AD 99-16-10

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AD Number:
99-16-10
Document Type:
AD Final Rules
Docket Number:
99-NM-61-AD
Subject Heading:
Airworthiness Directives; BOEING Model 747-400 Series Airplanes
Subject:
Satellite Communications (SATCOM) Rack
Status:
Current
Citation:
(Federal Register: August 09, 1999 (Volume 64, Number 152))
Citation Publish Date:
08/09/1999
Effective Date:
08/24/1999
Make:
The Boeing Company
Model:
747-400 Series | 747-400D Series | 747-400F Series
Product Type:
Aircraft
Product Subtype:
Large Airplane
Affected AD:
Superseded AD:
Affected By:
Superseded By:
Service/Office:
Office of Primary Responsibility:
CFR Part Reference:
Part 39 (64 FR 43053 No. 152 08/09/99)
Comments:
AIRWORTHINESS DIRECTIVES FINAL RULES: 99-16-10
CITATION:   [Federal Register: August 09, 1999 (Volume 64, Number 152)]

PAGE NUMBER:   [Page 43053]

DOCKET NUMBER:   99-NM-61-AD

AMENDMENT:   39-11245

AD NUMBER:   99-16-10

SUBJECT HEADING:   Airworthiness Directives; BOEING Model 747-400 Series Airplanes

ACTION:   Final rule; request for comments

SUMMARY:  
This amendment adopts a new airworthiness directive (AD), applicable to certain Boeing Model 747-400 series airplanes. This action requires repetitive inspections of the E-42 satellite communications (SATCOM) rack and fuselage (supporting) structure to detect fatigue cracking of the area surrounding the fastener holes, and to detect broken or missing fasteners; and corrective actions, if necessary. This amendment is prompted by reports indicating that fatigue 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 fatigue 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 August 24, 1999. The incorporation by reference of certain publications listed in the regulations is approved by the Director of the Federal Register as of August 24, 1999. Comments for inclusion in the Rules Docket must be received on or before October 8, 1999.

ADDRESSES:  
Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 99-NM-61-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056.

The service information referenced in this AD may be obtained from Flight Structures Inc., 4407 172nd Street NE, Arlington, Washington 98223. This information may be examined at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the FAA, Transport Airplane Directorate, Los Angeles Aircraft Certification Office, 3960 Paramount Boulevard, Lakewood, California; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.

FOR FURTHER INFORMATION CONTACT:  
Jon Mowery, Aerospace Engineer, Airframe Branch, ANM-120L, FAA, Transport Airplane Directorate, Los Angeles Aircraft Certification Office, 3960 Paramount Boulevard, Lakewood, California 90712-4137; telephone (562) 627-5322; fax (562) 627-5210.

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:

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

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.

Related Rulemaking

On June 22, 1999, the FAA issued AD 99-14-04, amendment 39-11212 (64 FR 34707, June 29, 1999), applicable to certain Boeing Model 747-300 and -400 series airplanes, that requires repetitive 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 and missing fasteners; and corrective actions, if necessary.

Explanation of Relevant Service Information

The FAA has reviewed and approved Flight Structures Alert Service Bulletins 92FS024-53-A1, 92FS082-53-A1, and 94FS409-53-A2, all dated March 2, 1999, and 94FS448-53-A1, dated February 12, 1999. These alert service bulletins describe, among other things, procedures for a one-time close visual inspection of the E-42 SATCOM rack and fuselage (supporting) structure to detect fatigue cracking of the area surrounding the fastener holes, and to detect broken or missing fasteners.

Explanation of 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 fatigue cracking of the E-42 SATCOM rack and its supporting structure due to environmental vibration of the airplane. Such fatigue cracking 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 repetitive inspections of the E-42 SATCOM rack and fuselage (supporting) structure to detect fatigue cracking of the area surrounding the fastener holes, and to detect broken or missing fasteners; and corrective actions, if necessary. The actions are required to be accomplished in accordance with the applicable alert service bulletin described previously, except as discussed below. This AD also would require reporting the findings of the initial inspection to the FAA.

Differences Between AD and Service Information

While the alert service bulletins do not specify that the inspection of the E-42 SATCOM rack and fuselage (supporting) structure be repeated, this AD would require repetitive inspections of the E-42 SATCOM rack and fuselage (supporting) structure, even if fatigue cracking has been detected and repaired. As stated previously, the rigid joints of the SATCOM rack coupled with environmental vibration of the airplane could cause fatigue cracking to initiate in the area surrounding fastener holes. Furthermore, an isolated repair of an area and/or replacement of any fastener does not remove the unsafe condition for the entire E-42 SATCOM rack and fuselage (supporting) structure. In light of these factors, the FAA has determined that repetitive inspection at intervals not exceeding 3,000 flight hours, is warranted, and that it represents an appropriate means of addressing the unsafe condition while allowing affected airplanes to continue to operate without comprising safety.

