AD 2013-24-01

[Federal Register Volume 78, Number 229 (Wednesday, November 27, 2013)]
[Rules and Regulations]
[Pages 70851-70854]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2013-28638]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2013-0974; Directorate Identifier 2013-NM-209-AD; 
Amendment 39-17675; AD 2013-24-01]
RIN 2120-AA64


Airworthiness Directives; The Boeing Company Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule; request for comments.

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SUMMARY: We are adopting a new airworthiness directive (AD) for The 
Boeing Company Model 747-8 and 747-8F series airplanes and Model 787-8 
airplanes powered by GEnx engines. This AD requires revising the 
airplane flight manual to advise the flight crew of potential ice 
crystal icing (ICI) conditions at high altitudes, and to prohibit 
operation in moderate and severe ICI conditions. This AD also requires 
inspecting the engine after any ICI event is detected by the flight 
crew. This AD was prompted by reports of engine damage and thrust loss 
events as a result of flying in high altitude ICI conditions. We are 
issuing this AD to ensure that the flight crews have operating 
instructions to avoid flight into ICI conditions that can lead to 
engine damage and thrust loss events; unrecoverable thrust loss on 
multiple engines can lead to a forced landing.

DATES: This AD is effective November 27, 2013.
    We must receive comments on this AD by January 13, 2014.

ADDRESSES: You may send comments, using the procedures found in 14 CFR 
11.43 and 11.45, by any of the following methods:
    <bullet> Federal eRulemaking Portal: Go to <a href="http://www.regulations.gov">http://www.regulations.gov</a>. Follow the instructions for submitting comments.
    <bullet> Fax: 202-493-2251.
    <bullet> 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.
    <bullet> Hand Delivery: U.S. Department of Transportation, Docket 
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New 
Jersey Avenue SE., Washington, DC 20590, between 9 a.m. and 5 p.m., 
Monday through Friday, except Federal holidays.

Examining the AD Docket

    You may examine the AD docket on the Internet at <a href="http://www.regulations.gov">http://www.regulations.gov</a>; 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 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: Sue Lucier, Aerospace Engineer, 
Propulsion Branch, ANM-140S, FAA, Seattle Aircraft Certification Office 
(ACO), 1601 Lind Avenue SW., Renton, Washington 98057-3356; phone: 425-
917-6438; fax: 425-917-6590; email: <a href="/cdn-cgi/l/email-protection#9be8eee1faf5f5feb5f7eef8f2fee9dbfdfafab5fcf4ed"><span class="__cf_email__" data-cfemail="5f2c2a253e31313a71332a3c363a2d1f393e3e71383029">[email&#160;protected]</span></a>.

SUPPLEMENTARY INFORMATION: 

Discussion

    Over the past decade, we have been aware of temporary engine thrust 
loss, and other engine-related events that occurred in ice crystal 
icing (ICI) conditions at high altitudes. These events have prompted 
the release of ADs on various airplane models equipped with General 
Electric (GE) CF6-80 series engines. Each event was in or near 
convective weather conditions that included ice crystal icing.
    This type of icing does not appear on radar due to its low 
reflectivity, and neither the airplane ice detector nor visual 
indications reliably indicate the presence of icing conditions. 
Therefore, it is often undetected by the flight crew. Flight in these 
conditions can cause ice crystals to accumulate in the core gas flow 
path of the engine. In the events leading to those prior ADs, the ice 
has shed during throttle transients and in the descent phase of flight, 
causing temporary thrust loss.
    Since the beginning of 2013, similar events have now occurred on 
Model 747-8 and 747-8F series airplanes powered by GEnx-2B engines and 
Model 787-8 airplanes powered by GEnx-1B engines. The new events that 
prompted this AD, however, have occurred during the cruise phase of 
flight and caused permanent damage (beyond maintenance manual limits) 
to the engine compressor. In all thrust loss events, data indicate that 
ice crystals entered and collected in the initial stages of the 
compressor. Engine temperature data indicate small ice accretions were 
shed through the core of the engine.
    All of these ICI events occurred during cruise at 33,000 feet or 
above, either within or after the airplane traversed a large Mesoscale 
Convective System (MCS). MCSs are areas where several thunderstorms 
have merged, with a continuous cloud larger than 100 kilometers (62 
miles) across.
    Within or near MCSs, ICI events have occurred where convective 
activity has driven a significant quantity of moisture, in the form of 
ice crystals, to altitudes at or above the tropopause. ICI events tend 
to occur in warm geographic locations.
    As of the date of this AD, there have been nine events on Model 
747-8 airplanes and Model 787-8 airplanes.
    During two events on Model 747-8F airplanes, two engines 
experienced thrust losses during the cruise phase of flight. In one of 
these events, one of the engines recovered to idle but would not 
accelerate and was left at idle for the rest of the flight. The other 
engine recovered and operated normally for the rest of the flight. In 
both airplane events, subsequent inspections of all four engines 
revealed compressor damage on both of the event engines as well as 
damage to a third engine that had not experienced a thrust loss.
    In four other events--one on a Model 787-8 airplane and three on 
Model 747-8 airplanes--uncommanded engine decelerations (i.e., thrust 
losses) of approximately 20 seconds in duration occurred. All engines 
automatically recovered commanded thrust without crew action and 
operated normally for the rest of the flight.
    In three other events on Model 747-8 airplanes, at least one engine 
showed elevated vibrations on the low-speed engine spool (N1) while in 
ICI conditions. The vibrations stopped after the airplanes exited the 
weather system, and the engines operated normally for the rest of the 
flight.
    Unrecoverable thrust loss on multiple engines, due to operation in 
high altitude clouds containing ice crystals, could lead to a forced 
landing.

