[Federal Register Volume 77, Number 233 (Tuesday, December 4, 2012)]
[Proposed Rules]
[Pages 71731-71734]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2012-29177]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2012-1221; Directorate Identifier 2012-NM-151-AD]
RIN 2120-AA64


Airworthiness Directives; The Boeing Company

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: We propose to adopt a new airworthiness directive (AD) for 
certain The Boeing Company Model 777-200 and -300 series airplanes. 
This proposed AD was prompted by reports of hydraulic fluid 
contamination found in the strut forward dry bay. This proposed AD 
would require repetitive general visual inspections of the strut 
forward dry bay for the presence of hydraulic fluid, and related 
investigative and corrective actions if necessary. We are proposing 
this AD to detect and correct hydraulic fluid contamination of the 
strut forward dry bay, which could result in hydrogen embrittlement of 
the titanium forward engine mount bulkhead fittings, and consequent 
inability of the fittings to carry engine loads, resulting in the loss 
or departure of an engine. Hydraulic embrittlement could cause a 
through-crack formation across the fittings through which an engine 
fire could breach into the strut, resulting in an uncontained strut 
fire.

DATES: We must receive comments on this proposed AD by January 18, 
2013.

ADDRESSES: You may send comments, using the procedures found in 14 CFR 
11.43 and 11.45, by any of the following methods:
     Federal eRulemaking Portal: Go to http://www.regulations.gov. Follow the instructions for submitting comments.
     Fax: 202-493-2251.
     Mail: U.S. Department of Transportation, Docket 
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New 
Jersey Avenue SE., Washington, DC 20590.
     Hand Delivery: Deliver to Mail address above between 9 
a.m. and 5 p.m., Monday through Friday, except Federal holidays.
    For service information identified in this proposed AD, contact 
Boeing Commercial Airplanes, Attention: Data & Services Management, P. 
O. Box 3707, MC 2H-65, Seattle, WA 98124-2207; telephone 206-544-5000, 
extension 1;

[[Page 71732]]

fax 206-766-5680; Internet https://www.myboeingfleet.com. You may 
review copies of the referenced service information at the FAA, 
Transport Airplane Directorate, 1601 Lind Avenue SW., Renton, WA. For 
information on the availability of this material at the FAA, call 425-
227-1221.

Examining the AD Docket

    You may examine the AD docket on the Internet at http://www.regulations.gov; or in person at the Docket Management Facility 
between 9 a.m. and 5 p.m., Monday through Friday, except Federal 
holidays. The AD docket contains this proposed AD, the regulatory 
evaluation, any comments received, and other information. The street 
address for the Docket Office (phone: 800-647-5527) is in the ADDRESSES 
section. Comments will be available in the AD docket shortly after 
receipt.

FOR FURTHER INFORMATION CONTACT: Kevin Nguyen, Aerospace Engineer, 
Propulsion Branch, ANM-140S, FAA, Seattle Aircraft Certification 
Office, 1601 Lind Avenue SW., Renton, WA 98057-3356; phone: 425-917-
6501; fax: 425-917-6590; email: [email protected].

SUPPLEMENTARY INFORMATION:

Comments Invited

    We invite you to send any written relevant data, views, or 
arguments about this proposal. Send your comments to an address listed 
under the ADDRESSES section. Include ``Docket No. FAA-2012-1221; 
Directorate Identifier 2012-NM-151-AD'' at the beginning of your 
comments. We specifically invite comments on the overall regulatory, 
economic, environmental, and energy aspects of this proposed AD. We 
will consider all comments received by the closing date and may amend 
this proposed AD because of those comments.
    We will post all comments we receive, without change, to http://www.regulations.gov, including any personal information you provide. We 
will also post a report summarizing each substantive verbal contact we 
receive about this proposed AD.

Discussion

    We received reports of hydraulic fluid contamination in the strut 
forward dry bay caused by the clogged and blocked forward strut drain 
lines not allowing fluids (water, fuel, engine oil and hydraulic) to 
drain properly, resulting in fluids backing up to the dry bay. The 
presence of hydraulic fluid and temperatures above 270 degrees 
Fahrenheit can cause hydrogen embrittlement of the titanium forward 
engine mount bulkhead fittings. This condition, if not corrected, could 
result in the inability of the forward engine mount bulkhead fittings 
to carry engine loads, resulting in the loss or departure of an engine; 
or cause a through-crack formation across the fittings through which an 
engine fire could breach into the strut, resulting in an uncontained 
strut fire.

