AD NUMBER: 2018-23-52

PRODUCT: Leonardo S.p.A. Model AW169 and AW189 helicopters.

ACTION: Final Rule.

SUMMARY: This emergency AD was prompted by an accident of a Model AW169 helicopter. This emergency AD requires inspecting the tail rotor (T/R) servo-actuator feedback lever link, applying a paint stripe or torque seal on a nut, and reporting information. The actions in this emergency AD are intended to prevent failure of a T/R servo-actuator feedback lever link, which could result in loss of T/R control and subsequent loss of control of the helicopter.

The European Aviation Safety Agency (EASA), which is the Technical Agent for the Member States of the European Union, has issued EASA AD No. 2018-0241-E, dated November 7, 2018, to correct an unsafe condition for Leonardo S.p.A. Model AW169 and AW189 helicopters. EASA advises of an accident of a Model AW169 helicopter that appears to have lost yaw control during its take-off low forward speed phase of flight.

The root cause of the accident has not been identified and the investigation is on-going. As a precaution, the EASA AD requires inspecting the T/R servo-actuator for correct installation on Model AW169 and Model AW189 helicopters. EASA has included Model AW189 helicopters due to design similarity. If there is any damage or other finding from this inspection, the EASA AD requires contacting Leonardo Helicopters.

The EASA AD also requires applying a paint mark on the nut and reporting the inspection results to Leonardo Helicopters. EASA states that the incorrect installation of the T/R servo-actuator could result in loss of control of the helicopter, depending on the flight condition.

This emergency AD requires inspecting the nut, cotter pin, lock-wire, hinge bracket connected to the T/R servo-actuator feedback lever link, and each connection of the T/R servo-actuator feedback lever link. This emergency AD also requires applying a paint stripe or torque seal on the nut and reporting certain information to Leonardo Helicopters.

COST: The FAA estimates that this emergency AD affects 7 helicopters of U.S. registry. Operators may incur the following costs in order to comply with this AD:

Inspecting the T/R servo-actuator feedback lever link and applying a paint stripe or torque seal takes about 2 work-hours, and reporting information to Leonardo Helicopters takes about 1 work-hour. Based on these estimates, the total cost of this emergency AD is $255 per helicopter and $1,785 for the U.S. fleet.

FMI: AD