[Federal Register Volume 71, Number 69 (Tuesday, April 11, 2006)]
[Rules and Regulations]
[Pages 18194-18197]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 06-3378]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2005-22471; Directorate Identifier 2005-NM-142-AD; 
Amendment 39-14550; AD 2006-07-23]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 757 Airplanes

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

ACTION: Final rule.

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SUMMARY: The FAA is adopting a new airworthiness directive (AD) for all 
Boeing Model 757 airplanes. This AD requires repetitive measurements of 
the freeplay of each of the three power control units (PCUs) that move 
the rudder; repetitive lubrication of rudder components; and corrective 
actions if necessary. This AD results from a report of freeplay-induced 
vibration of the rudder. The potential for vibration of the control 
surface should be avoided because the point of transition from 
vibration to divergent flutter is unknown. We are issuing this AD to 
prevent excessive vibration of the airframe during flight, which could 
result in divergent flutter and loss of control of the airplane.

DATES: This AD becomes effective May 16, 2006.
    The Director of the Federal Register approved the incorporation by 
reference of certain publications listed in the AD as of May 16, 2006.

ADDRESSES: You may examine the AD docket on the Internet at http://dms.dot.gov or in person at the Docket Management Facility, U.S. 
Department of Transportation, 400 Seventh Street SW., Nassif Building, 
room PL-401, Washington, DC.
    Contact Boeing Commercial Airplanes, P.O. Box 3707, Seattle, 
Washington 98124-2207, for service information identified in this AD.

FOR FURTHER INFORMATION CONTACT: Dennis Stremick, Aerospace Engineer, 
Airframe Branch, ANM-120S, Seattle Aircraft Certification Office, FAA, 
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 
917-6450; fax (425) 917-6590.

SUPPLEMENTARY INFORMATION:

Examining the Docket

    You may examine the airworthiness directive (AD) docket on the 
Internet at http://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 street address stated in the ADDRESSES section.

Discussion

    The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 
CFR part 39 to include an AD that would apply to all Boeing Model 757 
airplanes. That NPRM was published in the Federal Register on September 
21, 2005 (70 FR 55321). That NPRM proposed to require repetitive 
measurements of the freeplay of each of the three power control units 
(PCUs) that move the rudder; repetitive lubrication of rudder 
components; and corrective actions if necessary.

Comments

    We provided the public the opportunity to participate in the 
development of this AD. We have considered the comments received.

Request To Revise Discussion Section's Reference to Freeplay-Induced 
Flutter

    Boeing requests that we revise the wording in the first sentence of 
the Discussion section of the NPRM to replace the phrase ``freeplay-
induced flutter'' with the phrase ``freeplay-induced vibration.'' 
Boeing states that the event noted in the Discussion section was not 
divergent flutter, but was a constant amplitude event induced by 
excessive freeplay. Boeing states that the service event is 
consistently described as freeplay-induced vibration elsewhere in the 
NPRM. Boeing points out that using the phrase ``freeplay-induced 
flutter'' in relation to the service event may lead readers to the 
incorrect conclusion that the service event was divergent flutter.
    We agree that the Discussion section incorrectly stated that there 
has been one report of ``freeplay-induced flutter,'' rather than 
``freeplay-induced vibration.'' Since the Discussion section of the 
preamble does not reappear in the final rule, we have not changed that 
section. However, we have changed the unsafe condition in the Summary 
paragraph and in paragraph (d) of this AD to include clarification 
about freeplay-induced vibration.

Request To Clarify Paragraph (e), ``Compliance''

    Boeing also requests that we change paragraph (e), ``Compliance,'' 
which states, ``* * * unless the actions have already been done.'' 
Boeing requests that we clarify the sentence by stating, ``* * * unless 
the actions have already been done per the appropriate service bulletin 
referenced in paragraph (f) below.'' Boeing requests that we give 
credit for lubrications accomplished previously in accordance with the 
airplane maintenance manual (AMM). Boeing also states that the service 
bulletins specified in paragraph (f) of the NPRM institute significant 
improvements in the freeplay measurements and procedures over those in 
the AMM. Boeing would like to ensure that freeplay checks performed per 
the AMM are not considered

