hecilopter
Well Known Member
Part 1
I decided this morning I was going to see how fast my -7A was as it was smooth and I was by myself and I wanted an excuse to fly. My gross at takeoff was about 1100 empty + 40 gals (240) + me (230!) = 1570 lbs. I have all fairings on and I'm unpainted.
I made a 4 way speed run at 2500 ft on the altimeter, OAT 58 F, altimeter setting 30.03. This worked out to a density altitude of about 3000 ft. I was WOT, 2600 RPM. I have a Superior XP-360 180 HP carbureted, mags, and the Hartzell 74" blended airfoil prop.
GPS
Heading Groundspeed
180 189 kts
090 184 kts
000 168 kts
270 174 kts
using the true airspeed calculator here http://www.csgnetwork.com/tasgpscalc.html it came to 181 kts true. This is almost exactly 208 MPH just like Van's web site says for top speed. Would it be faster down low (500 ft off the deck?). At any rate I believe Van's numbers.
Part 2
With a smile on my face, I headed back to base only to turn final, pull the power and ------ POP, POP, BACKFIRE, ALMOST DEAD ENGINE! Pushed the power back in and found that it would run smoothly above about 1800 rpm.
Got it back on the ground, and had to jockey with the throttle to get it to keep running to get back to the hangar. Uncowled the beast and lo and behold - the spring held in place idle mixture set screw had come off in flight and departed the airplane! I have a new Precision Airmotive MA-4-5 carb. I called them and they said they would send a new one all expenses paid, I should have it back in a couple of days. Great customer service.
Has anyone else experienced this?
Thanks!
I decided this morning I was going to see how fast my -7A was as it was smooth and I was by myself and I wanted an excuse to fly. My gross at takeoff was about 1100 empty + 40 gals (240) + me (230!) = 1570 lbs. I have all fairings on and I'm unpainted.
I made a 4 way speed run at 2500 ft on the altimeter, OAT 58 F, altimeter setting 30.03. This worked out to a density altitude of about 3000 ft. I was WOT, 2600 RPM. I have a Superior XP-360 180 HP carbureted, mags, and the Hartzell 74" blended airfoil prop.
GPS
Heading Groundspeed
180 189 kts
090 184 kts
000 168 kts
270 174 kts
using the true airspeed calculator here http://www.csgnetwork.com/tasgpscalc.html it came to 181 kts true. This is almost exactly 208 MPH just like Van's web site says for top speed. Would it be faster down low (500 ft off the deck?). At any rate I believe Van's numbers.
Part 2
With a smile on my face, I headed back to base only to turn final, pull the power and ------ POP, POP, BACKFIRE, ALMOST DEAD ENGINE! Pushed the power back in and found that it would run smoothly above about 1800 rpm.
Got it back on the ground, and had to jockey with the throttle to get it to keep running to get back to the hangar. Uncowled the beast and lo and behold - the spring held in place idle mixture set screw had come off in flight and departed the airplane! I have a new Precision Airmotive MA-4-5 carb. I called them and they said they would send a new one all expenses paid, I should have it back in a couple of days. Great customer service.
Has anyone else experienced this?
Thanks!