AD 2021-17-10 Prompted By A Report Of Un-Commanded Activation Of The Rotor Brake System

The FAA is adopting a new airworthiness directive (AD) for certain Leonardo S.p.a. Model A109A, A109A II, A109C, A109E, A109K2, A109S, and AW109SP helicopters, having a certain rotor brake kit installed.

This AD was prompted by a report of un-commanded activation of the rotor brake system before take-off due to a jammed rotor brake control cable and subsequent partially open brake control valve. This AD requires repetitive inspections of the rotor brake control cable and replacement of the rotor brake control cable, if necessary, as specified in a European Union Aviation Safety Agency (EASA) AD, which is incorporated by reference. The FAA is issuing this AD to address the unsafe condition on these products. This AD becomes effective September 7, 2021.

Supplementary Information: EASA, which is the Technical Agent for the Member States of the European Union, has issued EASA AD 2021-0067, dated March 9, 2021 (EASA AD 2021-0067), to correct an unsafe condition on Leonardo S.p.a. (formerly Finmeccanica S.p.A., AgustaWestland S.p.A., Agusta S.p.A., Costruzioni Aeronautiche Giovanni Agusta) Model A109A, A109AII, A109C, A109E, A109K2, A109S, and AW109SP helicopters with a certain rotor brake kit installed.

EASA AD 2021-0067 was prompted by a report of un-commanded activation of the rotor brake system before take-off due to a jammed rotor brake control cable and subsequent partially open brake control valve. This resulted in hydraulic pressure delivered to the rotor brake, even with the rotor brake lever in the OFF position. To address this condition, EASA AD 2021-0067 requires repetitive inspections of the rotor brake control cable and replacement, if necessary. The FAA is issuing this AD to address un-commanded activation of the rotor brake system, which could lead to failure of the rotor brake system with consequent damage to surrounding critical equipment, resulting in loss of control of the helicopter.

FMI: www.regulations.gov