tracstarr
01-06-2021, 09:20 AM
In doing my fuel flow test (multiple times now to make sure my numbers were repeatable) - I'm seeing numbers way higher than anyone I've read on this forum.
I setup with a 20 degree attitude as suggested in several other posts (and as by FAA? seems there is no recommendation by Transport Canada here). Filled the tanks and disconnected the fuel line at the fuel rail. With each pump individually on and then together, all tests resulted in about 4L/min, or 240L/hr which is 63.4 gph. The pumps individually are suppose to be rated at only 120L/hr max. The 912iS at max requires about 27L/h (6.9gph). So if that's the case I'm seeing way way way way more than the minimum 125% over requirement.
I've checked all the filters and the bypass valve (making sure it was actually working and even putting it in backwards on purpose) without any change. What I do notice is that pumps don't have to be on to get flow to the engine (gravity) - would this make a difference? Should I only be testing with a minimum amount of fuel?
I also called the Canadian distributor to discuss and was told they also got similar numbers on another personal aircraft and that I shouldn't be concerned. However, why is this not the normal? Another friend here only gets 130% on his 912is.
Thoughts? Concerns?
I setup with a 20 degree attitude as suggested in several other posts (and as by FAA? seems there is no recommendation by Transport Canada here). Filled the tanks and disconnected the fuel line at the fuel rail. With each pump individually on and then together, all tests resulted in about 4L/min, or 240L/hr which is 63.4 gph. The pumps individually are suppose to be rated at only 120L/hr max. The 912iS at max requires about 27L/h (6.9gph). So if that's the case I'm seeing way way way way more than the minimum 125% over requirement.
I've checked all the filters and the bypass valve (making sure it was actually working and even putting it in backwards on purpose) without any change. What I do notice is that pumps don't have to be on to get flow to the engine (gravity) - would this make a difference? Should I only be testing with a minimum amount of fuel?
I also called the Canadian distributor to discuss and was told they also got similar numbers on another personal aircraft and that I shouldn't be concerned. However, why is this not the normal? Another friend here only gets 130% on his 912is.
Thoughts? Concerns?