2018-20950. Airworthiness Directives; Bombardier, Inc., Airplanes

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

We propose to supersede Airworthiness Directive (AD) 2008-24-14, which applies to all Bombardier, Inc., Model CL-600-2B19 (Regional Jet Series 100 & 440) airplanes. AD 2008-24-14 requires revising the instructions for continued airworthiness to incorporate certain airworthiness limitations for the main landing gear (MLG) trunnion fitting assembly. Since we issued AD 2008-24-14, new airworthiness limitation (AWL) tasks have been introduced with revised inspection, modification, and safe-life requirements. This proposed AD would require revising the maintenance or inspection program, as applicable, to incorporate certain AWLs. It would also require reworking the trunnion fitting in order to meet new structural safe-life limits. We are proposing this AD to address the unsafe condition on these products.

DATES:

We must receive comments on this proposed AD by November 15, 2018.

ADDRESSES:

You may send comments, using the procedures found in 14 CFR 11.43 and 11.45, by any of the following methods:

• Federal eRulemaking Portal: Go to http://www.regulations.gov. Follow the instructions for submitting comments.
• Fax: [phone].
• Mail: U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue SE, Washington, DC 20590.
• Hand Delivery: Deliver to Mail address above between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays.

For service information identified in this NPRM, contact Bombardier, Inc., 400 Côte-Vertu Road West, Dorval, Québec H4S 1Y9, Canada; Widebody Customer Response Center North America toll-free telephone [phone] or direct-dial telephone [phone]; fax [phone]; email [e-mail]; internet http://www.bombardier.com. You may view this referenced service information at the FAA, Transport Standards Branch, 2200 South 216th St., Des Moines, WA. For information on the availability of this material at the FAA, call 206-231-3195.

Examining the AD Docket

You may examine the AD docket on the internet at http://www.regulations.gov by searching for and locating Docket No. FAA-2018-0801; or in person at the Docket Management Facility between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The AD docket contains this NPRM, the regulatory evaluation, any comments received, and other information. The street address for the Docket Operations office (telephone [phone]) is in the ADDRESSES section. Comments will be available in the AD docket shortly after receipt.

FOR FURTHER INFORMATION CONTACT:

Aziz Ahmed, Aerospace Engineer, Airframe and Mechanical Systems Section, FAA, New York ACO Branch, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; telephone [phone]; fax [phone].

SUPPLEMENTARY INFORMATION:

Comments Invited

We invite you to send any written relevant data, views, or arguments about this proposal. Send your comments to an address listed under the ADDRESSES section. Include “Docket No. FAA-2018-0801; Product Identifier 2017-NM-147-AD” at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of this proposed AD. We will consider all comments received by the closing date and may amend this proposed AD based on those comments.

We will post all comments we receive, without change, to http://www.regulations.gov,, including any personal information you provide. We will also post a report summarizing each substantive verbal contact we receive about this proposed AD.

Discussion

We issued AD 2008-24-14, Amendment 39-15758 (73 FR 73785, December 4, 2008) (“AD 2008-24-14”), for all Bombardier, Inc., Model CL-600-2B19 (Regional Jet Series 100 & 440) airplanes. AD 2008-24-14 requires revising the Airworthiness Limitations Section (ALS) of the Instructions for Continued Airworthiness to incorporate new structural inspection requirements. AD 2008-24-14 resulted from reports of the discovery of cracks on the MLG trunnion fitting web during fatigue testing. We issued AD 2008-24-14 to detect and correct fatigue cracking of the MLG trunnion fitting web.

Actions Since AD 2008-24-14 Was Issued

Since we issued AD 2008-24-14, new AWL tasks have been introduced with revised inspection, modification, and safe-life requirements, and we have determined that the trunnion fitting lower flange and both forward and aft bore holes are also subject to fatigue cracking.

