2024-09019. Airworthiness Directives; The Boeing Company Airplanes

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Supplemental notice of proposed rulemaking (SNPRM).

SUMMARY:

The FAA is revising a notice of proposed rulemaking (NPRM) that applied to certain The Boeing Company Model 757-200, -200CB, and -200PF series airplanes. This action revises the NPRM by adding airplanes to the applicability. The FAA is proposing this airworthiness directive (AD) to address the unsafe condition on these products. Since these actions would impose an additional burden over that in the NPRM, the FAA is requesting comments on this SNPRM.

DATES:

The FAA must receive comments on this SNPRM by June 13, 2024.

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 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.

AD Docket: You may examine the AD docket at regulations.gov under Docket No. FAA-2023-1488; 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 SNPRM, any comments received, and other information. The street address for Docket Operations is listed above.

Material Incorporated by Reference:

• For service information identified in this SNPRM, contact Boeing Commercial Airplanes, Attention: Contractual & Data Services (C&DS), 2600 Westminster Blvd., MC 110-SK57, Seal Beach, CA 90740-5600; telephone [phone]; website myboeingfleet.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 by searching for and locating Docket No. FAA-2023-1488.

FOR FURTHER INFORMATION CONTACT:

Wayne Ha, Aviation Safety Engineer, FAA, 2200 South 216th Street, Des Moines, WA 98198; phone: [phone]; email: [e-mail].

SUPPLEMENTARY INFORMATION:

Comments Invited

The FAA invites you to send any written relevant data, views, or arguments about this proposal. Send your comments to an address listed under ADDRESSES . Include “Docket No. FAA-2023-1488; Project Identifier AD-2023-00182-T” at the beginning of your comments. The most helpful comments reference a specific portion of the proposal, explain the reason for any recommended change, and include supporting data. The FAA will consider all comments received by the closing date and may again revise this proposal because of those comments.

Except for Confidential Business Information (CBI) as described in the following paragraph, and other information as described in 14 CFR 11.35, the FAA will post all comments received, without change, to regulations.gov, including any personal information you provide. The agency will also post a report summarizing each substantive verbal contact received about this proposed AD.

Confidential Business Information

CBI is commercial or financial information that is both customarily and actually treated as private by its owner. Under the Freedom of Information Act (FOIA) (5 U.S.C. 552), CBI is exempt from public disclosure. If your comments responsive to this SNPRM contain commercial or financial information that is customarily treated as private, that you actually treat as private, and that is relevant or responsive to this SNPRM, it is important that you clearly designate the submitted comments as CBI. Please mark each page of your submission containing CBI as “PROPIN.” The FAA will treat such marked submissions as confidential under the FOIA, and they will not be placed in the public docket of this SNPRM. Submissions containing CBI should be sent to Wayne Ha, Aviation Safety Engineer, FAA, 2200 South 216th Street, Des Moines, WA 98198; phone: [phone]; email: [e-mail]. Any commentary that the FAA receives that is not specifically designated as CBI will be placed in the public docket for this rulemaking.

Background

The FAA issued an NPRM to amend 14 CFR part 39 by adding an AD that would apply to The Boeing Company Model 757-200, -200CB, and -200PF series airplanes. The NPRM published in the Federal Register on August 4, 2023 (88 FR 51745). The NPRM was prompted by a report of cracks found at the main deck cargo door cutout forward and aft hinge attachment holes. In the NPRM, the FAA proposed to require a maintenance record check for repairs at the forward and aft hinge areas of the main deck cargo door cutout; repetitive open-hole high frequency eddy current (HFEC) inspections for cracks in the unrepaired areas of the bear strap, skin, doubler, and upper sill chord at the main deck cargo door forward and aft hinge attachment holes; and corrective actions including obtaining and following procedures for alternative inspections and crack repairs.

Actions Since the NPRM Was Issued

Since the FAA issued the NPRM, the FAA determined that airplanes that have been modified from a passenger to a freighter configuration using VT Mobile Aerospace Engineering (VT MAE) Supplemental Type Certificate (STC) ST03562AT, ST03952AT, or ST04242AT were inadvertently omitted in the NPRM.

Comments

The FAA received comments from VT MAE, FedEx Express (FedEx), United Parcel Service (UPS), Boeing, Aviation Partners Boeing (APB), and two individuals. The following presents the comments received on the NPRM and the FAA's response to each comment.

Effect of Winglets on Accomplishment of the Proposed Actions

APB stated that accomplishing STC ST01518SE on 757-200 passenger airplanes that have been converted to freighters using Boeing STC ST00916WI-D does not affect the actions specified in the proposed rule.

