2023-25494. Airworthiness Directives; MHI RJ Aviation ULC (Type Certificate Previously Held by Bombardier, Inc.) Airplanes

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Final rule.

SUMMARY:

The FAA is adopting a new airworthiness directive (AD) for all MHI RJ Aviation ULC Model CL–600–2B19 (Regional Jet Series 100 & 440) airplanes. This AD was prompted by a report of missing insulation in the engine pylon area. This AD requires, for certain airplanes, inspecting the engine pylon structure for discrepancies and repair if necessary. This AD also requires revising the existing maintenance or inspection program, as applicable, to incorporate a new certification maintenance requirement (CMR) task. The FAA is issuing this AD to address the unsafe condition on these products.

DATES:

This AD is effective December 26, 2023.

The Director of the Federal Register approved the incorporation by reference of certain publications listed in this AD as of December 26, 2023.

ADDRESSES:

AD Docket: You may examine the AD docket at regulations.gov under Docket No. FAA–2023–1404; or in person at Docket Operations between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The AD docket contains this final rule, the mandatory continuing airworthiness information (MCAI), any comments received, and other information. The address for Docket Operations is U.S. Department of Transportation, Docket Operations, M–30, West Building Ground Floor, Room W12–140, 1200 New Jersey Avenue SE, Washington, DC 20590.

Material Incorporated by Reference:

• For service information identified in this final rule, contact MHI RJ Aviation Group, Customer Response Center, 3655 Ave. des Grandes-Tourelles, Suite 110, Boisbriand, Québec J7H 0E2 Canada; North America toll-free telephone [phone] or direct-dial telephone [phone]; email: [e-mail]; website: mhirj.com.

• You may view this service information at the FAA, Airworthiness Products Section, Operational Safety Branch, 2200 South 216th St., Des Moines, WA. For information on the availability of this material at the FAA, call 206–231–3195. It is also available at regulations.gov under Docket No. FAA–2023–1404.

FOR FURTHER INFORMATION CONTACT:

Fatin Saumik, Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; telephone [phone]; email [e-mail].

SUPPLEMENTARY INFORMATION:

Background

The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 by adding an AD that would apply to all MHI RJ Aviation ULC Model CL–600–2B19 (Regional Jet Series 100 & 440) airplanes. The NPRM published in the Federal Register on July 12, 2023 (88 FR 44226). The NPRM was prompted by AD CF–2023–19, dated March 13, 2023 (Transport Canada AD CF–2023–19) (also referred to after this as the MCAI), issued by Transport Canada, which is the aviation authority for Canada. The MCAI states there was a report of a missing 12-inch piece of insulation in the 14th stage bleed ducts installed in both left hand (LH) and right hand (RH) engine pylon areas.

In the NPRM, the FAA proposed to require, for certain airplanes, inspecting the engine pylon structure for discrepancies and repair if necessary. The NPRM also proposed to require revising the existing maintenance or inspection program, as applicable, to incorporate a new CMR task.

The FAA is issuing this AD to address missing or damaged insulation in the engine pylon area. The unsafe condition, if not addressed, could result in the bleed duct to radiate heat to the surrounding structure and, if not corrected, could lead to the loss of the structural integrity of the engine pylon and possible loss of the engine.

You may examine the MCAI in the AD docket at regulations.gov under Docket No. FAA–2023–1404.

Discussion of Final Airworthiness Directive

Comments

The FAA received comments from Air Line Pilots Association, International (ALPA) who supported the NPRM without change.

The FAA received additional comments from Air Wisconsin Airlines and MHI RJ Aviation ULC (MHI RJ). The following presents the comments received on the NPRM and the FAA's response to each comment.

Request To Refer New Temporary Revision

MHI RJ requested that the FAA revise the proposed AD to refer to MHI RJ Temporary Revision 2A–77, dated May 8, 2023, which was issued to revise the phase-in (initial) compliance time in MHI RJ Temporary Revision 2A–76, dated September 29, 2022, from 40 months to 48 months.