Transport Canada Civil Aviation (TCCA), which is the aviation authority for Canada, has issued Canadian Airworthiness Directive CF-2017-27, dated August 2, 2017 (referred to after this as the Mandatory Continuing Airworthiness Information, or “the MCAI”), to correct an unsafe condition for certain Bombardier, Inc., Model CL-600-2B19 (Regional Jet Series 100 & 440) airplanes. The MCAI states:

Cracks on the main landing gear (MLG) trunnion fitting web discovered during fatigue testing led to the issuance of [Canadian] AD CF-2008-21 [which corresponds to FAA AD 2008-24-14], which mandated new inspection requirements to ensure that fatigue cracking of the trunnion web would be detected and corrected.

Additional fatigue test article findings and in-service findings have shown that the trunnion fitting lower flange and both forward and aft bore holes are also subject to fatigue cracking. Failure of the main landing gear trunnion fitting could result in the collapse of the main landing gear. Bombardier Inc. has decided to implement a series of design changes to improve the fatigue life of the trunnion fitting that is now a safe-life assembly.

New and revised Airworthiness Limitation (AWL) tasks for the MLG trunnion fitting assembly have been introduced in order to require new inspection, modification, and safe-life requirements. This [Canadian] AD mandates the incorporation of these new and revised AWL tasks, and removal of the AWL tasks they replace, to ensure that fatigue cracking of the MLG trunnion fitting is detected and corrected. This [Canadian] AD also requires rework of the trunnion fitting in order to meet new structural safe-life limits.

You may examine the MCAI in the AD docket on the internet at http://www.regulations.gov by searching for and locating Docket No. FAA-2018-0801.

Related Service Information Under 1 CFR Part 51

Bombardier has issued the following service information.

• Bombardier Service Bulletin 601R-57-046, Revision C, dated December 20, 2012, describes the cold working of fastener holes in the MLG trunnion fitting, and related investigative and corrective actions.
• Bombardier Service Bulletin 601R-57-047, Revision B, dated October 2, 2012, describes the installation of forcemate bushings in the MLG trunnion, and related investigative and corrective actions.
• Bombardier Service Bulletin 601R-57-048, Revision C, dated June 6, 2013, describes the cold working of holes on the web of the MLG trunnion, and related investigative and corrective actions.

These documents are distinct because they apply to different parts of the airplane.

The following service information describes certain AWL tasks for the MLG trunnion fitting assembly.

• Bombardier Maintenance Requirements Manual Temporary Revision (TR) 2B-2237, dated June 19, 2014.
• Bombardier Maintenance Requirements Manual Temporary Revision (TR) 2B-2238, dated June 19, 2014.
• Bombardier Maintenance Requirements Manual Temporary Revision (TR) 2B-2239, dated June 19, 2014.
• Bombardier Maintenance Requirements Manual Temporary Revision (TR) 2B-2241, dated June 19, 2014.
• Bombardier Maintenance Requirements Manual Temporary Revision (TR) 2B-2242, dated June 19, 2014.
• Bombardier Maintenance Requirements Manual Temporary Revision (TR) 2B-2246, dated November 7, 2014.

These documents are distinct because they describe different actions. This service information is reasonably available because the interested parties have access to it through their normal course of business or by the means identified in the ADDRESSES section.

FAA's Determination and Requirements of This Proposed AD

This product has been approved by the aviation authority of another country, and is approved for operation in the United States. Pursuant to our bilateral agreement with the State of Design Authority, we have been notified of the unsafe condition described in the MCAI and service information referenced above. We are proposing this AD because we evaluated all pertinent information and determined an unsafe condition exists and is likely to exist or develop on other products of the same type design.

This proposed AD would require 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 this proposed AD, 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 (p)(1) of this proposed AD. The request should include a description of changes to the required actions that will ensure the continued operational safety of the airplane.

