What happened
On January 20, 2001, a KW-1 "Quero-Queredo" glider, registration PT-PHK, was performing a landing approach at the Fazenda Ipuã aerodrome in Caçapava, Brazil. While entering the traffic pattern at approximately 1,000 feet, the aircraft entered a right-hand spin. The aircraft's nose pitched down aggressively before impacting the ground near the side of the runway at a nearly 90-degree angle. The impact was so violent that the wings were torn from the fuselage, and the pilot sustained fatal injuries at the scene. The aircraft was destroyed.
The investigation
CENIPA investigators examined the wreckage and the pilot's training records. The investigation confirmed that the pilot was licensed and medically certified but possessed very limited flight experience, with only 21 hours of total flight time and just 1 hour and 44 minutes in the KW-1 model.
Technical analysis of the aircraft revealed that the glider was operating outside of its certified weight and balance limits. The pilot's weight, combined with the aircraft's empty weight, exceeded the maximum takeoff weight of 280kg by approximately 20kg. This caused the center of gravity to be positioned forward of the allowable limit. While maintenance records were up to date, investigators noted signs of moisture infiltration and wood decay in the wings, though no structural failure prior to impact was identified.
Findings
- Inadequate flight monitoring: The pilot failed to maintain an efficient cross-check of basic flight parameters, such as airspeed and attitude, which allowed the aircraft to reach a critical angle of attack.
- Exceeding weight limits: The aircraft was operated with a center of gravity forward of the limit due to the total weight exceeding the maximum takeoff weight.
- Limited experience: The pilot's lack of experience in both total flight time and specifically in the KW-1 model contributed to the inability to recover from the stall/spin.
- Operational oversight: The operator failed to ensure the aircraft remained within the specified weight and balance envelopes.