Airworthiness Directive · Amendment 39-23121 · Tail rotor control system
MD Helicopters, LLC
This AD applies to MD Helicopters, LLC, Model 369 (Army YOH-6A), 369A (Army OH-6A), 369D, 369E, 369F, 369FF, 369H, 369HE, 369HM, 369HS, 500N, and 600N helicopters, certificated in any category, with a tail rotor (T/R) pedal support bracket part number (P/N) 369A7505-7, 369A7505-8, 369A7505-14, 369A7505-15, 369N2640-1, or 369N2640-2, installed.
The FAA is adopting a new airworthiness directive (AD) for certain MD Helicopters, LLC, Model 369 (Army YOH-6A), 369A (Army OH- 6A), 369D, 369E, 369F, 369FF, 369H, 369HE, 369HM, 369HS, 500N, and 600N helicopters. This AD was prompted by multiple reports of cracked tail rotor (T/R) pedal support brackets. This AD requires repetitively inspecting certain part-numbered T/R pedal support brackets and depending on the results, replacing the T/R pedal support bracket or refinishing any exposed areas. This AD also prohibits installing certain part-numbered T/R pedal support brackets. The FAA is issuing this AD to address the unsafe condition on these products.
(1) Within 25 hours time-in-service (TIS) and thereafter at intervals not to exceed 100 hours TIS, using a 10X power magnification glass, mirror, and flashlight, visually inspect each T/R pedal support bracket for cracks and corrosion by following the Accomplishment Instructions, paragraph 2.A.(2)., of MD Helicopters Service Bulletin SB369D-231R2, SB369E-131R2, SB369F-122R2, SB369H-265R2, SB500N-068R2, or SB600N-082R2, each dated November 1, 2023 (collectively referred to as “the service bulletins”), as applicable to your helicopter model; you may use a borescope as specified in the note in paragraph 2.A.(2) of the service bulletins. For the purpose of this AD, for MD Helicopters, LLC, Model 369 (Army YOH-6A) and 369A (Army OH-6A) helicopters, use MD Helicopters Service Bulletin SB369D-231R2, dated November 1, 2023, to accomplish the actions required by this AD.
(i) If there is a crack or any corrosion as a result of the inspections required by the introductory text of paragraph (g)(1) of this AD, before further flight, remove the T/R pedal support bracket from service and replace it with a serviceable T/R pedal support bracket P/N 369N2640-1 or 369N2640-2.
(ii) If there is not a crack and there is no corrosion as a result of the inspections required by the introductory text of paragraph (g)(1) of this AD, before further flight, refinish any exposed areas.
(2) Within 50 hours TIS and thereafter at intervals not to exceed 300 hours TIS, eddy current, dye penetrant, or fluorescent penetrant inspect each T/R pedal support bracket for a crack by following the Accomplishment Instructions, paragraph 2.B.(2)., of the service bulletins, as applicable to your helicopter model.
(i) If there is a crack as a result of the actions required by the introductory text of paragraph (g)(2) of this AD, before further flight, remove the T/R pedal support bracket from service and replace it with a serviceable T/R pedal support bracket P/N 369N2640-1 or 369N2640-2.
(ii) If there is not a crack as a result of the actions required by the introductory text of paragraph (g)(2) of this AD, before further flight, refinish any exposed areas and ensure the T/R pedal support bracket is cleaned from any penetrant residue.
(3) As of the effective date of this AD, do not install magnesium cast T/R pedal support bracket P/N 369A7505-7, 369A7505-8, 369A7505-14, or 369A7505-15 on any helicopter.
