What happened
On October 31, 1993, an AB-1-115 aircraft, registration PP-GKR, was conducting a training flight at the Porto Velho Aeroclube in Rondônia. Following two successful landings on runway 19, the crew decided to perform an unplanned "pista" landing. During the traffic pattern, the aircraft was operated below the standard prescribed altitude.
As the aircraft entered the base leg, it struck a lightning rod wire belonging to a high-voltage power line. The impact with the wire anchored the aircraft, causing it to rotate on its lateral axis. The aircraft subsequently struck a second, decommissioned power line before impacting the ground on its dorsal side in a residential yard. The impact occurred with zero longitudinal velocity.
The investigation
CENIPA's investigation focused on the operational and human factors surrounding the collision. Investigators examined the flight profiles, the qualifications of the crew, and the physical circumstances of the impact. The investigation revealed that while the crew had sufficient flight hours in the aircraft type, the pilot in the rear seat was not qualified or authorized to act as a flight instructor.
Furthermore, the investigation looked into the ergonomic challenges of the AB-115, noting that the rear seat position limits visibility, a problem exacerbated by the height difference between the two occupants. The investigation also reviewed the meteorological conditions, noting the presence of Cumulonimbus clouds and the proximity to sunset, which may have contributed to pilot distraction.
Findings
- The pilot in the rear seat was not qualified to perform flight instruction duties.
- The flight was conducted at an altitude below the standard requirements for the traffic pattern.
- The student pilot's improper control inputs led to a loss of lift and an abnormal attitude during the turn.
- The instructor's attention was diverted by observing meteorological formations in the eastern sector of the aerodrome.
- The student pilot suffered a fatal head injury due to the lack of adequate head protection and the minimal clearance between his head and the aircraft ceiling.
- The instructor suffered facial injuries because the rear seat lacked proper suspenders, causing him to strike the control column during the impact.
- The aeroclube permitted an unauthorized individual to conduct instructional flight operations.