What happened
On April 8, 2004, an Agusta A109E Power, registration I-SCTA, was conducting a scheduled annual proficiency check at Vergiate Airport. The flight crew, consisting of a pilot and a Type Rating Examiner (TRE), was performing a series of simulated emergency procedures.
The incident occurred during a simulated single-engine failure maneuver during a vertical takeoff from a pad. As the aircraft attempted to climb, the instructor simulated the loss of one engine. Following the instructor's suggestion, the pilot adopted a slight nose-down attitude. This maneuver, combined with a tailwind and the aircraft's high weight, caused the helicopter to lose altitude rapidly. The crew attempted to correct the descent by increasing collective pitch, but this action inadvertently worsened the descent rate. The helicopter struck the runway approximately 20 meters before the takeoff pad and slid for about 20 meters. Both pilots escaped the aircraft without injury.
The investigation
The ANSV investigation examined the flight maneuvers, the aircraft's technical condition, and the environmental factors. The investigation focused on the specific flight profile used during the engine failure simulation and the adherence to the flight manual. Investigators also reviewed the instructor's role in directing the maneuvers and the decision-making process regarding the takeoff direction relative to the wind.
Findings
- The helicopter was operating at a weight near its maximum allowable limit.
- The takeoff was performed using runway 34, which resulted in a tailwind component, violating the flight manual's prohibition on takeoff with winds from behind.
- The pilot followed the instructor's suggestion to adopt a nose-down attitude, which was less aggressive than the 20-degree pitch prescribed in the flight manual.
- The aircraft entered a vortex ring state (power settling) due to the combination of high weight, a high rate of descent, and low forward airspeed.
- Increasing the collective pitch during the descent exacerbated the loss of lift, leading to the loss of control.
- The instructor failed to intervene or abort the simulation when the aircraft's flight path became unstable.
Safety action
- The ANSV recommended that the national aviation authority ensure Type Rating Training Organisations (TRTOs) implement standardized instructor update programs.
- A recommendation was made to review the takeoff parameters specified in the A109E flight manual, as the required climb rate of 500 feet per minute was considered excessively high for Category A operations.