Erroneously high fuel consumption?
in 912 / 914 Technical Questions
7 years ago
Hello everyone,
I own a 2012 Tecnam P2002 JF (european certified VLA class up to 600kg), equipped with a 100hp Rotax 912 S2. I've had it for about half a year now, and I have tried to use that time to determine my average fuel flow, accumulating around 60 hours in the last few months.
I have been wondering for quite some time now, with everyone talking about an 18L/h consumption, and me always reaching higher values, but my last flight definitely brought me to the edge: I was airborne for about 2 hours 9 minutes, with total ground time of 15 minutes due to incoming traffic, delaying my departure, and I was cruising at around 2500ft MSL. I used up exactly 50L of Mogas during that period of time (topped it of before take off and after landing).
I don't exactly know how much the 912 burns at idle to 1000 RPM on the ground, but lets assume I used 2L for the 15 minute ground time (which seems to me like a generous estimate). Leaves 48L for 129 minutes of flight, at 2150 prop RPM (I have a prop rpm gauge, not a engine rpm gauge), which converted to engine rpm makes roughly 5225RPM. Conditions were about ISA +10. That equals a fuel burn of 22.3L/h! My handbook mentions a value around 18.5L/h!
How come my engine uses so much fuel?
Best regards,
Pascal
I own a 2012 Tecnam P2002 JF (european certified VLA class up to 600kg), equipped with a 100hp Rotax 912 S2. I've had it for about half a year now, and I have tried to use that time to determine my average fuel flow, accumulating around 60 hours in the last few months.
I have been wondering for quite some time now, with everyone talking about an 18L/h consumption, and me always reaching higher values, but my last flight definitely brought me to the edge: I was airborne for about 2 hours 9 minutes, with total ground time of 15 minutes due to incoming traffic, delaying my departure, and I was cruising at around 2500ft MSL. I used up exactly 50L of Mogas during that period of time (topped it of before take off and after landing).
I don't exactly know how much the 912 burns at idle to 1000 RPM on the ground, but lets assume I used 2L for the 15 minute ground time (which seems to me like a generous estimate). Leaves 48L for 129 minutes of flight, at 2150 prop RPM (I have a prop rpm gauge, not a engine rpm gauge), which converted to engine rpm makes roughly 5225RPM. Conditions were about ISA +10. That equals a fuel burn of 22.3L/h! My handbook mentions a value around 18.5L/h!
How come my engine uses so much fuel?
Best regards,
Pascal
