Having survived a couple of days of fog, rain, and low clouds, I was itching to go flying in the clear blue of the Houston skies this afternoon. I had gotten a PM request from someone for my speed numbers the other day, and I was curious to see if they had changed any from my test flying a little over a year ago. While hardly scientific, I found that things matched pretty well, and since they are handy on my knee-board, I might as well let folks see them.
This data was taken directly off of my EFIS, which gives me real-time TAS derived from IAS, altitude, and temperature. My EFIS ASI and backup ASI are in agreement to within a knot, so either they are both off, or the numbers are pretty accurate (During Phase 1, I flew numerous wind triangles to work out the CAS corrections, and these numbers should be as close as we can expect to get in the homebuilders world). I stabilized the airplane at each altitude based on realtime Density Altitude, then took took the readings. And the Sea Level numbers were actually taken at maybe fifty feet - a slight error, and a benefit of living on the coast...
The percent power numbers are taken off the EFIS, which computed them from available data. All these readings were at Wide Open Throttle, and full RPM (2650). Engine leaned for peak HP above 5,000'
Sea Level, 29.0 inches Hg, 102% HP - 186 KTAS
1500', 28.1 inches Hg, 98% HP - 184 KTAS
6000', 24.1 inches Hg, 83% HP - 180 KTAS
10,000', 20.7 inches Hg, 70% HP - 175 KTAS
Out of curiosity, at 10,000', I then brought the RPM back to my normal cruise of 2350, and got:
10,000', 20.7 inches Hg, 65% HP - 170 KTAS
And then I decided I'd done enough boring data takes, and had some fun on the way down! Performance is pretty much what I got durign Phase I.
Data is worth what you paid for it....
Paul
This data was taken directly off of my EFIS, which gives me real-time TAS derived from IAS, altitude, and temperature. My EFIS ASI and backup ASI are in agreement to within a knot, so either they are both off, or the numbers are pretty accurate (During Phase 1, I flew numerous wind triangles to work out the CAS corrections, and these numbers should be as close as we can expect to get in the homebuilders world). I stabilized the airplane at each altitude based on realtime Density Altitude, then took took the readings. And the Sea Level numbers were actually taken at maybe fifty feet - a slight error, and a benefit of living on the coast...
The percent power numbers are taken off the EFIS, which computed them from available data. All these readings were at Wide Open Throttle, and full RPM (2650). Engine leaned for peak HP above 5,000'
Sea Level, 29.0 inches Hg, 102% HP - 186 KTAS
1500', 28.1 inches Hg, 98% HP - 184 KTAS
6000', 24.1 inches Hg, 83% HP - 180 KTAS
10,000', 20.7 inches Hg, 70% HP - 175 KTAS
Out of curiosity, at 10,000', I then brought the RPM back to my normal cruise of 2350, and got:
10,000', 20.7 inches Hg, 65% HP - 170 KTAS
And then I decided I'd done enough boring data takes, and had some fun on the way down! Performance is pretty much what I got durign Phase I.
Data is worth what you paid for it....
Paul