Landing gear manufacturer fined $135K after workers injured in explosion

A manufacturer of structural landing gear components for aircraft in Woodbridge, Ontario has been fined $135,000 by Ontario provincial court after pleading guilty to a charge by the Ontario Ministry of Labour, Training and Skills Development after two workers were critically injured in an explosion at its plant.

Noranco Inc., which operates as PCC Aerostructure GTA Woodbridge, also received a 25 per cent victim fine surcharge, credited to a special provincial government fund to assist victims of crime.

The incident took place on May 3, 2018, when two workers were attempting to disassemble a landing gear sub-assembly known as a shock strut that had been returned to Noranco by a customer for a retrofit upgrade.

A Ministry of Labour investigation found that the shock strut was suspended from an overhead crane. Unknown to the two workers, the shock strut had been returned by the customer fully pressurized with nitrogen after it had been installed on an aircraft.

During disassembly, the strut exploded, separating the piston from the cylinder. The piston was moving upward with such force that it struck the overhead crane and dislodged it from its mooring, forcing it to the ground. The piston and other components struck both workers. Both workers received critical injuries.

Noranco’s quality control department reviews returned items before releasing them for work and tags the part to indicate any special warnings to workers. No tag was attached to the shock strut to indicate the part was pressurized.

This disassembly process had never been done before at Noranco for a pressurized returned part; there were no written procedures for the task.

Following the investigation, Noranco subsequently implemented a policy to ensure that all shock struts returned by a customer are depressurized, a procedure put in place to ensure any residual pressure is released prior to disassembly, and that a secondary restraint cable is to remain in place until a strut unit is fully depressurized to atmospheric pressure.

The Occupational Health and Safety Act states that “where repairs or alterations are to be made on a drum, tank, pipeline or other container [it] shall have internal pressures adjusted to atmospheric pressure before any fastening is removed.”