AD 2020-19-07 Airworthiness Directives; Leonardo S.p.a. Helicopters

This AD becomes effective October 27, 2020.

(1) The Manager, Rotorcraft Standards Branch, FAA, may approve AMOCs for this AD. Send your proposal to: Matt Fuller, AD Program Manager, Continued Operational Safety Branch, Airworthiness Products Section, General Aviation and Rotorcraft Unit, 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, the FAA suggests 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.

The subject of this AD is addressed in European Aviation Safety Agency (now European Union Aviation Safety Agency) (EASA) No. 2017-0255, dated December 22, 2017. You may view the EASA AD on the internet at https://www.regulations.gov in Docket No. FAA-2020-0258.

(1) Within 60 hours time-in-service, modify the WoW support installation as follows: (i) Perform a short circuit connection between pin 26 of connector J343 and pin N of connector J319. (ii) Cut the lockwire that locks the WoW microswitch and disconnect the WoW microswitch from the WoW support as depicted in Figure 1 of Leonardo Helicopters Alert Service Bulletin No. 169-047, Revision A, dated February 19, 2018 (ASB 169-047). (iii) Unscrew the nut and remove the washer and bolt. Remove from service the nut and bolt, but replace the washer. (iv) Remove the WoW support from the MLG and remove any paint and clean areas where indicated by Figure 2 in ASB 169-047. (v) Apply Alodine 1132 on cleaned areas of WoW support and landing gear strut leaving a 10 mm wide strip on the WoW support for structural glue EA934 application. (vi) Apply a 10 mm wide strip of structural glue EA934 on the WoW support and install the WoW support on the MLG using a nut, bolt, and washer. (vii) Torque the nut to 2.5 thru 3.5 Nm. Clean any excess glue and cure the glue on the structures for one hour at 60 °C/140 °F or eight days at room temperature (22 °C-26 °C/71.6 °F-78.8 °F). (viii) Apply liquid jointing compound AMS-S-8802 Type 2 Class B, or equivalent, to the bolt and nut, as depicted in Figure 3 of ASB 169-047 and perform a microswitch adjustment for correct operation of the microswitch. (ix) Mark the MLG nameplate by adding the letter “B” at the end of the S/N. (x) Remove the short circuit connection between pin 26 of connector J343 and pin N of connector J319 as performed in paragraph (e)(1)(i) of this AD. (2) After the effective date of this AD, do not install on any helicopter a LH or RH MLG assembly with a P/N and S/N listed in paragraph (a) of this AD unless it has been modified in accordance with the requirements of paragraph (e)(1) of this AD.

This AD defines the unsafe condition as an improperly tightened weight on wheels (WoW) support resulting in a rotation of the support and improper WoW switch performance, which if not corrected could lead to degraded attitude stabilization, and subsequent loss of control of the helicopter.