Transport Canada has issued a Safety Alert warning operators of all models of Bell LongRangers to inspect the engine mounting legs for corrosion and cracking and to replace them if needed. Six mounting legs hold the engine in place, and not all corrosion inside these parts is visible during normal visual inspections as they are sometimes obscured by wiring and tubing clamps. Similarly, corrosion inside the legs also is not visible.
If any are cracked or corroded, the remaining legs might not be able to support the engine under all load conditions, Transport Canada cautioned. Bell Helicopter has introduced a replacement leg made of stainless steel that ameliorates the propensity for corrosion.
Transport Canada is recommending that all surfaces of mounting legs are inspected thoroughly by removing all wiring, clamps and hosing; the replacement or repair of parts in accordance with maintenance manual; and replacing the engine mounting legs if there is any doubt about their serviceability. If one leg is replaced, the agency is recommending that all legs on that helicopter of similar age/use be replaced.