[Federal Register Volume 62, Number 161 (Wednesday, August 20, 1997)]
[Rules and Regulations]
[Pages 44204-44206]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-21773]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 97-NM-124-AD; Amendment 39-10104; AD 97-17-02]
RIN 2120-AA64
Airworthiness Directives; Boeing Model 777-200 Series Airplanes
AGENCY: Federal Aviation Administration, DOT.
ACTION: Final rule; request for comments.
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SUMMARY: This amendment adopts a new airworthiness directive (AD) that
is applicable to certain Boeing Model 777-200 series airplanes. This
action requires repetitive torquing of the bushing retainer nuts of the
pivot pins in the horizontal stabilizer hinge assembly to tighten loose
nuts to the new torque value; and repetitive visual inspections, if
necessary, to detect bushing migration or damage to adjacent
structures, and repair of any damage. This proposal also provides for
an optional terminating action for the repetitive inspections. This
amendment is prompted by a report of a loose bushing retainer nut,
which may be attributed to low nut torque. The actions specified in
this AD are intended to detect and correct loose bushing retainer nuts
of the pivot pins in the horizontal stabilizer hinge assembly, which
could result in bushing migration and consequent damage to the adjacent
structure, and reduced controllability of the airplane.
DATES: Effective September 4, 1997.
The incorporation by reference of certain publications listed in
the regulations is approved by the Director of the Federal Register as
of September 4, 1997.
Comments for inclusion in the Rules Docket must be received on or
before October 20, 1997.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-103,
Attention: Rules Docket No. 97-NM-124-AD, 1601 Lind Avenue, SW.,
Renton, Washington 98055-4056.
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 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.
FOR FURTHER INFORMATION CONTACT: Stan Wood, Aerospace Engineer,
Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office,
1601 Lind Avenue, SW., Renton, Washington; telephone (425) 227-2772;
fax (425) 227-1181.
SUPPLEMENTARY INFORMATION: Boeing recently notified the FAA that an
unsafe condition may exist on certain Boeing Model 777-200 series
airplanes. Investigation revealed that a loose bushing retainer nut of
the pivot pin in the horizontal stabilizer hinge assembly was found on
a Boeing Model 777-200 flight test airplane that had accumulated
approximately 2,000 total flight cycles. The cause of the loose bushing
retainer nut may be attributed to low nut torque. A loose bushing
retainer nut of the pivot pin in the horizontal stabilizer hinge
assembly, if not corrected, could result in bushing migration and
consequent damage to the adjacent structure, and reduced
controllability of the airplane.
[[Page 44205]]
Explanation of Relevant Service Information
Boeing has issued Service Bulletin 777-53-0006, dated May 8, 1997,
which describes procedures for repetitive inspections of the bushing
retainer nuts of the pivot pins in the horizontal stabilizer hinge
assembly to detect and correct loose bushing retainer nuts, migration
of the bushings, or damage to adjacent structures. This service
bulletin also describes optional procedures for tightening the bushing
retainer nuts to a torque level of 1,000 to 1,500 in-lbs. In addition,
this service bulletin describes procedures for tightening the bushing
retainer nuts and installing anti-rotation brackets to prevent the nuts
from rotating, which would eliminate the need for repetitive
inspections.
Explanation of the Requirements of the Rule
Since an unsafe condition has been identified that is likely to
exist or develop on other Boeing Model 777-200 series airplanes of the
same type design, this AD is being issued to detect and correct loose
bushing retainer nuts of the pivot pins in the horizontal stabilizer
hinge assembly, which could result in bushing migration and consequent
damage to the adjacent structure, and reduced controllability of the
airplane. This action requires repetitive torquing of the bushing
retainer nuts of the pivot pins in the horizontal stabilizer hinge
assembly to tighten loose nuts to the new torque value of 1,000 to
1,500 in-lbs; and repetitive visual inspections, if necessary, to
detect bushing migration or damage to adjacent structures. This
proposal also provides for an optional action of installing brackets to
prevent rotation of the bushing retainer nuts, which would constitute
termination for the repetitive inspections. These actions are required
to be accomplished in accordance with the service bulletin described
previously.
