Airworthiness Directives; The Boeing Company Airplanes

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

The FAA proposes to adopt a new airworthiness directive (AD) for all The Boeing Company Model 707 and Model 727 airplanes. This proposed AD was prompted by a report indicating cracking in fastener holes at the center wing box and at certain positions of the rear spar and lower skin on a Model 737-300 airplane. A cross model review determined that similar cracking of the fastener holes in the center wing box lower skin could occur on Model 707 and Model 727 airplanes. For Model 707 airplanes this proposed AD would require repetitive detailed inspections of the center wing box lower skin for cracking and repetitive high frequency eddy current (HFEC) and ultrasonic (UT) inspections of the rear spar lower chord at a certain position for cracking, repetitive sealant application, and repair if necessary. For Model 727 airplanes this proposed AD would require repetitive detailed inspections of the center wing box, lower skin, and rear spar lower chord at a certain location for cracking, repetitive sealant application, and repair if necessary. The FAA is proposing this AD to address the unsafe condition on these products.

DATES:

The FAA must receive comments on this proposed AD by October 31, 2022.

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 https://www.regulations.gov. Follow the instructions for submitting comments.

• Fax: 202-493-2251.

• 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 Boeing Commercial Airplanes, Attention: Contractual & Data Services (C&DS), 2600 Westminster Blvd., MC 110-SK57, Seal Beach, CA 90740-5600; telephone 562-797-1717; internet https://www.myboeingfleet.com. You may view this referenced 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 https://www.regulations.gov by searching for and locating Docket No. FAA-2022-1051.

Examining the AD Docket

You may examine the AD docket at https://www.regulations.gov by searching for and locating Docket No. FAA-2022-1051; 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 NPRM, any comments received, and other information. The street address for Docket Operations is listed above.

FOR FURTHER INFORMATION CONTACT:

Sean Newell, Aerospace Engineer, Airframe Section, FAA, Los Angeles ACO Branch, 3960 Paramount Boulevard, Lakewood, CA 90712-4137; phone: 562-627-5266; email: Sean.M.Newell@faa.gov.

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-2022-1051; Project Identifier AD-2022-00089-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 amend 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 https://www.regulations.gov, including any personal information you provide. The agency will also post a report summarizing each substantive verbal contact received about this NPRM.

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 NPRM 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 NPRM, 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 NPRM. Submissions containing CBI should be sent to Sean Newell, Aerospace Engineer, Airframe Section, FAA, Los Angeles ACO Branch, 3960 Paramount Boulevard, Lakewood, CA 90712-4137; phone: 562-627-5266; email: Sean.M.Newell@faa.gov. 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 received a report from an operator of a Model 737-300 airplane indicating cracking in fastener holes at the center wing box, station 663.75 rear spar, lower skin located at left body buttock line (LBBL) 6.50. The lower skin cracks were hidden between the center wing box lower chord on the upper surface and the keel beam upper chord on the lower surface. The Model 737-300 airplane had a total of 72,702 flight hours and 44,369 flight cycles at the time of the finding. A cross model review determined that similar cracking of the fastener holes in the center wing box lower skin could occur on Model 707 and Model 727 airplanes. The FAA is issuing this AD to address cracking in the center wing box lower skin or rear spar lower chord, which could result in the inability of the structure to sustain limit load and adversely affect the structural integrity of the airplane.

FAA's Determination

The FAA is issuing this NPRM after determining that the unsafe condition described previously is likely to exist or develop on other products of the same type design.

Explanation of Applicability

Model 727-100 airplanes having line numbers 1 through 47 have a limit of validity (LOV) of 50,000 total flight cycles, and the actions proposed in this NPRM, as specified in Boeing Alert Requirements Bulletin 727-57A0190 RB, dated September 13, 2021, would be required at a compliance time occurring after that LOV. Although operation of an airplane beyond its LOV is prohibited by 14 CFR 121.1115 and 129.115, this NPRM would include those airplanes in the applicability so that these airplanes are tracked in the event the LOV is extended in the future.

Related Service Information Under1 CFR Part 51

The FAA reviewed Boeing 707 Alert Requirements Bulletin A3544 RB, dated November 1, 2021. This service information specifies procedures for repetitive internal detailed inspections of the center wing box lower skin for cracking and repetitive internal surface HFEC and UT inspections of the rear spar lower chord between LBBL 40 and right body buttock line (RBBL) 40 for cracking, repetitive sealant application, and repair.

The FAA reviewed Boeing Alert Requirements Bulletin 727-57A0190 RB, dated September 13, 2021. This service information specifies procedures for repetitive internal detailed inspections for cracking of the center wing box, lower skin, and rear spar lower chord between LBBL 34.7 and RBBL 34.7, repetitive sealant application, and repair.

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 NPRM

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 https://www.regulations.gov by searching for and locating Docket No. FAA-2022-1051.

