Airworthiness directives: Boeing,

[Federal Register: June 29, 1999 (Volume 64, Number 124)]

[Rules and Regulations]

[Page 34707-34710]

From the Federal Register Online via GPO Access [wais.access.gpo.gov]

[DOCID:fr29jn99-3]

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 99-NM-45-AD; Amendment 39-11212; AD 99-14-04]

RIN 2120-AA64

Airworthiness Directives; Boeing Model 747-300 and -400 Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule; request for comments.

SUMMARY: This amendment adopts a new airworthiness directive (AD) that is applicable to certain Boeing Model 747-300 and -400 series airplanes. This action requires repetitive inspections of the E-42 satellite communications (SATCOM) rack and fuselage (supporting) structure to detect cracking in the area surrounding the fastener holes, and to detect broken and missing fasteners; and corrective actions, if necessary. This amendment is prompted by reports indicating that cracking and broken and/or missing fasteners were found on the E- 42 SATCOM equipment rack structure that attaches to the fuselage structure. The actions specified in this AD are intended to detect and repair cracking of the E-42 SATCOM rack and its supporting structure, which could result in the SATCOM equipment falling from the rack, loss of SATCOM capabilities, injury to passengers, and reduced controllability of the airplane.

DATES: Effective July 14, 1999.

The incorporation by reference of certain publications listed in the regulations is approved by the Director of the Federal Register as of July 14, 1999.

Comments for inclusion in the Rules Docket must be received on or before August 30, 1999.

ADDRESSES: Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 99-NM-45-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056.

The service information referenced in this AD may be obtained from Boeing Commercial Airplane Group, P.O. Box 3707, Seattle, Washington 98124-2207. This information may be examined 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.

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FOR FURTHER INFORMATION CONTACT: Elizabeth A. Gnehm, Aerospace Engineer, Airframe Branch, ANM-120S, FAA, Transport Airplane Directorate, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 227-1426; fax (425) 227-1181.

SUPPLEMENTARY INFORMATION: The FAA has received reports indicating that cracking and broken and/or missing fasteners were found on the E-42 SATCOM equipment rack structure that attaches to the fuselage structure on several Boeing Model 747-300 and -400 series airplanes. Investigation revealed that one of the four stanchions (i.e., a supporting prop or brace) was found completely broken on two airplanes (one that had accumulated 23,693 total flight hours and the other with 24,752 total flight hours). Further investigation revealed that the rigid joints of the supporting structure of the E-42 SATCOM rack, coupled with environmental vibration of the airplane, may have caused the cracking to initiate in the area surrounding the fastener holes (located at the rigid joints) of the supporting structure of the E-42 SATCOM rack. The FAA also has received a report indicating that cracking has been detected on four freighter airplanes; one of the airplanes had accumulated less than 1,500 total flight hours.

On all airplanes, the E-42 SATCOM rack hangs above the main deck ceiling. On freighter airplanes and ``combi'' airplanes (i.e., configurations with provisions for passenger seating and cargo on the main deck), the E-42 SATCOM rack is located near rudder and elevator control cables, and the SATCOM wires run above the rudder and elevator control cables.

On all airplanes, failure of the rack and its supporting structure could result in loss of support for the E-42 SATCOM equipment, which could lead to chafing and arcing of the electrical wires and loss of SATCOM capabilities. Such failure also could result in the following unsafe conditions:

‹bullet› On passenger-only airplanes, the E-42 SATCOM equipment could break through the ceiling, which could result in injury to passengers.

‹bullet› On freighter and ``combi'' airplanes, the E-42 SATCOM equipment could fall and cause the SATCOM wires to pull and possibly break the rudder and/or elevator control cables, which could result in reduced controllability of the airplane. Failure of the SATCOM rack on ``combi'' airplanes carrying passengers also could result in injury to the passengers.

Explanation of Relevant Service Information

The FAA has reviewed and approved Boeing Alert Service Bulletin 747-53A2428, dated December 17, 1998, which describes procedures for repetitive close visual inspections of the E-42 SATCOM rack and fuselage (supporting) structure to detect cracking in the area surrounding the fastener holes, and to detect broken or missing fasteners.

Explanation of the Requirements of the Rule

Since an unsafe condition has been identified that is likely to exist or develop on other airplanes of the same type design, this AD is being issued to detect and repair cracking of the E-42 SATCOM rack and its supporting structure, which could result in the SATCOM equipment falling from the rack, loss of SATCOM capabilities, injury to passengers, and reduced controllability of the airplane. This AD requires accomplishment of the actions specified in the alert service bulletin described previously, except as discussed below. This AD also requires that operators report results of initial inspection findings to the manufacturer.

