What happened
On December 30, 2000, a Schweizer 269C helicopter, registration I-MAGB, was performing a commercial flight for tourism purposes at Modena Marzaglia Airport (LIPM). During the takeoff phase, the pilot attempted a steep climb, reaching an altitude of approximately 20 feet (65 ft) above the ground. At this height, the pilot experienced a loss of engine power.
In response to the power loss, the pilot initiated an emergency landing in a field parallel to runway 11. During the descent, the aircraft struck the ground with its belly while maintaining a controlled flight attitude but with a relatively high vertical velocity. The impact caused the helicopter to tilt to the left, resulting in the main rotor blades striking the ground. The aircraft sustained substantial damage, though there were no injuries to the pilot or the passenger.
The investigation
The ANSV investigation focused on the mechanical integrity of the powerplant and the flight parameters during the departure. Investigators performed a complete disassembly of the engine, including all components and accessories, but found no evidence of mechanical failure, breakage, or malfunctions that would account for a loss of power. Maintenance records for the aircraft were found to be in order and up to date.
Analysis of the flight profile revealed that the pilot was operating within a specific altitude and speed range that is critical for emergency procedures. The investigation examined the relationship between the steep climb maneuver and the engine's performance during the transition from low translational velocity to higher speeds.
Findings
- The primary cause of the incident was a sudden loss of engine power during the climb.
- The pilot's decision to perform a steep takeoff at low translational velocity was a significant contributing factor, as this maneuver placed the aircraft in a flight regime where the engine's performance was compromised.
- The flight manual specifically warns against performing takeoffs with low translational velocity, as such conditions make the execution of the standard engine failure emergency procedure (for altitudes between 7 ft and 450 ft) much more difficult and less likely to be successful without consequences.