[Federal Register Volume 65, Number 229 (Tuesday, November 28, 2000)]
[Proposed Rules]
[Pages 70819-70821]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 00-30320]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2000-NM-279-AD]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 707 Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes the adoption of a new airworthiness 
directive (AD) that is applicable to certain Boeing Model 707 series 
airplanes. This proposal would require modification of certain areas of 
the upper skin of the wing. This action is necessary to prevent 
cracking of the upper skin of the wing, which could result in reduced 
structural integrity of the wing. This action is intended to address 
the identified unsafe condition.

DATES: Comments must be received by January 12, 2001.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 2000-NM-279-AD, 1601 Lind Avenue, SW., 
Renton, Washington 98055-4056. Comments may be inspected at this 
location between 9:00 a.m. and 3:00 p.m., Monday through Friday, except 
Federal holidays. Comments may be submitted via fax to (425) 227-1232. 
Comments may also be sent via the Internet using the following address: 
[email protected]. Comments sent via fax or the Internet must 
contain ``Docket No. 2000-NM-279-AD'' in the subject line and need not 
be submitted in triplicate. Comments sent via the Internet as attached 
electronic files must be formatted in Microsoft Word 97 for Windows or 
ASCII text.
    The service information referenced in the proposed rule 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.

FOR FURTHER INFORMATION CONTACT: James Rehrl, Aerospace Engineer, 
Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 
227-2783; fax (425) 227-1181.

SUPPLEMENTARY INFORMATION:   

Comments Invited

    Interested persons are invited to participate in the making of the 
proposed 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 above. All 
communications received on or before the closing date for comments, 
specified above, will be considered before taking action on the 
proposed rule. The proposals contained in this action may be changed in 
light of the comments received.
    Submit comments using the following format:
     Organize comments issue-by-issue. For example, discuss a 
request to change the compliance time and a request to change the 
service bulletin reference as two separate issues.
     For each issue, state what specific change to the proposed 
AD is being requested.
     Include justification (e.g., reasons or data) for each 
request.
    Comments are specifically invited on the overall regulatory, 
economic, environmental, and energy aspects of the proposed 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 summarizing each FAA-public contact concerned with 
the substance of this proposal will be filed in the Rules Docket.
    Commenters wishing the FAA to acknowledge receipt of their comments 
submitted in response to this action must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 2000-NM-279-AD.'' The postcard will be date stamped 
and returned to the commenter.

Availability of NPRMs

    Any person may obtain a copy of this NPRM by submitting a request 
to the FAA, Transport Airplane Directorate, ANM-114, Attention: Rules 
Docket No. 2000-NM-279-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    The FAA has received reports indicating that cracking has been 
detected in the upper skin of the wing at wing stringers 10A and 11A on 
both the left- and right-hand wings of certain Boeing Model 707 series 
airplanes. The cracking has been attributed to skin fatigue. This 
condition, if not corrected, could result in reduced structural 
integrity of the wing.

Explanation of Relevant Service Information

    The FAA has reviewed and approved Boeing Service Bulletin 2378, 
Revision 1, dated June 30, 1967, which, among other actions, describes 
procedures for modification of the upper skin of the wing at wing 
stringers 10A and 11A. The modification involves removing fasteners at 
the inboard and outboard ends of the stringer, inspecting these 
fastener holes using an eddy current method to detect cracking, 
counterboring the inner surface of the stringer at each fastener hole, 
installing an anti-fretting strip between the wing and stringer, 
enlarging fastener holes to remove fatigued metal, and installing new, 
improved fasteners. Accomplishment of the actions specified in the 
service bulletin is intended to adequately address the identified 
unsafe condition.

Explanation of Requirements of Proposed Rule

    Since an unsafe condition has been identified that is likely to 
exist or develop on other products of this same type design, the 
proposed AD would require accomplishment of the modification specified 
in the service bulletin described previously, except as discussed 
below.