Operators should note that, although the alert service bulletins specify repair instructions for certain conditions and recommend that the manufacturer of the SATCOM rack be contacted for disposition of certain other conditions, this AD will require the repair of those conditions to be accomplished in accordance with a method approved by the FAA.

Explanation of Compliance Time

This AD would require compliance in terms of the number of days after the effective date of this AD, whereas the alert service bulletins (previously described) recommend compliance based on the number of flight hours, as specified below:

For airplanes identified in the alert service bulletin as Group 1: Within 500 flight hours from receipt of alert service bulletin, or 12,000 flight hours since the E-42 SATCOM rack was installed and populated with equipment.

For airplanes identified in the alert service bulletin as Group 2: Within 1,000 flight hours from receipt of alert service bulletin, 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:

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

For airplanes identified in the alert service bulletin as Group 2: 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.

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.

Cost Impact

None of the Model 747-400 series airplanes affected by this action are on the U.S. Register. All airplanes included in the applicability of this rule currently are operated by non-U.S. operators under foreign registry; therefore, they are not directly affected by this AD action. However, the FAA considers that this rule is necessary to ensure that the unsafe condition is addressed in the event that any of these subject airplanes are imported and placed on the U.S. Register in the future.

Should an affected airplane be imported and placed on the U.S. Register in the future, it would require approximately 3 work hours to accomplish the required inspection, at an average labor rate of $60 per work hour. Based on these figures, the cost impact of this AD would be $180 per airplane, per inspection cycle.

Determination of Rule's Effective Date

Since this AD action does not affect any airplane that is currently on the U.S. register, it has no adverse economic impact and imposes no additional burden on any person. Therefore, prior notice and public procedures hereon are unnecessary and the amendment may be made effective in less than 30 days after publication in the Federal Register.

Comments Invited

Although this action is in the form of a final rule and was not preceded by notice and 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 filed in 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-61-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.

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:

REGULATORY TEXT:  
99-16-10 BOEING: Amendment 39-11245. Docket 99-NM-61-AD.

Applicability: Model 747-400 series airplanes as listed in Flight Structures Alert Service Bulletins 92FS082-53-A1, 92FS024-53-A1, and 94FS409-53-A2, all dated March 2, 1999, and 94FS448-53-A1, dated February 12, 1999; 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 fatigue cracking of the E-42 satellite communications (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 Inspections

(a) Perform a detailed visual inspection of the E-42 SATCOM rack and fuselage (supporting) structure to detect fatigue cracking of the area surrounding the fastener holes, and to detect broken or missing fasteners, at the time specified in paragraph (a)(1) or (a)(2) of this AD, as applicable; in accordance with Flight Structures Alert Service Bulletin 92FS082-53-A1, 92FS024-53-A1, or 94FS409-53-A2, all dated March 2, 1999; or 94FS448-53-A1, dated February 12, 1999, as applicable. Thereafter, repeat the inspection at intervals not to exceed 3,000 flight hours.

(1) For all airplanes identified as Group 1 in the applicable alert service bulletin: Inspect within 30 days after the effective date of this AD.

(2) For all airplanes identified as Group 2 in the applicable alert service bulletin: Inspect 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 fatigue 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, Los Angeles Aircraft Certification Office (ACO), FAA, Transport Airplane Directorate. Thereafter, repeat the inspection required by paragraph (a) of this AD, at intervals not to exceed 3,000 flight hours.

Reporting Requirements

(c) Submit a report of the initial inspection findings (positive and negative) to the Manager, Los Angeles ACO, 3960 Paramount Boulevard, Lakewood, California 90712-4137; telephone (562) 627-5322; fax (562) 627-5210; at the applicable time specified in paragraph (c)(1) or (c)(2) of the AD, as applicable. The report must include the initial inspection results, a description of any discrepancy found, the airplane serial number, 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.

(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 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, Los Angeles ACO. Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, Los Angeles ACO.

NOTE 3: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Los Angeles 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 Flight Structures Alert Service Bulletin 92FS082-53-A1, dated March 2, 1999; Flight Structures Alert Service Bulletin 92FS024-53-A1, dated March 2, 1999; Flight Structures Alert Service Bulletin 94FS409-53-A2, dated March 2, 1999; or Flight Structures Alert Service Bulletin 94FS448-53-A1, dated February 12, 1999, as applicable. 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 Flight Structures Inc., 4407 172nd Street NE, Arlington, Washington 98223. Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at Los Angeles ACO, 3960 Paramount Boulevard, Lakewood, California 90712-4137; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.

(g) This amendment becomes effective on August 24, 1999.

FOOTER: