Dallas Airmotive is reminding operators of Bombardier 300-series Challengers, Gulfstream G280s, and Embraer Legacy 450/500 twinjets that it's time to have the Z-gap on their LPT2 rotor blades inspected, if it's been more than 4,000 hours since the last borescope inspection on their HTF7000 engines. Engine OEM Honeywell issued a service bulletin in 2017, stating that there is a possibility on high-time engines for the blades on the second stage low-pressure turbine to separate, leading to vibration and potential damage to that engine section.
To avoid this, the engine maker instructed operators to review the Z-gap once the powerplant exceeds 4,000 to 4,200 hours. If the blades pass the inspection, they can remain in service until the next scheduled inspection. If not, Honeywell’s Special Pricing Notice SPN #02 will offer special pricing if replacement blades are required. For Honeywell MSP plan holders, this repair is covered.
According to Dallas Airmotive, its field service representatives can perform the required inspection on-wing, and if replacement blades are required, can have the aircraft back in service within a week. For engines not covered by MSP, the MRO provider will offer a special rate for the inspection and repair.