Costs of Compliance

The FAA estimates that this AD, if adopted as proposed, would affect 48 airplanes of U.S. registry. The FAA estimates the following costs to comply with this proposed AD:

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

2. The FAA amends § 39.13 by adding the following new airworthiness directive:

The Boeing Company: Docket No. FAA-2022-1051; Project Identifier AD-2022-00089-T.

(a) Comments Due Date

The FAA must receive comments on this airworthiness directive (AD) by October 31, 2022.

(b) Affected ADs

None.

(c) Applicability

This AD applies to The Boeing Company airplanes specified in paragraphs (c)(1) through (3) of this AD, certificated in any category.

(1) Model 707-100 Long Body, -200, -100B Long Body, and -100B Short Body series airplanes.

(2) Model 707-300, -300B, -300C, and -400 series airplanes.

(3) Model 727, 727C, 727-100, 727-100C, 727-200, and 727-200F series airplanes.

(d) Subject

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

(e) Unsafe Condition

This AD was prompted by a report indicating cracking in fastener holes at the center wing box and at certain positions of the rear spar and lower skin on a Model 737-300 airplane. A cross model review determined that similar cracking of the fastener holes in the center wing box lower skin could occur on Model 707 and Model 727 airplanes. The FAA is issuing this AD to address cracking in the center wing box lower skin or rear spar lower chord, which could result in the inability of the structure to sustain limit load and adversely affect the structural integrity of the airplane.

(f) Compliance

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

(g) Required Actions for Group 1 Model 727 Airplanes

For airplanes identified as Group 1 in Boeing Alert Requirements Bulletin 727-57A0190 RB, dated September 13, 2021: Within 120 days after the effective date of this AD, inspect the airplane and do all applicable on-condition actions using a method approved in accordance with the procedures specified in paragraph (j) of this AD.

(h) Required Actions for Groups 2 and 3 Model 727 Airplanes and All Model 707 Airplanes

Except as specified by paragraph (i) of this AD: At the applicable times specified in the “Compliance” paragraph of Boeing 707 Alert Requirements Bulletin A3544 RB, dated November 1, 2021; or Boeing Alert Requirements Bulletin 727-57A0190 RB, dated September 13, 2021; as applicable, do all applicable actions identified in, and in accordance with, the Accomplishment Instructions of Boeing 707 Alert Requirements Bulletin A3544 RB, dated November 1, 2021; or Boeing Alert Requirements Bulletin 727-57A0190 RB, dated September 13, 2021, as applicable.

Note 1 to paragraph (h): Guidance for accomplishing the actions required by this AD can be found in Boeing 707 Alert Service Bulletin A3544, dated November 1, 2021, which is referred to in Boeing 707 Alert Requirements Bulletin A3544 RB, dated November 1, 2021; and Boeing Alert Service Bulletin 727-57A0190, dated September 13, 2021, which is referred to in Boeing Alert Requirements Bulletin 727-57A0190 RB, dated September 13, 2021.

(i) Exceptions to Service Information Specifications

(1) Where the Compliance Time columns of the tables in the “Compliance” paragraph of Boeing 707 Alert Requirements Bulletin A3544 RB, dated November 1, 2021, uses the phrase “the original issue date of Requirements Bulletin 707A3544 RB” this AD requires using “the effective date of this AD.”

(2) Where the Compliance Time columns of the tables in the “Compliance” paragraph of Boeing Alert Requirements Bulletin 727-57A0190 RB, dated September 13, 2021, uses the phrase “the original issue date of Requirements Bulletin 727-57A0190 RB” this AD requires using “the effective date of this AD.”

(3) Where Boeing 707 Alert Requirements Bulletin A3544 RB, dated November 1, 2021, specifies contacting Boeing for repair instructions: This AD requires doing the repair using a method approved in accordance with the procedures specified in paragraph (j) of this AD.

(4) Where Boeing Alert Requirements Bulletin 727-57A0190 RB, dated September 13, 2021, specifies contacting Boeing for repair instructions: This AD requires doing the repair using a method approved in accordance with the procedures specified in paragraph (j) of this AD.

(j) Alternative Methods of Compliance (AMOCs)

(1) The Manager, Los Angeles 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 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 (k)(1) of this AD. Information may be emailed to: 9-ANM-LAACO-AMOC-Requests@faa.gov.

(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, Los Angeles ACO Branch, FAA, 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.

(k) Related Information

(1) For more information about this AD, contact Sean Newell, Aerospace Engineer, Airframe Section, FAA, Los Angeles ACO Branch, 3960 Paramount Boulevard, Lakewood, CA 90712-4137; phone: 562-627-5266; email: Sean.M.Newell@faa.gov.

(2) 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 562-797-1717; internet https://www.myboeingfleet.com. You may view this referenced 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.