Interim Action

This is considered to be interim action. The manufacturer has advised that it currently is developing a modification that will positively address the unsafe condition addressed by this AD. Once this modification is developed, approved, and available, the FAA may consider additional rulemaking.

Differences Between AD and Alert Service Bulletin

Operators should note that, although the Boeing alert service bulletin specifies that the manufacturer may be contacted for disposition of certain conditions, this proposal would require the repair of those conditions to be accomplished in accordance with a method approved by the FAA.

Operators also should note that the Boeing alert service bulletin specifies that the manufacturer determine the repetitive inspection intervals in the event a repair and/or replacement of the fasteners is necessary. This AD would require repetitive inspections of the E-42 SATCOM rack and its supporting structure at intervals not exceeding 3,000 flight cycles, whether a repair and/or replacement of fasteners is required or not. While a manufacturer Designated Engineering Representative (DER) is authorized to determine whether a design or repair method complies with a specific requirement, at this time the FAA has not delegated the authority to a manufacturer DER to make the discretionary determination for repetitive inspection requirements.

Explanation of Applicability

Operators should note that the Boeing alert service bulletin (previously described), does not specify the line number for the effectivity of Boeing Model 747-400 series airplanes, but states that ``a line number will be specified at a later date,'' when a design improvement can be incorporated into the production line. To account for this interpretative effectivity, this AD is applicable to Boeing Model 747-300 series airplanes as listed in the alert service bulletin and Boeing Model 747-400 series airplanes equipped with a Boeing- installed E-42 SATCOM rack. As discussed previously, because this AD is considered interim action, applicability may be revised accordingly in subsequent AD action.

Explanation of Compliance Time

Operators should note that the Boeing alert service bulletin (previously described) recommends that the initial inspection be performed at the applicable time, as specified below:

‹bullet› For airplanes identified in the alert service as Group 1: Within 500 flight hours or within 14,000 flight hours since the E-42 SATCOM rack was installed and populated with equipment.

‹bullet› For airplanes identified in the alert service as Groups 2, 3, and 4: Within 500 flight hours or 20,000 flight hours since the E-42 SATCOM rack was installed and populated with equipment.

This AD would require that the initial inspection be performed at the applicable time, as specified below:

‹bullet› For airplanes identified in the alert service bulletin as Group 1: Within 30 days after the effective date of this AD.

‹bullet› For airplanes identified in the alert service bulletin as Groups 2, 3, and 4: Within 90 days after the effective date of this AD.

The FAA finds that, in view of a recent report indicating that cracking has been detected on an airplane that had accumulated less than 1,500 total flight hours, and because of the safety implications and consequences associated with such cracking, the initial compliance time specified in this AD is appropriate.

Determination of Rule's Effective Date

Since a situation exists that requires the immediate adoption of this regulation, it is found that notice and

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opportunity for prior public comment hereon are impracticable, and that good cause exists for making this amendment effective in less than 30 days.

Comments Invited

Although this action is in the form of a final rule that involves requirements affecting flight safety and, thus, was not preceded by notice and an opportunity for public comment, comments are invited on this rule. Interested persons are invited to comment on this rule by submitting such written data, views, or arguments as they may desire. Communications shall identify the Rules Docket number and be submitted in triplicate to the address specified under the caption ADDRESSES. All communications received on or before the closing date for comments will be considered, and this rule may be amended in light of the comments received. Factual information that supports the commenter's ideas and suggestions is extremely helpful in evaluating the effectiveness of the AD action and determining whether additional rulemaking action would be needed.

Comments are specifically invited on the overall regulatory, economic, environmental, and energy aspects of the rule that might suggest a need to modify the rule. All comments submitted will be available, both before and after the closing date for comments, in the Rules Docket for examination by interested persons. A report that summarizes each FAA-public contact concerned with the substance of this AD will be filedin the Rules Docket.

Commenters wishing the FAA to acknowledge receipt of their comments submitted in response to this rule must submit a self-addressed, stamped postcard on which the following statement is made: ``Comments to Docket Number 99-NM-45-AD.'' The postcard will be date stamped and returned to the commenter.

Regulatory Impact

The regulations adopted herein will not have substantial direct effects 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, in accordance with Executive Order 12612, it is determined that this final rule does not have sufficient federalism implications to warrant the preparation of a Federalism Assessment.

The FAA has determined that this regulation is an emergency regulation that must be issued immediately to correct an unsafe condition in aircraft, and that it is not a ``significant regulatory action'' under Executive Order 12866. It has been determined further that this action involves an emergency regulation under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979). If it is determined that this emergency regulation otherwise would be significant under DOT Regulatory Policies and Procedures, a final regulatory evaluation will be prepared and placed in the Rules Docket. A copy of it, if filed, 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.

