Airworthiness Directives; Boeing Model 777 Airplanes, 16061-16063 [E6-4619]

Agencies

• Federal Aviation Administration
• DEPARTMENT OF TRANSPORTATION

[Federal Register Volume 71, Number 61 (Thursday, March 30, 2006)]
[Proposed Rules]
[Pages 16061-16063]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: E6-4619]


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Proposed Rules
                                                Federal Register
________________________________________________________________________

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. 71, No. 61 / Thursday, March 30, 2006 / 
Proposed Rules

[[Page 16061]]



DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2006-24270; Directorate Identifier 2005-NM-200-AD]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 777 Airplanes

AGENCY: Federal Aviation Administration (FAA), Department of 
Transportation (DOT).

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD) 
for all Boeing Model 777 airplanes. This proposed AD would require, for 
the drive mechanism of the horizontal stabilizer, repetitive detailed 
inspections for discrepancies; repetitive lubrication of the ballnut 
and ballscrew; repetitive measurements of the freeplay between the 
ballnut and the ballscrew; and corrective action if necessary. This 
proposed AD results from a report of extensive corrosion of a ballscrew 
in the drive mechanism of the horizontal stabilizer on a Boeing Model 
757 airplane, which is similar in design to the ballscrew on certain 
Model 777 airplanes. We are proposing this AD to prevent an undetected 
failure of the primary load path for the ballscrew in the horizontal 
stabilizer and subsequent wear and failure of the secondary load path, 
which could lead to loss of control of the horizontal stabilizer and 
consequent loss of control of the airplane.

DATES: We must receive comments on this proposed AD by May 15, 2006.

ADDRESSES: Use one of the following addresses to submit comments on 
this proposed AD.
     DOT Docket Web site: Go to https://dms.dot.gov and follow 
the instructions for sending your comments electronically.
     Government-wide rulemaking Web site: Go to https://
www.regulations.gov and follow the instructions for sending your 
comments electronically.
     Mail: Docket Management Facility, U.S. Department of 
Transportation, 400 Seventh Street, SW., Nassif Building, room PL-401, 
Washington, DC 20590.
     Fax: (202) 493-2251.
     Hand Delivery: Room PL-401 on the plaza level of the 
Nassif Building, 400 Seventh Street, SW., Washington, DC, between 9 
a.m. and 5 p.m., Monday through Friday, except Federal holidays.
    Contact Boeing Commercial Airplanes, P.O. Box 3707, Seattle, 
Washington 98124-2207, for the service information identified in this 
proposed AD.

FOR FURTHER INFORMATION CONTACT: Kelly McGuckin, Aerospace Engineer, 
Systems and Equipment Branch, ANM-130S, FAA, Seattle Aircraft 
Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98055-
4056; telephone (425) 917-6490; fax (425) 917-6590.

SUPPLEMENTARY INFORMATION:

Comments Invited

    We invite you to submit any relevant written data, views, or 
arguments regarding this proposed AD. Send your comments to an address 
listed in the ADDRESSES section. Include the docket number ``FAA-2006-
24270; Directorate Identifier 2005-NM-200-AD'' at the beginning of your 
comments. We specifically invite comments on the overall regulatory, 
economic, environmental, and energy aspects of the proposed AD. We will 
consider all comments received by the closing date and may amend the 
proposed AD in light of those comments.
    We will post all comments we receive, without change, to https://
dms.dot.gov, including any personal information you provide. We will 
also post a report summarizing each substantive verbal contact with FAA 
personnel concerning this proposed AD. Using the search function of 
that web site, anyone can find and read the comments in any of our 
dockets, including the name of the individual who sent the comment (or 
signed the comment on behalf of an association, business, labor union, 
etc.). You may review DOT's complete Privacy Act Statement in the 
Federal Register published on April 11, 2000 (65 FR 19477-78), or you 
may visit https://dms.dot.gov.

Examining the Docket

    You may examine the AD docket on the Internet at https://
dms.dot.gov, or in person at the Docket Management Facility office 
between 9 a.m. and 5 p.m., Monday through Friday, except Federal 
holidays. The Docket Management Facility office (telephone (800) 647-
5227) is located on the plaza level of the Nassif Building at the DOT 
street address stated in the ADDRESSES section. Comments will be 
available in the AD docket shortly after the Docket Management System 
receives them.