The FAA concurs with the request and has revised paragraph (h) of this AD to refer to MHI RJ Temporary Revision 2A–77, dated May 8, 2023, for the new CMR task. The FAA has also provided credit for using MHI RJ Temporary Revision 2A–76, dated September 29, 2022, in paragraph (j)(2) of this AD. The CMR task and interval is the same in both temporary revisions. In addition, there is no change to initial compliance time because paragraph (j) of the proposed AD did not refer to MHI RJ Temporary Revision 2A–76, dated September 29, 2022, for the initial compliance time and instead specified “The initial compliance time for doing the task is within 48 months or 6,600 flight hours, whichever occurs first after the effective date of this AD.” The compliance time change in MHI RJ Temporary Revision 2A–77, dated May 8, 2023, is within the initial compliance time specified in this AD.

Request To Revise Compliance Time

MHI RJ stated it noticed that the FAA is re-starting the clock in paragraph (h) of the proposed AD from the effective date of the AD rather than the issue date of the temporary revision: MHI RJ states that the task interval should start from September 29, 2022, which is the issue date of MHI RJ Temporary Revision 2A–76. MHI RJ stated that, in this particular case, the start of the compliance from September 29, 2022, is critical for safety. The FAA infers that MHI RJ is requesting that the agency reduce the initial compliance time specified in paragraph (h) of this AD by referring to the September 29, 2022, date instead of the effective date of this AD.

The FAA acknowledges MHI RJ's concern. However, reducing the compliance time in paragraph (h) of this AD would result in a more restrictive compliance time that would necessitate issuing a supplemental NPRM, delaying the issuance of the final rule. Since the detailed visual inspection of spar FS654.50, spar FS672.20, and the firewall for discrepancies specified in paragraph (g) of this AD would be delayed if a supplemental NPRM is issued, any increase in the level of safety by reducing the compliance time in paragraph of (h) of this AD may be offset by delaying the inspections in paragraph (g) of this AD. The FAA has determined to delay this action is not appropriate in this case as the compliance times in this AD will ensure an acceptable level of safety.

Request To Clarify Compliance Time

Air Wisconsin Airlines asked if the “40 months” specified in MHI RJ Temporary Revision 2A–76, dated September 29, 2022, is in error. Air Wisconsin Airlines noted that both paragraphs (g) and (h) of the proposed AD mention “within 48 months.”

The FAA agrees to clarify. As stated previously, MHI RJ Temporary Revision 2A–76, dated September 29, 2022, was revised by MHI RJ Temporary Revision 2A–77, dated May 8, 2023, to correct the “40 months” and change it to “48 months.” The FAA has not changed this AD in this regard.

Request To Revise Language in Paragraph (e) of the Proposed AD

MHI RJ requested that the proposed AD should not only mention missing insulation but damaged insulation as well and stated the sentence in paragraph (e) of the proposed AD should read: “The FAA is issuing this AD to address missing or damaged insulation in the engine pylon area.”

The FAA concurs and has revised paragraph (e) of this AD accordingly. The tasks associated with the new CMR task specifies inspecting for damaged insulation as well as missing insulation. Therefore, it is accurate to state that the FAA is issuing this AD to address both conditions.

Conclusion

This product has been approved by the aviation authority of another country and is approved for operation in the United States. Pursuant to the FAA's bilateral agreement with this State of Design Authority, it has notified the FAA of the unsafe condition described in the MCAI referenced above. The FAA reviewed the relevant data, considered the comments received, and determined that air safety requires adopting this AD as proposed. Accordingly, the FAA is issuing this AD to address the unsafe condition on this product. Except for minor editorial changes, and any other changes described previously, this AD is adopted as proposed in the NPRM. None of the changes will increase the economic burden on any operator.

