ORIGINAL: Chad Veich
ORIGINAL: Pull Up Now!
Thanks for the info. My guess is the tail wheel retract is really costing me a lot of weight. I went back inside the model and threw everything I could forward. Rebalanced it, and this time it came to 17.8 lbs. A big improvement, but still heavy. Now it's 32 oz/ft2, with a 21mph stall speed. For safety, I have TWO elevator servos, meaning that I have to compensate for an extra pushrod, clevis, and control horn. All aft of the CG!
On a 71 inch Jug 32 oz/ft2 would be in the floater range. It sounded suspiciously light to me actually. Don't want to burst your bubble but I think you may be mis-calculating your wing loading. ESM provides the wing area as 5.95 sq/ft. Divide your total weight in ounces, 248.8, by 5.95 and the result is a wing loading of nearly 48 oz/ft2. That is still within reason for a six foot warbird and the 70 inch span Ziroli P-47 flies great in the 17-18 pound range as long as you have enough power to haul the weight. I imagine the ESM is no different.
Hey Chad, thanks for the information on wing loading. I was sure I did not make a math error, so I double checked the basic plane data I used, which is printed on the ESM P47 box. I've included pics from that label below. It turns out there is a huge discrepancy. The label lists the wing area as 8.95 ft2, whereas TBM's website uses 5.95 ft2. Also, the label's wingspan is wrong; it says 73.5 whereas the real wingspan is 71". Interestingly, TBM has corrected the wing area in their website's "SPEC" tab, but they still list the wrong wingspan. So, I created my own CAD model of the wing and made my own area calculation. Turns out, by my model, the area is 5.65 ft2. I did not count the center section where there is a huge round bubble that follows the fuse more than it is an airfoil.
Bottom line, Chad, you are right. The wing loading is far higher than I realized, thanks to the Chinese playing loose with the numbers. They really need to improve their accuracy.