The FAA agrees with the commenter. The FAA has redesignated paragraph (c) of the proposed AD as paragraph (c)(1) of this proposed AD and added paragraph (c)(2) of this proposed AD to state that installation of STC ST01518SE does not affect the ability to accomplish the actions required by this proposed AD. Therefore, for airplanes on which APB STC ST01518SE is installed, a “change in product” alternative method of compliance (AMOC) approval request is not necessary to comply with the requirements of 14 CFR 39.17.

Request To Add Actions for Certain Airplanes

FedEx asked for clarification regarding what actions should be done on its fleet. FedEx noted that its airplanes were converted to freighters using VT MAE STC ST03562AT and were not included in the proposed AD due to this conversion. FedEx stated that the intent of the proposed AD applies to its fleet since the STC is based on the design of Boeing 757-200 special freighter (SF) airplanes. VT MAE noted that the installation of the main deck cargo door hinge using VT MAE STCs ST03562AT, ST03952A, and ST04242AT is identical to Boeing 757-200 SF airplanes (those converted using Boeing STC ST00916WI-D). FedEx and VT MAE proposed to use the actions and compliance times specified for Group 2 airplanes as identified in Boeing Alert Requirements Bulletin 757-53A0106 RB, dated January 3, 2023, for airplanes modified under one of the specified VT MAE STCs. The commenters noted that this would include an initial action time related to the time since the aircraft was converted to a freighter.

The FAA agrees that the 757-200 airplanes that have been modified under VT MAE STCs ST03562AT, ST03952AT, and ST04242AT are affected by the identified unsafe condition and has revised paragraph (c)(1) of this proposed AD to include airplanes modified using those STCs. At this time, whether the VT MAE and Boeing STCs are identical in the areas affected by this proposed AD or using the compliance methods and times for Group 2 airplanes adequately addresses the identified unsafe condition has not been determined. Therefore, the FAA has redesignated paragraph (g) of the proposed AD as paragraph (g)(1) of this proposed AD and added paragraph (g)(2) of this proposed AD to specify the applicable compliance times and actions for those airplanes. However, under the provisions of paragraph (i) of this AD, the FAA will consider requests for alternative compliance times or methods if sufficient data are provided to substantiate the request. The FAA is seeking comments on the applicable compliance time and actions for airplanes modified with one of the identified VT MAE STCs. The applicable compliance times and actions for those airplanes may change depending upon comments and data the FAA may receive and review.

Request for Additional Information on Requirements and Unsafe Condition

Two individuals requested that the proposed AD specify the location and size of the liner holes that need to be inspected, as well as the acceptable tolerance for the hole diameter and the plug fit; guidance on how to repair cracks if they are found, such as the type and size of the fasteners, sealants, and patches to be used; a compliance time for the inspections and repairs, based on the number of flight cycles and flight hours of the airplane; and the reason for the unplugged liner holes and how they cause stress concentration and cracks. The commenters stated that this information would help operators to perform the inspections more accurately and consistently, ensure that the repairs are done in accordance with the Boeing standards and specifications, prioritize the most critical aircraft while preventing further crack propagation, and educate operators and maintenance personnel on how to prevent the problem.

The FAA agrees to clarify. The inspection requirements, compliance times, and repair instructions are addressed in Boeing Alert Requirements Bulletin 757-53A0106 RB, dated January 3, 2023, which is mandated by paragraph (g) of this proposed AD. This service information is available in the docket for interested parties. Additionally, the NPRM provided details on the cause of the identified unsafe condition and how to address it. No change is necessary to this proposed AD.

Request To Require Replacement of Skin Panel Under Certain Conditions

The individual commenters suggested that the proposed AD should specify that if the cracks exceed a specified maximum allowable length or maximum allowable width, as specified in the Boeing 757 Structural Repair Manual, then the affected area must be replaced with a new section of skin panel. The commenters added that the replacement procedure must follow any instructions and drawings provided by Boeing, the new section must be inspected for proper installation and fit, and the replacement must be done before further flight. One individual stated that the repair should be universal for all affected models.

The FAA does not agree with the commenters' request. If any crack is found, this proposed AD requires repairing it; there is no maximum allowable length or width for cracking. The crack repair instructions are addressed in Boeing Alert Requirements Bulletin 757-53A0106 RB, dated January 3, 2023, which is required by paragraph (g) of this proposed AD. If an operator finds any cracks, they must follow the procedures outlined in paragraph (h)(2) of this proposed AD to obtain customized repair instructions. No change is necessary to this proposed AD.

