dee_bee_que
Active Member
A friend offered me a ride in his Experimental. Basically it is a reverse engineered E-2 Cub, but with PA-18 type wing attachment points. It also sports a full (E-2: no rounded tips) length wing that uses a GA30U-613.5 airfoil. As configured he gets about 58 hp at maximum cruise speed. The parasol fuselage is "draggier" than my Vagabond-- but lighter-- and the parasol has a longer wing of the same chord.
I have venerable round gauges supported by feet of hose, line, and multi-strand cable, so his three fancy new three colored electro-gizmo-multiple function gauges may have been providing gibberish, but being in the front seat I got a good look at 'em... I was offered a little stick time, and the weather was a little blustery, but the handling seemed to bear out what those "liar-gauges" said...
Probably just the power to weight ratio, and wing loading, but it climbed really well, stalled really gentle and straight ahead at idle, and at max cruise would easily outrun my PA-15. I've flown 4412s*, looking it up online the 613.5 appears to my untrained but somewhat experienced eye to look quite similar.
I'm sure there is a technical term for this, but it looks like the underside of the Ribbett comes back to "horizontal" faster (by .525 or .55-ish chord) whereas the 4412 gets there at .725 - .75-ish which would I guess accelerate the air underneath just a bit more. It reminds me of what I remember about Robinson cuffs on a Cessna 2412 (although I think they came "up" even quicker).
Feel free to correct me.
*EDIT: I originally incorrectly stated that the Taylorcraft had a 4412 airfoil. As Victor stated: It doesn't, the Aeronca / Champion line and Luscombes use the 4412. Taylorcrafts use the 23012.
I have venerable round gauges supported by feet of hose, line, and multi-strand cable, so his three fancy new three colored electro-gizmo-multiple function gauges may have been providing gibberish, but being in the front seat I got a good look at 'em... I was offered a little stick time, and the weather was a little blustery, but the handling seemed to bear out what those "liar-gauges" said...
Probably just the power to weight ratio, and wing loading, but it climbed really well, stalled really gentle and straight ahead at idle, and at max cruise would easily outrun my PA-15. I've flown 4412s*, looking it up online the 613.5 appears to my untrained but somewhat experienced eye to look quite similar.
I'm sure there is a technical term for this, but it looks like the underside of the Ribbett comes back to "horizontal" faster (by .525 or .55-ish chord) whereas the 4412 gets there at .725 - .75-ish which would I guess accelerate the air underneath just a bit more. It reminds me of what I remember about Robinson cuffs on a Cessna 2412 (although I think they came "up" even quicker).
Feel free to correct me.
*EDIT: I originally incorrectly stated that the Taylorcraft had a 4412 airfoil. As Victor stated: It doesn't, the Aeronca / Champion line and Luscombes use the 4412. Taylorcrafts use the 23012.
Last edited:
