Routinely recognized for its maintenance, repair and overhaul (MRO) work on naval aircraft, Fleet Readiness Center Southwest (FRCSW) also stands out as the Navy’s sole source for MRO services to the LM2500 engine.
First used to power the Spruance and Kidd-class destroyers in the 1970s, LM2500 production began in 1969. The engines proved so reliable that their use expanded in the 1980s to include Oliver Hazard Perry-class frigates, Ticonderoga-class cruisers, and Arleigh Burke-class destroyers.
The engine is manufactured by the General Electric Co., and for the past 42 years, FRCSW has worked on the two types of LM2500: single and twin shank, and low power turbine.
FRCSW customers include Naval Sea Systems Command (NAVSEA) and foreign navies.
“Low power turbines are treated as a separate component,” noted mechanic Lloyd Apgar. “The engines are gas generators and have a high pressure turbine in them, but that’s part of the engine itself.”
Unlike many aircraft platforms, LM2500 engines are not serviced under a planned maintenance interval; instead, they are repaired for significant cause.
“The engines are usually inducted for hot section degradation, meaning the turbine blades and turbine nozzles are starting to wear as they’re losing power or increasing fuel consumption. At that point they’re turned in for an overhaul,” Apgar said.
Mechanic Hether Troncatti said that during the overhaul procedure the engines are disassembled to their subassemblies (a total of nine components) that include two gearboxes, the compressor, stator casers, and high pressure turbine nozzle.
“We have about 20 people who work in the program. Most are mechanics, but we have four machinists who do things like the grinding of the rotor blades,” she said.
Key to a successful overhaul is the rebuilding of the engine’s compressor, she noted.
“We build the compressor in five different stages starting with the rear shaft,” said aircraft engine repairman Randy Balolong. “We have to make sure the unit is within certain specifications for installation, otherwise vibrations will cause the engine to be rejected.”
A typical engine overhaul requires approximately 3,000 manhours.
In addition to overhauls, the shop also handles service requests that cannot be completed in the fleet.
“NAVSEA may get an engine from a decommissioned ship, for example, and not want to do an overhaul, so we check and test it to make sure it’s still serviceable and it goes back into supply. Some years, we may do up to six of these,” Apgar said.
The FRCSW LM2500 program schedules about 15 engine overhauls annually.