What happened
The incident occurred during a flight proficiency check involving a helicopter. The specific phase of the maneuver required the student pilot to demonstrate an autorotation initiated from a stationary hover. During this critical transition, the pilot applied forward pressure to the collective control lever rather than the correct rearward pull. This incorrect input resulted in a hard landing impact.
Despite the severity of the touchdown, the check ride proceeded without further incident. Following the flight, a thorough post-flight inspection was conducted on the aircraft. The examination revealed significant structural damage, specifically a bent airframe support tube. Further review of the damage site indicated that the area had been previously repaired via spot welding.
The investigation
Post-accident analysis focused on the mechanical integrity of the helicopter following the hard landing. Inspectors identified a deformation in one of the primary airframe support tubes. Metallurgical and visual inspection of the bent section revealed evidence of prior repair work, specifically spot welds at the location of the bend.
Findings
The investigation highlighted several contributing factors to the structural failure:
- Improper control input by the student pilot during the autorotation maneuver
- Hard landing impact resulting from the incorrect collective management
- Pre-existing repair history at the site of the damage, specifically spot welding
- Structural compromise of the airframe support tube due to the combination of prior repair and impact load