   Sec. 39.13 [Amended]

2. Section 39.13 is amended by adding the following new airworthiness directive:

   99-14-04 Boeing: Amendment 39-11212. Docket 99-NM-45-AD.

   Applicability: Model 747-300 series airplanes, as listed in Boeing Alert Service Bulletin 747-53A2428, dated December 17, 1998; and Model 747-400 series airplanes equipped with a Boeing installed E-42 satellite communications (SATCOM) rack; certificated in any category.

   Note 1: This AD applies to each airplane identified in the preceding applicability provision, regardless of whether it has been modified, altered, or repaired in the area subject to the requirements of this AD. For airplanes that have been modified, altered, or repaired so that the performance of the requirements of this AD is affected, the owner/operator must request approval for an alternative method of compliance in accordance with paragraph (d) of this AD. The request should include an assessment of the effect of the modification, alteration, or repair on the unsafe condition addressed by this AD; and, if the unsafe condition has not been eliminated, the request should include specific proposed actions to address it.

   Compliance: Required as indicated, unless accomplished previously.

   To detect and repair cracking of the E-42 SATCOM rack and its supporting structure, which could result in the SATCOM equipment falling from the rack, loss of SATCOM capabilities, injury to passengers, and reduced controllability of the airplane, accomplish the following:

   Initial and Repetitive Detailed Visual Inspections

   (a) Perform a detailed visual inspection of the E-42 SATCOM rack and fuselage (supporting) structure to detect cracking in the area surrounding the fastener holes, and to detect broken or missing fasteners, in accordance with Boeing Alert Service Bulletin 747- 53A2428, dated December 17, 1998, at the time specified in paragraph (a)(1) or (a)(2) of this AD, as applicable. Thereafter, repeat the inspection at intervals not to exceed 3,000 flight hours.

   (1) For airplanes identified as Group 1: Within 30 days after the effective date of this AD.

   (2) For airplanes identified as Groups 2, 3, and 4: Within 90 days after the effective date of this AD.

   Note 2: For the purposes of this AD, a detailed inspection is defined as: ``An intensive visual examination of a specific structural area, system, installation or assembly to detect damage, failure or irregularity. Available lighting is normally supplemented with a direct source of good lighting at intensity deemed appropriate by the inspector. Inspection aids such as mirror, magnifying lenses, etc. may be used. Surface cleaning and elaborate access procedures may be required.''

   Corrective Actions

   (b) If any cracking is found, or if any fastener is broken or missing, during any inspection required by paragraph (a) of this AD, prior to further flight: Repair in accordance with a method approved by the Manager, Seattle Aircraft Certification Office (ACO), FAA, Transport Airplane Directorate; or in accordance with 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. Repeat the detailed visual inspection of the SATCOM rack and fuselage (supporting) structure thereafter at the intervals specified by paragraph (a) of this AD.

   Reporting Requirements

   (c) Submit a report of the initial inspection findings (positive and negative) to Boeing Commercial Airplane Group, Attention: Manager, Airline Support, P.O. Box 3707, Seattle, Washington 98124- 2207; at the time specified in paragraph (c)(1) or (c)(2) of this AD, as applicable. The report must include a description of any discrepancy found, the airplane serial number, the number of landings and flight hours on the airplane, and, when possible, sketches and photographs of the inspected area. Information collection requirements contained in this regulation have been approved by the Office of Management and Budget (OMB) under the provisions of the Paperwork Reduction Act of 1980 (44 U.S.C. 3501 et seq.) and have been assigned OMB Control Number 2120-0056.

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   (1) For airplanes on which the initial inspection is accomplished after the effective date of this AD: Submit the report within 10 days after performing the initial inspection required by paragraph (a) of this AD.

   (2) For airplanes on which the initial inspection has been accomplished prior to the effective date of this AD: Submit the report within 30 days after the effective date of this AD.

   Alternative Methods of Compliance

   (d) An alternative method of compliance or adjustment of the compliance time that provides an acceptable level of safety may be used if approved by the Manager, Seattle ACO. Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, Seattle ACO.

   Note 3: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Seattle ACO.

   Special Flight Permits

   (e) Special flight permits may be issued in accordance with sections 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 and 21.199) to operate the airplane to a location where the requirements of this AD can be accomplished, provided that all the equipment is removed from the E-42 SATCOM rack.

   Incorporation by Reference

   (f) The inspections shall be done in accordance with Boeing Alert Service Bulletin 747-53A2428, dated December 17, 1998. 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 Airplane Group, 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.

   (g) This amendment becomes effective on July 14, 1999.

   Issued in Renton, Washington, on June 22, 1999. D.L. Riggin, Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.

   [FR Doc. 99-16326Filed6-28-99; 8:45 am]

   BILLING CODE 4910-13-P