[Federal Register Volume 80, Number 48 (Thursday, March 12, 2015)]
[Proposed Rules]
[Pages 12954-12957]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2015-05032]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2015-0247; Directorate Identifier 2014-NM-178-AD]
RIN 2120-AA64


Airworthiness Directives; The Boeing Company Airplanes

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 
equipped with Rolls-Royce Trent 800 series engines. This proposed AD 
was prompted by a report of multiple cases of heat damage to the strut 
aft fairing heat shield primary seal, as well as heat and wear damage 
to the heat shield insulation blankets. This proposed AD would require 
repetitive inspections for heat damage to the strut aft fairing lower 
spar web structure (a flammable fluid zone barrier and fire wall) and 
heat shield primary seal, and heat and wear damage to heat shield 
insulation blankets; and related investigative and corrective actions 
if necessary. This proposed AD would also provide optional terminating 
action for the repetitive inspections. We are proposing this AD to 
detect and correct heat damage to the strut aft fairing lower spar web 
structure and heat shield primary seal, as well as heat and wear damage 
to the heat shield insulation blankets, which could lead to through-
cracks in the aft fairing web structure and heating of the aft fairing 
web structure, and consequent uncontrolled fire in the aft fairing, 
fuel tank ignition or possible departure of the engine, and subsequent 
loss of the airplane.

DATES: We must receive comments on this proposed AD by April 27, 2015.

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; fax 206-766-5680; Internet https://www.myboeingfleet.com. You may view this referenced service information 
at

[[Page 12955]]

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. It is also available on the Internet at https://www.regulations.gov by searching and locating Docket No. FAA-2015-0247.

Examining the AD Docket

    You may examine the AD docket on the Internet at http://www.regulations.gov by searching for and locating Docket No. FAA-2015-
0247; 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 
(ACO), 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-2015-0247; 
Directorate Identifier 2014-NM-178-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 have received a report of multiple cases of heat damage to the 
strut aft fairing heat shield primary seals, as well as heat and wear 
damage to the heat shield insulation blankets. Improper design of the 
strut aft fairing #1 heat shield (a titanium pan casting) and #1 heat 
shield insulation blanket allows hot turbulent gas from the exhaust 
nozzle to wear and cause degradation of the front face of the #1 
insulation blankets and flow into the heat shield cavity, the space or 
cavity between the heat shields and insulation blankets, and the strut 
aft fairing lower spar web structure. Continuous exposure to hot 
turbulent gas further damages the primary seal and #1 insulation 
blanket, increases the temperature in the heat shield cavity, and can 
damage all insulation blankets and lower web structure.
    The insulation blankets are attached underneath the lower spar web 
structure and are intended to protect the web from hot exhaust gas. The 
insulation blankets were not originally designed to withstand 
additional hot gas exposure, and consequently are unable to adequately 
protect the lower web structure. The strut aft fairing lower spar web 
structure is made of aluminum and designed to be a flammable fluid zone 
barrier and firewall, as part of the aft fairing fire protection 
system.
    Insufficient thermal protection and continuous exposure to hot 
gases and elevated temperatures can degrade the lower spar web 
structure material property. The heat-damaged web structures could 
become annealed and cracked from fatigue, compromising the firewall and 
allowing flammable fluids to leak onto the high-temperature heat 
shield, initiate a fire, and cause an uncontained fire in the aft 
fairing, potentially leading to fire in the wing tank. An uncontained 
fire in the aft fairing can weaken the diagonal brace and lower wing 
skin, which are primary structural elements that carry and support 
engine loads. This condition, if not corrected, could result in 
through-cracks in the aft fairing web structure and heating of the aft 
fairing web structure, and consequent uncontrolled fire in the aft 
fairing, fuel tank ignition or possible departure of the engine.

Related Service Information Under 1 CFR Part 51

    We reviewed the following service information:
     Boeing Service Bulletin 777-54A0031, Revision 1, dated May 
9, 2014.
     Boeing Service Bulletin 777-54-0030, dated May 27, 2014.
    The service information describes procedures for repetitive 
inspections for heat damage to the strut aft fairing lower spar web 
structure (a flammable fluid zone barrier and fire wall) and heat 
shield primary seal, and heat and wear damage to heat shield insulation 
blankets; and related investigative and corrective actions. For 
information on the procedures and compliance times, see this service 
information. This service information is reasonably available; see 
ADDRESSES for ways to access this service information.

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 the same type design.

Proposed AD Requirements

    This proposed AD would require accomplishing the actions specified 
in the service information described previously.
    The phrase ``related investigative actions'' is used in this 
proposed AD. ``Related investigative actions'' are follow-on actions 
that (1) are related to the primary actions, and (2) further 
investigate the nature of any condition found. Related investigative 
actions in an AD could include, for example, inspections.
    The phrase ``corrective actions'' is used in this proposed AD. 
``Corrective actions'' are actions that correct or address any 
condition found. Corrective actions in an AD could include, for 
example, repairs.

