[Federal Register Volume 61, Number 132 (Tuesday, July 9, 1996)]
[Rules and Regulations]
[Pages 35940-35942]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-16949]


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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 96-NM-134-AD; Amendment 39-9688; AD 96-14-06]
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 inspections for broken lockwires on the 
bearing retainer nut of the pivot fittings of the horizontal 
stabilizer. This AD also requires eventual modification of the bearing 
nut retention means, which, when accomplished, terminates the 
repetitive inspections. This amendment is prompted by reports of broken 
lockwires on the bearing retainer nut of the pivot fittings of the 
horizontal stabilizer due to inadequate torquing of the nut. The 
actions specified in this AD are intended to prevent failure of the 
lockwires, which could result in loosening of the retainer nut for the 
pivot bearing of the horizontal stabilizer, and subsequent migration of 
the pivot bearing. This condition, if not corrected, could result in 
reduced controllability of the airplane.

DATES: Effective July 24, 1996.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of July 24, 1996.
    Comments for inclusion in the Rules Docket must be received on or 
before September 9, 1996.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-103, 
Attention: Rules Docket No. 96-NM-134-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

[[Page 35941]]

Avenue, SW., Renton, Washington; telephone (206) 227-2772; fax (206) 
227-1181.

SUPPLEMENTARY INFORMATION: The FAA has received reports indicating that 
broken lockwires were found on the bearing retainer nut of the pivot 
fittings (bearings) of the horizontal stabilizer on Boeing Model 777-
200 series airplanes. In one of these incidents, the retainer nut on 
the left and right sides of the horizontal stabilizer also was loose. 
The lockwires may have broken and the retainer nuts may have become 
loose due to inadequate torquing of the nut. Failure of the lockwire 
could result in loosening of the retainer nut for the pivot bearing of 
the horizontal stabilizer. Loss of the retainer nut could result in 
migration of the pivot bearing. This condition, if not corrected, could 
result in reduced controllability of the airplane.

Explanation of Relevant Service Information

    The FAA has reviewed and approved Boeing Alert Service Bulletin 
777-55A0003, Revision 1, dated June 20, 1996, which describes 
procedures for repetitive visual inspections to detect broken lockwires 
on the bearing retainer nut of the pivot fittings of the horizontal 
stabilizer (left and right sides). The alert service bulletin also 
describes procedures for eventual modification of the bearing nut 
retention means, which, when accomplished, eliminates the need for the 
repetitive inspections. The modification involves removing all lockwire 
on the nut, tightening the nut, and installing a new nut retainer. 
Accomplishment of the modification will prevent rotation of the bearing 
retainer nut.

Explanation of the Requirements of the Rule

    Since an unsafe condition has been identified that is likely to 
exist or develop on other Model 777-200 series airplanes of the same 
type design, this AD is being issued to prevent reduced controllability 
of the airplane due to failure of the lockwire on the bearing retainer 
nut of the pivot fittings of the horizontal stabilizer, loosening of 
the retainer nut for the pivot bearing, and subsequent migration of the 
pivot bearing. This AD requires repetitive visual inspections for 
broken lockwires on the bearing retainer nut of the pivot fittings of 
the horizontal stabilizer (left and right sides). This AD also requires 
eventual modification of the bearing nut retention means, which, when 
accomplished, terminates the repetitive inspections. The actions are 
required to be accomplished in accordance with the alert service 
bulletin described previously.

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 96-NM-134-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.


Sec. 39.13  [Amended]

    2. Section 39.13 is amended by adding the following new 
airworthiness directive:

96-14-06 Boeing: Amendment 39-9688. Docket 96-NM-134-AD.

    Applicability: Model 777-200 series airplanes; line positions 1, 
3, 5, 7, 8, 9, 11, 12, 13, 15, 16, 17, 19, 20, 21, 22, and 23; 
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 (b) 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.

[[Page 35942]]

    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent reduced controllability of the airplane due to 
failure of the lockwire on the bearing retainer nut of the pivot 
fittings of the horizontal stabilizer, loosening of the retainer nut 
for the pivot bearing, and subsequent migration of the pivot 
bearing, accomplish the following:
    (a) Within 150 flight cycles after the effective date of this 
AD: Perform a visual inspection for broken lockwires on the bearing 
retainer nut of the pivot fittings of the horizontal stabilizer 
(left and right sides), in accordance with the Accomplishment 
Instructions of Boeing Alert Service Bulletin 777-55A0003, Revision 
1, dated June 20, 1996.
    (1) If no broken lockwire is found: Repeat the inspection within 
500 flight cycles following accomplishment of the initial 
inspection. Within 1,000 flight cycles after accomplishment of the 
initial inspection, modify the bearing nut retention means in 
accordance with Figure 3 of the alert service bulletin. Following 
accomplishment of the modification, no further action is required by 
paragraph (a) of this AD.
    (2) If only one broken lockwire is found: Repeat the inspection 
thereafter at intervals not to exceed 150 flight cycles. Within 450 
flight cycles after accomplishment of the initial inspection, modify 
the bearing nut retention means in accordance with Figure 3 of the 
alert service bulletin. Following accomplishment of the 
modification, no further action is required by paragraph (a) of this 
AD.
    (3) If two broken lockwires are found: Repeat the inspection and 
ensure that the bearing retainer nut is tight thereafter at 
intervals not to exceed 10 flight cycles. Within 100 flight cycles 
after accomplishment of the initial inspection, modify the bearing 
nut retention means in accordance with Figure 3 of the alert service 
bulletin. Following accomplishment of the modification, no further 
action is required by paragraph (a) of this AD.
    (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 2: 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 
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.
    (d) The actions shall be done in accordance with Boeing Alert 
Service Bulletin 777-55A0003, Revision 1, dated June 20, 1996. 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 July 24, 1996.

    Issued in Renton, Washington, on June 27, 1996.
S.R. Miller,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 96-16949 Filed 7-8-96; 8:45 am]
BILLING CODE 4910-13-U