AD 2010-23-04

You are responsible for having the actions required by this AD performed within the compliance times specified, unless the actions have already been done.

For airplanes having serial numbers 4001 through 4304 inclusive, 4314, and 4315: Within 100 flight hours after the effective date of this AD, do a detailed inspection for cracking, and a conductivity inspection on each of the 4 nacelle attachment fittings, in accordance with the Accomplishment Instructions of Bombardier Service Bulletin 84-54-14, Revision J, dated September 17, 2010. Repeat the detailed inspection at intervals not to exceed 300 flight hours, except as provided by paragraph (j) of this AD.

(1) If any nacelle attachment fitting is found cracked, before further flight, replace the fitting with a new fitting in accordance with paragraph (3) of Part A of the Accomplishment Instructions of Bombardier Service Bulletin 84-54-14, Revision J, dated September 17, 2010.

(2) If the conductivity of any test points on any fitting is found to be greater than 45.0 percent International Annealed Copper Standard (IACS) or if the conductivity of any test points on any fitting is found to be less than 38.0 percent IACS, do the actions required by paragraphs (g)(2)(i) and (g)(2)(ii) of this AD.

(i) Within 24 hours after accomplishing the conductivity inspection specified in paragraph (g) of this AD, do a detailed inspection of the nacelle attachment fitting for cracking, in accordance with the Accomplishment Instructions of Bombardier Service Bulletin 84-54-14, Revision J, dated September 17, 2010, and repeat thereafter at intervals not to exceed 24 hours. If cracking is found, before further flight, replace the fitting with a new fitting in accordance with the requirements of paragraph (g)(2)(ii) of this AD. Replacement of the fitting terminates the daily detailed inspection requirements of this paragraph.

(ii) Except as required by paragraph (g)(2)(i) of this AD: Within 300 flight hours after accomplishing the conductivity inspection specified in paragraph (g) of this AD, replace the fitting with a new fitting in accordance with paragraph (3) of Part A of the Accomplishment Instructions of Bombardier Service Bulletin 84-54-14, Revision J, dated September 17, 2010.

Submit a report of the findings (both positive and negative) of the conductivity inspection required by paragraph (g) of this AD to Bombardier, at the applicable time specified in paragraph (h)(1) or (h)(2) of this AD, in accordance with Bombardier Service Bulletin 84-54-14, Revision J, dated September 17, 2010. The report must include the inspection results, a description of any discrepancies found, the airplane serial number, and the number of flight cycles and flight hours on the airplane.

(1) If the inspection was done on or after the effective date of this AD: Submit the report within 14 days after the inspection.

(2) If the inspection was accomplished prior to the effective date of this AD: Submit the report within 14 days after the effective date of this AD.

(i) For airplanes having serial numbers 4305 through 4313 inclusive, and 4316 and subsequent: Within 1,200 flight hours after the effective date of this AD, do a detailed inspection for cracking on each of the 4 nacelle attachment fittings, in accordance with the Accomplishment Instructions of Bombardier Service Bulletin 84-54-14, Revision J, dated September 17, 2010. If any nacelle attachment fitting is found cracked, before further flight, replace the fitting with a new fitting in accordance with paragraph (3) of Part A of the Accomplishment Instructions of Bombardier Service Bulletin 84-54-14, Revision J, dated September 17, 2010. Thereafter, repeat the detailed inspection at intervals not to exceed 300 flight hours, except as provided by paragraph (j) of this AD.

For any fitting that is replaced in accordance with paragraph (3) of Part A of the Accomplishment Instructions of Bombardier Service Bulletin 84-54-14, Revision J, dated September 17, 2010, as specified in paragraph (g) or (i) of this AD: Within 1,200 flight hours after replacing the fitting, do a detailed inspection of that replaced fitting as specified in paragraph (g) or (i) of this AD, and repeat the detailed inspection thereafter at intervals not to exceed 300 flight hours.

Accomplishing the replacement of the nacelle fittings in accordance with any Bombardier service bulletin identified in Table 1 of this AD before the effective date of this AD is also acceptable for compliance with the fitting replacements specified in paragraphs (g) and (i) of this AD.

Accomplishment of the inspections required by paragraphs (g) and (i) of this AD before the effective date of this AD in accordance with any Bombardier service bulletin identified in Table 1 of this AD is acceptable for compliance with the corresponding actions required by paragraphs (g) and (i) of this AD.

Note 1: This AD differs from the MCAI and/or service information as follows: Although the MCAI does not state a requirement for submitting inspection reports, this AD requires inspection reports to be submitted to the manufacturer so the manufacturer can gather information on the extent of the problem and develop corrective actions. Based on the results of these reports, we might determine that further rulemaking is warranted. This difference has been coordinated with TCCA.