Jaybird180
Final Approach
I'm running some numbers from my last XC and the numbers look suspicious. Of course I don't have laboratory quality measurements for fuel used, but I derive ~5.5 GPH fuel consumption based on calculations of fuel used divided by Hobbs time (tach time was .1 higher but only would have added another variable into the calculations).
IAS was on-target based on RPM selection (115kts @ 2500RPM). The book contains performance charts for temps of 15c and -5c and 29.92". IIRC, it was about 30.3" and +5c over the 2 days. Fuel flow showed about 9 GPH during most of the enroute portions of the trip and peaked above 12 during climb. I figured that I'd get about 8.5GPH (at best) and 9.5 if I screwed things up. My enroute (unplanned) fuel stop was based on time with the conservative assumption that I screwed up. When I stopped to fill up, I was surprised by how little fuel she took to fill the tanks. I had 3 Takeoffs and climbs that should have consumed about 10-12 Gallons that is reflected in my GPH calculation as aggregate, making me scratch my head even more (I should have used more fuel).
Raw data:
Approx 28 Gallons consumed in 5.1hrs (including all taxi, run-up, takeoff, climb, approach and landing operations).
What do you guys think? 180HP Lycoming with insufficient instrumentation for safe LOP operations.
IAS was on-target based on RPM selection (115kts @ 2500RPM). The book contains performance charts for temps of 15c and -5c and 29.92". IIRC, it was about 30.3" and +5c over the 2 days. Fuel flow showed about 9 GPH during most of the enroute portions of the trip and peaked above 12 during climb. I figured that I'd get about 8.5GPH (at best) and 9.5 if I screwed things up. My enroute (unplanned) fuel stop was based on time with the conservative assumption that I screwed up. When I stopped to fill up, I was surprised by how little fuel she took to fill the tanks. I had 3 Takeoffs and climbs that should have consumed about 10-12 Gallons that is reflected in my GPH calculation as aggregate, making me scratch my head even more (I should have used more fuel).
Raw data:
Approx 28 Gallons consumed in 5.1hrs (including all taxi, run-up, takeoff, climb, approach and landing operations).
What do you guys think? 180HP Lycoming with insufficient instrumentation for safe LOP operations.