E8-24579. Airworthiness Directives; Boeing Model 767 Airplanes

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Supplemental notice of proposed rulemaking (NPRM); reopening of comment period.

SUMMARY:

We are revising an earlier proposed airworthiness directive (AD) for certain Boeing Model 767 airplanes. The original NPRM would have required sealing certain fasteners and stiffeners in the fuel tank, and changing certain wire bundle clamp configurations on the fuel tank walls. The original NPRM resulted from fuel system reviews conducted by the manufacturer. This action revises the original NPRM by adding inspections, for certain airplanes, of additional fasteners in the fuel tanks and of the method of attachment of the vortex generators, and corrective action if necessary. We are proposing this supplemental NPRM to prevent possible ignition sources in the auxiliary fuel tank, main fuel tanks, and surge tanks caused by a wiring short or lightning strike, which could result in fuel tank explosions and consequent loss of the airplane.

DATES:

We must receive comments on this supplemental NPRM by November 10, 2008.

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 AD, contact Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124-2207.

Examining the AD Docket

You may examine the AD doc ket 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:

Judy Coyle, Aerospace Engineer, Propulsion Branch, ANM-140S, 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 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-2007-28035; Directorate Identifier 2006-NM-293-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 issued a notice of proposed rulemaking (NPRM) (the “original NPRM”) to amend 14 CFR part 39 to include an airworthiness directive (AD) that would apply to certain Boeing Model 767 airplanes. That original NPRM was published in the Federal Register on April 30, 2007 (72 FR 21166). That original NPRM proposed to require sealing certain fasteners and stiffeners in the fuel tank, and changing certain wire bundle clamp configurations on the fuel tank walls.

Actions Since Original NPRM Was Issued

The NPRM referred to Boeing Alert Service Bulletins 767-57A0102, dated October 25, 2006, and 767-57A0100, dated August 21, 2006, as the appropriate sources of service information for the proposed requirements. Since we issued the NPRM, Boeing revised the service bulletins.

Service Bulletin 767-57A0102, Revision 1, dated November 27, 2007, provides the following changes:

• Corrects the specified location of fasteners that must be sealed on the rear spar in the auxiliary fuel tank;
• Corrects the specified location of fasteners that must be sealed at rib 28 on the front spar;
• Adds work packages, for airplanes on which the original issue of the service bulletin was accomplished, for general visual inspections of the sealant of the fasteners in the auxiliary fuel tank center bay and the fasteners at rib 28 of the left and right main fuel tanks, and sealing any unsealed fasteners;
• Identifies additional access doors necessary for access to the fuel tanks; and
• Specifies permitted alternative fuel tank sealants.

The new work packages are necessary because the original issue of this service bulletin specified incorrect locations for certain fasteners on the rear spar of the auxiliary fuel tank and the front spar of the main wing. If the correct fasteners are not sealed, there is a risk that arcing from a short can enter the fuel tank and become an ignition source. We have revised paragraphs (c) and (g) of this supplemental NPRM to refer to Revision 1 of the service bulletin.

Service Bulletin 767-57A0100, Revision 1, dated June 19, 2008, adds procedures for certain airplanes (Group 3 airplanes) for a general visual inspection to determine the method of attachment of the vortex generators. For vortex generators attached with adhesive alone, no more work is necessary. For vortex generators attached with fasteners, the service bulletin provides procedures for sealing the fasteners.

Comments

We gave the public the opportunity to participate in developing this AD. We considered the comments received.

Support for the NPRM

Continental Airlines has no objection to the NPRM. The Air Transport Association (ATA) agrees with the intent of the NPRM. American Airlines understands and agrees with our efforts to prevent the identified unsafe condition.

Request for Warranty Coverage

Hawaiian Airlines questions why Service Bulletin 767-57A0102 is not covered under warranty. The commenter states that the original equipment manufacturer (OEM) should cover the costs to do the required extra protection for fuel ignition shorts. The commenter added that 335 work hours and about $2,000 for parts per airplane is very costly for airline operators.

We have no involvement in warranty agreements between the airlines and the OEM. We have not changed the final rule regarding this issue.

Request To Extend Compliance Time

The ATA and American Airlines request that we extend the proposed compliance time from 60 months to 72 months. The longer interval would minimize fuel tank entry and corresponds to the existing “4C” maintenance interval established by the Boeing 767 Maintenance Review Board (MRB), when significant maintenance (such as maintenance requiring fuel tank entry) is scheduled. The ATA states that the use of that interval would avoid the need to accomplish the proposed actions in portions of airline inventories during unique, unscheduled visits. American Airlines states that its cost to comply with the AD would be 7 percent higher with the proposed 60-month compliance time (versus a 72-month compliance time).

