AD 2012-07-08 Airworthiness Directives; Empresa Brasileira de Aeronautica S.A. (EMBRAER) Airplanes

Models named: ERJ 170-100 LR, -100 STD, -100 SE, -100 SU, ERJ 170-200 LR, -200 SU, -200 STD. Read the applicability below — it usually turns on serial or part numbers too.

(1) This AD applies to all Empresa Brasileira de Aeronautica S.A. (EMBRAER) Model ERJ 170-100 LR, -100 STD, -100 SE., and -100 SU airplanes; and Model ERJ 170-200 LR, -200 SU, and -200 STD airplanes; certificated in any category. (2) This AD requires revisions to certain operator maintenance documents to include new actions ( e.g., inspections). Compliance with these actions is required by 14 CFR 91.403(c). For airplanes that have been previously modified, altered, or repaired in the areas addressed by these inspections, the operator may not be able to accomplish the actions described in the revisions. In this situation, to comply with 14 CFR 91.403(c), the operator must request approval for an alternative method of compliance according to paragraph (k) of this AD. The request should include a description of changes to the required inspections that will ensure the continued damage tolerance of the affected structure. The FAA has provided guidance for this determination in Advisory Circular (AC) 25.1529-1A ( http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgAdvisoryCircular.nsf/list/AC%2025.1529-1A/$FILE/AC%2025.1529-1A.pdf ).

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

(1) Within 90 days after July 6, 2010 (the effective date of AD 2010-11-13, Amendment 39-16318 (75 FR 30284, June 1, 2010)), revise the ALS of the Instructions for Continued Airworthiness (ICA) to incorporate the inspection tasks identified in the EMBRAER temporary revisions (TRs) to Appendix A—Part 2 of the EMBRAER 170 MRBR MRB-1621 listed in table 1 of this AD. (2) The initial compliance times for the tasks start from the applicable threshold times specified in the temporary revisions (TRs) for the corresponding tasks of the maintenance review board report or within 500 flight cycles after July 6, 2010, whichever occurs later. For certain tasks, the compliance times depend on the pre-modification and post-modification status of the actions specified in the associated service bulletin, as specified in the “Applicability” column of the applicable TRs identified in table 1 of this AD. (3) The threshold values stated in the TRs referenced in table 1 of this AD are total flight cycles on the airplane since the date of issuance of the original Brazilian airworthiness certificate or the date of issuance of the original Brazilian export certificate of airworthiness. Table 1—Inspection Tasks TR Date Subject Task No. TR 4-1 October 15, 2007 Ram air turbine compartment, support structure and cutout structure—internal 53-10-012-0002 53-10-012-0003   Nose landing gear wheel well metallic structure 53-10-021-0005 53-10-021-0006 TR 4-3 December 6, 2007 Wing stub spar 3 side fitting—internal 57-01-012-001   Wing upper skin panels—external 57-10-010-0002   Fixed trailing edge lower skin panel—external 57-50-002-0002   Fixed trailing edge rib 4A—external 57-50-005-0003   Fixed trailing edge rib 6—internal 57-50-005-0004 TR 4-4 January 18, 2008 Wing stub main box lower—internal 57-01-002-003

This AD was prompted by cracks found in certain structural components during full scale fatigue testing of the airplane. Analysis of these cracks resulted in manufacturer modifications of the airworthiness limitations section (ALS) of EMBRAER 170 Maintenance Review Board Report (MRBR), which include new inspections tasks, or modification of the current tasks and their respective thresholds and intervals. We are issuing this AD to detect and correct fatigue cracking which could result in the loss of structural integrity of the airplane.

This AD supersedes AD 2010-11-13, Amendment 39-16318 (75 FR 30284, June 1, 2010).