AD 2018-05-09 Airworthiness Directives; Airbus Helicopters

This AD becomes effective March 26, 2018.

A federal agency may not conduct or sponsor, and a person is not required to respond to, nor shall a person be subject to a penalty for failure to comply with a collection of information subject to the requirements of the Paperwork Reduction Act unless that collection of information displays a current valid OMB Control Number. The OMB Control Number for this information collection is 2120-0056. Public reporting for this collection of information is estimated to be approximately 30 minutes per response, including the time for reviewing instructions, completing and reviewing the collection of information. All responses to this collection of information are mandatory. Comments concerning the accuracy of this burden and suggestions for reducing the burden should be directed to the FAA at: 800 Independence Ave. SW, Washington, DC 20591, Attn: Information Collection Clearance Officer, AES-200.

(1) The Manager, Safety Management Section, Rotorcraft Standards Branch, FAA, may approve AMOCs for this AD. Send your proposal to: Martin R. Crane, Aviation Safety Engineer, Regulations & Policy Section, Rotorcraft Standards Branch, FAA, 10101 Hillwood Pkwy., Fort Worth, TX 76177; telephone (817) 222-5110; email 9-ASW-FTW-AMOC-Requests@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.

(1) Within 25 hours time-in-service, inspect each T/R hinge as follows: (i) Point each T/R blade downward and perform a tactile inspection of each hinge for friction points. Record whether there is a friction point. (ii) Measure play in the drag plane depicted as “J” in Figure 1 of Airbus Helicopters Emergency Alert Service Bulletin No. 64.00.43, Revision 0, dated November 21, 2017 (EASB 64.00.43), and record the measurement. (iii) Measure the tightening torque of each spindle bolt and record the measurement. (A) If the tightening torque is less than 564 inch-pounds or more than 955 inch-pounds, before further flight, dye-penetrant inspect the spindle bolt for a crack and record whether there is a crack. Remove the spindle bolt and the hexagonal castellated nut from service. (B) If the tightening torque is between 564 inch-pounds and 955 inch-pounds, inspect the spindle bolt for corrosion and fretting and record whether there is corrosion or fretting. If there is corrosion or fretting that cannot be removed by hand with an abrasive pad, before further flight, dye-penetrant inspect the spindle bolt for a crack in areas Z1 and Z2 as depicted in Figure 2 of EASB 64.00.43. If there is a crack, before further flight, record that there is a crack and remove from service the spindle bolt, hexagonal castellated nut, inner ring, stop washers, needle bearings or set of needle bearings, seals, and split washer. (iv) Remove the inner ring and stop washers. (v) Inspect the bearing race inner ring and bearing needles for spalling. If there is any spalling, before further flight, record that there is spalling and replace the bearing race. (vi) Measure the thickness of each stop washer. If the thickness is less than 1.5 mm (.060 inch), before further flight, remove the stop washer from service. Record that the stop washer was removed from service because of thickness. (vii) Inspect the inner ring for brinelling. (A) If there is brinelling more than 0.1 mm (.004 inch) in depth, before further flight, record that there is brinelling and repair the hinge. (B) If there is brinelling 0.1 mm (.004 inch) or less in depth, before further flight, turn the inner ring to position the area with brinelling on the T/R hub pin side. Record the brinelling and the turning of the inner ring. Dye-penetrant inspect the inner ring for a crack in the area depicted as “Z3” of Figure 3 of EASB 64.00.43. If there is a crack, before further flight, record that there is a crack in the inner ring and remove from service the spindle bolt, hexagonal castellated nut, inner ring, stop washers, needle bearings or set of needle bearings, seals, and split washer. (2) Within 10 days after the inspection, submit a report of the measurements and findings of the inspection required by paragraph (e)(1) of this AD, as specified in the Appendix of EASB 64.00.43, to support.technical-dyncomp.ah@airbus.com.

This AD defines the unsafe condition as failure of a tail rotor (T/R) flapping hinge link (hinge). This condition could result in unbalance of the T/R, detachment of the T/R gearbox and hub, and subsequent loss of control of the helicopter.