04-4922. Airworthiness Directives; Boeing Model 767-200 and -300 Series Airplanes

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Final rule.

SUMMARY:

This amendment adopts a new airworthiness directive (AD), applicable to certain Boeing Model 767-200 and -300 series airplanes, that requires repetitive inspections of the aft pressure bulkhead web, and corrective action, if necessary. This action is necessary to detect and correct fatigue cracks in the aft pressure bulkhead web, which could result in uncontrolled rapid decompression. This action is intended to address the identified unsafe condition.

DATES:

Effective April 13, 2004.

The incorporation by reference of certain publications listed in the regulations is approved by the Director of the Federal Register as of April 13, 2004.

ADDRESSES:

The service information referenced in this AD may be obtained from Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124-2207. This information may be examined at the Federal Aviation Administration (FAA), Transport Airplane Directorate, Rules Docket, 1601 Lind Avenue, SW., Renton, Washington; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.

FOR FURTHER INFORMATION CONTACT:

Suzanne Masterson, Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone [phone]; fax [phone].

SUPPLEMENTARY INFORMATION:

A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) to include an airworthiness directive (AD) that is applicable to all Boeing Model 767-200, -300, and -300F series airplanes was published in the Federal Register on October 6, 2003 (68 FR 57639). That action proposed to require repetitive inspections of the aft pressure bulkhead web, and corrective action, if necessary.

Comments

Interested persons have been afforded an opportunity to participate in the making of this amendment. Due consideration has been given to the comments received.

Concur With Proposed AD

One commenter has reviewed the proposed AD and concurs with the proposed inspections and corrective action.

Add Provision for Flight Cycles With Cabin Differential Pressure Less Than 2.0 psi

One commenter requests that a provision be added allowing flight cycles to not be counted if cabin differential pressure was below 2.0 pounds per square inch (psi), provided that cabin pressure records be maintained for each airplane, and that no fleet averaging of cabin pressure is allowed. The commenter notes that there is a provision in Boeing Alert Service Bulletin 767-53A0087, dated October 21, 1999, which is the source of service information for this AD. In the “General Notes” of the Accomplishment Instructions of the service bulletin, paragraph 6. specifies that “flight-cycles, as defined herein, need not be counted if cabin differential pressure was below 2.0 psi.”

We do not agree with the commenter's request to add a provision for flight cycles with cabin differential pressure less than 2.0 psi. Cabin differential pressure of 2.0 psi or less is not typical of normal operation of the affected airplanes. We do not consider it appropriate to include various provisions in an AD applicable to unique uses of an affected airplane. We have determined that mitigating factors, such as total number of low pressure cycles, could best be evaluated through requests for alternative methods of compliance, as provided by paragraph (e) of this AD. In addition, we have clarified paragraphs (a) and (b) of this AD by referring to the “Work Instructions” of the service bulletin instead of the “Accomplishment Instructions.”

Change Effectivity and Revise Affected Models

One commenter requests the applicability be changed to line numbers 1 through 423 inclusive and that Model -300F series airplanes be removed from the list of affected models. The commenter states that AD 2003-18-10, amendment 39-13301 (68 FR 53503, September 11, 2003), mandates the current revision of Section 9 of the Maintenance Planning Data document, which contains inspection item number 53-80-I01A. Inspection item number 53-80-I01A is the same as the proposed actions for line numbers 424 and on. This would cause duplicate requirements for the same actions, causing confusion for operators as to what inspections to accomplish and how to comply with both ADs.

The FAA agrees with the commenter's request. For line numbers 424 and on, the Airworthiness Limitations for Boeing Model 767 series airplanes are currently in effect and AD 2003-18-10 adequately mandates the proposed inspections and corrective action. We have changed the applicability to line numbers 1 through 423 inclusive and removed Model -300F series airplanes from the list of affected models. Because of the new applicability, we also removed Group 3 and Group 4 from Table 1 of this AD, revised paragraph (b) of this AD, and changed the number of affected airplanes in the “Cost Impact” paragraph of the AD.

Conclusion

After careful review of the available data, including the comments noted above, the FAA has determined that air safety and the public interest require the adoption of the rule with the changes previously described. The FAA has determined that these changes will neither increase the economic burden on any operator nor increase the scope of the AD.