Differences Between the AD and the Relevant Service Information
Operators should note that, although Boeing Service Bulletin 777-
53-0006 provides procedures to eliminate the need for repetitive
inspections after accomplishment of a third inspection (2,150 flight
cycles), this AD requires repetitive inspections at intervals not to
exceed 1,000 flight cycles, until accomplishment of the terminating
action. In developing an appropriate compliance time for this AD, the
FAA has determined that the repetitive inspections should not be
extended to a third inspection (2,150 flight cycles) and that, in order
to provide an acceptable level of safety, repetitive intervals should
not exceed 1,000 flight cycles.
Operators should also note that, although the service bulletin
specifies that the manufacturer must be contacted for instructions in
the repair of damage, this AD requires the repair to be accomplished in
accordance with a method approved by the FAA.
Interim Action
The FAA is considering further rulemaking to supersede this AD to
require installing anti-rotation brackets to prevent the nuts from
rotating. However, the planned compliance time for accomplishment of
this action is sufficiently long so that prior notice and time for
public comment will be practicable.
Determination of Rule's Effective Date
Since a situation exists that requires the immediate adoption of
this regulation, it is found that notice and opportunity for prior
public comment hereon are impracticable, and that good cause exists for
making this amendment effective in less than 30 days.
Comments Invited
Although this action is in the form of a final rule that involves
requirements affecting flight safety and, thus, was not preceded by
notice and an 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 97-NM-124-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.
The FAA has determined that this regulation is an emergency
regulation that must be issued immediately to correct an unsafe
condition in aircraft, and that it is not a ``significant regulatory
action'' under Executive Order 12866. It has been determined further
that this action involves an emergency regulation under DOT Regulatory
Policies and Procedures (44 FR 11034, February 26, 1979). If it is
determined that this emergency regulation otherwise would be
significant under DOT Regulatory Policies and Procedures, a final
regulatory evaluation will be prepared and placed in the Rules Docket.
A copy of it, if filed, 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.
[[Page 44206]]
Sec. 39.13 [Amended]
2. Section 39.13 is amended by adding the following new
airworthiness directive:
97-17-02 Boeing: Amendment 39-10104. Docket 97-NM-124-AD.
Applicability: Model 777-200 series airplanes, line numbers 3,
5, 7 through 9 inclusive, 11 through 13 inclusive, 15 through 17
inclusive, and 19 through 22 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
otherwise 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 correct loose bushing retainer nuts of the pivot
pins in the horizontal stabilizer hinge assembly, which could result
in bushing migration and consequent damage to the adjacent
structure, and reduced controllability of the airplane, accomplish
the following:
(a) Within 150 flight cycles after the effective date of this
AD, torque the bushing retainer nuts to the new torque value of
1,000 to 1,500 in-lbs, in accordance with Figure 2 of the Boeing
Service Bulletin 777-53-0006, dated May 8, 1997. Repeat the torquing
thereafter at intervals not to exceed 1,000 flight cycles.
Note 2: Where there are differences between the AD and the
service bulletin, the AD prevails.
(b) If any bushing retainer nut is loose and is not correctly
attached to the bushing, prior to further flight, perform a visual
inspection to determine whether bushing migration has occurred, in
accordance with Figure 2 of the Boeing Service Bulletin 777-53-0006,
dated May 8, 1997.
(1) If bushing migration has not occurred, prior to further
flight, tighten the bushing retainer nuts in accordance with Figure
2 of the service bulletin. Repeat the visual inspection thereafter
at intervals not to exceed 1,000 flight cycles.
(2) If bushing migration has occurred, prior to further flight,
inspect/replace the bushing and other affected components and repair
any damage, in accordance with a method approved by the Manager,
Seattle Aircraft Certification Office (ACO), FAA, Transport Airplane
Directorate.
(c) Accomplishment of installing an anti-rotation bracket in
accordance with Figure 3 of Boeing Service Bulletin 777-53-0006,
dated May 8, 1997, 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 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 3: 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.
(f) Certain actions shall be done in accordance with Boeing
Service Bulletin 777-53-0006, dated May 8, 1997. 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.
(g) This amendment becomes effective on September 4, 1997.
Issued in Renton, Washington, on August 11, 1997.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 97-21773 Filed 8-19-97; 8:45 am]
BILLING CODE 4910-13-U