AD NUMBER: 2018-13-05

PRODUCT: Certain Honeywell International Inc. (Honeywell) TPE331 turboprop and TSE331 turboshaft engines.

ACTION: Final Rule.

SUMMARY: This AD was prompted by recent reports of failures of the direct drive fuel control gears and bearings in the hydraulic torque sensor gear assembly, part number (P/N) 3101726-3.

This AD requires initial and repetitive engine oil filter sampling and analysis of the affected engines and inspections of certain hydraulic torque sensor gear assemblies.

DATES: This AD is effective July 26, 2018.

COST: The FAA estimates that this AD affects 3,831 engines installed on airplanes of U.S. registry. The agency estimates that estimate all engines will require a records review to determine if they have an affected hydraulic torque sensor gear assembly installed. That review is expected to cost $85 for one hour of labor.

The agency estimates that 2,542 engines operating under Parts 121 or 135 and 544 engines operating under Part 91 will be required to perform oil filter sampling and analysis. Those costs are estimated as follows:

• Oil filter sampling and analysis: Part 91 operators - $1,184 for parts and labor
• Oil filter sampling and analysis: Part 121 and 135 operators - $296  for parts and labor.

An estimated 242 engines will require that the hydraulic torque sensor gear assembly be overhauled during the first year of inspection at an estimated cost of $10,850 for parts and labor.

An estimated 217 engines will require hydraulic torque sensor gear assembly inspection after an unacceptable oil filter analysis during the first year of inspection at a estimated cost of $3,425 for parts and labor.

FMI: AD