2021-23-08: Wing, Center Box

1. The authority citation for part 39 continues to read as follows: Authority: 49 U.S.C. 106(g), 40113, 44701. 2. The FAA amends § 39.13 by adding the following new airworthiness directive: 2021-23-08 Learjet Inc.: Amendment 39-21806; Docket No. FAA-2021-0157; Project Identifier AD-2020-00483-T. (a) Effective Date This airworthiness directive (AD) is effective January 10, 2022. (b) Affected ADs None. (c) Applicability This AD applies to Learjet Inc. Model 45 (Learjet 40), Model 45 (Learjet 45), Model 45 (Learjet 70), and Model 45 (Learjet 75) airplanes, serial numbers 45-002 through 45-596 and 45-2001 through 45-2146, certificated in any category. (d) Subject Joint Aircraft System Component (JASC) Code 5714, Wing, Center Box. (e) Unsafe Condition This AD was prompted by reports of corrosion found on the upper surface of the lower center wing mid spar splice plate. The FAA is issuing this AD to detect and correct corrosion or deterioration of protective treatments on the center wing area. The unsafe condition, if not addressed, could result in failure of the wing centerline joint and lead to partial wing separation with consequent loss of control of the airplane. (f) Compliance Comply with this AD within the compliance times specified, unless already done. (g) Applicable Service Bulletins Use the following service bulletin, as applicable to your airplane model configuration, to perform the actions required by paragraph (h) of this AD: (1) Bombardier Learjet 40 Service Bulletin 40-57-06, Revision 1, dated October 26, 2020; (2) Bombardier Learjet 45 Service Bulletin 45-57-13, Revision 1, dated October 26, 2020; (3) Bombardier Learjet 70 Service Bulletin 70-57-02, Revision 1, dated October 26, 2020; or (4) Bombardier Learjet 75 Service Bulletin 75-57-01, Revision 2, dated April 19, 2021. (h) Wing Center Spar Inspection, Related Investigative Inspections, and Corrective Actions At the applicable initial compliance time specified in paragraph (h)(1) or (2) of this AD and thereafter at intervals not to exceed 8 years, inspect the center wing area for corrosion and deterioration of protective treatments and perform all related corrective actions by following the Accomplishment Instructions, steps 3.A. and 3.B., of the applicable service bulletin listed in paragraph (g) of this AD. (1) For airplanes with 8 or fewer years since the date of issuance of the original airworthiness certificate or the date of issuance of the original export certificate of airworthiness, whichever date is earlier: Before or upon accumulating 8 years or within 12 months after the effective date of this AD, whichever occurs later; or (2) For airplanes that have accumulated more than 8 years since the date of issuance of the original airworthiness certificate or the date of issuance of the original export certificate of airworthiness, whichever date is earlier: Within 12 months after the effective date of this AD. (i) Service Information Exception Where Bombardier Learjet 40 Service Bulletin 40-57-06, Revision 1, dated October 26, 2020, Bombardier Learjet 45 Service Bulletin 45-57-13, Revision 1, dated October 26, 2020, Bombardier Learjet 70 Service Bulletin 70-57-02, Revision 1, dated October 26, 2020, and Bombardier Learjet 75 Service Bulletin 75-57-01, Revision 2, dated April 19, 2021, specify contacting Learjet Inc. for appropriate action: Before further flight, repair using a method approved in accordance with the procedures specified in paragraph (l) of this AD. (j) Reporting Requirement Within 30 days after completing the initial inspection required by paragraph (h) of this AD or within 30 days after the effective date of this AD, whichever occurs later, submit a report of the findings (both positive and negative) of the inspection to: Wichita-COS@faa.gov; or Ann Johnson, Wichita ACO Branch, FAA, 1801 Airport Road, Wichita, KS 67209. This reporting requirement is limited to the initial inspection results only. The report must include: The name of the owner; the address of the owner; the name of the organization doing the actions required by this AD; the date the inspection was completed; the name of the person submitting the report; the address, telephone number, and email of the person submitting the report; the airplane serial number; the date of issuance of the original airworthiness certificate, or the date of issuance of the original export certificate of airworthiness (whichever date is earlier); whether protective treatments are deteriorated, and if so, the location of deteriorated areas; whether corrosion was detected, and if so, the location of corrosion; and a list of parts replaced if