[Federal Register Volume 65, Number 2 (Tuesday, January 4, 2000)]
[Proposed Rules]
[Pages 250-251]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 00-50]
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Proposed Rules
Federal Register
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This section of the FEDERAL REGISTER contains notices to the public of
the proposed issuance of rules and regulations. The purpose of these
notices is to give interested persons an opportunity to participate in
the rule making prior to the adoption of the final rules.
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Federal Register / Vol. 65, No. 2 / Tuesday, January 4, 2000 /
Proposed Rules
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 99-NM-346-AD]
RIN 2120-AA64
Airworthiness Directives; Boeing Model 777 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 777 series
airplanes. This proposal would require a one-time inspection to detect
cracking of the fastener holes common to the upper wing skins and
trailing edge panels of both wings, and corrective actions, if
necessary. This proposal also would require coldwork of the fastener
holes and installation of new or serviceable fasteners. This proposal
is prompted by a report indicating that fatigue cracks have been found
in the upper wing skin of both wings. The actions specified by the
proposed AD are intended to prevent fatigue cracking of the upper wing
skin, which could result in reduced structural integrity of the wing.
DATES: Comments must be received by February 18, 2000.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-114,
Attention: Rules Docket No. 99-NM-346-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: Stan Wood, Aerospace Engineer,
Airframe Branch, ANM-120S, FAA, Transport Airplane Directorate, Seattle
Aircraft Certification Office, 1601 Lind Avenue, SW., Renton,
Washington 98055-4056; telephone (425) 227-2772; 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 99-NM-346-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. 99-NM-346-AD, 1601 Lind Avenue, SW., Renton, Washington
98055-4056.
Discussion
The FAA has received a report indicating that fatigue cracks have
been found in the upper wing skin of both wings on a Boeing Model 777
test airplane. During fatigue testing of the airplane, two cracks were
detected at 80,813 flight cycles. Both cracks were detected at the tab
out for the outboard support fitting of the main landing gear beam. The
crack found on the left upper wing skin was 1.5 inches in length, and
the crack found in the right upper wing skin was 5.1 inches in length.
Examination of the cracked parts was inconclusive as to when the cracks
had initiated. Such fatigue cracking, if not detected and corrected,
could result in reduced structural integrity of the wing.
Explanation of Relevant Service Information
The FAA has reviewed and approved Boeing Alert Service Bulletin
777-57A0022, dated August 26, 1999, which describes procedures for a
one-time eddy current inspection to detect cracking of the fastener
holes common to the upper wing skins and trailing edge panels of both
wings, and corrective actions, if necessary. The corrective actions
involve rework and re-inspection of the fastener hole. Additionally,
for any fastener hole that may require rework and re-inspections, the
corrective actions also involve measurement of the fastener hole
diameter and edge margin to ensure specific limits are maintained. The
alert service bulletin also describes procedures for coldwork of the
fastener holes and installation of new or serviceable fasteners.
Accomplishment of the actions specified in the alert 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 alert service bulletin described previously, except as discussed
below.
Differences Between Proposed Rule and Alert Service Bulletin
Operators should note that, although the 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
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accordance with a method approved by the FAA.
Cost Impact
There are approximately 82 airplanes of the affected design in the
worldwide fleet. The FAA estimates that 33 airplanes of U.S. registry
would be affected by this proposed AD, that it would take approximately
13 work hours per airplane to accomplish the proposed actions, and that
the average labor rate is $60 per work hour. Required parts would cost
approximately $216 per airplane. Based on these figures, the cost
impact of the proposed AD on U.S. operators is estimated to be $32,868,
or $996 per airplane.
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 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.
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 99-NM-346-AD.
Applicability: Model 777 series airplanes having line numbers 1
through 119 inclusive, except line numbers 94, 102, 104, and 118,
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 fatigue cracking of the upper wing skin, which could
result in reduced structural integrity of the wing, accomplish the
following:
Eddy Current Inspection of Fastener Holes
(a) Prior to the accumulation of 16,000 total flight cycles or
40,000 total flight hours, whichever occurs earlier, perform a one-
time eddy current inspection to detect cracking of the fastener
holes common to the upper wing skins and trailing edge panels of
both wings, in accordance with Boeing Alert Service Bulletin 777-
57A0022, dated August 26, 1999.
Rework and Re-Inspection of Fastener Hole
(b) If any cracking is detected during the inspection required
by paragraph (a) of this AD, prior to further flight, oversize the
fastener hole and perform additional eddy current inspections to
detect cracking of the fastener holes until all cracking is no
longer detectable by means of eddy current inspection. Perform the
actions in accordance with Boeing Alert Service Bulletin 777-
57A0022, dated August 26, 1999. Prior to further flight, oversize
the fastener hole an additional \1/32\-inch minimum and measure the
starting hole diameter and edge margin of the fastener hole, in
accordance with the alert service bulletin.
(1) If the fastener hole diameter or the edge margin of any
fastener hole is not within the limits specified in the alert
service bulletin, prior to further flight, repair in accordance with
a method approved by the Manager, Seattle Aircraft Certification
Office (ACO), FAA, Transport Airplane Directorate, or a Boeing
Company Designated Engineering Representative who has been
authorized by the FAA to make such findings. For a repair method to
be approved by the Manager, Seattle ACO, as required by this
paragraph, the Manager's approval letter must specifically reference
this AD.
(2) If the fastener hole diameter and edge margin of all the
fastener holes are within the limits specified in the alert service
bulletin, prior to further flight, accomplish the requirements of
paragraph (c) of this AD.
Coldwork of Fastener Holes
(c) If no cracking is detected during the eddy current
inspection required by paragraph (a), or the fastener hole diameter
and edge margin of all the fastener holes are within the limits
required by paragraph (b) of this AD, prior to further flight,
coldwork the fastener holes and install new or serviceable
fasteners, in accordance with Boeing Alert Service Bulletin 777-
57A0022, dated August 26, 1999.
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 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
(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 December 28, 1999.
D.L. Riggin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 00-50 Filed 1-3-00; 8:45 am]
BILLING CODE 4910-13-U