[[Page 18195]]

equivalent to the service bulletin procedures.
    We partially agree with Boeing. We disagree with the request to 
change paragraph (e), ``Compliance,'' of this AD. Paragraph (e) is 
written specifically in reference to the actions in this AD and not in 
reference to the actions performed in accordance with any document that 
is not specifically referenced in this AD; the actions must be 
accomplished exactly as prescribed by the AD. Paragraph (e) of this AD 
allows for compliance only when the required actions have already been 
done in accordance with the required service information. Therefore, 
the freeplay measurement must be done in accordance with the procedures 
specified in the service bulletins referenced in the AD. For the 
lubrication, the service bulletins reference the AMM for the 
procedures. The AMM is not referenced in the AD. Compliance with any 
revision of the AMM is acceptable for compliance with the lubrication 
requirements of this AD. We have not changed the AD in this regard. 
However, the operators may request approval of an alternative method of 
compliance (AMOC) in accordance with the procedures in paragraph (k) of 
this AD.

Request To Shorten Compliance Time for Lubrication

    The Airline Pilot's Association (ALPA) agrees with the actions in 
the NPRM; however, ALPA states that the proposed implementation period 
is too long, considering the possible results. ALPA states that the 
lubrication requirement, in particular, should be required in as little 
as 90 days. ALPA recommends that we consider shortening the required 
compliance time for each element of the AD.
    We disagree. ALPA did not provide technical data to support the 
requests. The compliance time for the lubrication is 9 months after the 
effective date of the AD. This compliance time agrees with the 
manufacturer's recommendation. In addition, service history shows that 
the lubrication is not an urgent issue that requires action within 90 
days. We have not changed the AD in this regard.

Request To Express Repetitive Interval in Terms of Flight Hours

    US Airways and the Air Transport Association (ATA) request that we 
specify the repetitive intervals for both the freeplay measurement and 
the rudder lubrication only in terms of flight hours so that both 
requirements can be accomplished, to the greatest extent possible, 
during compatible, scheduled maintenance visits. The commenters explain 
that expressing the compliance times only in terms of flight hours 
would allow for completing both requirements during the heavy 
maintenance C-check, which U.S. Airways does at the earlier of 6,000 
flight hours or 592 days. The proposed rule would require repetitive 
freeplay measurements at the earlier of 12,000 flight hours or 36 
months; and repetitive lubrications at the earlier of 6,000 flight 
hours or 18 months. U.S. Airways states that it would like to complete 
both actions at the same time during the heavy maintenance visit 
because the environment, away from the elements with a tail stand set 
up, would better facilitate these actions. The commenters state that 
the rule, as proposed, would require the lubrication to be accomplished 
during special line maintenance visits, and the rudder freeplay 
measurement to be done twice as frequently to fit into its existing C-
checks.
    We disagree with the commenters' request to state the compliance 
times only in terms of flight hours. The lubrication is required at 
intervals not to exceed the earlier of 3,000 flight hours or 9 months 
for airplanes on which BMS 3-33 grease is not used; and the earlier of 
6,000 flight hours or 18 months for airplanes on which BMS 3-33 grease 
is used. U.S. Airways did not indicate which grease it uses. In 
addition, the commenters did not provide technical substantiation 
allowing the calendar time to exceed 9 months or 18 months, depending 
on the type of grease used. The compliance times in the NPRM are 
consistent with the manufacturer's recommendations. We have determined 
that the compliance times in the AD represent the maximum interval of 
time allowable for the affected airplanes to continue to safely operate 
before the actions are done. Since maintenance schedules vary among 
operators, there would be no assurance that the actions would be done 
during that maximum interval. We have not changed the AD in this 
regard. However, the commenters may request approval of an AMOC in 
accordance with the procedures in paragraph (k) of this AD.

Request To Include Procedures for Rudder Lubrication

    Northwest Airlines and the ATA request that we specify in the AD 
the procedures required for rudder lubrication, or require that those 
procedures be specified in the applicable service bulletins. The 
commenters explain that the AMMs referenced in the service bulletins 
are not identified by date, and that there could be subsequent 
revisions by Boeing or an airplane operator, unaware that the procedure 
is mandated by an AD. The commenters add that AMMs are not subject to 
FAA approval. If the FAA is concerned that future AMM revisions could 
change the intent of the NPRM, Northwest Airlines states that the FAA 
should identify the lubrication procedures in the NPRM or the service 
bulletin so that FAA approval is required before the procedures are 
revised.
    We disagree with including specific lubrication procedures in the 
AD. The unsafe condition is caused by excessive freeplay, which allows 
control surfaces to vibrate. The lubrication minimizes wear and 
corrosion in all critical mechanical joints in the rudder control 
surfaces. The service bulletins contain specific procedures for 
measuring the freeplay. The AMMs referred to in the service bulletins 
show where to apply grease and specify which grease to use. These AMMs 
give lubrication procedures that follow industry standard practices. In 
addition, the AD specifies that using one grease (BMS 3-33) maximizes 
the repetitive interval for the lubrications. We have not changed the 
AD in this regard.