While we agree that reducing fuel tank entries minimizes both the potential for damage and the disruption to operators' maintenance schedules, we find that extending the compliance time is not appropriate. In developing the compliance time for this AD action, we considered not only the safety implications of the identified unsafe condition, but the average utilization rate of the affected fleet, the practical aspects of accomplishing the AD on the fleet during regular maintenance periods, the availability of required parts, and the time necessary for the rulemaking process. The proposed compliance time was determined to be appropriate. However, paragraph (h) of this supplemental NPRM would provide operators the opportunity to request adjustments to the compliance time and submit data to substantiate that such an adjustment would provide an acceptable level of safety. We have not changed this supplemental NPRM regarding this issue.

Clarification of Inspection Type

In this supplemental NPRM, the “general visual inspection” specified in Revision 1 of the referenced service information is referred to as a “detailed inspection.” We have included the definition for a detailed inspection in a note in the supplemental NPRM.

FAA's Determination and Proposed Requirements of the Supplemental NPRM

We are proposing this supplemental NPRM because we evaluated all pertinent information and determined that an unsafe condition exists and is likely to exist or develop on other products of the same type design. Certain changes described above expand the scope of the original NPRM. As a result, we have determined that it is necessary to reopen the comment period to provide additional opportunity for the public to comment on this supplemental NPRM.

Costs of Compliance

There are about 925 airplanes of the affected design in the worldwide fleet. The following table provides the estimated costs for U.S. operators to comply with this proposed AD. There are no U.S.-registered airplanes in Group 3 of Service Bulletin 767-57A0102. The average labor rate is $80 per work hour.

Estimated Costs

Service Bulletin	Group	Work hours	Parts	Cost per airplane	Number of U.S.-registered airplanes	Fleet cost
767-57A0100	1	6	minimal	$480	341	$163,680
	2	114	minimal	9,120	21	191,520
	3	1	none	80	17	1,360
767-57A0102	1	246	1,632	21,312	341	7,267,392
	2	874	1,304	71,224	21	1,495,704
	3	24	338	2,258	0	0

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
• 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:

Boeing: Docket No. FAA-2007-28035; Directorate Identifier 2006-NM-293-AD.

Comments Due Date

(a) We must receive comments by November 10, 2008.

Affected ADs

(b) None.

Applicability

(c) This AD applies to Model 767-200, −300, −300F, and −400ER series airplanes; certificated in any category; as identified in Boeing Alert Service Bulletin 767-57A0100, Revision 1, dated June 19, 2008; and Boeing Service Bulletin 767-57A0102, Revision 1, dated November 27, 2007.

Unsafe Condition

(d) This AD results from fuel system reviews conducted by the manufacturer. We are issuing this AD to prevent possible ignition sources in the auxiliary fuel tank, main fuel tanks, and surge tanks caused by a wiring short or lightning strike, which could result in fuel tank explosions and consequent loss of the airplane.

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.

Fastener Sealant Application

(f) For airplanes identified in Boeing Alert Service Bulletin 767-57A0100, Revision 1, dated June 19, 2008: Within 60 months after the effective date of this AD, do the actions in paragraphs (f)(1) and (f)(2) of this AD. Do the actions in accordance with the Accomplishment Instructions of the service bulletin, as applicable.

(1) For Groups 1 and 2 airplanes: Seal the ends of the fasteners on the brackets that hold the vortex generators, and seal the ends of the fasteners on certain stiffeners on the rear spar, as applicable.

(2) For Group 3 airplanes: Do a detailed inspection to determine the method of attachment of the vortex generators, and, before further flight, do all applicable specified corrective actions.

Wire Bundle Sleeve and Clamp Installation and Fastener Sealant Application

(g) For airplanes identified in Boeing Service Bulletin 767-57A0102, Revision 1, dated November 27, 2007: Within 60 months after the effective date of this AD, do the actions specified in paragraphs (g)(1), (g)(2), and (g)(3) of this AD, as applicable. Do the actions in accordance with the Accomplishment Instructions of the service bulletin.

(1) Change the wire bundle clamp configurations at specified locations on the fuel tank walls.

(2) Seal the fasteners and certain stiffeners at specified locations on the fuel tank.

(3) Do a detailed inspection of the sealant of the fasteners in the auxiliary tank center bay and rib 28 of the left and right main fuel tanks. Seal any unsealed fasteners before further flight.

Note 1:

For the purposes of this AD, a detailed inspection is: “An intensive examination of a specific item, installation, or assembly to detect damage, failure, or irregularity. Available lighting is normally supplemented with a direct source of good lighting at an intensity deemed appropriate. Inspection aids such as mirror, magnifying lenses, etc., may be necessary. Surface cleaning and elaborate procedures may be required.”

Alternative Methods of Compliance (AMOCs)

(h)(1) The Manager, Seattle Aircraft Certification Office (ACO), FAA, ATTN: Judy Coyle, Aerospace Engineer, ANM-140S, 1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone [phone]; fax [phone]; has the authority to approve AMOCs for this AD, if requested in accordance with the procedures found in 14 CFR 39.19.

(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 appropriate principal inspector (PI) in the FAA Flight Standards District Office (FSDO), or lacking a PI, your local FSDO.

Issued in Renton, Washington, on October 6, 2008.

Ali Bahrami,

Manager, Transport Airplane Directorate, Aircraft Certification Service.