What happened
On August 28, 2002, a student pilot was conducting a solo training flight in a Robinson R22 Beta, registration SE-JUV, at Stockholm/Bromma airport. After completing a navigation flight from Norrtälje, the pilot approached a landing ramp near a flight school hangar. The touchdown and initial flare proceeded without issue.
Immediately after the helicopter touched down on the apron, the pilot moved the collective lever to the fully down position. However, before securing the collective, the pilot released the lever to begin adjusting the cyclic stick friction brake. Because the engine and rotor were still operating at high RPM, the sudden release of the collective caused the aircraft to spontaneously lift off the ground.
As the helicopter became airborne, the pilot attempted to regain control by quickly pushing the collective back down. This maneuver triggered an intense, uncontrollable yawing motion. In an attempt to stabilize the aircraft, the pilot applied rudder, but the rotation accelerated, causing the helicopter to spin and "hop" off the surface. The aircraft eventually wobbled and struck the ground with significant force, resulting in substantial damage to the airframe, including a severed tail boom. The pilot sustained minor injuries and was able to evacuate the aircraft safely.
The investigation
The Swedish Accident Investigation Board (SHK) examined the wreckage and the flight controls of the Robinson R22 Beta. The investigation confirmed that there were no mechanical or technical failures present in the aircraft's systems. Investigators also reviewed the pilot's training records and the flight school's procedures.
Crucially, the investigation focused on the post-landing checklist. It was determined that the pilot had interchanged the sequence of the first two checklist items, failing to apply the collective friction before attempting to adjust the cyclic friction. The investigation also noted that the existing checklist sequence required the pilot to manipulate controls while the engine was still at high RPM, creating an inherent risk of unintended movement.
Findings
- The student pilot was properly qualified for the flight.
- The aircraft was airworthy and no technical malfunctions contributed to the event.
- The pilot failed to follow the prescribed checklist sequence regarding the application of friction brakes.
- The helicopter lifted off because the pilot released the collective while the engine and rotor were still at high RPM without having first applied the collective friction brake.
- The manufacturer's checklist sequence for post-landing procedures was identified as illogical, as it encouraged the release of controls while power was still high.