Discussion

    On January 31, 2000, there was an accident involving a McDonnell 
Douglas Model DC-9-83 (MD-83) airplane. The National Transportation 
Safety Board (NTSB) determined that the probable cause of the accident 
was a loss of airplane pitch control resulting from the in-flight 
failure of the acme nut threads of the jackscrew assembly of the 
horizontal stabilizer trim system. The NTSB concluded that the thread 
failure was caused by excessive wear, resulting from insufficient 
lubrication of the jackscrew assembly.
    The drive mechanism of the horizontal stabilizer on Model DC-9-83 
(MD-83) airplanes has a jackscrew assembly with an acme screw. The 
drive mechanism of the horizontal stabilizer on Boeing Model 777 
airplanes uses a ballscrew assembly. Acme screws and ballscrews have 
some differences in design, but perform similar functions and have the 
same airplane-level effect following failure. The manufacturer's safety 
analysis of the Model 777 drive mechanism found no safety problems with 
the configuration of the drive mechanism, but showed that changes to 
the maintenance procedures and maintenance intervals are required to 
keep the drive mechanism properly maintained and operating as designed.
    We have received a report indicating that the ballscrew in the 
drive mechanism of the horizontal stabilizer on a Boeing Model 757 
airplane showed extensive corrosion, which could lead to excessive 
wear. The ballscrew on certain Model 757 airplanes is similar to that 
on the Model 777 airplanes that are the subject of this proposed AD. 
Therefore, both of these airplane models could have the same unsafe 
condition.

[[Page 16062]]

We are considering separate rulemaking action for Model 757 airplanes 
and other similar Boeing airplanes.
    Extensive corrosion of the ballscrew in the drive mechanism of the 
horizontal stabilizer, if not corrected, could cause an undetected 
failure of the primary load path for the ballscrew and subsequent wear 
and failure of the secondary load path, which could lead to loss of 
control of the horizontal stabilizer and consequent loss of control of 
the airplane.

Relevant Service Information

    We have reviewed Boeing Alert Service Bulletin 777-27A0059, 
Revision 1, dated August 18, 2005. The service bulletin describes 
procedures for performing repetitive detailed inspections of the 
horizontal stabilizer trim actuator ballnut and ballscrew for 
discrepancies; repetitive measurements (inspections) of the freeplay 
between the actuator ballnut and ballscrew; repetitive lubrication of 
the actuator ballnut and ballscrew; and, if necessary, replacing the 
actuator with a new or serviceable actuator. Discrepancies of the 
actuator ballnut and ballscrew may include cracking; metal flaking; 
thread deformation, cross threading, and stripping; corrosion; metal 
particles or corrosion products in the lubricating grease; large 
amounts of grease exuding from the top seal of the ballnut or around 
the ballnut return tubes; bent or lifted ballnut return tubes; loose or 
missing ball bearings; and other damage or obvious wear. Accomplishing 
the actions specified in the service information is intended to 
adequately address the unsafe condition.
    The service bulletin refers to the Boeing 777 Aircraft Maintenance 
Manual (AMM), subjects 12-21-05, 27-41-13, and 29-11-00, as additional 
sources of service information for accomplishing the detailed 
inspections, lubrications, freeplay measurements, and replacement of 
the horizontal stabilizer trim actuator.

FAA's Determination and Requirements of the Proposed AD

    We have evaluated all pertinent information and identified an 
unsafe condition that is likely to exist or develop on airplanes of 
this type design. For this reason, we are proposing this AD, which 
would require accomplishing the actions specified in the service 
information described previously, except as discussed under 
``Difference Between the Proposed AD and Service Information.''

Differences Between the Proposed AD and Service Information

    The Summary Action section and paragraph 1.D ``Description'' of the 
service bulletin specify changing the position of the horizontal 
stabilizer to allow inspecting the entire ballscrew. However, this 
instruction does not appear in the Work Instructions of the service 
bulletin or in the referenced AMM sections. To ensure that the detailed 
inspection is performed properly, we have included this instruction in 
paragraph (h) of the proposed AD.
    Although the service bulletin does not require a maintenance 
records check to determine prior replacement of the horizontal 
stabilizer trim actuator, this proposed AD would include such a 
requirement in order to ensure that all subject actuators meet the 
requirements of this proposed AD.

