2010-28605. Airworthiness Directives; The Boeing Company Model 747-200B, -300, -400, -400D, and -400F Series Airplanes Powered by Pratt and Whitney 4000 or General Electric CF6-80C2 Series Engines

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

We propose to adopt a new airworthiness directive (AD) for certain Model 747-200B, -300, -400, -400D, and -400F series airplanes. This proposed AD would require an inspection to determine the part number of the door and to determine if the correct mid-pivot access door is installed, and the installation of a marker on the mid-pivot access door, and if necessary, repetitive ultrasonic inspections for cracking of the mid-pivot bolt assembly and eventual replacement of the mid-pivot bolt assembly. This proposed AD results from a report that the left and right spring beam mid-pivot bolt assembly access doors for the No. 1 strut were inadvertently installed in the incorrect position during strut modification. We are proposing this AD to detect and correct incorrectly installed mid-pivot bolt assemblies on the spring beam on the outboard struts. Incorrectly installed bolt assemblies could lead to fatigue cracking and consequent fracturing of the mid-pivot bolt assembly, which could lead to loss of the spring beam load path and the possible separation of a strut and engine from the airplane during flight.

DATES:

We must receive comments on this proposed AD by December 30, 2010.

ADDRESSES:

You may send comments 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: U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue, SE., Washington, DC 20590, between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays.

For service information identified in this proposed AD, contact Boeing Commercial Airplanes, Attention: Data & Services Management, P.O. Box 3707, MC 2H-65, Seattle, Washington 98124-2207; telephone [phone], extension 1; fax [phone]; e-mail, [e-mail]; Internet https://www.myboeingfleet.com. You may review copies of the referenced service information at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington. For information on the availability of this material at the FAA, call 425-227-1221.

Examining the AD Docket

You may examine the AD docket on the Internet at http://www.regulations.gov;​; 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 proposed AD, the regulatory evaluation, any comments received, and other information. The street address for the Docket Office (telephone [phone]) is in the ADDRESSES section. Comments will be available in the AD docket shortly after receipt.

FOR FURTHER INFORMATION CONTACT:

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

SUPPLEMENTARY INFORMATION:

Comments Invited

We invite you to send any written relevant data, views, or arguments about this proposed AD. Send your comments to an address listed under the ADDRESSES section. Include “Docket No. FAA-2010-1111; Directorate Identifier 2010-NM-129-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 because of 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 have received a report that the mid-pivot access doors on the No. 1 strut were inadvertently installed in the incorrect position during strut modification. The design of the access doors can allow the doors to be installed on either side of the strut. The mid-pivot access door has machined tabs that fit the slots in the head of the mid-pivot bolt assembly. The machined tabs correctly orient the mid-pivot bolt assembly and prevent the mid-pivot bolt from rotating in the spring beam. The correct orientation of the mid-pivot bolt reduces the fatigue on the cross-drilled lubrication channel. If the lubrication channel is not in the correct orientation, fatigue cracking could develop in the mid-pivot bolt assembly. The fatigue cracking could lead to the fracture of the mid-pivot bolt assembly. Fracture of the mid-pivot bolt assembly could result in the loss of the spring beam load path. Loss of the spring beam load path could result in the separation of a strut and engine from the airplane during flight.

Relevant Service Information

We have reviewed Boeing Alert Service Bulletin 747-54A2232, dated April 15, 2010. The service bulletin describes procedures for doing an inspection to determine the part number of the door and to determine if the correct mid-pivot access door is installed. For airplanes on which the correct door is installed, the service bulletin describes procedures for installing a marker on the mid-pivot access door. For airplanes on which the correct access door is not installed, Boeing Alert Service Bulletin 747-54A2232, dated April 15, 2010, describes procedures for rotating the mid-pivot bolt assembly to the correct orientation and replacing the access door, and installing the marker on the mid-pivot access door. In addition, for those airplanes without the correct door, the service bulletin describes procedures for doing one of two options:

• Doing repetitive ultrasonic inspections for cracks of the mid-pivot bolt assembly, and if no cracking is found, eventually replacing the assembly.
• Replacing the mid-pivot bolt assembly before further flight. Replacing the mid-pivot bolt assembly terminates the need for repetitive inspections.

FAA's Determination and Requirements of This Proposed AD

We are proposing this AD because we evaluated all relevant information and determined the unsafe condition described previously is likely to exist or develop in other products of these same type designs. This proposed AD would require accomplishing the actions specified in the service information described previously.

