Opinions on Wag-Aero's Sport Trainer

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NX-4L

Coming soon to a lake near me.
HBA Supporter
Log Member
Joined
Jul 27, 2021
Messages
33
Location
Three miles down Four Mile Lake
-Not an aerodynamicist
Perhaps not, but the aerodynamicists Piper hired when they designed the Super Pawnee (PA-36) agree with you.
NX-4L - maybe consider changing the wing tips. The rounded stock tips do look good, but squared (in planform) tips perform a lot better. Shape the tips like the STOL boys have done - either a slight droop tip or even a simple slashed tip (when viewed from the from the front - not just a straight cut-off) helps maintain lift out to the tip whereas the rounded tip sheds airflow.
The Pawnee (PA-25) had the Super Cubs wings, and Piper had a detailed study made of airflow over the wings. Thousands of strings were glued to the surfaces so conventional photographs could be made of the airflow. Squared tips worked best. The study was probably before the advent of the down turned tip. The "experts" empirically quantified that many things perceived to be aerodynamic, like elliptical wings, were not in fact aerodynamic.

I actually thought that people recommending "clipped wings" were referring to squaring off the wing tips. I have seen a lot of Cubs, Champs, Chiefs, and wooden winged Luscombes where the tips have been squared off at the last rib. Sometimes the aileron is squared off as well-- or more properly built out to square. I imagine that STOL tips made to fit the PA-18 would fit the J-3 as well.

I conversed with someone who built a WA Sport Trainer and he confirmed their "no accessories" light weight of 684 pounds with stock wheels and an A-65-8 powerplant. Mine won't have an X or an H or tail spring and brace tubes, brakes, or any wheeled gear parts, which will lighten it over 40 pounds.

640 pounds of airplane plus 135 pounds of floats, 340 pounds of people, 80 pounds of gas, and 8 pounds of oil is only 1203 pounds, well under WA's recommended 1250 pounds and Zenair's maximum 1278 pounds.
 
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NX-4L

Coming soon to a lake near me.
HBA Supporter
Log Member
Joined
Jul 27, 2021
Messages
33
Location
Three miles down Four Mile Lake
Wooden winged Luscombes? Prior to the Phantom?
Must have been before my time, born in '38.
The Model 8 (pre A-65, 8A) was approved for production on August 11, 1938, with a Cont. A-50-1. The wing ribs of the earliest aircraft were built up spruce trusses. Around 1939 and c/n 801 (I think at 833, because only aircraft bearing c/n 833 and above are eligible for metalized wings) the trusses were made of aluminum. Postwar the ribs changed again to stamped aluminum. Wings built as new with stressed aluminum skins required fewer ribs and had some false ribs for streamlining.

A mechanic who has repaired or rebuilt wings after damage on a couple of these early aircraft backward-engineered new construction wooden trusses for repairs and there are a few wooden winged Luscombe 8s out there. Not many, only 800 or 832/6000 as built and many/most of those are sadly no longer around. Maybe a handful were converted after being damaged because field maintenance is easier.
 
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Mcmark

Well-Known Member
Joined
Sep 24, 2013
Messages
453
Location
Owings, MD
I have a mount for the Lycoming conical for that airplane if you decide to go backcountry.
Brand new built buy BBI.
 
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