Differences Between This Proposed AD and the Service Information

The MCAI includes the following statement: “If it is not possible to complete all of the instructions in the SBs . . . due to the configuration of the aircraft, contact Bombardier Inc. for approved instructions.” This issue is addressed in 14 CFR 39.17, which states that “If a change in a product affects your ability to accomplish the actions required by the AD in any way, you must request FAA approval of an AMOC [alternative method of compliance]. . . .” Since we do not currently have the authority to delegate AMOC approvals to foreign civil aviation authorities, the FAA is responsible for these approvals.

Costs of Compliance

We estimate that this proposed AD affects 460 airplanes of U.S. registry. We estimate the following costs to comply with this proposed AD:

Estimated Costs

Action	Labor cost	Parts cost	Cost per product	Cost on U.S. operators
Retained actions	1 work-hour × $85 per hour = $85	$0	>$85	$39,100.
Rework trunnion bearings (new proposed actions)	Up to 178 work-hours × $85 per hour = Up to $15,130	38,928	Up to $54,058	Up to $24,866,680.

We have determined that revising the maintenance or inspection program takes an average of 90 work-hours per operator, although we recognize that this number may vary from operator to operator. In the past, we have estimated that this action takes 1 work-hour per airplane. Since operators incorporate maintenance or inspection program changes for their affected fleet(s), we have determined that a per-operator estimate is more accurate than a per-airplane estimate. Therefore, we estimate the total cost per operator to be $7,650 (90 work-hours × $85 per work-hour).

We have received no definitive data that would enable us to provide cost estimates for the on-condition actions specified in this proposed AD.

According to the manufacturer, some or all of the costs of this AD may be covered under warranty, thereby reducing the cost impact on affected individuals. We do not control warranty coverage for affected individuals. As a result, we have included all costs in our cost estimate.

Authority for This Rulemaking

Title 49 of the United States Code specifies the FAA's authority to issue rules on aviation safety. Subtitle I, section 106, describes the authority of the FAA Administrator. “Subtitle VII: Aviation Programs,” describes in more detail the scope of the Agency's authority.

We are issuing this rulemaking under the authority described in “Subtitle VII, Part A, Subpart III, Section 44701: General requirements.” Under that section, Congress charges the FAA with promoting safe flight of civil aircraft in air commerce by prescribing regulations for practices, methods, and procedures the Administrator finds necessary for safety in air commerce. This regulation is within the scope of that authority because it addresses an unsafe condition that is likely to exist or develop on products identified in this rulemaking action.

This proposed AD is issued in accordance with authority delegated by the Executive Director, Aircraft Certification Service, as authorized by FAA Order 8000.51C. In accordance with that order, issuance of ADs is normally a function of the Compliance and Airworthiness Division, but during this transition period, the Executive Director has delegated the authority to issue ADs applicable to transport category airplanes to the Director of the System Oversight Division.

Regulatory Findings

We determined that this proposed AD would not have federalism implications under Executive Order 13132. This proposed AD would not have a substantial direct effect on the States, on the relationship between the national Government and the States, or on the distribution of power and responsibilities among the various levels of government.

For the reasons discussed above, I certify this proposed regulation:

1. Is not a “significant regulatory action” under Executive Order 12866,

2. Is not a “significant rule” under the DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979),

3. Will not affect intrastate aviation in Alaska, and

4. Will not have a significant economic impact, positive or negative, on a substantial number of small entities under the criteria of the Regulatory Flexibility Act.

List of Subjects in 14 CFR Part 39

• Air transportation
• Aircraft
• Aviation safety
• Incorporation by reference
• Safety

The Proposed Amendment

Accordingly, under the authority delegated to me by the Administrator, the FAA proposes to amend 14 CFR part 39 as follows:

PART 39—AIRWORTHINESS DIRECTIVES

1. The authority citation for part 39 continues to read as follows:

Authority: 49 U.S.C. 106(g), 40113, 44701.

