AD 2013-19-24 Airworthiness Directives; MD Helicopters, Inc., Helicopters

This AD supersedes AD No. 2003-08-51, Amendment 39-13215 (68 FR 39449, July 2, 2003; correction 68 FR 47447, August 11, 2003).

(1) Before further flight, for each applicable blade, revise the Airworthiness Limitations section of the maintenance manual to reflect that the blade has a retirement life of 400 hours time-in-service (TIS). (2) For helicopters with an applicable blade installed that has 390 through 700 hours TIS, within 10 hours TIS, replace the blade with an airworthy blade. (3) For all other applicable helicopters, within 60 days, and thereafter at intervals not to exceed one year, remove the paint from the blade pitch control arm in accordance with the Accomplishment Instructions, Section 2.A.(1) through 2.A.(3), of MDHI Service Bulletins SB369D-210, SB369E-105, SB369F-091, and SB369H-252, all dated November 21, 2011, as applicable to your model helicopter. (i) Using a 10X or higher power magnifying glass, inspect all four sides and the pocket of the blade pitch control arm for a crack, pitting, or corrosion and for the condition of the dimpled shot peen surface by referring to Figure 1 of MDHI Service Bulletins SB369D-210, SB369E-105, SB369F-091, and SB369H-252, as applicable to your model helicopter, and by reviewing the rotorcraft maintenance records to determine whether rework was done in this area. (ii) If there is pitting, corrosion, a crack, blending or removal of any of the dimpled shot peen surface, or any indication that the shot peen has not been done, replace the blade with an airworthy blade. (iii) If there is no pitting, corrosion, cracks, or blending or removal of any of the dimpled shot peen surface, refinish the stripped pitch control arm in accordance with the Accomplishment Instructions, Section 2.A.(6) through 2.A.(7), of MDHI Service Bulletins SB369D-210, SB369E-105, SB369F-091, and SB369H-252, as applicable to your model helicopter.

(1) The Manager, Los Angeles Aircraft Certification Office, FAA, may approve AMOCs for this AD. Send your proposal to: Fred Guerin, Aviation Safety Engineer, Los Angeles Aircraft Certification Office, Transport Airplane Directorate, FAA, 3960 Paramount Blvd., Lakewood, California 90712; telephone (562) 627-5232; email fred.guerin@faa.gov . (2) For operations conducted under a 14 CFR part 119 operating certificate or under 14 CFR part 91, subpart K, we suggest that you notify your principal inspector, or lacking a principal inspector, the manager of the local flight standards district office or certificate holding district office before operating any aircraft complying with this AD through an AMOC. (3) AMOCs approved previously in accordance with AD No. 2003-08-51 (68 FR 39449, July 2, 2003; correction 68 FR 47447, August 11, 2003) are approved as AMOCs for the corresponding requirements in this AD.

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.

This AD defines the unsafe condition as the tail rotor blade pitch horn (pitch horn) separating from the tail rotor blade, leading to an unbalanced condition, vibration, loss of tail rotor pitch control and loss of directional control of the helicopter.