FAA's Determination

    We are issuing this AD because we evaluated all the relevant 
information

[[Page 70852]]

and determined the unsafe condition described previously is likely to 
exist or develop in other products of these same type designs.

AD Requirements

    This AD requires revising the Certificate Limitations and Operating 
Procedures chapters of the AFM to advise the flight crew of potential 
ICI conditions at high altitudes, and to provide procedures to prohibit 
flight into those conditions.
    This AD also requires engine inspections after any event where the 
flight crew reports the appearance of the ``ENGINE THRUST'' message on 
the engine indication and crew alert system (EICAS) for any engine. The 
intent of the inspection requirement is to verify the airworthiness of 
the airplane for future flights. Because of thrust requirements on the 
different airplane models, the inspection is required before further 
flight on a minimum of three engines on Model 747-8 and 747-8F series 
airplanes, and on both engines on Model 787-8 airplanes.

Interim Action

    We consider this AD interim action. If final action is later 
identified, we might consider further rulemaking then.

FAA's Justification and Determination of the Effective Date

    An unsafe condition exists that requires the immediate adoption of 
this AD. The FAA has found that the risk to the flying public justifies 
waiving notice and comment prior to adoption of this rule because 
flight in potential ICI at high altitudes could result in engine damage 
and loss of thrust and consequent forced landing. Therefore, we find 
that notice and opportunity for prior public comment are impracticable 
and that good cause exists for making this amendment effective in less 
than 30 days.

Comments Invited

    This AD is a final rule that involves requirements affecting flight 
safety and was not preceded by notice and an opportunity for public 
comment. However, we invite you to send any written data, views, or 
arguments about this AD. Send your comments to an address listed under 
the ADDRESSES section. Include the docket number FAA-2013-0974 and 
Directorate Identifier 2013-NM-209-AD at the beginning of your 
comments. We specifically invite comments on the overall regulatory, 
economic, environmental, and energy aspects of this AD. We will 
consider all comments received by the closing date and may amend this 
AD because of those comments.
    We will post all comments we receive, without change, to <a href="http://www.regulations.gov">http://www.regulations.gov</a>, including any personal information you provide. We 
will also post a report summarizing each substantive verbal contact we 
receive about this AD.

Costs of Compliance

    We estimate that this AD affects 14 airplanes of U.S. registry. We 
estimate the following costs to comply with this AD:

                                         Estimated Costs: AFM Revisions
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                                                                                    Cost per       Cost on U.S.
               Action                        Labor cost           Parts cost        product         operators
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AFM revisions.......................  1 work-hour x $85 per                $0              $85           $1,190
                                       hour = $85.
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                                           Estimated Costs: Inspection
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               Action                        Labor cost           Parts cost            Cost per product
----------------------------------------------------------------------------------------------------------------
Inspection..........................  2 work-hours x $85 per               $0   $680 per airplane
                                       hour = $170 per engine.
----------------------------------------------------------------------------------------------------------------

    We have received no definitive data that would enable us to provide 
cost estimates for the on-condition corrective actions specified in 
this AD.

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

    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),
    (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.

Adoption of the Amendment

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


[[Page 70853]]


2013-24-01 The Boeing Company: Amendment 39-17675; Docket No. FAA-
2013-0974; Directorate Identifier 2013-NM-209-AD.