§ 39.13

[Amended]

2. The FAA amends § 39.13 by removing Airworthiness Directive (AD) 2008-24-14, Amendment 39-15758 ( 73 FR 73785, December 4, 2008), and adding the following new AD:

Bombardier, Inc.: Docket No. FAA-2018-0801; Product Identifier 2017-NM-147-AD.

(a) Comments Due Date

We must receive comments by November 15, 2018.

(b) Affected ADs

This AD replaces AD 2008-24-14, Amendment 39-15758 (73 FR 73785, December 4, 2008) (“AD 2008-24-14”).

(c) Applicability

This AD applies to Bombardier, Inc., Model CL-600-2B19 (Regional Jet Series 100 & 440) airplanes, certificated in any category, serial numbers 7002 and subsequent.

(d) Subject

Air Transport Association (ATA) of America Code 57, Wings.

(e) Reason

This AD was prompted by reports of cracks on the main landing gear trunnion (MLG) fitting during fatigue testing, the introduction of new airworthiness limitation (AWL) tasks with revised inspection, modification, and safe-life requirements, and a determination that the trunnion fitting lower flange and both forward and aft bore holes are also subject to fatigue cracking. We are issuing this AD to detect and correct fatigue cracking of the MLG trunnion fitting. Failure of the MLG trunnion fitting web could compromise the structural integrity of the trunnion fitting and result in MLG collapse.

(f) Compliance

Comply with this AD within the compliance times specified, unless already done.

(g) Retained Revision of Airworthiness Limitation Section With No Changes

This paragraph restates the requirements of paragraph (f)(1) of AD 2008-24-14, with no changes. Within 30 days after December 19, 2008 (the effective date of AD 2008-24-14), revise the Airworthiness Limitations Section (ALS) of the Instructions for Continued Airworthiness to incorporate AWL 57-21-161, as identified in Bombardier Temporary Revision 2B-2136, dated May 1, 2008, to the Bombardier CL-600-2B19 Maintenance Requirements Manual, Part 2, Appendix B—Airworthiness Limitations. The initial compliance time for the task starts from the applicable time specified in table 1 or table 2 to paragraphs (g) and (j) of this AD, as applicable. Repeat the inspection thereafter at the applicable interval specified in Bombardier Temporary Revision 2B-2136, dated May 1, 2008.

(h) Retained No Alternative Actions or Intervals With New Exception

This paragraph restates the requirements of paragraph (f)(2) of AD 2008-24-14, with a new exception: Except as required by paragraph (i) of this AD, after accomplishing the actions specified in paragraph (g) of this AD, no alternative inspections or inspection intervals may be used unless the inspection or inspection interval is approved as an alternative method of compliance (AMOC) in accordance with the procedures specified in paragraph (p)(1) of this AD.

(i) New Requirement of This AD: Revision of Maintenance or Inspection Program

(1) Within 60 days after the effective date of this AD: Revise the maintenance or inspection program, as applicable, by incorporating the AWL tasks specified in figure 1 to paragraphs (i) and (o) of this AD. Except as specified in paragraph (j) of this AD, the initial compliance times for the tasks are at the applicable times specified in the temporary revisions (TRs) identified in figure 1 to paragraph (i) and (o) of this AD, or within 60 days after the effective date of this AD, whichever occurs later. When the information in AWL tasks identified in the TRs specified in figure 1 to paragraphs (i) and (o) of this AD has been included in the general revisions of Bombardier Maintenance Requirements Manual (MRM), CSP A-053, Part 2, Appendix B, the general revisions may be inserted in the MRM, and the TRs may be removed.

(2) Within 60 days after the effective date of this AD: Revise the maintenance or inspection program, as applicable, by removing the AWL tasks specified in figure 2 to paragraph (i) of this AD.

(j) New Requirement of This AD: Initial Compliance Times for AWL Tasks

(1) For AWL 57-21-161, the compliance time for the initial inspection of AWL 57-21-161 is as specified in tables 1 or 2 to paragraphs (g) and (j) of this AD, as applicable; or within 60 days after the effective date of this AD, whichever occurs later.