Cost Impact

There are approximately 406 airplanes of the affected design in the worldwide fleet. The FAA estimates that 182 airplanes of U.S. registry will be affected by this AD, that it will take approximately 14 work hours per airplane to accomplish the required inspection, and that the average labor rate is $65 per work hour. Based on these figures, the cost impact of the AD on U.S. operators is estimated to be $165,620, or $910 per airplane.

The cost impact figure discussed above is based on assumptions that no operator has yet accomplished any of the requirements of this AD action, and that no operator would accomplish those actions in the future if this AD were not adopted. The cost impact figures discussed in AD rulemaking actions represent only the time necessary to perform the specific actions actually required by the AD. These figures typically do not include incidental costs, such as the time required to gain access and close up, planning time, or time necessitated by other administrative actions.

Regulatory Impact

The regulations adopted herein will 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. Therefore, it is determined that this final rule does not have federalism implications under Executive Order 13132.

For the reasons discussed above, I certify that this action (1) is not a “significant regulatory action” under Executive Order 12866; (2) is not a “significant rule” under 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. A final evaluation has been prepared for this action and it is contained in the Rules Docket. A copy of it may be obtained from the Rules Docket at the location provided under the caption ADDRESSES.

List of Subjects in 14 CFR Part 39

• Air transportation
• Aircraft
• Aviation safety
• Incorporation by reference
• Safety

Adoption of the Amendment

Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration amends part 39 of the Federal Aviation Regulations (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. Section 39.13 is amended by adding the following new airworthiness directive:

2004-05-16 Boeing: Amendment 39-13511. Docket 2003-NM-49-AD.

Applicability: Model 767-200 and -300 series airplanes, line numbers 1 through 423 inclusive; certificated in any category.

Compliance: Required as indicated, unless accomplished previously.

To detect and correct fatigue cracks in the aft pressure bulkhead web, which could result in uncontrolled rapid decompression, accomplish the following:

Initial and Repetitive Inspections

(a) Do high frequency eddy current inspections of the aft pressure bulkhead web, per the Work Instructions of Boeing Alert Service Bulletin 767-53A0087, dated October 21, 1999; at the later of the applicable “Threshold” and “Grace Period” times specified in Table 1 of this AD. Table 1 is as follows:

Table 1.—Compliance Times for Inspection

For—	Compliance times—
	Threshold—	Grace period—
(1) Group 1 airplanes as identified in the service bulletin	Prior to the accumulation of 37,500 total flight cycles	Within 18 months or within 3,000 flights after the effective date of this AD, whichever comes first
(2) Group 2 airplanes as identified in the service bulletin	Prior to the accumulation of 50,000 total flight cycles	Within 18 months or within 3,000 flights after the effective date of this AD, whichever comes first

(b) If no crack is found during any inspection required by paragraph (a) of this AD, repeat the high frequency eddy current inspections thereafter at intervals not to exceed 6,000 flight cycles, per the Work Instructions of Boeing Alert Service Bulletin 767-53A0087, dated October 21, 1999.

Corrective Actions

(c) If any crack is found during any inspection required by paragraph (a) or (b) of this AD and Boeing Alert Service Bulletin 767-53A0087, dated October 21, 1999, specifies to contact Boeing for repair: Before further flight, repair per a method approved by the Manager, Seattle Aircraft Certification Office (ACO), FAA; or per data meeting the type certification basis of the airplane approved by a Boeing Company Designated Engineering Representative who has been authorized by the Manager, Seattle ACO, to make such findings. For a repair method to be approved, the approval must specifically reference this AD.

Previously Installed Repairs

(d) If previously installed repairs are installed in the inspection area, and Boeing Alert Service Bulletin 767-53A0087, dated October 21, 1999, specifies to contact Boeing for inspection details, an alternative method of compliance must be approved as required by sections 39.15, 39.17, and 39.19 of the Code of Federal Regulations (14 CFR 39.15, 39.17, 39.19).

Alternative Methods of Compliance

(e) In accordance with 14 CFR 39.19, the Manager, Seattle ACO, FAA, is authorized to approve alternative methods of compliance for this AD.

Incorporation by Reference

(f) Unless otherwise specified in this AD, the actions shall be done in accordance with Boeing Alert Service Bulletin 767-53A0087, dated October 21, 1999. This incorporation by reference was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained from Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124-2207. Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.

Effective Date

(g) This amendment becomes effective on April 13, 2004.

Issued in Renton, Washington, on February 25, 2004.

Kalene C. Yanamura,

Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.