ALLIEDSIGNAL IS planning a four-year revitalisation programme of the LT101 turbine engine, representing an investment of more than $15 million. The programme concentrates on improving reliability and cutting cost.
"We know things haven't been good. We know there are a lot of things we'd like to change, and we would like to substantially improve reliability," says LT101 programme manager, Bob Miller.
The priority is tackling the problem of frequently required turbine blade inspections. "It's a significant burden to the fleet," says Miller. The engine is mainly fitted on Eurocopter BK117 and Aerospatiale HH-65 Dolphin helicopters.
Inspection intervals will be increased by up to 30% if the redesigned power turbine rotor proves itself over an experimental period when lead-the-fleet operators will accumulate 100,000 cycles. "The first two engines will be out of the door in late February," says Miller. The redesign tackles the problem of blade shifting.
Other changes include a redesigned No 3 bearing thrust link which does not let the bearing "walk" during the transition from ground idle to higher power. To improve power retention, the material in the gas-producer nozzle has been changed from Inconel 713 to a Lycoming-developed material called C101.
In addition, rig testing is about to start on a new low-carbon combustor liner designed to reduce faster-than-expected erosion of single-crystal blades. The company is also working with Chandler-Evans to develop tests for a revised fuel-pump design and various spline-drive differences following pump problems.
AlliedSignal is also discussing extending the service-bulletin requirement for fitting a more contaminant-resistant fuel-control bearing, developed by Bendix, in the lubrication system.
Cost is primarily being tackled with a 2% across-the-board price reduction on all parts.
Source: Flight International
