What happened
On December 20, 2005, an AS 350 BA helicopter, registration PT-YYY, was conducting a proficiency check flight at the Jacarepaguá Aerodrome (SBJR) in Rio de Janeiro. The flight crew consisted of a pilot and a Civil Aviation Inspector (INSPAC). The mission involved a series of maneuvers, including autorotations and a simulated hydraulic failure landing.
During the final stage of the flight, the pilot simulated a hydraulic system failure by deactivating the system. While attempting to execute a go-around (arremetida) from a hovering position near the ground, the pilot increased power and torque. This sudden increase in power caused a significant leftward yaw due to insufficient pedal input. The tail rotor struck the runway, causing the aircraft to lose control, spin, and eventually collide with the ground. The pilot escaped without injury, while the inspector sustained minor injuries. The aircraft suffered severe damage to its main rotor components, skids, and tail boom.
The investigation
CENIPA's investigation focused on the operational sequence and the cockpit environment. Investigators found that the aircraft was not configured for dual controls; the cyclic handle and pedals for the left seat were missing because the operator had scheduled a passenger flight immediately following the check. The inspector noted this deficiency but agreed to proceed with the flight at the pilot's request.
The investigation also examined the communication between the crew. Although the inspector had explicitly told the pilot to abort the maneuver if they felt unsafe, the pilot did not communicate any difficulty during the procedure and did not initiate a go-around at a safe altitude. The investigation also looked into the pilot's training history and the technical aspects of the hydraulic failure maneuver.
Findings
- Lack of cockpit coordination and assertiveness: The pilot failed to report increasing difficulty in controlling the aircraft and did not request a cancellation of the procedure or a safe go-around.
- Improper judgment by the pilot: The pilot attempted a high-risk maneuver (go-around from a hover with simulated hydraulic failure) without being able to effectively manage the resulting torque.
- Improper judgment by the inspector: The inspector proceeded with the proficiency check despite knowing the aircraft lacked dual controls, which prevented direct intervention in the event of an error.
- Inadequate aircraft configuration: The absence of dual controls in a flight intended for proficiency checking increased the operational risk.
- Operational risk of the maneuver: The application of power during a simulated hydraulic failure landing creates a high risk of leftward yaw, especially when the aircraft is near the ground.