Costs of Compliance

    We estimate that this proposed AD affects 57 airplanes of U.S. 
registry.
    We estimate the following costs to comply with this proposed AD:

                                                 Estimated Costs
----------------------------------------------------------------------------------------------------------------
                                                                                                 Cost on U.S.
              Action                    Labor cost        Parts cost     Cost per  product        operators
----------------------------------------------------------------------------------------------------------------
Inspections......................  40 work-hours x $85            $0   $3,400 per            $193,800 per
                                    per hour = $3,400                   inspection cycle.     inspection cycle.
                                    per inspection
                                    cycle.
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[[Page 12956]]

    We estimate the following costs to do any necessary replacements 
that would be required based on the results of the proposed inspection. 
We have no way of determining the number of airplanes that might need 
these replacements:

                                               On-Condition Costs
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                                                                                                     Cost per
                    Action                                 Labor cost               Parts cost        product
----------------------------------------------------------------------------------------------------------------
Heat shield primary seal replacement..........  10 work-hours x $85 per hour =            $1,940          $2,790
                                                 $850.
Cracked or damaged parts replacement..........  110 work-hours x $85 per hour =           52,992          62,342
                                                 $9,350.
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    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

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 FAA amends Sec.  39.13 by adding the following new airworthiness 
directive (AD):

The Boeing Company: Docket No. FAA-2015-0247; Directorate Identifier 
2014-NM-178-AD.

(a) Comments Due Date

    We must receive comments by April 27, 2015.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to The Boeing Company Model 777-200 and -300 
series airplanes equipped with Rolls-Royce Trent 800 series engines, 
certificated in any category, as identified in Boeing Service 
Bulletin 777-54A0031, Revision 1, dated May 9, 2014.

(d) Subject

    Air Transport Association (ATA) of America Code 54, Nacelles/
Pylons.

(e) Unsafe Condition

    This AD was prompted by reports of heat damage to the strut aft 
fairing heat shield primary seal, as well as heat and wear damage to 
the heat shield insulation blankets. We are issuing this AD to 
detect and correct heat damage to the strut aft fairing lower spar 
web structure (a flammable fluid zone barrier and fire wall) and 
heat shield primary seal, as well as heat and wear damage to the 
heat shield insulation blankets, which could lead to through-cracks 
in the aft fairing web structure and heating of the aft fairing web 
structure, and consequent uncontrolled fire in the aft fairing, fuel 
tank ignition or possible departure of the engine.

(f) Compliance

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

(g) Repetitive Inspections

    At the applicable time specified in paragraph 1.E., 
``Compliance,'' of Boeing Service Bulletin 777-54A0031, Revision 1, 
dated May 9, 2014, except as required by paragraph (i) of this AD: 
Do the inspections specified in paragraphs (g)(1), (g)(2), and 
(g)(3) of this AD, and do all applicable related investigative and 
corrective actions, in accordance with the Accomplishment 
Instructions of Boeing Service Bulletin 777-54A0031, Revision 1, 
dated May 9, 2014. Do all applicable related investigative and 
corrective actions before further flight. Repeat the inspections 
specified in paragraphs (g)(1), (g)(2), and (g)(3) of this AD at the 
applicable time specified in paragraph 1.E., ``Compliance,'' of 
Boeing Service Bulletin 777-54A0031, Revision 1, dated May 9, 2014.
    (1) Do a detailed inspection for cracks and heat damage of the 
aft fairing lower spar upper surface.
    (2) Do a conductivity inspection for heat damage of the aft 
fairing lower spar upper surface.
    (3) Do a detailed inspection for wear of the heat shield primary 
seal.

(h) Optional Terminating Action

    The concurrent accomplishment of the actions specified in 
paragraphs (h)(1) and (h)(2) of this AD terminates the requirements 
of paragraph (g) of this AD.
    (1) Replacement of all heat shield insulation blankets (rub 
strips, heat shield pan casting, Velcro strips, aft fairing web 
drain sump, drain screen, and drain tubes, as applicable) in 
accordance with the Accomplishment Instructions of Boeing Service 
Bulletin 777-54-0030, dated May 27, 2014.
    (2) A one-time detailed inspection for cracks and heat damage of 
the aft fairing lower spar upper surface, conductivity inspection 
for heat damage of the aft fairing lower spar upper surface, and 
detailed inspection for wear of heat shield primary seal, and all 
applicable related investigative and corrective actions, in 
accordance with the Accomplishment Instructions of Boeing Service 
Bulletin 777-54A0031, Revision 1, dated May 9, 2014, provided all 
applicable

[[Page 12957]]

related investigative and corrective actions are done before further 
flight.

(i) Exception to Service Information Specifications

    Where Boeing Service Bulletin 777-54A0031, Revision 1, dated May 
9, 2014, specifies a 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.

(j) Credit for Previous Actions

    This paragraph provides credit for the actions specified in 
paragraphs (g)(1), (g)(2), (g)(3) and (h)(2) of this AD, if those 
actions were performed before the effective date of this AD using 
Boeing Alert Service Bulletin 777-54A0031, dated June 7, 2013.

(k) 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 paragraph (l)(1) 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.

(l) Related Information

    (1) For more information about this AD, contact Kevin Nguyen, 
Aerospace Engineer, Propulsion Branch, ANM-140S, FAA, Seattle 
Aircraft Certification Office (ACO), 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 view this 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 February 19, 2015.
Jeffrey E. Duven,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2015-05032 Filed 3-11-15; 8:45 am]
 BILLING CODE 4910-13-P