CH146485 Griffon - Epilogue

Report / September 29, 2014 / Project number: CH146485 - B Category

Location: Mahone Bay, Nova Scotia
Date: 29 September 2014
Status: Investigation Complete

427 Special Operations Aviation Squadron (SOAS) were on deployment to 12 Wing Shearwater, NS to conduct a Canadian Special Operations Forces Command (CANSOFCOM) Maritime Security Operations (MSO) training mission.  The mission entailed three CH146 Griffon helicopters simulating the insertion of Special Operations Force (SOF) assaulters aboard a simulated Vessel of Interest (VOI).  This was a “dry run” meaning that there were no assaulters aboard the helicopters and no one would be rappelling down to the ship.  As such, the plan was to simulate the insertion by simply holding a steady hover over the ship for several seconds prior to returning to base.  The Canadian Coast Guard Ship (CCGS) Sir William Alexander was used as the VOI.

Leading up to the simulated insertion, the 3‑ship formation of Griffon helicopters was operating tactically over the water at 100 feet (ft) Above Sea Level (ASL) off the coast of Chester, NS.  The crews, visually aided with Night Vision Goggles (NVG), initiated the manoeuvres running in towards the ship from approximately ninety degrees off the starboard side of the ship.

As the First Officer (FO) of the number 1 helicopter settled into a hover over the forward section of the ship, vibrations were felt when the main rotor blades made contact with one of the ship’s antennas located towards the forward edge of the ship’s bridge.

The FO immediately initiated an overshoot, departing forward and away from the ship.  The Aircraft Commander (AC) then took control of the helicopter and headed for nearby land to find a safe place to make an emergency landing.  A safe landing was made in the back yard of a residence on an island 1 Nautical Mile (NM) from the ship.

The helicopter suffered serious damage to the main rotor blades as a result of the contact with the ship’s antenna as well as minor damage to the tail rotor blades that made contact with tree branches during the emergency landing into the confined area.

The preventive measures recommend changes at the supervisory and organizational levels, including the implementation of a formal risk assessment tool such as a Mission Acceptance and Launch Authorization mechanism (MA-LA) and better Standard Operating Procedures (SOP). It also includes recommendations for enhanced training in Human Performance in Military Aviation (HPMA).

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