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I am about to have my 701 finally inspected - next week I hope and have been calibrating fuel tanks, fuel flow etc and am a bit worried about the amount of residual fuel left in my tanks when simulating a downward pitch.
I have built a Czech Kit with the supplied fuel tanks - a bit larger than the American ones being longer at the "thin" trailing wing edge end. They hold 45 litres full and have the fuel outlet at the back inboard corner as with the "normal" plans.
I jacked my plane up on blocks and took the air out of the front tyre simulating a 10degree nose down pitch, then again at 8 degrees and 5.5degrees. My results are concerning! I allowed the fuel to be pumped out at each level (with my electric pump) until air came through, then returned the plane to level and measured the fuel remaining on my calibrated dip stick - results as follows:
At 10 degrees nose down, air is introduced with 33 litres of fuel remaining - ie at 70% full tank
At 8 degrees nose down, 22 litres remain - ie at almost half full
At 5.5 degrees nose down, 14 litres remain - ie at one third full
This was of course in the static situation with no wing movement / changing gravitational forces etc and one tank at a time.
My question is to you guys experienced flying 701's - Is this a real problem?? Can I safely make an approach with less than half tanks?
What should I be writing in my aircraft logbook as far as unusable fuel is concerned??
Would appreciate your collective wisdom on this