eschrom
Well-Known Member
I've been curious about Vy because I've never really checked it so today after eating lunch at a nice little airport with a paved runway 65 s.m. away I made several takeoffs and climbs to 1000' AGL. This isn't the way to measure ROC per se but it's a valid comparison. The method:
-Taxi to takeoff position
-Start timer.
-Push throttle in.
-Take off and stay low until reaching test speed.
-Climb at test speed to 1000' AGL.
Results:
85 mph, 1:17
90 mph, 1:27
100 mph, 1:28
110 mph, 1:30.
I was surprised that 85 gave the shortest time. Would have guessed 90-100. But there are lots of potential sources of error in my data recording so a repeat isn't a bad idea. And if it comes out the same 80 would be the next to try.
Some other interesting stats... Cruise to and from this airport was at 24" MAP, ~3250 rpm, 137 IAS at 3500' and 140 IAS at 2500'. Outside air temperature on the ground was mid to upper 50s.
Total flight time for the day was 2.1 hr and there were 5 takeoffs total, as well as the usual idling on the ground. I burned 6.7 gal. 6.7/2.1 = 3.2 gph average fuel consumption. Economy like that from a plane that will cruise at 140 is hard to beat.
Ed
2LS with GP 2276 and Sterba 54 x 46 prop
-Taxi to takeoff position
-Start timer.
-Push throttle in.
-Take off and stay low until reaching test speed.
-Climb at test speed to 1000' AGL.
Results:
85 mph, 1:17
90 mph, 1:27
100 mph, 1:28
110 mph, 1:30.
I was surprised that 85 gave the shortest time. Would have guessed 90-100. But there are lots of potential sources of error in my data recording so a repeat isn't a bad idea. And if it comes out the same 80 would be the next to try.
Some other interesting stats... Cruise to and from this airport was at 24" MAP, ~3250 rpm, 137 IAS at 3500' and 140 IAS at 2500'. Outside air temperature on the ground was mid to upper 50s.
Total flight time for the day was 2.1 hr and there were 5 takeoffs total, as well as the usual idling on the ground. I burned 6.7 gal. 6.7/2.1 = 3.2 gph average fuel consumption. Economy like that from a plane that will cruise at 140 is hard to beat.
Ed
2LS with GP 2276 and Sterba 54 x 46 prop