Clarification of Compliance Times

    The manufacturer determined that, if an operator has previously 
removed and replaced the actuator, it is possible that the replacement 
actuator might not meet the serviceability criteria intended by the 
actions specified in the service bulletin. Therefore, the manufacturer 
determined that a revised initial compliance time was necessary, as 
specified in paragraph (l) of this AD.
    The service bulletin specifies ``recommended'' intervals for 
repeating specified actions. However, we have determined that the 
``acceptable'' intervals also specified by the service bulletin will 
allow operators to accomplish all specified repetitive actions without 
an unacceptable increase in safety risk to any airplane. Therefore, we 
have specified the ``acceptable'' intervals in this proposed AD.

Costs of Compliance

    There are about 596 airplanes of the affected design in the 
worldwide fleet. This proposed AD would affect about 130 airplanes of 
U.S. registry.
    The proposed detailed inspection would take about 1 work hour per 
airplane, at an average labor rate of $80 per work hour. Based on these 
figures, the estimated cost of the proposed inspection for U.S. 
operators is $10,400, or $80 per airplane, per inspection cycle.
    The proposed freeplay measurement would take about 5 work hours per 
airplane, at an average labor rate of $80 per work hour. Based on these 
figures, the estimated cost of the proposed freeplay measurement for 
U.S. operators is $52,000, or $400 per airplane, per measurement cycle.
    The proposed lubrication would take about 1 work hour per airplane, 
at an average labor rate of $80 per work hour. Based on these figures, 
the estimated cost of the proposed lubrication for U.S. operators is 
$10,400, or $80 per airplane, per lubrication cycle.

Authority for This Rulemaking

    Title 49 of the United States Code specifies the FAA's authority to 
issue rules on aviation safety. Subtitle I, Section 106, describes the 
authority of the FAA Administrator. Subtitle VII, Aviation Programs, 
describes in more detail the scope of the Agency's authority.
    We are issuing this rulemaking under the authority described in 
Subtitle VII, Part A, Subpart III, Section 44701, ``General 
requirements.'' Under that section, Congress charges the FAA with 
promoting safe flight of civil aircraft in air commerce by prescribing 
regulations for practices, methods, and procedures the Administrator 
finds necessary for safety in air commerce. This regulation is within 
the scope of that authority because it addresses an unsafe condition 
that is likely to exist or develop on products identified in this 
rulemaking action.

Regulatory Findings

    We have determined that this proposed AD would not have federalism 
implications under Executive Order 13132. This proposed AD 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.
    For the reasons discussed above, I certify that the 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. 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.
    We prepared a regulatory evaluation of the estimated costs to 
comply with this proposed AD and placed it in the AD docket. See the 
ADDRESSES section for a location to examine the regulatory evaluation.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Safety.

[[Page 16063]]

The Proposed Amendment

    Accordingly, under the authority delegated to me by the 
Administrator, the FAA proposes to amend 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. The Federal Aviation Administration (FAA) amends Sec.  39.13 by 
adding the following new airworthiness directive (AD):

Boeing: Docket No. FAA-2006-24270; Directorate Identifier 2005-NM-
200-AD.

Comments Due Date

    (a) The FAA must receive comments on this AD action by May 15, 
2006.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to all Boeing Model 777-200, -300, and -
300ER series airplanes, certificated in any category.

Unsafe Condition

    (d) This AD results from a report of extensive corrosion of a 
ballscrew in the drive mechanism of the horizontal stabilizer of a 
Boeing Model 757 airplane, which is similar in design to the 
ballscrew on certain Model 777 airplanes. We are issuing this AD to 
prevent an undetected failure of the primary load path for the 
ballscrew in the drive mechanism of the horizontal stabilizer and 
subsequent wear and failure of the secondary load path, which could 
lead to loss of control of the horizontal stabilizer and consequent 
loss of control of the airplane.

Compliance

    (e) You are responsible for having the actions required by this 
AD performed within the compliance times specified, unless the 
actions have already been done.

Service Bulletin Reference

    (f) The term ``service bulletin,'' as used in this AD, means 
Boeing Alert Service Bulletin 777-27A0059, Revision 1, dated August 
18, 2005.

    Note 1: The service bulletin refers to the Boeing 777 Aircraft 
Maintenance Manuals (AMM), subjects 12-21-05, 27-41-13, and 29-11-
00, as additional sources of service information for accomplishing 
the actions required by this AD.