Request To Clarify Repairs Requiring Additional Actions

UPS requested that the FAA clarify the proposed AD regarding the repairs found during the required maintenance record check. UPS noted that Boeing Alert Requirements Bulletin 757-53A0106 RB, dated January 3, 2023, requires a maintenance record check for “any repair” at the forward and aft hinge areas of the main deck cargo door cutout. UPS stated that Boeing 757-200PF Structural Repair Manual (SRM) 53-00-01-1A-1 allows for smooth dents, edge and surface blends, and rivet plugging of lightning strike or small hole damage in accordance with SRM 53-00-01-2R-6. UPS added that rivet plugs using solid rivets are a Category A repair with no supplemental inspections, so any repairs within the SRM allowable limits and small damage repair do not appreciably affect damage tolerance of the fuselage skin at the door cutout and surround structure. Additionally, UPS noted the potential for non-reinforcing repairs (dents, blends, etc.) that are beyond SRM allowable limits but approved by Boeing to remain as-is without supplemental inspections. UPS stated that it believes the intent of the maintenance record check is to identify and report existing reinforcing and freeze plug repairs in the inspection areas that may affect damage tolerance of the skin and door surround structure. UPS added that Boeing confirmed this intent in Boeing Message SRID 4-5882455484. UPS therefore requested that the proposed AD be revised to require using “any reinforcing or freeze plug repair” in lieu of “any repair.”

The FAA does not agree with the commenter's request. The FAA has no way of knowing the type or extent of repairs that might be on a given airplane or how those repairs would impact the actions required by this AD. Therefore, any existing repair, including any non-reinforced repair, needs to be evaluated for any potential effect on the inspection requirements. No change is necessary to this proposed AD.

Request To Revise Certain Wording

Boeing requested the FAA to revise the Background section and paragraph (e) of the proposed AD to clarify the affected structure and align the wording with the service information. Boeing requested that verbiage regarding what prompted the proposed AD be revised to specify “cargo deck cutout” rather than “cargo deck.” Boeing also requested that verbiage regarding the possible effects of undetected cracks be revised to specify “cargo door hinge area” rather than “cargo door hinge.”.

The FAA agrees with the commenter's request. The FAA has revised the Background section and paragraph (e) of this proposed AD accordingly.

FAA's Determination

The FAA is proposing this AD after determining the unsafe condition described previously is likely to exist or develop in other products of the same type design. Certain changes described above expand the scope of the NPRM. As a result, it is necessary to reopen the comment period to provide additional opportunity for the public to comment on this SNPRM.

Related Service Information Under 1 CFR Part 51

The FAA reviewed Boeing Alert Requirements Bulletin 757-53A0106 RB, dated January 3, 2023. This service information specifies procedures for a maintenance record check for repairs at the forward and aft hinge areas of the main deck cargo door cutout; repetitive open-hole HFEC inspections for cracks in the unrepaired areas of the bear strap, skin, doubler, and upper sill chord at the main deck cargo door forward and aft hinge attachment holes; and corrective actions including obtaining and following procedures for alternative inspections and crack repairs.

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 ADDRESSES .

Proposed AD Requirements in This SNPRM

This proposed AD would require accomplishing the actions specified in the service information already described, except for any differences identified as exceptions in the regulatory text of this proposed AD. For information on the procedures and compliance times, see this service information at regulations.gov by searching for and locating Docket No. FAA-2023-1488.

Costs of Compliance

The FAA estimates that this AD, if adopted as proposed, would affect 564 airplanes of U.S. registry. The FAA estimates the following costs to comply with this proposed AD:

Estimated Costs

Action	Labor cost	Parts cost	Cost per product	Cost on U.S. operators
Maintenance record check	1 work-hour * × $85 per hour = $85	$0	$85	$47,940
HFEC inspections	26 work-hours × $85 per hour = $2,210, per inspection cycle	0	2,210 per inspection cycle	1,246,440 per inspection cycle
* The time to do the maintenance record check will vary by operator but would likely take no more than 1 work-hour per airplane.

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

The FAA 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) Would not affect intrastate aviation in Alaska, and

(3) Would 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 adding the following new airworthiness directive:

The Boeing Company: Docket No. FAA-2023-1488; Project Identifier AD-2023-00182-T.

(a) Comments Due Date

The FAA must receive comments on this airworthiness directive (AD) by June 13, 2024.

(b) Affected ADs

None.

