What happened
On May 13, 2018, a Cessna 208B Grand Caravan, registered G-KNYS, departed from Clonbullogue Airfield for a specialized parachuting operation. During the flight, the aircraft entered a significant descent, dropping from 12,000 feet to approximately 2,176 feet. While attempting to return toward the airfield, the aircraft initiated a descending left-hand turn. During this maneuver, the aircraft's speed increased significantly, exceeding its maximum maneuvering speed. The aircraft subsequently entered a near-vertical, nose-down attitude, striking the ground near Clonbull and resulting in 2 fatalities, including the pilot and one passenger.
The investigation
The AAIU examination of the wreckage and flight data revealed that the aircraft, engine, and propeller were functioning normally prior to the impact. Investigators analyzed data from the aircraft's Data Acquisition System (ADAS), ATC radar, and even CCTV footage from a nearby security system. The investigation also reviewed the operational framework of the Irish parachute club and the UK-based leasing company that owned the aircraft. Evidence showed the aircraft was being operated under Specialised Operations (Part-SPO) regulations, but the investigation identified several gaps in the club's operations manual regarding aircraft leasing and passenger carriage.
Findings
- The primary cause of the accident was an impact with terrain following a loss of control during a steeply banked left-hand turn.
- The aircraft was maneuvering at speeds well above its maximum structural maneuvering speed (VA).
- A rapid increase in engine torque, likely an attempt by the pilot to recover the aircraft, contributed to the loss of control due to propeller torque reaction.
- The aircraft was flying at an altitude that provided insufficient time to recover from the steep bank and subsequent descent.
- The aircraft was being operated with a passenger on board, which violated regulations prohibiting the carriage of persons not essential to the mission during specialized operations.
Safety action
Following the investigation, several recommendations were made to improve safety in parachute operations. These include requirements for the Irish parachute club to update its operations manual regarding aircraft leasing and pilot employment. Additionally, recommendations were issued to the aircraft owner and the Irish Aviation Authority (IAA) to ensure that regulations regarding the carriage of unauthorized passengers during specialized operations are strictly enforced and clearly communicated.