so how much will a 75 F model hold fuel wise

[Yetti]

On 5/28/2022 at 3:39 PM, Marauder said:

You got a picture of the placard?


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I can get one.   I removed the fuel by removing the sample port.

[A64Pilot]

On 5/28/2022 at 6:00 PM, carusoam said:

There is probably a specific procedure used to drain and measure useable fuel….

Which probably includes all of the fuel that is available to be pumped out of the tanks using the electric fuel pump….

It may be specific to being level in two dimensions….  Because you can get more out of a tank by raising the nose… and lifting the wing…. Which may not be viable in all regimes of flight…. So, not useable…

expect fuel lines and the upper part of the water separator to be included in the number…. And if carburetor equipped… the carb’s bowl carries a few ounces too…. 

PP thoughts only, not a mechanic…

Best regards,

-a-

There is, it’s at flight attitude, I’d attach a photo of it being done but you know how attachments are.

Crop Duster held 114 gls a side, wet wing just like a Mooney and there were some variations, as part of the build process we had to measure capacity and record each tank capacity, had to ensure each tank would hold at least 114, as we filled the tank we calibrated the fuel gauge.

We only had capacity in the POH, so when we were Certifying a new aircraft the unusable fuel “thing” came up. We had a 4.5 gl header tank that was never included in the 228 gls capacity, so it turned out when measured that we had a capacity of 228 gls and about 231 gls of usable fuel, so we ended up leaving the POH alone.

I’d expect if you put a Mooney at flight attitude and drained every drop out that you would get more than placarded capacity. There was a procedure in place if we ever built a wing of less than 114 gls, an Engineering deviance if you will but it would be a special by serial number POH etc. so we made sure when the 114 number was set that it was a number that we could always get.

‘What the heck I’ll delete it in a few days, this was a Military aircraft we developed with a partner but it’s the pic I have, years ago a ramp was built with a jack for the tail wheel to raise the aircraft to flight attitude, we would let air out of a main the level the aircraft.