Maintenance Records Check

    (g) Within 180 days or 3,500 flight hours after the effective 
date of this AD, whichever occurs first: Perform a maintenance 
records check or inspect to determine if any horizontal stabilizer 
trim actuator has been replaced for any issue described in the 
service bulletin with a serviceable actuator that was not new or 
overhauled, and has not received a detailed inspection and freeplay 
measurement since the replacement.
    (1) If the actuator has not been replaced, perform all actions 
of this AD except for paragraph (l) of this AD.
    (2) If the actuator has been replaced, perform the actions 
specified by paragraph (l) of this AD.

Detailed Inspection

    (h) Before the accumulation of 15,000 total flight hours or 
within 18 months after the effective date of this AD, whichever 
occurs later, except as provided by paragraph (l) of this AD: 
Perform a detailed inspection for discrepancies of the horizontal 
stabilizer trim actuator ballnut and ballscrew in accordance with 
Part 1 of the Accomplishment Instructions of the service bulletin, 
changing the position of the horizontal stabilizer as needed to 
allow inspecting the entire ballscrew. Repeat the detailed 
inspection thereafter at intervals not to exceed 3,500 flight hours 
or 12 months, whichever occurs first. If any discrepancy is found 
during any inspection required by this AD, before further flight, 
replace the actuator with a new or serviceable actuator in 
accordance with the service bulletin.

Freeplay Measurement (Inspection)

    (i) Before the accumulation of 15,000 total flight hours or 
within 18 months after the effective date of this AD, whichever 
occurs later, except as provided by paragraph (l) of this AD: 
Perform a freeplay measurement of the ballnut and ballscrew in 
accordance with Part 2 of the Accomplishment Instructions of the 
service bulletin. Repeat the freeplay measurement thereafter at 
intervals not to exceed 18,000 flight hours or 60 months, whichever 
occurs first. If the freeplay is found to exceed the limits 
specified in the service bulletin during any measurement required by 
this AD, before further flight, replace the actuator with a new or 
serviceable actuator in accordance with the service bulletin.

Lubrication

    (j) Before the accumulation of 15,000 total flight hours or 
within 18 months after the effective date of this AD, whichever 
occurs later: Lubricate the ballnut and ballscrew in accordance with 
Part 3 of the Accomplishment Instructions of the service bulletin. 
Repeat the lubrication thereafter at intervals not to exceed 2,000 
flight hours or 12 months, whichever occurs first.

Credit for Using Original Issue of Service Bulletin

    (k) Actions performed prior to the effective date of this AD in 
accordance with Boeing Alert Service Bulletin 777-27A0059, dated 
September 18, 2003, are considered acceptable for compliance with 
the corresponding actions of this AD.

Prior Replacement of Actuator

    (l) If, prior to the effective date of this AD, any horizontal 
stabilizer trim actuator was replaced in accordance with Boeing 
Alert Service Bulletin 777-27A0059, dated September 18, 2003, with a 
serviceable actuator that was not new or overhauled, and has not 
received a detailed inspection and freeplay measurement since the 
replacement, perform an inspection and freeplay measurement of that 
actuator as required by paragraphs (h) and (i) of this AD within 24 
months or 3,500 flight hours after the effective date of this AD, 
whichever occurs first.

Parts Installation

    (m) As of the effective date of this AD, no person may install, 
on any airplane, a horizontal stabilizer trim actuator that is not 
new or overhauled, unless a detailed inspection and freeplay 
measurement of that actuator is performed before further flight, in 
accordance with paragraphs (h) and (i) of this AD.

Alternative Methods of Compliance (AMOCs)

    (n)(1) The Manager, Seattle Aircraft Certification Office, FAA, 
has the authority to approve AMOCs for this AD, if requested in 
accordance with the procedures found in 14 CFR 39.19.
    (2) Before using any AMOC approved in accordance with Sec.  
39.19 on any airplane to which the AMOC applies, notify the 
appropriate principal inspector in the FAA Flight Standards 
Certificate Holding District Office.

    Issued in Renton, Washington, on March 22, 2006.
Michael Zielinski,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
 [FR Doc. E6-4619 Filed 3-29-06; 8:45 am]
BILLING CODE 4910-13-P