It’s the stuff of nightmares. You launch uneventfully, engine roaring at full power during the initial climb. Everything seems fine until you reach 500 feet agl, and then—silence. The engine quits.
With back-pressure and right rudder from the climb still applied, the aircraft quickly decelerates toward an uncoordinated stall. You correct just in time, pitching down for best glide. The windscreen fills with rapidly approaching terrain. Behind you lies a mile of smooth, level pavement, beckoning like a Siren’s song. Your mind races. The call grows louder. Slamming the yoke hard left you succumb, drawn by the dubious promise of safe harbor.
You begin the “impossible turn.”
On Oct. 28, 2006, a Vans RV-6 experienced a loss of engine power on climbout from Turlock Municipal Airport in Turlock, Calif. While the pilot was maneuvering in an attempt to return to the runway, the aircraft stalled and collided with the ground. The pilot and a passenger were seriously injured.
The aircraft departed Runway 30 at 4 p.m. for a local VFR flight. The pilot configured the airplane for the initial climb. After reaching about 500 feet agl, the engine lost power and the airspeed dropped. The pilot responded by beginning a turn back toward the runway. During the maneuver, the airplane stalled and the pilot attempted to recover. The airplane entered a secondary stall, descended rapidly, and collided with the ground, eventually coming to rest inverted.
A post-accident examination of the engine revealed spark plug fouling and other factors that contributed to the loss of engine power. The NTSB cited broken piston rings as the cause of the mechanical failure. The crash was attributed to the pilot’s failure to maintain adequate airspeed while maneuvering for a forced landing, which resulted in a “stall/mush.”
The return-to-airport maneuver has been labeled the “impossible turn” with good reason: It requires substantial altitude and involves aggressive maneuvering. Taken by surprise, pilots often fail to maintain airspeed and end up having stall/spin accidents. For a gliding aircraft attempting to maintain airspeed, any banking of the wing will increase the sink rate. And the banking doesn’t end after the 180-degree turn. More maneuvering is necessary to overcome the lateral offset from the runway and point the nose down the centerline. Meanwhile, stall speed is increasing with angle of bank. For a crippled airplane already flying low and slow, this combination of lost altitude and rising stall speed can quickly turn a bad situation into a tragic one.
How high should you be before attempting to turn back to the airport if the engine dies? It depends on the aircraft and the circumstances. Tests conducted for a July 2002 AOPA Pilot article, “Engine Out!” found that a Cessna 172 requires nearly 500 feet of altitude to return to the runway using an aggressive 45-degree bank and allowing the nose to fall fairly dramatically through the turn in order to maintain airspeed. This test was conducted under ideal conditions and assumed only a four-second lag from the time the engine quit until the pilot took decisive action. For most of us, four seconds isn’t much time to overcome the shock and denial of becoming an impromptu glider pilot, especially if smoke and oil are pouring from the failed engine.
Unless the airplane is close to pattern altitude, or you’ve already started a turn when the engine fails, it’s generally safer to land within the area you can see out the windscreen. Statistics bear this out. According to the AOPA Air Safety Foundation’s Nall Report, most maneuvering-related crashes are fatal. By contrast, only about 10 percent of forced landing accidents involve a fatality. Maintaining control of the airplane all the way to the ground, even if landing off airport, greatly increases the chances of walking away from a mishap.
The accident pilot and his passenger were very fortunate to survive this crash. With the benefit of 20/20 hindsight, the pilot told the NTSB that the accident “could have been prevented if he had more engine-out practice.”