Flight training requires lots of book study, but even more learning by doing. Texts and simulators may flatten the learning curve, but airmanship has to be learned in the air. Cross-country flight planning doesn’t come together until you’ve planned a cross-country flight. Even the apparently straightforward preflight inspection leaves room for error—errors that become essential lessons when (and if) they’re caught by a watchful CFI.
On June 1, 2008, a Cessna 172H left Brockport, New York, to practice takeoffs and landings at Genesee County Airport, 14 nm away. Aboard were a 14-hour student and his instructor, an airline transport pilot with more than 17,000 hours. After doing touch and goes in gusty winds, they headed home at about 1,000 feet agl.
Less than half a mile from home, the engine began shaking and then quit completely. The instructor took the controls and tried to land in a field. The airplane hit trees, seriously injuring both pilots, and came to rest 150 feet beyond the tree line.
The FAA investigator found no sign of any mechanical failure. He also found no fuel in the line from the tanks to the fuel strainer, about a quart of fuel in the left tank, and a gallon in the right. The 172H carries one gallon of unusable fuel.
The student told the investigators that he’d done the preflight and “observed” six gallons in each tank. The instructor only recalled checking the fuel gauges in flight, when both seemed to show one-quarter full—about five gallons a side.
Already we have a problem. Cessna calculated that the accident flight—1.1 hours, mostly takeoffs and landings—would have burned 8.4 gallons. If the flight had actually started with 12 gallons, it would have finished with 3.6 gallons. Allowing for the unusable gallon, this is less than the required VFR minimum reserve of a half hour at cruise power—and every pilot eventually learns that legal isn’t necessarily safe.
But clearly, the flight didn’t have 12 gallons. It’s hard to blame a low-time student for not being able to tell six gallons from three or four while peering into a 19-gallon tank. The student might, however, have asked whether 12 was really enough, or asked his instructor verify the estimate. The instructor certainly should have looked for himself after learning the tanks were close to empty. A calibrated dipstick could have demonstrated the limits of visual estimation without bending any aluminum. An even better lesson would have been that adding fuel until you’re sure you have enough is time and money well spent.
The AOPA Air Safety Foundation recommends making certain you have got at least an hour’s reserve every time you land. If you want to keep flying, it’s a good rule to follow.
David Jack Kenny is manager of aviation safety analysis for the AOPA Air Safety Foundation, an instrument-rated commercial pilot, and owner of a Piper Arrow.
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