(a) Effective Date

    This AD is effective November 27, 2013.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to The Boeing Company airplanes, certificated in 
any category, identified in paragraphs (c)(1) and (c)(2) of this AD.
    (1) Model 747-8 and 747-8F series airplanes powered by GEnx-2B67 
or GEnx-2B67B engines.
    (2) Model 787-8 airplanes powered by GEnx-1B64, GEnx-1B67, GEnx-
1B70, GEnx-1B64/P1, GEnx-1B67/P1, GEnx-1B70/P1, or GEnx-1B70/75/P1 
engines.
    Note 1 to paragraph (c)(2) of this AD: The engine nameplate may 
also include a suffix such as ``G03,'' which is the applicable Bill 
of Materials (See FAA Type Certification Data Sheet T00021SE basic 
model identifier).

(d) Subject

    Air Transport Association (ATA) of America Code 71, Power plant.

(e) Unsafe Condition

    This AD was prompted by reports of engine damage and thrust loss 
events as a result of flying in high altitude ice crystal icing 
(ICI) conditions. We are issuing this AD to ensure that the flight 
crews have operating instructions to avoid flight into ICI 
conditions that can lead to engine damage and thrust loss events. We 
are also issuing this AD to ensure the airplane has a minimum number 
of airworthy engines following a potential high altitude ICI 
encounter. Operation with more than one engine having icing damage 
can lead to a common cause loss of thrust on multiple engines, which 
can lead to a forced landing.

(f) Compliance

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

(g) Revision of Airplane Flight Manual (AFM): Certificate Limitations

    Within 7 days after the effective date of this AD, revise the 
Certificate Limitations chapter of the applicable Boeing AFM to 
include the statement provided in figure 1 to paragraph (g) of this 
AD. This may be done by inserting a copy of this AD into the AFM.

Figure 1 to Paragraph (g) of This AD--Certificate Limitations

AVOIDANCE OF ICE CRYSTAL ICING

(Required by AD 2013-24-01.)

    In order to prevent loss of thrust and engine damage due to ice 
crystal icing, for operations at or above 30,000 feet, when 
approaching, or in, instrument meteorological conditions or visible 
moisture:
    The flight crew must comply with the Avoidance of Ice Crystal 
Icing procedure contained in the Operating Procedures chapter of 
this manual.
    When following the Avoidance of Ice Crystal Icing procedure, 
flight is prohibited within 50NM of amber or red radar returns that 
are displayed below the airplane's flight path.

    Note 2 to figure 1 to paragraph (g), figure 2 to paragraph (h), 
and figure 3 to paragraph (i) of this AD:  When statements identical 
to those in figures 1, 2, and 3 to paragraphs (g), (h), and (i) of 
this AD, respectively, have been included in the applicable chapters 
of the general revisions of the applicable AFM, the general 
revisions may be inserted into the AFM, and the copy of this AD may 
be removed from the AFM.

(h) AFM Revision: Model 747-8 and 747-8F Operating Procedures

    For Model 747-8 (Intercontinental) and 747-8F (Freighter) series 
airplanes: Within 7 days after the effective date of this AD, revise 
the Operating Procedures chapter of the Boeing 747-8 AFM to include 
the statement provided in figure 2 to paragraph (h) of this AD. This 
may be done by inserting a copy of this AD into the AFM.

Figure 2 to Paragraph (h) of This AD--Model 747-8 Operating Procedures

AVOIDANCE OF ICE CRYSTAL ICING

(Required by AD 2013-24-01.)

    This procedure is required by the AVOIDANCE OF ICE CRYSTAL ICING 
limitation contained in the Certificate Limitations chapter of this 
manual. The language below shall not be modified.
    Operations in ice crystal icing can cause unrecoverable loss of 
thrust and engine damage due to ice crystal icing.
    For operations at or above 30,000 feet, when approaching, or in, 
instrument meteorological conditions or visible moisture:
    Operate weather radar in automatic mode and gain knob set to the 
12 o'clock position, or if in manual mode adjust gain to maximum and 
set tilt between -1 and -3.
    If areas of green, amber or red weather radar returns are 
observed along the flight path:
    Use manual weather radar tilt control mode and vary the tilt 
between -3 and -5 degrees and set the gain knob to the 12 o'clock 
position to determine if amber or red returns are present below the 
airplane's flight path.
    Flight is prohibited within 50NM of amber or red radar returns 
that are displayed below the airplane's flight path.

(i) AFM Revision: Model 787-8 Operating Procedures

    For Model 787-8 airplanes: Within 7 days after the effective 
date of this AD, revise the Operating Procedures chapter of the 
Boeing 787 AFM to include the statement provided in figure 3 to 
paragraph (i) of this AD. This may be done by inserting a copy of 
this AD into the AFM.

