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Full houseFull house

By David Jack Kenny

Flight instruction is necessarily incomplete. The training curriculum and practical test standards are intended to assure that a new pilot knows how to address situations likely to arise after the checkride, but there’s no way to demonstrate every single one during training. Among students who learn to fly in four-seat or larger aircraft, one of those most widely overlooked is flying with all the seats filled. It’s common to pass the private pilot checkride without ever having experienced how the aircraft handles near its maximum gross weight—and few instructors will risk taking off significantly above it.

About 8:20 p.m. on Aug. 25, 2014, a 20-year-old private pilot reserved a Cessna 172R operated by a flying club based at the Cuyahoga County Airport just outside Cleveland. He’d joined the club 10 months earlier but only flown its airplanes four times, twice that previous October and two more times in June. His membership application listed 104.3 hours of total flight experience.

He arrived with three passengers around 9 p.m. All four were students at Case Western Reserve University. One passenger and the pilot were fraternity brothers; the other two, both freshmen, were prospective members. All three passengers were members of the Case Western wrestling team. Workers at the adjacent corporate hangar saw the four board the aircraft and start it up, and reported that they spent an unusually long time—perhaps 20 or 30 minutes—running up the engine.

At 9:46 p.m., the pilot contacted ground control and was cleared to taxi to Runway 6. After one wrong turn, he reached the threshold and advised the tower controller that he was ready to take off “to the east … we’re just doing some sightseeing and then we’ll be back here in a little bit.” The Skyhawk was cleared to take off on Runway 6 with a right turn out.

Three witnesses at the FBO at the north end of the field saw it lift off about 2,000 feet down the runway, only to struggle to climb. One minute and 20 seconds after starting the takeoff roll, the pilot radioed that “we’re not climbing fast ... We’re gonna make a left turn if that’s possible, immediately, to turn around.” The tower controller approved the left turn, then watched the Cessna roll hard to the left and crash just beyond the airport fence. Fire consumed most of the aircraft before first responders reached the scene. No one on board survived.

The NTSB’s accident investigators found that the airplane was configured correctly, with the fuel selector set to “Both,” mixture full rich, and flaps retracted. The engine appeared to have been making normal power up to the moment of impact.  Pathology results were negative for all potentially impairing drugs, including alcohol. The airplane’s center of gravity was within limits, but depending on the exact weights of the passengers, the Cessna was at least 95 pounds and perhaps as much as 165 pounds above its authorized maximum gross weight. Witnesses at the fraternity house recalled that when he’d offered the ride, the pilot had asked his prospective passengers for their weights, “did the math in his head to see if they would be below the weight limit, and he believed they would be.”

One of general aviation’s unsavory secrets is that pilots do sometimes attempt overweight takeoffs. Once you exceed the maximum gross weight established by the manufacturer, though, there’s no way beyond trial and error to know how much is too much. At some point, an airplane simply can’t climb out of ground effect. A little lighter, and it will climb—but just barely, and on the verge of a stall.

A highly experienced pilot, feeling how close to stalling the airplane is with wings level, might realize that it couldn’t maintain altitude in a turn. The only options left would be to land straight ahead—not inviting at night—or coax the craft up to a thousand feet or so in a straight-ahead climb. With some altitude, descending through the turns would make it possible to conserve airspeed and keep the angle of attack below its critical value. It would still be a delicate business, even in daylight.  After the accident, the young man’s instructor advised the FAA inspector assisting with the investigation that “though he was not very experienced ... he was always very cautious, never took chances, and never was even a hint of reckless or foolhardy.” The NTSB was correct to note that he should have calculated the aircraft weight more precisely. Once that mistake was made, though, his lack of exposure to that corner of the flight envelope left him little chance of figuring out how to cope with a bewilderingly unfamiliar situation.

Related links

Aeronautical Decision Making Safety Spotlight

Essential Aerodynamics: Stalls, Spins, and Safety online course

Takeoffs and Landings Safety Spotlight