Relevant Service Information

    We reviewed Boeing Special Attention Service Bulletin 777-54-0028, 
dated May 25, 2012. The service information describes procedures for 
repetitive general visual inspections for hydraulic fluid contamination 
of the strut forward dry bay, and related investigative and corrective 
actions if necessary. Related investigative actions include a detailed 
inspection for hydraulic fluid coking, heat discoloration, damage to 
sealant and primer, damage to leveling compound, cracking, and etching 
or pitting of the interior strut forward dry bay; a detailed and high 
frequency eddy current (HFEC) inspection for cracking, etching, or 
pitting of the bulkhead upper and lower fittings of the strut forward 
engine mount; and checking drain lines for blockage. Corrective actions 
include cleaning and restoring sealant, primer, and leveling compound 
of the detail parts in the strut forward dry bay; cleaning or replacing 
drain lines; and contacting the manufacturer for repair instructions 
and doing the repair.
    The compliance time for the initial inspection is within 600 flight 
cycles or 12 months, whichever occurs first. The compliance times for 
the related investigative actions are before further flight. The 
compliance times for corrective actions vary between before further 
flight, and within 25 flight cycles or 10 days, whichever occurs first 
(depending on the condition). The repetitive inspection intervals do 
not exceed 1,200 flight cycles.

FAA's Determination

    We are proposing this AD because we evaluated all the relevant 
information and determined the unsafe condition described previously is 
likely to exist or develop in other products of these same type 
designs.

Proposed AD Requirements

    This proposed AD would require accomplishing the actions specified 
in the service information described previously, except as discussed 
under ``Differences Between the Proposed AD and the Service 
Information.''

Differences Between the Proposed AD and the Service Information

    Although the service bulletin specifies that operators may contact 
the manufacturer for disposition of certain repair conditions, this 
proposed AD would require operators to repair those conditions using a 
method approved by the FAA.

Costs of Compliance

    We estimate that this proposed AD affects 55 airplanes of U.S. 
registry.
    We estimate the following costs to comply with this proposed AD:

                                                                     Estimated Costs
--------------------------------------------------------------------------------------------------------------------------------------------------------
               Action                          Labor cost            Parts cost     Cost per product                  Cost on U.S. operators
--------------------------------------------------------------------------------------------------------------------------------------------------------
Repetitive general visual             5 work-hours x $85 per hour            $0  $425 per inspection     $23,375 per inspection cycle.
 inspections.                          = $425 per inspection cycle.               cycle.
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    We estimate the following costs to do any actions that would be 
required based on the results of the proposed inspection. We have no 
way of determining the number of aircraft that might need these 
actions.

                                               On-Condition Costs
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                                                                                                       Cost per
                    Action                                    Labor cost                 Parts cost    product
----------------------------------------------------------------------------------------------------------------
Detailed inspection...........................  8 work-hours x $85 per hour = $680....           $0         $680

[[Page 71733]]

 
Check drain lines (including cleaning or        5 work-hours x $85 per hour = $425....            0          425
 replacing).
Detailed inspection and high frequency eddy     8 work-hours x $85 per hour = $680....            0          680
 current inspection.
Clean and restore sealant, primer and leveling  8 work-hours x $85 per hour = $680....            0          680
 compound.
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    We have received no definitive data that would enable us to provide 
a cost estimate for the on-condition repair specified in this proposed 
AD.
    According to the manufacturer, some of the costs of this proposed 
AD may be covered under warranty, thereby reducing the cost impact on 
affected individuals. We do not control warranty coverage for affected 
individuals. As a result, we have included all costs in our cost 
estimate.

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 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 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),
    (3) Will not affect intrastate aviation in Alaska, and
    (4) 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.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

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 FAA amends Sec.  39.13 by adding the following new 
airworthiness directive (AD):
The Boeing Company: Docket No. FAA-2012-1221; Directorate Identifier 
2012-NM-151-AD.

(a) Comments Due Date

    We must receive comments by January 18, 2013.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to The Boeing Company Model 777-200 and -300 
series airplanes; certificated in any category; equipped with Pratt 
& Whitney 4000 engines; as identified in Boeing Special Attention 
Service Bulletin 777-54-0028, dated May 25, 2012.

(d) Subject

    Joint Aircraft System Component (JASC)/Air Transport Association 
(ATA) of America Code 54, Nacelles/pylons.

