Some of my RC model airplanes 3.

This is a slightly modified version of the Ampmaster by Al Eastman featured on E Zone. I kept the outline, but changed the flat bottom Clark Y airfoil to the semisymmetrical E374. The first flight almost ended in a disaster since the recomended CG placement on the spar resulted in an overly sensitive pitch control. I already had a bad feeling about the CG placement prior the first flight, but I guess I was to lazy to move it forward and increase the safety margin.

The model is powered by the Kyosho-Magnetic-Mayhem ferrite motor geared 1:2 to the 9x8 Master Airscrew. On 9 N1700SCR the motor pulls 25~30A at full throtle. With the flying weight at 1.7kg (~60 oz) the output power loading is around 100W/kg (~50W/pound) giving a reasonable sport model.