[Federal Register Volume 63, Number 225 (Monday, November 23, 1998)]
[Proposed Rules]
[Pages 64657-64659]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-31175]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-NM-278-AD]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 767 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 767 series 
airplanes. This proposal would require repetitive inspections of 
certain H-11 tension bolts at each side-of-body kick-load fitting and 
on the lower splice plate (both located on the wing rear spar) to 
detect damaged, broken, or improperly sealed bolts; and follow-on 
actions, if necessary. This proposal also would require eventual 
replacement of the existing bolts with new, improved bolts, which 
constitutes terminating action for the repetitive inspections. This 
proposal is prompted by a report that an operator found two broken H-11 
tension bolts on the side-of-body kick-load fitting on one airplane. 
The actions specified by the proposed AD are intended to prevent 
cracking of the bolts due to stress corrosion, which could result in 
reduced structural integrity of the wing-to-body joint structure.

DATES: Comments must be received by January 7, 1999.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 98-NM-278-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.
    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 G. Rehrl, Aerospace Engineer, 
Airframe Branch, ANM-120S, FAA, Transport Airplane Directorate, Seattle 
Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, 
Washington

[[Page 64658]]

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 notice may be changed in 
light of the comments received.
    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 notice must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 98-NM-278-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. 98-NM-278-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    The FAA has received a report indicating that an operator found two 
broken H-11 tension bolts on a Boeing Model 767 series airplane. The 
broken bolts were on the side-of-body kick-load fitting, which is 
located on the wing rear spar. The broken bolts were attributed to 
stress corrosion cracking that resulted from a combination of factors, 
such as deterioration of the bolt finish, an existing pre-load, and the 
presence of moisture. Such stress corrosion cracking, if not detected, 
could result in reduced structural integrity of the wing-to-body joint 
structure.

Explanation of Relevant Service Information

    The FAA has reviewed and approved Boeing Service Bulletin 767-
57A0064, Revision 1, dated July 9, 1998. That service bulletin 
describes procedures for repetitive detailed visual inspections of 
certain H-11 tension bolts at each side-of-body kick-load fitting and 
on the lower splice plate (both located on the wing rear spar) to 
detect damaged, broken, or improperly sealed bolts; and follow-on 
actions, if necessary. The service bulletin specifies two inspection 
options for the operator to choose from when performing the 
inspections: Option 1 allows the operator to defer the inspection of 
the four H-11 tension bolts on the lower splice plate, provided that 
the detailed visual inspections of the H-11 tension bolts on the kick-
load fitting are repeated at 90-day intervals. Option 2 allows the 
operator to repeat the detailed visual inspections of the H-11 tension 
bolts on the kick-load fitting at 18-month intervals, provided the 
operator also inspects the H-11 tension bolts on the lower splice plate 
at the same time.
    The service bulletin also describes procedures for replacement of 
any damaged or broken bolts with new, improved bolts, which would 
eliminate the need for the repetitive inspections. 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 actions specified in 
the service bulletin described previously, except as discussed below.

Differences Between Proposed Rule and Service Bulletin

    Operators should note that this AD proposes to mandate, within 
6,000 flight cycles or 48 months after the effective date of this AD, 
whichever occurs first, the replacement of all four H-11 tension bolts 
at each side-of-body kick-load fitting with new, improved bolts as 
described in Boeing Service Bulletin 767-57A0064, Revision 1, as 
terminating action for the repetitive inspections.
    The FAA has determined that long-term continued operational safety 
will be better assured by design changes to remove the source of the 
problem, rather than by repetitive inspections. Long-term inspections 
may not be providing 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 replacement requirement 
is in consonance with these conditions.