Related Service Information Under 1 CFR Part 51

The FAA reviewed MHI RJ Service Bulletin 601R–54–006, Revision A, dated May 24, 2023. This service information specifies procedures for doing a detailed visual inspection of spar FS654.50, spar FS672.20, and the firewall for discrepancies, including corrosion, cracks, web waviness or flatness and damaged fasteners.

The FAA reviewed MHI RJ Temporary Revision 2A–77, dated May 8, 2023. This service information specifies a new CMR task, number C36–12–133–01, “Detailed Visual Inspection for missing insulation/heat shield on the 14th stage bleed duct, running through the pylon area between FS654 and FS672.”

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.

Costs of Compliance

The FAA estimates that this AD affects 338 airplanes of U.S. registry. The FAA estimates the following costs to comply with this AD:

Estimated Costs for Required Actions *

Labor cost	Parts cost	Cost per product	Cost on U.S. operators
6 work-hours × $85 per hour = $510	$0	$510	$172,380
* This table does not include the cost of revising the existing maintenance or inspection program.

The FAA has determined that revising the existing maintenance or inspection program takes an average of 90 work-hours per operator, although the agency recognizes that this number may vary from operator to operator. Since operators incorporate maintenance or inspection program changes for their affected fleet(s), the FAA has determined that a per-operator estimate is more accurate than a per-airplane estimate. Therefore, the agency estimates the average total cost per operator to be $7,650 (90 work-hours × $85 per work-hour).

The FAA has received no definitive data on which to base the cost estimates for the on-condition repairs specified in this AD.

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.

The FAA is 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.

Regulatory Findings

This AD will not have federalism implications under Executive Order 13132. This AD will 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 that this AD:

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

(2) Will not affect intrastate aviation in Alaska, and

(3) 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 Amendment

Accordingly, under the authority delegated to me by the Administrator, the FAA amends 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 adding the following new airworthiness directive:

2023–21–12 MHI RJ Aviation ULC (Type Certificate Previously Held by Bombardier, Inc.): Amendment 39–22584; Docket No. FAA–2023–1404; Project Identifier MCAI–2023–00451–T.

(a) Effective Date

This airworthiness directive (AD) is effective December 26, 2023.

(b) Affected ADs

None.

(c) Applicability

This AD applies to all MHI RJ Aviation ULC (Type Certificate previously held by Bombardier, Inc.) Model CL–600–2B19 (Regional Jet Series 100 & 440) airplanes, certificated in any category.

(d) Subject

Air Transport Association (ATA) of America Code: 36, Pneumatic.

(e) Unsafe Condition

This AD was prompted by a report of missing insulation in the engine pylon area. The FAA is issuing this AD to address missing or damaged insulation in the engine pylon area. The unsafe condition, if not addressed, could result in the bleed duct to radiate heat to the surrounding structure and, if not corrected, could lead to the loss of the structural integrity of the engine pylon and possible loss of the engine.

(f) Compliance

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

(g) Detailed Visual Inspection

For airplanes having serial numbers 7031, 7045, 7069, 7078, 7089, 7102, 7110, 7168, 7188, 7203, 7212, 7217, 7229, 7231, 7236, 7243, 7257, 7258, 7269, 7271, 7276, 7284, 7290, 7302, 7304, 7306, 7310, 7328, 7339, 7342, 7355, 7358, 7360, 7401, 7404, 7437, 7441, 7448, 7458, 7474, 7476, 7479, 7495, 7502, 7503, 7517, 7527, 7530, 7532, 7548, 7551, 7574, 7575, 7579, 7582, 7586, 7588, 7599, 7600, 7606, 7609, 7623, 7632, 7648, 7657, 7658, 7664, 7667, 7674, 7681, 7682, 7683, 7687, 7715, 7727, 7743, 7748, 7749, 7750, 7758, 7760, 7769, 7780, 7810, 7817, 7818, 7821, 7822, 7857, 7859, 7871, 7873, 7889, 7892, 7895, 7909, 7912, 7913, 7920, 7922, 7923, 7926, 7929, 7932, 7935, 7937, 7954, 7961, 7964, and 8011: Within 48 months or 6,600 flight hours, whichever occurs first after the effective date of this AD, do a detailed visual inspection for discrepancies of spar FS654.50, spar FS672.20, and the firewall, in accordance with Section 2.B. of the Accomplishment Instructions of MHI RJ Service Bulletin 601R–54–006, Revision A, dated May 24, 2023. If any discrepancies are found, before further flight, repair using a method approved by the Manager, International Validation Branch, FAA; or Transport Canada or MHI RJ Aviation ULC's Transport Canada Design Approval Organization (DAO). If approved by the DAO, the approval must include the DAO-authorized signature.

