What happened
On February 28, 1998, a KW-1 QUERO-QUERO glider, registration PT-PKC, was performing a training flight at the Luziânia Aerodrome in Goiás, Brazil. The flight began with a conventional tow by an Aeroboero AB-180, reaching an altitude of approximately 2,000 feet AGL. After 85 minutes of flight, the glider released from the tow cable.
During the approach for landing on runway 11, the pilot failed to follow standard traffic patterns, arriving on the final approach at an excessive altitude of only 50 meters. In an attempt to lose altitude, the pilot executed a 360-degree left turn. When this maneuver failed to reduce height sufficiently, a second 360-degree left turn was initiated. During this second turn, the aircraft entered a left spin at a low altitude of 50 meters, striking the ground and bushes. The impact resulted in severe injuries to the pilot and the total destruction of the aircraft.
The investigation
CENIPA's investigation focused on the pilot's recent flight history and the adequacy of the flight school's retraining procedures. The investigation established that the pilot had not flown this specific aircraft type for over four months. Although the pilot had completed a 12-minute transition flight in a different aircraft (a NEIVA-B) on the day of the accident, the investigation found this was insufficient to prepare for the specific performance characteristics of the KW-1 QUERO-QUERO.
Investigators also examined the pilot's physiological and psychological state, noting evidence of fatigue due to a lack of sleep and high levels of anxiety regarding professional expectations. Maintenance records for PT-PKC were found to be adequate and up to date.
Findings
- Inexperience and lack of continuity: The pilot had only 11 hours of experience in the KW-1 QUERO-QUary and had been away from the aircraft type for more than four months.
- Improper maneuvering: The pilot executed the second 360-degree turn with a high nose attitude, low airspeed, and extended spoilers, creating conditions highly susceptible to a loss of lift.
- Poor judgment: The pilot's failure to maintain standard traffic pattern altitudes led to the necessity of high-risk altitude-loss maneuvers at very low altitudes.
- Human factors: The pilot's performance was likely degraded by accumulated fatigue and significant anxiety.
- Inadequate supervision: The flight club's decision to authorize a solo flight after only a 12-minute transition flight was a critical contributing factor.
Safety action
Following the investigation, several safety recommendations were issued to prevent similar occurrences:
- The Aeroclube de Brasília was directed to revise its instructor and retraining programs, establishing clear minimum flight hour requirements and theoretical instruction for pilots returning to flight after extended absences.
- Regional aviation authorities (SERAC) were advised to ensure more rigorous checks of pilot skills and theoretical knowledge during proficiency checks.
- Flight clubs were encouraged to establish standardized safety criteria for pilot retraining based on the duration of time a pilot has been away from an aircraft type.