Cost Impact

    There are approximately 177 airplanes of the affected design in the 
worldwide fleet. The FAA estimates that 70 airplanes of U.S. registry 
would be affected by this proposed AD.
    It would take approximately 2 work hours per airplane to accomplish 
the proposed inspection of the kick-load fitting, at an average labor 
rate of $60 per work hour. Based on these figures, the cost impact of 
the inspection of the kick-load fitting proposed by this AD on U.S. 
operators is estimated to be $8,400, or $120 per airplane, per 
inspection cycle.
    It would take approximately 23 work hours per airplane to 
accomplish the proposed inspection of the splice plate, at an average 
labor rate of $60 per work hour. Based on these figures, the cost 
impact of the inspection of the splice plate proposed by this AD on 
U.S. operators is estimated to be $96,600, or $1,380 per airplane, per 
inspection cycle.
    It would take approximately 140 work hours per airplane to 
accomplish the proposed replacement, at an average labor rate of $60 
per work hour. Parts would be provided by the manufacturer at no cost 
to the operators. Based on these figures, the cost impact of the 
replacement proposed by this AD on U.S. operators is estimated to be 
$588,000, or $8,400 per airplane.
    The cost impact figures discussed above are 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 AD were not adopted.

Regulatory Impact

    The regulations proposed herein would 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 
proposal would not have sufficient federalism implications to warrant 
the preparation of a Federalism Assessment.

[[Page 64659]]

    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 98-NM-278-AD.
    Applicability: Model 767 series airplanes, line positions 1 
through 177 inclusive, 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 prevent cracking of the H-11 tension bolts on the side-of-
body kick-load fitting due to stress corrosion, which could result 
in reduced structural integrity of the wing-to-body joint structure, 
accomplish the following:
    (a) Within 90 days after the effective date of this AD: Perform 
a detailed visual inspection of the four H-11 tension bolts at each 
side-of-body kick-load fitting located on the wing rear spar to 
detect damaged, broken, or improperly sealed bolts; and accomplish 
the requirements in either paragraph (a)(1) or (a)(2) of this AD, in 
accordance with the Accomplishment Instructions of Boeing Service 
Bulletin 767-57A0064, Revision 1, dated July 9, 1998.
    (1) Option 1: Repeat the detailed visual inspection at each 
side-of-body kick-load fitting thereafter at intervals not to exceed 
90 days, until accomplishment of the actions specified in paragraph 
(c) of this AD. Or
    (2) Option 2: Perform a detailed visual inspection of the four 
H-11 tension bolts on the lower splice plate located on the wing 
rear spar to detect damaged, broken, or improperly sealed bolts. 
Repeat the detailed visual inspection of each side-of-body kick-load 
fitting and the lower splice plate thereafter at intervals not to 
exceed 18 months, until accomplishment of the actions specified in 
paragraph (c) of this AD.
    (b) If evidence of any damaged, broken, or improperly sealed 
bolt is detected, prior to further flight, replace the discrepant 
bolt with a new, improved bolt in accordance with Boeing Service 
Bulletin 767-57A0064, Revision 1, dated July 9, 1998. Thereafter, 
repeat the detailed visual inspection in either paragraph (a)(1) or 
(a)(2) of this AD, as applicable, until accomplishment of the 
actions specified in paragraph (c) of this AD.
    (c) Within 6,000 flight cycles or 48 months after the effective 
date of this AD, whichever occurs first, replace all four H-11 
tension bolts at each side-of-body kick-load fitting with new, 
improved bolts, and perform a detailed visual inspection to detect 
any damaged, broken, or improperly sealed bolt of the lower splice 
plate located on the wing rear spar, in accordance with Boeing 
Service Bulletin 767-57A0064, Revision 1, dated July 9, 1998. If any 
damaged, broken, or improperly sealed bolt is detected during the 
inspection, prior to further flight, replace the discrepant bolt 
with a new, improved bolt in accordance with Boeing Service Bulletin 
767-57A0064, Revision 1, dated July 9, 1998. Accomplishment of the 
actions specified in this paragraph constitutes terminating action 
for the repetitive inspection requirements of this AD.
    (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 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 2: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Seattle ACO.

    (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.

    Issued in Renton, Washington, on November 16, 1998.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 98-31175 Filed 11-20-98; 8:45 am]
BILLING CODE 4910-13-U