the level of corrosion required replacement of parts. (k) Credit for Previous Actions You may take credit for the initial wing spar inspection required by the introductory text to paragraph (h) of this AD if you performed the visual inspection before the effective date of this AD using Bombardier Learjet 40 Service Bulletin 40-57-06, Basic Issue, dated February 25, 2019; Bombardier Learjet 40 Maintenance Manual MM-105, Temporary Revision No. 4-32, Inspection Reference Number AC5710190, dated March 25, 2021; Bombardier Learjet 40 Maintenance Manual MM-105, Inspection Reference Number AB5710190, dated April 29, 2019, or November 14, 2019; Bombardier Learjet 45 Service Bulletin 45-57-13, Basic Issue, dated February 25, 2019; Bombardier Learjet 45 Maintenance Manual MM-104, Temporary Revision No. 4-47, Inspection Reference Number AC5710190, dated March 25, 2021; Bombardier Learjet 45 Maintenance Manual MM-104, Inspection Reference Number AB5710190, dated April 29, 2019, or November 14, 2019; Bombardier Learjet 70 Service Bulletin 70-57-02, Basic Issue, dated February 25, 2019; Bombardier Learjet 70/75 eINSPECTOR version (2019.2.25) thru version (2021.4.23), Inspection Reference Number 5710190; Bombardier Learjet 75 Service Bulletin 75-57-01, Basic Issue, dated February 25, 2019; or Bombardier Learjet 75 Service Bulletin 75-57-01, Revision 1, dated October 26, 2020. (1) To take credit for the initial inspection, you must comply with paragraph (j) of this AD within 30 days after the effective date of this AD. (2) You cannot take credit for the recurring inspections, only the initial inspection. (l) Alternative Methods of Compliance (AMOCs) (1) The Manager, Wichita ACO Branch, FAA, has the authority to approve AMOCs for this AD, if requested using the procedures found in 14 CFR 39.19. In accordance with 14 CFR 39.19, send your request to your principal inspector or local Flight Standards District Office, as appropriate. If sending information directly to the manager of the certification office, send it to the attention of the person identified in paragraph (m) of this AD. (2) Before using any approved AMOC, notify your appropriate principal inspector, or lacking a principal inspector, the manager of the local flight standards district office/certificate holding district office. (3) An AMOC that provides an acceptable level of safety may be used for any repair, modification, or alteration required by this AD if it is approved by a Learjet Inc. Designated Engineering Representative, or a Unit Member of the Learjet Organization Designation Authorization, that has been authorized by the Manager, Wichita ACO Branch, to make those findings. To be approved, the repair, modification, or alteration method must meet the certification basis of the airplane, and the approval must specifically refer to this AD. (m) Related Information For more information about this AD, contact Tara Shawn, Aviation Safety Engineer, Wichita ACO Branch, FAA, 1801 Airport Road, Wichita, KS 67209; phone: (316) 946-4141; fax: (316) 946-4107; email: tara.shawn@faa.gov. (n) Material Incorporated by Reference (1) The Director of the Federal Register approved the incorporation by reference (IBR) of the service information listed in this paragraph under 5 U.S.C. 552(a) and 1 CFR part 51. (2) You must use this service information as applicable to do the actions required by this AD, unless the AD specifies otherwise. (i) Bombardier Learjet 40 Service Bulletin 40-57-06, Revision 1, dated October, 26, 2020. (ii) Bombardier Learjet 45 Service Bulletin 45-57-13, Revision 1, dated October, 26, 2020. (iii) Bombardier Learjet 70 Service Bulletin 70-57-02, Revision 1, dated October, 26, 2020. (iv) Bombardier Learjet 75 Service Bulletin 75-57-01, Revision 2, dated April 19, 2021. (3) For service information identified in this AD, contact Learjet Inc., One Learjet Way, Wichita, KS 67209; phone: (316) 946-2000; email: ac.ict@aero.bombardier.com; website: businessaircraft.bombardier.com/en/aircraft/learjet.html. (4) You may view this service information at FAA, Airworthiness Products Section, Operational Safety Branch, 901 Locust, Kansas City, MO 64106. For information on the availability of this material at the FAA, call (816) 329-4148. (5) You may view this service information that is incorporated by reference at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, email: fr.inspection@nara.gov, or go to: https://www.archives.gov/federal-register/cfr/ibr-locations.html. Issued on October 28, 2021. Lance T. Gant, Director, Compliance & Airworthiness Division, Aircraft Certification Service. [FR Doc. 2021-26330 Filed 12-3-21; 8:45 am]BILLING CODE 4910-13-P