AD NUMBER: 2017-26-08

PRODUCT: Certain ATR-GIE Avions de Transport Régional Model ATR42-500 and ATR72-212A airplanes.

ACTION: Final rule; request for comments.

SUMMARY: This AD requires revising the airplane flight manual (AFM) to provide procedures to the flight crew for operational restrictions affecting in-flight use of the autopilot (AP) or yaw damper (YD) during dual-engine operation.

This AD also provides an optional software modification, which would terminate the AFM requirement. This AD was prompted by flight test evaluations that revealed that after engine failure during AP or YD re-engagement, the YD unit commanded the rudder to return to neutral position, leading to inadequate balancing of the asymmetric power.

DATES: This AD becomes effective January 18, 2018. Comments must be received by February 20, 2018.

COST: The FAA estimates there are no affected U.S.-registered airplanes. If an affected airplane is imported and placed on the U.S. Register in the future, the following cost estimates are provided to comply with this AD:

• $85 per product for inspection.
• Optional modification will take about 3 work-hours for a cost of $255 per product.

FMI: AD