Costs of Compliance

We estimate that this proposed AD would affect 95 airplanes of U.S. registry. We also estimate that it would take about 3 work-hours per product to comply with this proposed AD. The average labor rate is $85 per work-hour. Based on these figures, we estimate the cost of this proposed AD to the U.S. operators to be $24,225, or $255 per product.

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 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), 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.

You can find our regulatory evaluation and the estimated costs of compliance in the AD Docket.

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 AD:

The Boeing Company: Docket No. FAA-2010-1111; Directorate Identifier 2010-NM-129-AD.

Comments Due Date

(a) We must receive comments by December 30, 2010.

Affected ADs

(b) None.

Applicability

(c) This AD applies to The Boeing Company Model 747-200B, -300, -400, -400D, and -400F series airplanes, certificated in any category; equipped with Pratt and Whitney 4000 or General Electric CF6-80C2 series engines, as identified in Boeing Alert Service Bulletin 747-54A2232, dated April 15, 2010.

Subject

(d) Air Transport Association (ATA) of America Code 54: Nacelles/pylons.

Unsafe Condition

(e) This AD results from a report that the left and right spring beam mid-pivot bolt assembly access doors for the no. 1 strut were inadvertently installed in the incorrect position during strut modification. The Federal Aviation Administration is issuing this AD to detect and correct incorrectly installed mid-pivot bolt assemblies on the spring beam on the outboard struts. Incorrectly installed bolt assemblies could lead to fatigue cracking and consequent fracturing of the mid-pivot bolt assembly, which could lead to loss of the spring beam load path and the possible separation of a strut and engine from the airplane during flight.

Compliance

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

Inspection To Determine if Correct Door Is Installed

(g) Within 24 months after the effective date of this AD, do an inspection to determine if the correct mid-pivot access door is installed, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 747-54A2232, dated April 15, 2010.

(h) If, during the inspection required by paragraph (g) of this AD, the correct mid-pivot door is found to be installed, before further flight, install a marker on the mid-pivot access door, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 747-54A2232, dated April 15, 2010.

(i) If, during the inspection required by paragraph (g) of this AD, the correct mid-pivot door is not found to be installed, before further flight, do the actions required by paragraphs (i)(1), (i)(2), and (i)(3) of this AD, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 747-54A2232, dated April 15, 2010.

(1) Rotate the mid-pivot bolt assembly to the correct orientation and replace the mid-pivot access door with a new or serviceable mid-pivot access door.

(2) Install a marker on the mid-pivot access door.

(3) Do the actions required by paragraph (i)(3)(i) or (i)(3)(ii) of this AD.

(i) (Option 1) Do an ultrasonic inspection for cracking of the mid-pivot bolt assembly.

(A) If no cracking is found, do the actions required by paragraphs (i)(3)(i)(A)(1) and (i)(3)(i)(A)(2) of this AD.

(1) Repeat the ultrasonic inspection for cracking of the mid-pivot bolt assembly thereafter at intervals not to exceed 24 months until the action required by paragraph (i)(3)(i)(A)(2) of this AD is done.

(2) Within 60 months after the effective date of this AD, replace the mid-pivot bolt assembly with a new mid-pivot bolt assembly. Replacement terminates the repetitive inspections required by paragraph (i)(3)(i)(A)(1) of this AD.

(B) If any cracking is found, replace the mid-pivot bolt assembly with a new mid-pivot bolt assembly, before further flight.

(ii) (Option 2) Replace the mid-pivot bolt assembly with a new mid-pivot bolt assembly.

Alternative Methods of Compliance (AMOCs)

(j)(1) The Manager, Seattle Aircraft Certification Office (ACO), FAA, has the authority to approve AMOCs for this AD, if requested using the procedures found in 14 CFR 39.19. Send information to Attn: Kenneth Paoletti, Aerospace Engineer, Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office (ACO), 1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone [phone]; fax [phone]. Information may be e-mailed to: [e-mail].

(2) 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 principal maintenance inspector (PMI) or principal avionics inspector (PAI), as appropriate, or lacking a principal inspector, your local Flight Standards District Office. The AMOC approval letter must specifically reference this AD.

(3) An AMOC that provides an acceptable level of safety may be used for any repair required by this AD if it is approved by the Boeing Commercial Airplanes Organization Designation Authorization (ODA) that 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, and the approval must specifically refer to this AD.

Issued in Renton, Washington, on November 2, 2010.

Jeffrey E. Duven,

Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.