(2) For AWL 57-21-161, the compliance time for the limitation section is at the applicable time specified in AWL 57-21-161 or within 2,000 flight cycles after the effective date of this AD, whichever occurs later.

(3) For AWL 57-21-145 and AWL 57-21-155, the compliance times for the initial inspections are at the applicable times specified in AWL 57-21-145 and AWL 57-21-155 or within 2,000 flight cycles after the effective date of this AD, whichever occurs later.

(k) New Requirement of This AD: No Alternative Actions or Intervals

After the maintenance or inspection program has been revised as required by paragraph (i) of this AD, no alternative actions (e.g., inspections) or intervals may be used unless the actions or intervals are approved as an alternative method of compliance (AMOC) in accordance with the procedures specified in paragraph (p)(1) of this AD.

(l) New Requirement of This AD: Rework of MLG Trunnion To Meet Structural Safe-Life Limits

Except as specified in paragraphs (m)(1) and (m)(2) of this AD: Within the phase-in times specified in paragraphs (j)(2) and (j)(3) of this AD, rework the MLG trunnion in accordance with the Accomplishment Instructions of the service information identified in paragraphs (l)(1) through (l)(3) of this AD, as applicable.

(1) Bombardier Service Bulletin 601R-57-046, Revision C, dated December 20, 2012, for the cold working of fastener holes in the MLG trunnion fitting, and related investigative and corrective actions.

(2) Bombardier Service Bulletin 601R-57-047, Revision B, dated October 2, 2012, for the installation of forcemate bushings in the MLG trunnion, and related investigative and corrective actions.

(3) Bombardier Service Bulletin 601R-57-048, Revision C, dated June 6, 2013, for the cold work of holes on the web of the MLG trunnion, and related investigative and corrective actions.

(m) Exceptions to Rework Requirements

(1) For airplanes on which Bombardier Service Bulletin 601R-57-046, Revision A, dated December 21, 2009; or Bombardier Service Bulletin 601R-57-046, Initial Issue, dated July 17, 2009; was accomplished prior to the effective date of this AD: Within 6 months after the effective date of this AD, do Part G of the Accomplishment Instructions of Bombardier Service Bulletin 601R-57-046, Revision C, dated December 20, 2012.

(2) For airplanes on which Bombardier Service Bulletin 601R-57-048, Revision A, dated November 24, 2009; or Bombardier Service Bulletin 601R-57-048, Initial Issue, dated July 17, 2009; was accomplished prior to the effective date of this AD: Within 6 months after the effective date of this AD, do Part C of the Accomplishment Instructions of Bombardier Service Bulletin 601R-57-048, Revision C, dated June 6, 2013.

(n) Credit for Previous Actions

(1) This paragraph provides credit for actions required by paragraph (l)(1) of this AD, if those actions were performed before the effective date of this AD, using Bombardier Service Bulletin 601R-57-046, Revision B, dated August 24, 2012.

(2) This paragraph provides credit for actions required by paragraph (l)(2) of this AD, if those actions were performed before the effective date of this AD, using the service information specified in paragraph (n)(2)(i) or (n)(2)(ii) of this AD.

(i) Bombardier Service Bulletin 601R-57-047, Revision A, dated February 1, 2012.

(ii) Bombardier Service Bulletin 601R-57-047, Initial Issue, dated June 29, 2011.

(3) This paragraph provides credit for actions required by paragraph (l)(3) of this AD, if those actions were performed before the effective date of this AD, using Bombardier Service Bulletin 601R-57-048, Revision B, dated August 24, 2012.

(4) This paragraph provides credit for actions required by paragraph (m)(1) of this AD, if those actions were performed before the effective date of this AD, using Part G of the Accomplishment Instructions of Bombardier Service Bulletin 601R-57-046, Revision B, dated August 24, 2012.

