AD 2020-26-03 Requires Inspecting Certain Ball Pivots...

The FAA is superseding Airworthiness Directive (AD) 2007-26-51 which applied to certain Airbus Helicopters Deutschland GmbH Model EC135 helicopters. AD 2007-26-51 required inspecting the tail rotor control rod (control rod) and ball pivot and, depending on findings, replacing those parts.

This new AD requires inspecting certain ball pivots, applying corrosion preventative compound on the ball pivot, and corrective action, as applicable. This AD also requires replacing the control rod with a newly developed control rod. This AD was prompted by the manufacturer's development of a new control rod, which the FAA has determined must be installed in order to address the identified unsafe condition. The actions of this AD are intended to address an unsafe condition on these products. This AD is effective January 22, 2021.

Supplementary Information: The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 to remove AD 2007-26-51, Amendment 39-15357 (73 FR 6008, February 1, 2008) (AD 2007-26-51), and add a new AD. AD 2007-26-51 applied to certain Airbus Helicopters Deutschland GmbH (type certificate previously held by Eurocopter Deutschland GmbH) Model EC135 helicopters, serial number (S/N) 0005 up to and including S/N 0444, except S/N 0028, and with control rod part number (P/N) L672M2005207, installed. The NPRM was published in the Federal Register on June 18, 2020 (85 FR 36816).

The NPRM proposed to require inspecting certain ball pivots for damage and freedom of movement, applying corrosion preventative compound on the ball pivot, and corrective action, as applicable. The NPRM also proposed to require replacing the control rod with the newly developed control rod that the FAA determined was necessary to address the unsafe condition.

The NPRM was prompted by EASA AD No. 2010-0227R1, dated April 7, 2017 (referred to after this as the Mandatory Continuing Airworthiness Information, or “the MCAI”), issued by EASA, which is the Technical Agent for the Member States of the European Union, to correct an unsafe condition for all Model EC135 P1, EC135 P2, EC135 P2+, EC135 T1, EC 135 T2, and EC135 T2+ helicopters; and Model EC635 T1, EC635 P2+, and EC635 T2+ helicopters. EASA advises that in 2007 an accident occurred on an EC135 helicopter in Japan. Preliminary investigation results indicated that loss of control was due to failure of the control rod. EASA issued EASA Emergency AD 2007-0301-E, dated December 13, 2007 (EASA AD 2007-0301-E) to inspect the affected control rod P/N L672M2005207 and the ball pivot (which correspond to the actions required by AD 2007-26-51). EASA AD 2007-0301-E was subsequently superseded by EASA AD 2007-0313, dated December 21, 2007, to require repetitive inspections and, depending on findings, the replacement of the control rod and ball pivot, only for helicopters not equipped with an automatic flight control system (AFCS). After review of the inspection results, EASA issued EASA AD 2008-0064, dated April 4, 2008, and later revised to EASA AD 2008-0064 R1, dated April 15, 2008 (EASA AD 2008-0064 R1), to apply the requirements to helicopters equipped with an AFCS.

EASA also advises that after EASA AD 2008-0064R1 was issued, Eurocopter Deutschland GmbH developed a new control rod P/N L672M2006101, installation of which constituted terminating action for the repetitive inspections. Consequently, EASA issued EASA AD 2010-0227, dated November 3, 2010, and corrected November 8, 2010, retaining the requirements of EASA AD 2008-0064R1, and requiring the replacement of control rod P/N L672M2005207 with the new control rod P/N L672M2006101. The FAA has determined that this new control rod must be installed in order to address the unsafe condition.

In addition, EASA advises that following a review of data and feedback received from in-service helicopters, it has been determined that the repetitive inspections of the ball pivot are no longer required to address the unsafe condition. The repetitive inspections of the ball pivot are now included in Chapter 05 of the aircraft maintenance manual. Therefore, EASA issued EASA AD 2010-0227R1 to remove the requirement for repetitive inspections of the control rod and of the ball pivot.

You may examine the MCAI in the AD docket on the internet at https://www.regulations.gov by searching for and locating Docket No. FAA-2020-0572.

FMI: www.regulations.gov