, on a C150 to verify their method of zero thrust tests for the CAFE testing.

#### arp67

##### Member
After some more thought, I think it might be easier to build a Cub look-a-like (Wag Aero Sport Trainer) and customize it with Wittman Tailwind design elements (windshield, tailfeathers, Wittman style landing gear). I love the cowling used on most of the W-10s with Lycoming engines, don't know how to make a cowling like that work on the front of a J-3 style fuse/firewall?

#### cluttonfred

##### Well-Known Member
HBA Supporter
Nope, just plugged the gross weight, clean CL max, and aspect ratio into my LAA performance estimation spreadsheet and tweaked the desired stall speed until the span and area came out right. I don't claim to have anywhere near the knowledge or experience of someone like Steve Wittman, but I do look at claims of fuselage lift with skepticism. Time and time again, actual calibrated testing has shown unexpectedly low stall speeds to be measurement errors related to the high angle of attack messing with a fixed pitot tube.

I don’t know if any actual testing has been done to verify it, but Witt claimed that the fuselage produced a significant amount of lift. Did you allow for that in your analysis?

#### Tiger Tim

##### Well-Known Member
After some more thought, I think it might be easier to build a Cub look-a-like (Wag Aero Sport Trainer) and customize it with Wittman Tailwind design elements (windshield, tailfeathers, Wittman style landing gear).
I must have missed it. Why is the Buttercup a no-go?

#### arp67

##### Member
That picture looks like a W-10 to me? Unless its a Buttercup with the fuselage lines straightened to look like a W-10?

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#### samyguy

##### Well-Known Member
OK I may regret this. I have W-10 that will meet LSA.
Empty weight 593# wing span 27.5 ft. wittman tips.
A75 motor
Calbie Woods Al. wings, And much correspondence between Steve W. and the builder.
.250th cuff under leading edge. Guy built 3 sets of wings to get it right.
Stall 44 mph top 130 mph
N847WL

#### TFF

##### Well-Known Member
What you have is exactly what is needed to do it, as discussed. Very light, 325 lbs lighter than the normal W10; very close to original. Small engine. Bigger wing with airfoil mods, and the Calbie wing is probably stronger to make it longer. You do come to the question, what is in a name?

One of the things I love about the Regular Tailwind is the wood wing. It’s actually why I don’t want to build Calbie’s Four Runner. I even thought of a clipped wing Bearhawk as I would rather have the speed. I want the slick ply covered wing like a Bellanca or wood wing Mooney.

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#### Michael Silvius

##### Well-Known Member
I know the Wittman Buttercup design can meet the ELSA specs, ......
yea its called the Szaraz Daphne
A Tailwind W8 fuselage with Stits Skycoupe wings

#### Mcmark

##### Well-Known Member
Tiger Tim that is the Butter Burger built by Jim Clements. Mostly ButterCup but no leading edge “cuff/flap” and some other changes.
He has also built one with a Tailwind size fuselage and 2 strut per wing with a 290 that meets LSA weight and stall but it’s not a Tailwind. It’s still too fast in cruise.

#### samyguy

##### Well-Known Member
ARP67 if want more information PM me, we can go from there. Have a good day all

#### stanislavz

##### Well-Known Member
HBA Supporter
ARP67 if want more information PM me, we can go from there. Have a good day all
No. I me, and others would to know it too.

#### Turd Ferguson

##### Well-Known Member
customize it with Wittman Tailwind design elements (windshield, tailfeathers, Wittman style landing gear). I love the cowling used on most of the W-10s with Lycoming engines, don't know how to make a cowling like that work on the front of a J-3 style fuse/firewall?
Tim Buttles has more champ than cub in his plane but he used flat plexi panels for the windshield. Not to be like a tailwind but because it's \$ cheaper than a molded windshield. Square off the tail, which I've seen cub clones with squared tail feathers. The pressure cowl is there so add tapered rod gear and you're
good to go!

#### BJC

##### Well-Known Member
HBA Supporter
That’s a neat aiirplane that I never have seen. Thanks, Turd.

Did he consider a flat-wraled windshield?

BJC

#### Turd Ferguson

##### Well-Known Member
That’s a neat aiirplane that I never have seen.
It was parked outside the Homebuilders Hangar for at least 2 yrs at OSH.

#### BJC

##### Well-Known Member
HBA Supporter
Well, I should have noticed it, but I don’t recall it.

BJC

#### cluttonfred

##### Well-Known Member
HBA Supporter
The Daphne is a great example of what it takes to make an LSA out of a Tailwind: 55% more wing area and a 33% thicker airfoil implemented with an entirely different wing and strut structure. All that's left is the Tailwind look, which is not a bad thing if that's what you like and LSA is the mission you have to fulfill. Here's an article on a Daphne from 1966.

yea its called the Szaraz Daphne
A Tailwind W8 fuselage with Stits Skycoupe wings

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#### stanislavz

##### Well-Known Member
HBA Supporter
The Daphne is a great example of what it takes to make an LSA out of a Tailwind:
Scott ol' ironside could be used as visual example too:

#### Michael Silvius

##### Well-Known Member
The Daphne is a great example of what it takes to make an LSA out of a Tailwind: 55% more wing area and a 33% thicker airfoil implemented with an entirely different wing and strut structure. All that's left is the Tailwind look, which is not a bad thing if that's what you like and LSA is the mission you have to fulfill. Here's an article on a Daphne from 1966.
Yea whats not to like about it for us sub-farts getting a bit long in the tooth? That Sky-Coupe wing with a 35 kt stall should make for nice docile handling. I was fortunate to score a set of plans for it on E-bay a couple years ago.
• Length: 19 ft 7 in (5.97 m)
• Wingspan: 26 ft (7.9 m)
• Wing area: 130 sq ft (12 m2)
• Airfoil: NACA 4412
• Empty weight: 820 lb (372 kg)
• Gross weight: 1,300 lb (590 kg)
• Maximum speed: 130 kn (150 mph, 240 km/h)
• Cruise speed: 100 kn (120 mph, 190 km/h)
• Stall speed: 35 kn (40 mph, 64 km/h)
• Never exceed speed: 150 kn (170 mph, 270 km/h)

#### Michael Silvius

##### Well-Known Member
Scott ol' ironside could be used as visual example too:
Yea and a composite foam and fiberglass build long before anyone else was doing it.
A couple Sport Aviation articles on it
Sadly it was destroyed a couple years ago.

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#### stanislavz

##### Well-Known Member
HBA Supporter
Sadly it was destroyed a couple years ago.
I think it is in restoration now ?