RE: AEROWORKS P51 Build
<div style="margin: 0in 0in 0pt">OK guys, here’s the report. Flew the Mustang today. Was only able to get one flight because prop pitch is way to low. We started with 8 degrees on pitch giving us 27 lbs of thrust at 6600 RPM static.</div><div style="margin: 0in 0in 0pt"></div><div style="margin: 0in 0in 0pt">The problem is when she unloads at full RPM in the air we lose so much thrust she almost doesn’t fly. It acts like a boat prop cavitating.</div><div style="margin: 0in 0in 0pt"></div><div style="margin: 0in 0in 0pt">Resolution: We didn’t realize how many RPM the DA 85 would pick up in flight. Anything over 6900 and the air between the blades becomes so unstable that the attacking blade has very little ability to produce thrust and it completely destabilizes. Almost like 0 Degree pitch.</div><div style="margin: 0in 0in 0pt"></div><div style="margin: 0in 0in 0pt">We are getting away from the 24 inch and going with 23 with a static RPM of 5600 RPM. This will keep us under the 6500 limit we have set and should give us 30-32 lbs of thrust static or 27-28 in unloaded flight.</div><div style="margin: 0in 0in 0pt"></div><div style="margin: 0in 0in 0pt">We set the factory specs for full throw on the surfaces with 60% expediential. Bad mistake. Plane was very mushy but could also be the 60 MPH flying speed we were producing.</div><div style="margin: 0in 0in 0pt"></div><div style="margin: 0in 0in 0pt">We planned on a few flights to get everything set up for a nice video this afternoon but we were not able to accomplish this. I have to say that the Aero Works Mustang slow flying characteristics really saved our asses.</div><div style="margin: 0in 0in 0pt"></div><div style="margin: 0in 0in 0pt">I did get to a high enough altitude to make a diving low pass across the field before landing the beast. Even at a washed out pitch her 4 blade prop was starting howl even over the Pitts mufflered DA 85.</div><div style="margin: 0in 0in 0pt"></div><div style="margin: 0in 0in 0pt">I really wanted to thank Forrest and his buddies at the sod farm for all the support and advice today. They gave us the perfect unlimited golf course grass runway to work with. 400 acres of absolute Mustang heaven.</div><div style="margin: 0in 0in 0pt"></div><div style="margin: 0in 0in 0pt">Another note for anyone following in our footsteps. NEVER NEVER use less than ½ throttle on this 4 blade. I was at 80 ft (maybe more) in a 40 degree dive for the runway with flaps down and it looked like I was going to overshoot the area I wanted to land in by a lot.</div><div style="margin: 0in 0in 0pt"></div><div style="margin: 0in 0in 0pt">I pulled the throttle back to compensate and it was a like I took half the airspeed away from the plane in a moment or threw out a drag chute behind me. We hit hard on the gear (no damage to the plane) and bent the top of the struts. This thing wants a lot of throttle on landing and will coax you into giving in but you can’t fall for it.</div><div style="margin: 0in 0in 0pt"></div><div style="margin: 0in 0in 0pt">This 4 blade is a super turbo charged tie me to a tree air brake under 2000 RPM. </div><div style="margin: 0in 0in 0pt"></div><div style="margin: 0in 0in 0pt">We will return to the field with camera, prop, new struts, and well earned confidence next weekend. Once she has the right setup it will be a baby in the air if we follow the Air Gods Mustang rules.</div><div style="margin: 0in 0in 0pt"></div><div style="margin: 0in 0in 0pt">More to come.</div><div style="margin: 0in 0in 0pt"></div><div style="margin: 0in 0in 0pt">Fred</div>