Request To Extend Initial Threshold

    American Airlines and the ATA request that we revise paragraphs (g) 
and (i) to account for operators who use BMS 3-33 grease. The 
commenters request that the interval for the initial freeplay 
measurement be extended from 18 months to 36 months, and that the 
interval for the initial lubrication be extended from 9 months to 18 
months. The commenters state that these changes would be consistent 
with the proposed repetitive intervals. American Airlines explains that 
the safety of flight issue with the rudder load loop is the lack of 
rudder component lubrication. The lack of lubrication allows metal-to-
metal contact and infiltration of water and contaminants into the 
bearing surfaces, causing corrosion and inducing freeplay into the 
rudder system. The commenters point out that the recommended changes to 
the proposed AD would allow operators that currently use BMS 3-33 
grease every 18 months or 6,000 flight hours to extend the initial 
intervals.
    We disagree. The commenters do not account for the fact that flight 
hours, particularly at cruise, exacerbate the wear of all the critical 
joints; the freeplay in the flight control surface is cause by control-
system wear and corrosion. In addition, the commenters do not provide 
technical justification for extending the interval for the initial 
freeplay measurement. The initial

[[Page 18196]]

freeplay measurement done in accordance with the AD is critical to 
establish a baseline for the entire fleet. Service history for these 
airplanes has shown that the initial intervals for the freeplay 
measurement and lubrication are adequate. We have not changed the AD in 
this regard.

Clarification of AMOC Paragraph

    We have revised this action to clarify the appropriate procedure 
for notifying the principal inspector before using any approved AMOC on 
any airplane to which the AMOC applies.

Clarification of Service Bulletin Reference

    We have included in paragraph (f) of this AD a reference to 
Appendix A of Boeing Special Attention Service Bulletin 757-27-0148, 
dated June 16, 2005; and Boeing Special Attention Service Bulletin 757-
27-0149, dated June 16, 2005. The appendixes contain reference 
information for doing the actions in the Accomplishment Instructions. 
The NPRM referred only to the Accomplishment Instructions and excluded 
mention of the appendixes.

Conclusion

    We have carefully reviewed the available data, including the 
comments received, and determined that air safety and the public 
interest require adopting the AD with the changes described previously. 
We have determined that these changes will neither increase the 
economic burden on any operator nor increase the scope of the AD.

Costs of Compliance

    There are about 1,040 airplanes of the affected design in the 
worldwide fleet. The following table provides the estimated costs for 
U.S. operators to comply with this AD. No parts are necessary to 
accomplish either action.

                                                 Estimated Costs
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                                                                                  Number of
                                                 Average                            U.S.-
             Action                Work hours   labor rate   Cost per airplane    registered      Fleet cost
                                                 per hour                         airplanes
----------------------------------------------------------------------------------------------------------------
Freeplay measurement............            4          $65  $260, per                    679  $176,540, per
                                                             measurement cycle.                measurement
                                                                                               cycle.
Lubrication.....................            8           65  $520, per                    679  $353,080, per
                                                             lubrication cycle.                lubrication
                                                                                               cycle.
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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 AD will not have federalism 
implications under Executive Order 13132. This AD will 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 this AD:
    (1) Is not a ``significant regulatory action'' under Executive 
Order 12866;
    (2) Is not a ``significant rule'' under 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 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, Incorporation by 
reference, Safety.

Adoption of the Amendment

0
Accordingly, under the authority delegated to me by the Administrator, 
the FAA amends 14 CFR part 39 as follows:

PART 39--AIRWORTHINESS DIRECTIVES

0
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]

0
2. The Federal Aviation Administration (FAA) amends Sec.  39.13 by 
adding the following new airworthiness directive (AD):

2006-07-23 BOEING: Amendment 39-14550. Docket No. FAA-2005-22471; 
Directorate Identifier 2005-NM-142-AD.