Differences Between the Proposed Rule and Service Bulletin

    Operators should note that the service bulletin recommends, and 
describes procedures for, an initial ultrasonic inspection of the wing 
upper skin prior to the accumulation of 18,000 flight hours or within 
800 flight hours after receipt of the service bulletin, whichever 
occurs later. The service bulletin also recommends repetitive 
inspections at intervals not to exceed 1,600 flight hours, until 
accomplishment of a repair or

[[Page 70820]]

modification. The service bulletin suggests accomplishment of the 
modification described previously ``at the major overhaul closest to 
20,000 flight hours.''
    This proposed AD would not require the repetitive inspections 
specified in the service bulletin but would require the modification of 
the upper skin of the wing at wing stringers 10A and 11A prior to the 
accumulation of 20,000 flight hours or within 24 months after the 
effective date of this AD, whichever occurs later. Mandating the 
terminating action is based on the FAA's determination that long-term 
continued operational safety will be better assured by modifications or 
design changes to remove the source of the problem, rather than by 
repetitive inspections. Long-term inspections may not provide the 
degree of safety assurance necessary for the transport airplane fleet. 
This, coupled with a better understanding of the human factors 
associated with numerous continual inspections, has led the FAA to 
consider placing less emphasis on inspections and more emphasis on 
design improvements. The proposed modification requirement is 
consistent with these conditions. Also, because many of the airplanes 
that are affected by this AD will have already passed the compliance 
threshold of 20,000 flight hours, as suggested in the service bulletin, 
the FAA finds that it is appropriate to include a grace period of 24 
months after the effective date of this AD, to allow time for the 
modification to be accomplished on all affected airplanes in a timely 
manner.
    Operators also should note that, as explained previously, the 
procedures for the modification include an HFEC inspection of fastener 
holes ``to ensure that there are no cracks.'' However, the service 
bulletin does not include instructions for corrective actions if a 
crack is found during this inspection. Therefore, paragraph (b) of this 
AD states that, if any crack is found during the inspection that is 
included as part of the modification, the cracks must be repaired in 
accordance with the applicable chapter of the Boeing 707 Structural 
Repair Manual.

Cost Impact

    There are approximately 5 airplanes of the affected design in the 
worldwide fleet. The FAA estimates that 1 airplane of U.S. registry 
would be affected by this proposed AD, that it would take approximately 
8 work hours to accomplish the proposed actions, and that the average 
labor rate is $60 per work hour. Based on these figures, the cost 
impact of the proposed AD on the single U.S. operator is estimated to 
be $480.
    The cost impact figure discussed above is based on assumptions that 
no operator has yet accomplished any of the proposed requirements of 
this AD action, and that no operator would accomplish those actions in 
the future if this proposed 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 proposed herein 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. Therefore, it 
is determined that this proposal would not have federalism implications 
under Executive Order 13132.
    For the reasons discussed above, I certify that 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) if promulgated, 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 copy of the draft 
regulatory evaluation prepared for this action is contained in the 
Rules Docket. A copy of it may be obtained by contacting the Rules 
Docket at the location provided under the caption ADDRESSES.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Safety.

The Proposed Amendment

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration proposes to amend 
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:

Boeing:  Docket 2000-NM-279-AD.
    Applicability: Model 707 series airplanes; as listed in Boeing 
Service Bulletin 2378, Revision 1, dated June 30, 1967; 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 (c) 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 prevent cracking of the upper skin of the wing, which could 
result in reduced structural integrity of the wing, accomplish the 
following:

Modification

    (a) Prior to the accumulation of 20,000 total flight hours, or 
within 24 months after the effective date of this AD, whichever 
occurs later, modify the upper skin of the wing at wing stringers 
10A and 11A on both the left-and right-hand wings of the airplane, 
in accordance with Boeing Service Bulletin 2378, Revision 1, dated 
June 30, 1967.
    (b) During the high frequency eddy current inspection included 
as part of the modification required by paragraph (a) of this AD, if 
any crack is found, prior to further flight, repair in accordance 
with the applicable section of the Boeing 707 Structural Repair 
Manual.

Alternative Methods of Compliance

    (c) 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. 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 2: 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

    (d) 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.


[[Page 70821]]



    Issued in Renton, Washington, on November 21, 2000.
Donald L. Riggin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 00-30320 Filed 11-27-00; 8:45 am]
BILLING CODE 4910-13-P