What happened
On 16 February 2014, at approximately 1015Z, a Cessna 182A aircraft, registration ZS-CGN, was engaged in glider towing duties at Orient Aerodrome (FAOI) in Gauteng Province. The pilot, the sole occupant of the tug aircraft, had prepared the aircraft for a launch involving a Ventus CM glider.
Following the wing runner's signal, the takeoff roll commenced. Witnesses observed that the glider became airborne ahead of the tug aircraft and climbed to a significantly higher position. As the flight progressed through a period of turbulence, the glider climbed even further, moving out of its proper position relative to the tug. Although the glider pilot deployed the airbrolakes, the glider continued to climb rapidly.
Shortly thereafter, the Cessna 182A pitched into a sudden nose-down attitude. The aircraft descended toward the ground at a steep angle, impacting the extended centerline of runway 36. The impact was followed by an intense, fuel-fed fire that destroyed the aircraft. The pilot was found deceased within the wreckage. The glider pilot, however, was able to land safely on runway 18.
The investigation
SACAA AIID investigators examined the wreckage, the engine, and flight data from the glider's IGC profile. A teardown inspection of the Teledyne Continental engine revealed no mechanical failures that would have prevented normal operation prior to the accident. The investigation also reviewed eyewitness accounts and the glider's flight trace, which showed a rapid spike in altitude for the glider following takeoff. Investigators noted that the tow hook mechanism on the tug aircraft was found in the open position, and the tow rope was straight at the scene. The investigation also confirmed that the weather conditions were clear with light winds, and the aircraft possessed a valid Certificate of Airworthiness.
Findings
- The accident was caused by a vertical tow upset, which led to a momentary loss of control of the tug aircraft at a low altitude.
- There was insufficient altitude available for the pilot to recover the aircraft after the upset occurred.
- Neither the tow pilot nor the glider pilot initiated a timely release of the tow rope.
- There was a lack of radio communication between the two pilots to signal that the glider was out of position.
- The tow pilot likely failed to monitor the glider's position via rear-view mirrors as frequently as required during the critical takeoff phase.
- The glider experienced a rapid, unplanned gain in altitude following the launch.