(e) Unsafe Condition

    This AD was prompted by reports of hydraulic fluid contamination 
found in the strut forward dry bay. We are issuing this AD to detect 
and correct hydraulic fluid contamination of the strut forward dry 
bay, which could result in hydrogen embrittlement of the titanium 
forward engine mount bulkhead fittings, and consequent inability of 
the fittings to carry engine loads, resulting in the loss or 
departure of an engine. Hydraulic embrittlement could cause a 
through-crack formation across the fittings through which an engine 
fire could breach into the strut, resulting in an uncontained strut 
fire.

(f) Compliance

    Comply with this AD within the compliance times specified, 
unless already done.

(g) Inspection

    Except as provided by paragraph (h)(1) of this AD, at the times 
specified in paragraph 1.E., ``Compliance,'' of Boeing Special 
Attention Service Bulletin 777-54-0028, dated May 25, 2012: Do a 
general visual inspection for hydraulic fluid contamination of the 
interior of the strut forward dry bay, and do all applicable related 
investigative and corrective actions, in accordance with the 
Accomplishment Instructions of Boeing Special Attention Service 
Bulletin 777-54-0028, dated May 25, 2012, except as required by 
paragraph (h)(2) of this AD. Repeat the inspection thereafter at the 
times specified in paragraph 1.E., ``Compliance,'' of Boeing Special 
Attention Service Bulletin 777-54-0028, dated May 25, 2012. Except 
as required by paragraph (h)(3) of this AD, do all applicable 
related investigative and corrective actions at the times specified 
in paragraph 1.E., ``Compliance,'' of Boeing Special Attention 
Service Bulletin 777-54-0028, dated May 25, 2012.

(h) Exceptions

    (1) Where the Compliance time column of paragraph 1.E., 
``Compliance,'' of Boeing Service Bulletin 777-54-0028, dated May 
25, 2012, refers to the compliance time ``after the original issue 
date of this service bulletin,'' this AD requires compliance within 
the specified compliance time after the effective date of this AD.
    (2) Where Boeing Special Attention Service Bulletin 777-54-0028, 
dated May 25, 2012, specifies to contact Boeing for repair: Except 
as required by paragraph (h)(3) of this AD, at the applicable times 
specified in paragraph 1.E., ``Compliance,'' of Boeing Special 
Attention Service Bulletin 777-54-0028, dated May 25, 2012, repair, 
in accordance with a method approved by the Manager, Seattle 
Aircraft Certification Office (ACO), FAA. 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.
    (3) Where paragraph 1.E., ``Compliance,'' of Boeing Special 
Attention Service Bulletin

[[Page 71734]]

777-54-0028, dated May 25, 2012, specifies a compliance time of 
``within 25 flight-cycles or 10 days, whichever occurs first,'' this 
AD requires compliance within 25 flight cycles or 10 days after the 
most recent inspection required by paragraph (g) of this AD, 
whichever occurs first.

(i) Alternative Methods of Compliance (AMOCs)

    (1) The Manager, Seattle Aircraft Certification Office (ACO), 
FAA, has the authority to approve AMOCs for this AD, if requested 
using the procedures found in 14 CFR 39.19. In accordance with 14 
CFR 39.19, send your request to your principal inspector or local 
Flight Standards District Office, as appropriate. If sending 
information directly to the manager of the ACO, send it to the 
attention of the person identified in the Related Information 
section of this AD. Information may be emailed to: [email protected].
    (2) Before using any approved AMOC, notify your appropriate 
principal inspector, or lacking a principal inspector, the manager 
of the local flight standards district office/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 the 
Boeing Commercial Airplanes Organization Designation Authorization 
(ODA) that 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.

(j) Related Information

    (1) For more information about this AD, contact Kevin Nguyen, 
Aerospace Engineer, Propulsion Branch, ANM-140S, FAA, Seattle 
Aircraft Certification Office, 1601 Lind Avenue SW., Renton, WA 
98057-3356; phone: 425-917-6501; fax: 425-917-6590; email: 
[email protected].
    (2) For service information identified in this AD, contact 
Boeing Commercial Airplanes, Attention: Data & Services Management, 
P. O. Box 3707, MC 2H-65, Seattle, WA 98124-2207; telephone 206-544-
5000, extension 1; fax 206-766-5680; Internet https://www.myboeingfleet.com. You may review copies of the referenced 
service information at the FAA, Transport Airplane Directorate, 1601 
Lind Avenue SW., Renton, WA. For information on the availability of 
this material at the FAA, call 425-227-1221.

    Issued in Renton, Washington, on November 21, 2012.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2012-29177 Filed 12-3-12; 8:45 am]
BILLING CODE 4910-13-P