My aircraft is fitted with a EDM 700 + fuel computer....is most excellent
It is very interesting comparing what it says to the original fit rubbish fuel gauges...they are a useless waste of panel space...particularly at the E end of the scale
On a recent long trip I decided to check the actual useable fuel in each tank against the book useable figure. Book useable is 140 liters/side, 155 lt total.
When checking the right side I climbed on the left tank...burning 20 liters out of it before changing tanks. I then ran on the right tank only calculating it would burn dry between 160 and 175 used. At 175 liters used fuel pressure started fluctuating so I changed tanks before scaring my daughter in the back with a faultering engine...I had pre warned her of course but she had since fallen asleep.
Interesting that in the time period after 160 liters used I was experiencing light/moderate turbulence causing significant yawing and roll excursions...and despite having my hand on the fuel selector expecting unporting of the fuel intake never experienced any problems until the fuel finally ran out at 175 used...during a period of smooth conditions.
So I have added 20 liters to my 'useable' figure, leaving 5 lt per side 'unuseable'...and Beechcraft can kiss my ass
Having 'recalibrated' my fuel tanks I was more than happy to depart my next port of call, where no avgas was available, with only 60 liters total (45 'useable') in the left tank and fly somewhere 35nm away for fuel...absolutely safe in the knowledge I would land with 45 minutes reserve....more like 55 minutes + actually because on that short low level leg i was operating LOP and only burning 49 liters/hr...making 45 minutes reserve 37 liters..I pulled up at the bowser with 42 liters total...mind you the low fuel warnings on takeoff, where I was burning best part of 100 lt/hr, were a little interesting...but soon alleviated while watching the endurance figure climbing steadily as I leaned
How anyone can fly with only the original fit fuel gauges in old SE or twin piston aircraft is beyond me...how owners can sleep at night while the available technology is available so cheap also bemuses me no end.