Effective Date

    (a) This AD becomes effective May 16, 2006.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to all Boeing Model 757-200, -200PF, -200CB, 
and -300 series airplanes, certificated in any category.

Unsafe Condition

    (d) This AD results from a report of freeplay-induced vibration 
of the rudder. The potential for vibration of the control surface 
should be avoided because the point of transition from vibration to 
divergent flutter is unknown. We are issuing this AD to prevent 
excessive vibration of the airframe during flight, which could 
result in divergent flutter and 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 References

    (f) The term ``service bulletin,'' as used in this AD, means the 
Accomplishment Instructions and Appendix A of the following service 
bulletins, as applicable:
    (1) For Model 757-200, -200PF, -200CB series airplanes: Boeing 
Special Attention Service Bulletin 757-27-0148, dated June 16, 2005; 
and

[[Page 18197]]

    (2) For Model 757-300 series airplanes: Boeing Special Attention 
Service Bulletin 757-27-0149, dated June 16, 2005.

Repetitive Measurements

    (g) Within 18 months after the effective date of this AD: 
Measure the freeplay for each of the three power control units that 
move the rudder. Repeat the measurement thereafter at intervals not 
to exceed 12,000 flight hours or 36 months, whichever occurs first. 
Do all actions required by this paragraph in accordance with the 
applicable service bulletin.

Related Investigative and Corrective Actions

    (h) If any measurement found in paragraph (g) of this AD is 
outside certain limits specified in the service bulletin: Before 
further flight, do the applicable related investigative and 
corrective actions in accordance with the service bulletin.

Repetitive Lubrication

    (i) Within 9 months after the effective date of this AD: 
Lubricate the rudder components specified in the applicable service 
bulletin. Repeat the lubrication thereafter at the applicable 
interval in paragraph (i)(1) or (i)(2) of this AD. Do all actions 
required by this paragraph in accordance with the applicable service 
bulletin.
    (1) For airplanes on which BMS 3-33 grease is not used: 3,000 
flight hours or 9 months, whichever occurs first.
    (2) For airplanes on which BMS 3-33 grease is used: 6,000 flight 
hours or 18 months, whichever occurs first.

Concurrent Repetitive Cycles

    (j) If a freeplay measurement required by paragraph (g) of this 
AD and a lubrication cycle required by paragraph (i) of this AD are 
due at the same time or will be accomplished during the same 
maintenance visit, the freeplay measurement and applicable related 
investigative and corrective actions must be done before the 
lubrication is accomplished.

Alternative Methods of Compliance (AMOCs)

    (k)(1) The Manager, Seattle Aircraft Certification Office (ACO), 
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.
    (3) An AMOC that provides an acceptable level of safety may be 
used for any repair required by this AD, if it is approved by an 
Authorized Representative for the Boeing Commercial Airplanes 
Delegation Option Authorization Organization who has been authorized 
by the Manager, Seattle ACO, to make those findings. For a repair 
method to be approved, the repair must meet the certification basis 
of the airplane, and the approval must specifically refer to this 
AD.

Material Incorporated by Reference

    (l) You must use Boeing Special Attention Service Bulletin 757-
27-0148, dated June 16, 2005; or Boeing Special Attention Service 
Bulletin 757-27-0149, dated June 16, 2005; as applicable; to perform 
the actions that are required by this AD, unless the AD specifies 
otherwise. The Director of the Federal Register approved the 
incorporation by reference of these documents in accordance with 5 
U.S.C. 552(a) and 1 CFR part 51. Contact Boeing Commercial 
Airplanes, P.O. Box 3707, Seattle, Washington 98124-2207, for a copy 
of this service information. You may review copies at the Docket 
Management Facility, U.S. Department of Transportation, 400 Seventh 
Street SW., room PL-401, Nassif Building, Washington, DC; on the 
Internet at http://dms.dot.gov; or at the National Archives and 
Records Administration (NARA). For information on the availability 
of this material at the NARA, call (202) 741-6030, or go to http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html.

    Issued in Renton, Washington, on March 30, 2006.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 06-3378 Filed 4-10-06; 8:45 am]
BILLING CODE 4910-13-P