By David Jack Kenny
Opinions vary on the wisdom of attempting maximum-endurance flights. Skeptics see little benefit to justify the risk, particularly in those parts of the country where airports are plentiful. Defenders of the practice point to the virtue of learning to predict fuel consumption down to the ounce, the rigor required to plan those flights, and the close monitoring needed to complete them successfully, and insist they’re acceptably safe for pilots with the discipline to impose that rigor and exercise that vigilance. (And shouldn’t all flights be planned and flown with exacting attention to detail?) They agree, however, that “maximum endurance” doesn’t mean cutting into the minimum fuel reserves required by regulation—and that attaining it safely depends on the willingness to execute a thoughtful alternative plan before those reserves are threatened.
Hybrid Power Pilot Safety Announcement
Weather Wise: Ceilings and Visibility online course
"Fuel Awareness" Safety Advisor
Do the Right Thing: Decision Making for Pilots online course
At 11:20 a.m. on July 20, 2012, a witness near the town of Rutland in southeastern Ohio saw a small high-wing airplane flying very low—perhaps 130 feet agl—but just below the clouds. As it turned left from a westbound heading, its engine sputtered, stopped, and briefly restarted before stopping again. It then pitched down and crashed in a near-vertical attitude, killing the solo 72-year-old pilot.
First responders had to remove a cylindrical metal tank in order to extricate him. This turned out to be the airplane’s header fuel tank, which was empty. There was no fuel in the filters or either of the wing tanks, and no fuel stains or blighted foliage around the wreckage.
The airplane was a Just Escapade, a two-seat homebuilt qualified for operation under sport pilot rules. A handheld GPS found inside had recorded the track of the accident flight, though not its airspeed or altitude. After departing from the pilot’s home base of Lumberton, N.C., it followed an essentially straight northwesterly course for 250 nautical miles to the vicinity of Charleston, W.Va. There it began a series of meandering turns that included several near-reversals before following the general course of the Kanawha River away from town. Weather recorded at Yeager Airport during that time included a broken layer at 2,300 feet agl and an overcast at 5,500 feet agl. Investigators conjectured that the pilot had either attempted to descend through the deck or maintain VFR beneath it, but could not determine which. Hills in the vicinity rise 500 feet to 1,000 feet above the airport’s elevation, some of them topped by radio towers as tall as 1,500 feet.
Once clear of the Charleston area, the Escapade resumed a northwesterly heading toward the border town of Pomeroy on the Ohio River. Near the river it made a 90-degree right turn, and then a sweeping left turn to follow the curve of the river westbound. Just west of Pomeroy it turned back to the northwest and flew the last few miles to the accident site. Weather in the area was very low: The nearest airport, 11 miles from the accident site, reported a broken ceiling at 700 feet and an overcast at 1,200, with visibility of just a mile and a half underneath. The pilot was not instrument rated, and the airplane wasn’t equipped for instrument flight.
The previous year the pilot had followed the same route to Oshkosh, Wis., stopping for fuel at the Newark-Heath Airport in Ohio, and the investigators concluded that this flight was intended to follow the same plan. If so, this would have come pretty close to the definition of maximum endurance. The straight-line distance from Lumberton to Newark is 363 nautical miles—about 3.8 hours in neutral winds at the Escapade’s claimed 95-knot cruise speed. Its wing tanks held 18 gallons of fuel, enough to last 3.8 hours if the average burn was 4.7 gph (assuming the contents of the header tank were enough to power the climb to cruise).
The engine installed was an automotive conversion based on Honda parts. Its manufacturer cites fuel consumption of 5.5 gph at 75-percent power, making 4.7 at reduced power at least theoretically possible—and the company’s owner told investigators that the pilot “routinely” made the 350-nm flight from his base to the engine shop without refueling. (Their report notes that the altitudes and power settings for those flights are not known—and neither is the amount of fuel that remained when he landed.)
Between that and the previous year’s flight, there’s some reason to believe he might have made it to Newark if nothing went wrong (and also to doubt whether he’d have still had his 30-minute VFR reserve when he arrived). Once the weather required him to start zigging and zagging, though, that plan wasn’t going to work. A quick diversion to Charleston for fuel—and perhaps to wait out the weather—would have been a shrewd decision. As it is, the accident site was some 58 nm short of his destination. It wasn’t even close.