E7-10045. Airworthiness Directives; Boeing Model 747-100, -200B, -200C, and -200F Series Airplanes

AGENCY:

Federal Aviation Administration (FAA), Department of Transportation (DOT).

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

The FAA proposes to adopt a new airworthiness directive (AD) for certain Boeing Model 747-100, -200B, -200C, and -200F series airplanes. This proposed AD would require performing repetitive inspections for cracks in the fuselage skin at the cutout of the bulk cargo door light, and corrective actions if necessary. This proposed AD also provides terminating action for airplanes with a certain type of damage. This proposed AD results from a report of a 2-inch crack through the fuselage skin and internal bonded doubler at the cutout of the bulk cargo door light. We are proposing this AD to detect and correct cracks in the fuselage skin at the cutout of the bulk cargo door light, which could result in reduced structural integrity of the fuselage at the bulk cargo door and consequent rapid decompression of the fuselage.

DATES:

We must receive comments on this proposed AD by July 9, 2007.

ADDRESSES:

Use one of the following addresses to submit comments on this proposed AD.

• DOT Docket Web site: Go to http://dms.dot.gov and follow the instructions for sending your comments electronically.
• Government-wide rulemaking Web site: Go to http://www.regulations.gov and follow the instructions for sending your comments electronically.
• Mail: Docket Management Facility, U.S. Department of Transportation, 400 Seventh Street, SW., Nassif Building, room PL-401, Washington, DC 20590.
• Fax: [phone].
• Hand Delivery: Room PL-401 on the plaza level of the Nassif Building, 400 Seventh Street SW., Washington, DC, between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays.

Contact Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124-2207, for the service information identified in this proposed AD.

FOR FURTHER INFORMATION CONTACT:

Ivan Li, Aerospace Engineer, Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone [phone]; fax [phone].

SUPPLEMENTARY INFORMATION:

Comments Invited

We invite you to submit any relevant written data, views, or arguments regarding this proposed AD. Send your comments to an address listed in the ADDRESSES section. Include the docket number “FAA-2007-28257; Directorate Identifier 2007-NM-034-AD” at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of the proposed AD. We will consider all comments received by the closing date and may amend the proposed AD in light of those comments.

We will post all comments we receive, without change, to http://dms.dot.gov, including any personal information you provide. We will also post a report summarizing each substantive verbal contact with FAA personnel concerning this proposed AD. Using the search function of that web site, anyone can find and read the comments in any of our dockets, including the name of the individual who sent the comment (or signed the comment on behalf of an association, business, labor union, etc.). You may review DOT's complete Privacy Act Statement in the Federal Register published on April 11, 2000 (65 FR 19477-78), or you may visit http://dms.dot.gov.

Examining the Docket

You may examine the AD docket on the Internet at http://dms.dot.gov, or in person at the Docket Management Facility office between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The Docket Management Facility office (telephone [phone]) is located on the plaza level of the Nassif Building at the DOT street address stated in the ADDRESSES section. Comments will be available in the AD docket shortly after the Docket Management System receives them.

Discussion

We have received a report indicating that a 2-inch crack through the fuselage skin and internal bonded doubler at the cutout of the bulk cargo door light was found during a visual fuselage skin inspection on a Model 747-200F series airplane. The crack was located at the forward lower corner of the cutout of the bulk cargo door light between stations 2060 and 2070, stringers 32R and 33R. The airplane had accumulated approximately 24,613 flight cycles and 99,339 flight hours. This condition, if not corrected, could result in reduced structural integrity of the fuselage at the bulk cargo door and consequent rapid decompression of the fuselage.

The subject area on certain Model 747-100, 200B, and -200C series airplanes is almost identical to that on the affected Model 747-200F series airplanes. Therefore, those airplanes are subject to the unsafe condition revealed on the Model 747-200F series airplane.

Relevant Service Information

We have reviewed Boeing Alert Service Bulletin 747-53A2673, dated February 8, 2007. The service bulletin describes procedures for repetitive high frequency eddy current (HFEC) inspections for cracks in the fuselage skin at the cutout of the bulk cargo door light, and corrective actions if necessary. The corrective actions are as follows:

• For airplanes on which a crack is found that is 2.0 inches or less in length from the edge of the light cutout forward lower corner, Part 2 of the Accomplishment Instructions of the service bulletin describes procedures for installing a repair filler, doubler, and tripler, and performing an additional HFEC inspection of the trim edge for cracks and repairing any crack. Accomplishing these corrective actions eliminates the need for the repetitive inspections.
• For airplanes on which a crack is found that is more than 2.0 inches in total length from the edge of the light cutout forward lower corner, or is at a location other than the light cutout forward lower corner, the service bulletin recommends contacting Boeing for repair instructions and doing the repair.

