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Fuel flow alarm at 9,000 feet.

J

Jackkclark

Well Known Member
Climbing through 9,000 feet doing "Section F2-Flight Test Card-Flight #2 the fuel flow warning was persistent...exceding 10.2. Leveling off, it stopped. Should this be a concern?

Also could not get RPM to 5500 in level flight (at 10k feet)....but can get to 5500 at lower altitudes. Should I adjust prop or let engine "break in" further and test again later? 10 hours hobbs. Static wide open throttle is about 4950.
 
While in level cruise at 5000 RPM, calibrate Dynon fuel flow to read 4.9 GPH. That will give a good starting point. The general rule of thumb: if your GALS (or LTRS) USED reads higher than you expect, increase the K-factor; if it reads lower than you expect, decrease the K-factor. (per Dynon Install Manual page 6-14)
 
Mich48041 said:
. . . "While in level cruise at 5000 RPM, calibrate Dynon fuel flow to read 4.9 GPH." . . .
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What is the assumed pressure altitude for that scenario?
My SkyView fuel flow counter is in need of calibration. Majority of my flying is in Florida and greater SE.
 
What is the assumed pressure altitude for that scenario?
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I do not know. I got those numbers from the Rotax Operating Manual, but there was no mention of altitude. It is just a starting point to get in the ballpark. Fine tune as required.
 
Jackkclark said:
Climbing through 9,000 feet doing "Section F2-Flight Test Card-Flight #2 the fuel flow warning was persistent...exceding 10.2. Leveling off, it stopped. Should this be a concern?
Click to expand...

Do a search in this forum on "fuel flow". If you read all the previous reports of this phenomenon you will see that this is a known "glitch" that has never been explained satisfactorily. The solution for me was to switch off the electric fuel pump at altitude.
 
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I had a high flow alarm just as I lifted off once and aborted takeoff with visions of fuel leaking all over the engine compartment. It turned out to be spurious, but it put me on a wild goose chase. I moved the alarm setpoint to a high level to avoid the alarm, but My indication has been stable. Maybe it was a one-off occurrence. I have about 270 hours on the aircraft, and this happened at about 50 hours TT.
 
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