AD 94-06-08

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AD Number:
94-06-08
Document Type:
AD Final Rules
Docket Number:
93-NM-82-AD
Subject Heading:
Airworthiness Directives; Boeing Model 707 Series Airplanes
Subject:
Wing Front Spar Lower Chord
Status:
Current
Citation:
(Federal Register: March 22, 1994 (Volume 59, Number 55))
Citation Publish Date:
03/22/1994
Effective Date:
04/21/1994
Make:
The Boeing Company
Model:
707-300 Series | 707-300B Series | 707-300C Series | 707-400 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Superseded AD: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Superseded By: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 (59 FR 13446 NO. 55 03/22/94)
Comments:
AIRWORTHINESS DIRECTIVES FINAL RULES: 94-06-08
CITATION:   [Federal Register: March 22, 1994 (Volume 59, Number 55)]

PAGE NUMBER:   [Page 13446]

DOCKET NUMBER:   93-NM-82-AD

AMENDMENT:   39-8856

AD NUMBER:   94-06-08

SUBJECT HEADING:   Airworthiness Directives; Boeing Model 707 Series Airplanes

ACTION:   Final rule

SUMMARY:   This amendment adopts a new airworthiness directive (AD), applicable to Boeing Model 707 series airplanes, that requires the incorporation of a certain structural modification of the wing front spar lower chord. This amendment is prompted by an evaluation and recommendation by the Airworthiness Assurance Task Force to mandate the actions described in certain Boeing service bulletins as part of the "Aging Airplane Structural Modification Program." The actions specified by this AD are intended to prevent reduced structural integrity of the wing. The actions also reflect the FAA's decision that long term continued operational safety should be assured by actual modification of the airframe rather than repetitive inspections.

DATES:   Effective April 21, 1994. The incorporation by reference of certain publications listed in the regulations is approved by the Director of the Federal Register as of April 21, 1994.

ADDRESSES:   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 Federal Aviation Administration (FAA), Transport Airplane Directorate, Rules Docket, 1601 Lind Avenue, SW., Renton, Washington; or at Boeing Commercial Airplane Group, P.O. Box 3707, Seattle, Washington 98124-2207; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.

FOR FURTHER INFORMATION CONTACT:   Phil Forde, Aerospace Engineer, Airframe Branch, ANM-120S, FAA, Transport Airplane Directorate, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (206) 227-2771; fax (206) 227-1181.

SUPPLEMENTARY INFORMATION:   A proposal to amend part 39 of the Federal Aviation Regulations to include an airworthiness directive (AD) that is applicable to Boeing Model 707 series airplanes was published in the Federal Register on September 7, 1993 (58 FR 47085). That action proposed to require incorporation of a certain structural modification of the wing front spar lower chord.

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

One commenter supports the proposal.

Another commenter requests that the structural inspections and modifications referenced in Sections A.3 and A.4 of Appendix A of Boeing Document Number D6-54996, "Aging Airplane Service Bulletin Structural Modification and Inspection Program - Model 707/720," Revision D, dated January 23, 1992, be addressed in a single AD action, rather than in two different actions, as presently proposed by the FAA. This commenter points out that the FAA has issued a separate proposed AD, Docket 93-NM-80-AD (58 FR 53678, October 18, 1993), which would require the accomplishment of certain actions listed in Section 4 and Appendix A.4 of the Boeing Document, while this proposal (93-NM-82-AD) would require the accomplishment of actions referenced in Appendix A, Section A.3. The commenter contends that by issuing a single AD to cover both sections of the Boeing Document, the FAA will contribute to reducing the cost and complexity of publishing and tracking multiple AD's, while maintaining the same level of safety.

The FAA does not concur with the commenter's request, specifically because of the nature of the requirements of the currently proposed rules. The actions proposed in Docket 93-NM- 80-AD address structural inspections of both the Model 707 and Model 720, which are listed in Section 4 and Appendix A.4 of the Boeing Document. Those inspection actions entail various compliance times for implementation and a specified "phase-in" period for repetitive inspection intervals. On the other hand, the action proposed by this AD addresses a single modification of only Model 707 series airplanes, which is listed in Appendix A.3. of the Boeing Document. The modification action entails a specific compliance time for implementation based on either a flight cycle count or a calendar time limit. The FAA considers that to have combined the requirements for these dissimilar actions into one complex AD, would have created unnecessary confusion for affected operators. Therefore, as issued, there will be one AD addressing "inspections only" and another AD addressing the modification. This method of issuance will also ensure easier tracking of and proper compliance with the requirements of the AD's.

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 as proposed.

There are approximately 374 Model 707 series airplanes of the affected design in the worldwide fleet. The FAA estimates that 70 airplanes of U.S. registry will be affected by this AD within the initial threshold of 4 years. Approximately 194 work hours will be required to accomplish the modification, at an average labor charge of $55 per work hour. (This figure does not include downtime, planning, set up, familiarization, or tool acquisition costs.) The cost of the required modification kit is approximately $3,500 per airplane. Based on these figures, the total cost impact of this AD on U.S. operators within the initial threshold of 4 years is estimated to be $991,900, or $14,170 per airplane.

The total 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 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 14 CFR part 39 of the Federal Aviation Regulations as follows:

PART 39 - AIRWORTHINESS DIRECTIVES

1. The authority citation for part 39 continues to read as follows: Authority: 49 U.S.C. App. 1354(a), 1421 and 1423; 49 U.S.C. 106(g); and 14 CFR 11.89.

§ 39.13 - [Amended]
2. Section 39.13 is amended by adding the following new airworthiness directive:

REGULATORY TEXT:  
94-06-08 BOEING: Amendment 39-8856. Docket 93-NM-82-AD.

Applicability: Model 707-300, -300B, -300C, and -400 series airplanes, certificated in any category.

Compliance: Required as indicated, unless accomplished previously.

To prevent reduced structural integrity of the wing, accomplish the following:

(a) Prior to the accumulation of 20,000 total flight cycles or within the next 4 years after the effective date of this AD, whichever occurs later, accomplish the structural modification specified in Appendix A., Section A.3., of Boeing Document Number D6-54996, "Aging Airplane Service Bulletin Structural Modification and Inspection Program - Model 707/720," Revision D, dated January 23, 1992.

NOTE 1: Appendix A., Section A.3., of Boeing Document Number D6-54996 references Boeing Service Bulletin 3475 for procedures to modify the wing front spar lower chord at wing station 529.5.

NOTE 2: The modification required by this paragraph does not terminate the inspection requirements of any other AD unless that AD specifies that any such modification constitutes terminating action for the inspection requirements.

(b) 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 Aircraft Certification Office (ACO), FAA, Transport Airplane Directorate. 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.

(c) Special flight permits may be issued in accordance with FAR 21.197 and 21.199 to operate the airplane to a location where the requirements of this AD can be accomplished.

(d) The modification shall be done in accordance with Boeing Document Number D6-54996, "Aging Airplane Service Bulletin Structural Modification and Inspection Program - Model 707/720," Revision D, dated January 23, 1992, which contains the following list of effective pages:


Page Number
	
Revision Symbol Shown on Page
	
Date
Shown on Page

List of Active Pages
Pages c.1 and c.2	
D
	
(These pages are not dated)

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.

(e) This amendment becomes effective on April 21, 1994.

FOOTER: