Air In The Tanks
Ive owned Cessna T210s since 1977; first a 1969 J model and then a 1979 N model with a TSIO-520-R engine. In the 1980s, there were a number of fuel exhaustion accidents in 210s, all of them attributable to not getting a full fill and resulting in being shorted an hours supply when fueling stops after fuel backs up out of the filler port. The outboard sections of the fuel tanks are slightly higher than the bottom of the filler port. To get the last one-plus gallons in the tanks requires the slowest of fueling until reaching the real full point.