Accomplishing the actions specified in the service information is intended to adequately address the unsafe condition.

FAA's Determination and Requirements of the Proposed AD

We have evaluated all pertinent information and identified an unsafe condition that is likely to exist or develop on other airplanes of this same type design. For this reason, we are proposing this AD, which would require accomplishing the actions specified in the service information described previously, except as discussed under “Difference Between the Proposed AD and Service Information.”

Difference Between the Proposed AD and Service Information

The service bulletin specifies to contact the manufacturer for instructions on how to repair certain conditions, but this proposed AD would require repairing those conditions in one of the following ways:

• Using a method that we approve; or
• Using data that meet the certification basis of the airplane, and that have been approved by an Authorized Representative for the Boeing Commercial Airplanes Delegation Option Authorization Organization whom we have authorized to make those findings.

Costs of Compliance

There are about 65 airplanes of the affected design in the worldwide fleet. This proposed AD would affect about 36 airplanes of U.S. registry. The proposed actions would take about 2 work hours per airplane, at an average labor rate of $80 per work hour. Based on these figures, the estimated cost of the proposed AD for U.S. operators is $5,760, or $160 per airplane, per inspection cycle.

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.

Regulatory Findings

We have 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 that the 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); 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.

We prepared a regulatory evaluation of the estimated costs to comply with this proposed AD and placed it in the AD docket. See the ADDRESSES section for a location to examine the regulatory evaluation.

List of Subjects in 14 CFR Part 39

• Air transportation
• Aircraft
• Aviation safety
• 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 Federal Aviation Administration (FAA) amends § 39.13 by adding the following new airworthiness directive (AD):

Boeing: Docket No. FAA-2007-28257; Directorate Identifier 2007-NM-034-AD.

Comments Due Date

(a) The FAA must receive comments on this AD action by July 9, 2007.

Affected ADs

(b) None.

Applicability

(c) This AD applies to Boeing Model 747-100, -200B, -200C, and -200F series airplanes, certificated in any category; as identified in Boeing Alert Service Bulletin 747-53A2673, dated February 8, 2007.

Unsafe Condition

(d) This AD results from a report of a 2-inch crack through the fuselage skin and internal bonded doubler at the cutout of the bulk cargo door light. We are issuing this AD to detect and correct cracks in the fuselage skin at the cutout of the bulk cargo door light, which could result in reduced structural integrity of the fuselage at the bulk cargo door and consequent rapid decompression of the fuselage.

Compliance

(e) You are responsible for having the actions required by this AD performed within the compliance times specified, unless the actions have already been done.

Inspections/Corrective Actions

(f) Before the accumulation of 20,000 total flight cycles, or within 1,500 flight cycles after the effective date of this AD, whichever is later: Perform a high frequency eddy current (HFEC) inspection for cracks in the fuselage skin at the cutout of the bulk cargo door light, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 747-53A2673, dated February 8, 2007. Repeat the inspection thereafter at intervals not to exceed 3,000 flight cycles.

(1) If no crack is found: Repeat the inspection required by paragraph (f) of this AD at the time specified.

(2) If any crack is found that is 2.0 inches or less in length from the edge of the light cutout forward lower corner: Before further flight, do all the corrective actions (including an additional HFEC inspection for cracks) in accordance with Part 2 of the Accomplishment Instructions of the service bulletin. Accomplishing Part 2 ends the repetitive inspections required by paragraph (f) of this AD.

(3) If any crack is found during the inspection required by paragraph (f) of this AD that is more than 2.0 inches in total length from the edge of the light cutout forward lower corner, or is at a location other than the light cutout forward lower corner: Before further flight, repair using a method approved in accordance with the procedures specified in paragraph (g)(2) of this AD.

Alternative Methods of Compliance (AMOCs)

(g)(1) The Manager, Seattle Aircraft Certification Office (ACO), FAA, has the authority to approve AMOCs for this AD, if requested in accordance with the procedures found in 14 CFR 39.19.

(2) An AMOC that provides an acceptable level of safety may be used for any repair required by this AD, if it is approved by an Authorized Representative for the Boeing Commercial Airplanes Delegation Option Authorization Organization who has been authorized by the Manager, Seattle ACO, to make those findings. For a repair method to be approved, the repair must meet the certification basis of the airplane.

(3) To request a different method of compliance or a different compliance time for this AD, follow the procedures in 14 CFR 39.19. Before using any approved AMOC on any airplane to which the AMOC applies, notify your appropriate principal inspector (PI) in the FAA Flight Standards District Office (FSDO), or lacking a PI, your local FSDO.

Issued in Renton, Washington, on May 15, 2007.

Ali Bahrami,

Manager, Transport Airplane Directorate, Aircraft Certification Service.