(5) This paragraph provides credit for actions required by paragraph (m)(2) of this AD, if those actions were performed before the effective date of this AD, using Part C of the Accomplishment Instructions of Bombardier Service Bulletin 601R-57-048, Revision B, dated August 24, 2012.

(o) Repairs and Alternative Actions or Intervals

(1) If any damage is found during an inspection required by the AWLs identified in figure 1 to paragraphs (i) and (o) of this AD, repair before further flight using a method approved by the Manager, New York ACO Branch, FAA; or Transport Canada Civil Aviation (TCCA); or Bombardier, Inc.'s TCCA Design Approval Organization (DAO). If approved by the DAO, the approval must include the DAO-authorized signature. The approved repair instructions must specifically refer to this AD or Canadian AD CF-2017-27, dated August 2, 2017.

(2) Repairs approved by Bombardier, Inc., that deviate from the AWLs identified in figure 1 to paragraphs (i) and (o) of this AD are acceptable methods of compliance if approved by the Manager, New York ACO Branch, FAA; or TCCA; or Bombardier, Inc.'s TCCA DAO. If approved by the DAO, the approval must include the DAO-authorized signature. The approved repair instructions must specifically refer to this AD or Canadian AD CF-2017-27, dated August 2, 2017.

(3) For repairs approved before the effective date of this AD that affect the AWLs identified in figure 1 to paragraphs (i) and (o) of this AD and the approved repair instructions do not specifically refer to Canadian AD CF-2017-27, dated August 2, 2017: Within 6 months of the effective date of this AD, contact the Manager, New York ACO Branch, FAA; or TCCA; or Bombardier, Inc.'s TCCA DAO Inc., for new or revised limitations or inspection requirements on the repair area and comply with the revised limitations or inspections requirements. The new or revised limitations or inspection requirements must specifically refer to this AD or Canadian AD CF-2017-27, dated August 2, 2017.

(4) Canadian AMOC No. AARDG-2018/A21, dated May 1, 2018, which was approved before the effective date of this AD by TCCA, is an acceptable method of compliance to the corresponding requirements of this AD.

(p) Other FAA AD Provisions

(1) Alternative Methods of Compliance (AMOCs): The Manager, New York 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 ATTN: Program Manager, Continuing Operational Safety, FAA, New York ACO Branch, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; telephone [phone]; fax [phone]. 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.

(2) Contacting the Manufacturer: For any requirement in this AD to obtain corrective actions from a manufacturer, the action must be accomplished using a method approved by the Manager, New York ACO Branch, FAA; or TCCA; or Bombardier, Inc.'s TCCA DAO. If approved by the DAO, the approval must include the DAO-authorized signature. The approved corrective action instructions must specifically refer to this AD or Canadian AD CF-2017-27, dated August 2, 2017.

(q) Related Information

(1) Refer to Mandatory Continuing Airworthiness Information (MCAI) Canadian Airworthiness Directive CF-2017-27, dated August 2, 2017, for related information. This MCAI may be found in the AD docket on the internet at http://www.regulations.gov by searching for and locating Docket No. FAA-2018-0801.

(2) For more information about this AD, contact Aziz Ahmed, Aerospace Engineer, Airframe and Mechanical Systems Section, FAA, New York ACO Branch, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; telephone [phone]; fax [phone].

(3) For service information identified in this AD, contact Bombardier, Inc., 400 Côte-Vertu Road West, Dorval, Québec H4S 1Y9, Canada; Widebody Customer Response Center North America toll-free telephone [phone] or direct-dial telephone [phone]; fax [phone]; email [e-mail]; internet http://www.bombardier.com. You may view this service information at the FAA, Transport Standards Branch, 2200 South 216th St., Des Moines, WA. For information on the availability of this material at the FAA, call 206-231-3195.

Issued in Des Moines, Washington, on September 11, 2018.

Michael Kaszycki,

Acting Director, System Oversight Division, Aircraft Certification Service.