(h) Maintenance or Inspection Program Revision

Within 60 days after the effective date of this AD, revise the existing maintenance or inspection program, as applicable, to incorporate the information specified in MHI RJ Temporary Revision 2A–77, dated May 8, 2023, for certification maintenance requirements task number C36–12–133–01. The initial compliance time for doing the task is within 48 months or 6,600 flight hours, whichever occurs first after the effective date of this AD.

(i) No Alternative Actions or Intervals

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

(j) Credit for Previous Actions

(1) This paragraph provides credit for actions required by paragraph (g) of this AD, if those actions were performed before the effective date of this AD using MHI RJ Service Bulletin 601R–54–006, dated September 13, 2022.

(2) This paragraph provides credit for actions required by paragraph (h) of this AD, if those actions were performed before the effective date of this AD using MHI RJ Temporary Revision 2A–76, dated September 29, 2022.

(k) Additional AD Provisions

The following provisions also apply to this AD:

(1) Alternative Methods of Compliance (AMOCs): The Manager, International Validation 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 responsible Flight Standards Office, as appropriate. If sending information directly to the manager, International Validation Branch, mail it to the address identified in paragraph (l)(2) of this AD or email to: [e-mail]. Before using any approved AMOC, notify your appropriate principal inspector, or lacking a principal inspector, the manager of the responsible Flight Standards Office.

(2) Contacting the Manufacturer: For any requirement in this AD to obtain instructions from a manufacturer, the instructions must be accomplished using a method approved by the Manager, International Validation Branch, FAA; or Transport Canada or MHI RJ Aviation ULC's Transport Canada DAO. If approved by the DAO, the approval must include the DAO-authorized signature.

(l) Additional Information

(1) Refer to Transport Canada AD CF–2023–19, dated March 13, 2023, for related information. This Transport Canada AD may be found in the AD docket at regulations.gov under Docket No. FAA–2023–1404.

(2) For more information about this AD, contact Fatin Saumik, Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; telephone [phone]; email [e-mail].

(m) Material Incorporated by Reference

(1) The Director of the Federal Register approved the incorporation by reference 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 this AD specifies otherwise.

(i) MHI RJ Service Bulletin 601R–54–006, Revision A, dated May 24, 2023.

(ii) MHI RJ Temporary Revision 2A–77, dated May 8, 2023.

(3) For service information identified in this AD, contact MHI RJ Aviation Group, Customer Response Center, 3655 Ave. des Grandes-Tourelles, Suite 110, Boisbriand, Québec J7H 0E2 Canada; North America toll-free telephone [phone] or direct-dial telephone [phone]; email: [e-mail]; website: mhirj.com.

(4) You may view this service information at the FAA, Airworthiness Products Section, Operational Safety Branch, 2200 South 216th Street, Des Moines, WA. For information on the availability of this material at the FAA, call 206–231–3195.

(5) You may view this material at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, visit www.archives.gov/​federal-register/​cfr/​ibr-locations or email [e-mail].

Issued on October 20, 2023.

Ross Landes,

Deputy Director for Regulatory Operations, Compliance & Airworthiness Division, Aircraft Certification Service.