Airworthiness Directive · Amendment 39-17020 · -13-p
Agusta S.p.A. Helicopters
Superseded. A later AD replaced this one: AD 2021-14-18. Comply with the one in force.
This AD applies to Agusta Model AB139 and AW139 helicopters, with a tail rotor (T/R) blade, part number (P/N) 3G6410A00131 or P/N 4G6410A00131, certificated in any category.
We are publishing a new airworthiness directive (AD) for certain Agusta S.p.A. (Agusta) Model AB139 and AW139 helicopters that requires establishing a revised life limit for each tail rotor (T/R) blade and updating the helicopter's historical records, repetitively inspecting T/R blades for a crack, and replacing certain T/R blades. This AD is prompted by a fatal accident involving an Agusta Model AW139 helicopter, which may have been caused by cracks in a T/R blade. These actions are intended to detect and prevent a crack in a T/R blade, which could lead to failure of a T/R blade and subsequent loss of control of the helicopter.
You are responsible for performing each action required by this AD within the specified compliance time unless it has already been accomplished prior to that time.
(1) Within 5 hours time-in-service (TIS), establish a life limit of 600 hours TIS or 1,500 takeoff and landing cycles (cycles), whichever occurs first, on the affected T/R blades and update the helicopter's historical records. If a T/R blade's total number of cycles is unknown, determine the T/R blade cycles by multiplying the T/R blade's hours TIS by 4.
(2) For a T/R blade that, on the effective date of this AD, has already exceeded 600 hours TIS or 1,500 cycles, within 5 hours TIS replace the T/R blade with an airworthy T/R blade.
(3) Within 25 hours TIS, and thereafter at intervals not to exceed 25 hours TIS, visually inspect the T/R blade for a crack or damage that exceeds the limits of the applicable maintenance manual. Inspect in the area depicted in the following figure using a mirror, magnifying glass (5X or greater), and light source, or borescope.
(4) If there is a crack, or if there is damage that exceeds the limits of the applicable maintenance manual, before further flight, replace the T/R blade with an airworthy T/R blade.
(5) This AD revises the Airworthiness Limitations section of the maintenance manual by reducing the life limit of the T/R blade to 600 hours TIS or 1,500 cycles.
The aircraft, engines and makers this AD names, by the model designations in its text. A model listed here may still be outside the AD's serial ranges.
Aircraft
