What happened
On January 11, 2011, at approximately 14:30 UTC, a Robin DR400-180R, registration I-ITAV, was performing a glider towing operation at the Guidonia military airport. During the initial takeoff phase on runway 18, the aircraft impacted the asphalt runway at a 40-degree nose-down attitude, approximately three-quarters of the way down the runway. The impact occurred slightly left of the centerline at a 20-degree divergence from the runway axis.
Following the impact, fuel escaped from the aircraft's tank, ignited, and caused a fire that destroyed the airframe. The pilot, the sole occupant of the aircraft, was killed in the accident. During the event, the tow rope severed, causing the glider to separate from the aircraft. The glider continued its takeoff trajectory, performed a 180-degree turn at a very low altitude, and returned to the runway in the opposite direction. The two occupants of the glider were uninjured, and the glider sustained no structural damage.
The investigation
The ANSV investigation focused on the mechanical failure of the towing equipment and the flight dynamics of the impact. Investigators examined the tow rope and determined that it was not equipped with the required safety features, specifically the standardized break-away plates designed to protect against overloads. Evidence indicated that the rope snapped into two pieces due to an overload condition. Laboratory testing was ordered to determine the exact nature and magnitude of the stress that caused the rope to fail.
Findings
- The primary cause of the accident was the failure of the tow rope due to an overload condition.
- The tow rope lacked mandatory protection systems, such as pre-set breaking plates, intended to mitigate excessive tension.
- The impact of the Robin DR400-180R led to a fuel leak and subsequent intense fire.
- The investigation highlighted a lack of use of certified overload protection systems by glider flight operators.