Figure 3 to Paragraph (i) of This AD--Model 787-8 Operating Procedures

AVOIDANCE OF ICE CRYSTAL ICING

(Required by AD 2013-24-01.)

    This procedure is required by the AVOIDANCE OF ICE CRYSTAL ICING 
limitation contained in the Certificate Limitations chapter of this 
manual. The language below shall not be modified.
    Operations in ice crystal icing can cause unrecoverable loss of 
thrust and engine damage due to ice crystal icing.
    For operations at or above 30,000 feet, when approaching, or in, 
instrument meteorological conditions or visible moisture:
    Operate weather radar in automatic mode and 0 manual gain 
adjustment, or if in manual mode adjust gain to maximum and set tilt 
between -1 and -3.
    If areas of green, amber or red weather radar returns are 
observed along the flight path:
    Use manual weather radar tilt control mode and vary the tilt 
between -3 and -5 degrees and select 0 manual gain adjustment to 
determine if amber or red returns are present below the airplane's 
flight path.
    Flight is prohibited within 50NM of amber or red radar returns 
that are displayed below the airplane's flight path.

(j) Post-Event Inspections

    After any flight crew report of the appearance of an engine 
indicating and crew alerting system (EICAS) message that displays 
``ENG THRUST (L,R)'' (for Model 787-8 airplanes) or ``ENG (1, 2, 3, 
or 4) THRUST'' (for Model 747-8 and 747-8F airplanes) during 
operation at or above 30,000 feet pressure altitude: Do borescope 
inspections of the first stage blade of the high pressure compressor 
of the engines to detect damage, as specified in paragraph (j)(1) or 
(j)(2) of this AD, as applicable. Correct any damage before further 
flight.
    (1) For Model 747-8 and 747-8F series airplanes: Before further 
flight, inspect each engine for which an EICAS ENGINE THRUST message 
was displayed. A minimum total of 3 engines must be inspected before 
further flight. Within 5 flight cycles after the EICAS message was 
displayed, inspect the fourth engine, unless already accomplished as 
specified in this paragraph.
    (2) For Model 787-8 airplanes: Before further flight, inspect 
both engines.

(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 (k) of this AD. 
Information may be emailed to <a href="/cdn-cgi/l/email-protection#bf8692fef1f292ecdadecbcbd3da92fefcf092fef2f0fc92eddacecadacccbccffd9dede91d8d0c9"><span class="__cf_email__" data-cfemail="2a13076b646707794f4b5e5e464f076b6965076b67656907784f5b5f4f595e596a4c4b4b044d455c">[email&#160;protected]</span></a>.
    (2) Before using any approved AMOC, notify your appropriate 
principal inspector,

[[Page 70854]]

or lacking a principal inspector, the manager of the local flight 
standards district office/certificate holding district office.

(l) Related Information

    (1) For more information about this AD, contact Sue Lucier, 
Aerospace Engineer, Propulsion Branch, ANM-140S, FAA, Seattle 
Aircraft Certification Office (ACO), 1601 Lind Avenue SW., Renton, 
Washington 98057-3356; phone: 425-917-6438; fax: 425-917-6590; 
email: <a href="/cdn-cgi/l/email-protection#a6d5d3dcc7c8c8c388cad3c5cfc3d4e6c0c7c788c1c9d0"><span class="__cf_email__" data-cfemail="a8dbddd2c9c6c6cd86c4ddcbc1cddae8cec9c986cfc7de">[email&#160;protected]</span></a>.
    (2) Refer to the applicable information specified in paragraph 
(l)(2)(i) or (l)(2)(ii) of this AD for guidance on inspecting the 
engine and correcting damage.
    (i) For Model 747-8 and 747-8F series airplanes: Refer to Task 
72-00-00-290-801-G00, High Pressure Compressor Section (with a 
Borescope) Detailed Inspection, of Subject 72-00-00, Engine--
Inspection/Check, of Chapter 72, Engine, of the Boeing 747-8 
Aircraft Maintenance Manual.
    (ii) For Model 787-8 airplanes: Refer to Data Module DMC-B787-A-
G72-00-00-06B-280C-A, High Pressure Compressor Section (with a 
Borescope)--Special Detailed Inspection, of the Boeing 787-8 
Aircraft Maintenance Manual.
    (3) For Boeing service information identified in this AD that is 
not incorporated by reference, 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 <a href="https://www.myboeingfleet.com">https://www.myboeingfleet.com</a>. You may view 
this 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.

(m) Material Incorporated by Reference

    None.

    Issued in Renton, Washington, on November 22, 2013.
Jeffrey E. Duven,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2013-28638 Filed 11-26-13; 8:45 am]
BILLING CODE 4910-13-P