Aerometals PMA on Gears for MD500 Transmission
Aerometals has received PMA approval for spiral bevel gears for the main rotor transmission of the MD500. According to the company, the approval marks the first time the FAA has granted manufacturing approval for transmission gears to a company that is not the OEM. The testing required a test stand using a 500-hp electric motor instead of a gas turbine. The MD transmission is rated for 425 hp for up to five minutes, but Aerometals ran the gears for eight hours at 467 hp to satisfy FAA testing requirements.