Most of the maintenance Fleet Readiness Center Southwest (FRCSW) performs on H-60 Sea Hawk helicopters targets the airframes structural integrity. But when the helicopters engines need specialized repair or overhaul, the aircraft's squadrons remove, preserve and send them to the T700 engine shop in Building 379.
Since 1988, the turboshaft 401C model of the T700 engine class has powered the Sea Hawk. Manufactured by the General Electric Co., production of the 450-pound engine began in March 1987.
With more than 1,800 shaft horsepower, the 401C variant powers other helicopters including the AH-1Z Viper and UH-1Y Venom.
A staff of about 40 FRCSW Sailors overhaul, repair and perform testing on the 401C engines through five work centers in the T700 engine shop.
The command's artisans handle any depot-level issues, and work in the test cell and auxiliary power unit (APU) work centers.
The APU supplies electrical power to many of the aircraft's systems including the engine and air conditioning units. (FRCSW is the only Navy APU test facility on the West Coast. After testing, APUs are distributed through the Defense Logistics Agency.)
Maintenance and overhaul to the 401C is done in sections based upon the engines modular design: a cold section module, a power turbine section, a hot section between the two, and an accessory gearbox. Overhauls typically take about six days.
Engines are often inducted for low power issues, high oil consumption, or when they approach their life span of approximately 2,000 flight hours. Performance may also degrade if an internal component reaches a high-flight hour interval.
Borescopes are often used to pinpoint the internal cause for degradation of power. Compression, for example, can be adversely affected by a crack that allows air to escape.
Engines are also inspected to ensure their components are intact and afterward, preserved again to ward off corrosion. Repairs are made on a first-in, first-out basis.
FRCSWs Power Plants division issues more than 100 engines annually. Customers include Naval Air Station North Island squadrons, Naval Air Station Fallon, Nev., and Aviation Intermediate Maintenance Department (AIMD) Atsugi, Japan.