(c) Applicability

(1) This AD applies to The Boeing Company Model 757-200, -200CB, and -200PF series airplanes specified in paragraph (c)(1)(i) or (ii) of this AD, certificated in any category.

(i) Airplanes identified in Boeing Alert Requirements Bulletin 757-53A0106 RB, dated January 3, 2023.

(ii) Airplanes converted to a freighter configuration using VT MAE Supplemental Type Certificate (STC) ST03562AT, ST03952AT, or ST04242AT.

(2) Installation of STC ST01518SE does not affect the ability to accomplish the actions required by this AD. Therefore, for airplanes on which STC ST01518SE is installed, a “change in product” alternative method of compliance (AMOC) approval request is not necessary to comply with the requirements of 14 CFR 39.17.

(d) Subject

Air Transport Association (ATA) of America Code 53, Fuselage.

(e) Unsafe Condition

This AD was prompted by a report indicating an operator has found cracks on three Model 757-200PF airplanes at the main deck cargo door cutout forward and aft hinge attachment holes. The FAA is issuing this AD to detect and correct cracks in the main deck cargo door hinge area. Undetected cracks in the main deck cargo door hinge area could result in reduced structural integrity of the aircraft.

(f) Compliance

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

(g) Required Actions

(1) For the airplanes identified in paragraph (c)(1)(i) of this AD: Except as specified by paragraph (h) of this AD, at the applicable times specified in the “Compliance” paragraph of Boeing Alert Requirements Bulletin 757-53A0106 RB, dated January 3, 2023, do all applicable actions identified in, and in accordance with, the Accomplishment Instructions of Boeing Alert Requirements Bulletin 757-53A0106 RB, dated January 3, 2023.

Note 1 to paragraph (g)(1): Guidance for accomplishing the actions required by this AD can be found in Boeing Alert Service Bulletin 757-53A0106, dated January 3, 2023, which is referred to in Boeing Alert Requirements Bulletin 757-53A0106 RB, dated January 3, 2023.

(2) For the airplanes identified in paragraph (c)(1)(ii) of this AD: Within 30 days after the effective date of this AD, do a maintenance record check for any repair at the forward and aft hinge areas of the main deck cargo door cutout and obtain inspection instructions and applicable repair instructions using a method approved by the Manager, AIR-520, Continued Operational Safety Branch, FAA. Comply with all applicable instructions at the time specified in the instructions.

(h) Exceptions to Service Information Specifications

(1) Where the Compliance Time columns of the tables in the “Compliance” paragraph of Boeing Alert Requirements Bulletin 757-53A0106 RB, dated January 3, 2023, use the phrase the original issue date of Requirements Bulletin 757-53A0106 RB, this AD requires using the effective date of this AD.

(2) Where Boeing Alert Requirements Bulletin 757-53A0106 RB, dated January 3, 2023, specifies contacting Boeing for repair instructions or for alternative inspections, this AD requires doing the repair, or doing the alternative inspections and applicable on-condition actions using a method approved in accordance with the procedures specified in paragraph (i) of this AD.

(i) Alternative Methods of Compliance (AMOCs)

(1) The Manager, AIR-520, Continued Operational Safety 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 of the certification office, send it to the attention of the person identified in paragraph (j)(1) of this AD. Information may be emailed to: [e-mail].

(2) Before using any approved AMOC, notify your appropriate principal inspector, or lacking a principal inspector, the manager of the responsible Flight Standards 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 The Boeing Company Organization Designation Authorization (ODA) that has been authorized by the Manager, AIR-520, Continued Operational Safety Branch, to make those findings. To be approved, the repair method, modification deviation, or alteration deviation must meet the certification basis of the airplane, and the approval must specifically refer to this AD.

(j) Related Information

(1) For more information about this AD, contact Wayne Ha, Aviation Safety Engineer, FAA, 2200 South 216th Street, Des Moines, WA 98198; phone: [phone]; email: [e-mail].

(2) Service information identified in this AD that is not incorporated by reference is available at the address specified in paragraph (k)(3) of this AD.

(k) 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) Boeing Alert Requirements Bulletin 757-53A0106 RB, dated January 3, 2023.

(ii) [Reserved]

(3) For service information identified in this AD, contact Boeing Commercial Airplanes, Attention: Contractual & Data Services (C&DS), 2600 Westminster Blvd., MC 110-SK57, Seal Beach, CA 90740-5600; telephone [phone]; website myboeingfleet.com.

(4) 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.

(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 April 23, 2024.

Victor Wicklund,

Deputy Director, Compliance & Airworthiness Division, Aircraft Certification Service.