Document ID: FAA-2013-0792-0012
Agency: faa
Document Type: Rule
Title: Airworthiness Directives: The Boeing Company Airplanes
Posted Date: 2014-10-01T04:00Z

[Federal Register Volume 79, Number 190 (Wednesday, October 1, 2014)]
[Rules and Regulations]
[Pages 59096-59101]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2014-23231]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2013-0792; Directorate Identifier 2013-NM-118-AD; 
Amendment 39-17979; AD 2014-20-06]
RIN 2120-AA64

Airworthiness Directives; The Boeing Company Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

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SUMMARY: We are adopting a new airworthiness directive (AD) for all The 
Boeing Company Model 737-600, -700, -700C, -800, -900, and -900ER 
series airplanes, and Model 777 airplanes. This AD was prompted by 
testing reports on certain Honeywell phase 3 display units (DUs). These 
DUs exhibited susceptibility to radio frequency emissions in WiFi 
frequency bands at radiated power levels below the levels that the 
displays are required to tolerate for certification of WiFi system 
installations. The phase 3 DUs provide primary flight information 
including airspeed, altitude, pitch and roll attitude, heading, and 
navigation information to the flightcrew. This AD requires replacing 
the existing phase 3 DUs with phase 1, phase 2, or phase 3A DUs, and 
for certain replacement DUs, installing new DU database software. We 
are issuing this AD to prevent loss of flight-critical information 
displayed to the flightcrew during a critical phase of flight, such as 
an approach or takeoff, which could result in loss of airplane control 
at an altitude insufficient for recovery, or controlled flight into 
terrain.

DATES: This AD is effective November 5, 2014.
    The Director of the Federal Register approved the incorporation by 
reference of certain publications listed in this AD as of November 5, 
2014.

ADDRESSES: 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.

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-2013-
0792; 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 address for the Docket Office (phone: 800-647-
5527) is Docket Management Facility, U.S. Department of Transportation, 
Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 
New Jersey Avenue SE., Washington, DC 20590.

FOR FURTHER INFORMATION CONTACT: Jeffrey W. Palmer, Aerospace Engineer, 
Systems and Equipment Branch, ANM-130S, Seattle Aircraft Certification 
Office, FAA, 1601 Lind Avenue SW., Renton, WA 98057-3356; phone: 425-
917-6472; fax: 425-917-6590; email: jeffrey.w.palmer@faa.gov.

SUPPLEMENTARY INFORMATION: 

Discussion

    We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR 
part 39 by adding an AD that would apply to all The Boeing Company 
Model 737-600, -700, -700C, -800, -900, and -900ER series airplanes, 
and Model 777 airplanes. The NPRM published in the Federal Register on 
September 24, 2013 (78 FR 58487). The NPRM was prompted by testing 
reports on certain Honeywell phase 3 DUs. These DUs exhibited 
susceptibility to radio frequency emissions in WiFi frequency bands at 
radiated power levels below the levels that the displays are required 
to tolerate for certification of WiFi system installations. The phase 3 
DUs provide primary flight information including airspeed, altitude, 
pitch and roll attitude, heading, and navigation information to the 
flightcrew. The NPRM proposed to require replacing the existing phase 3 
DUs with new phase 3A DUs and installing new DU database software. We 
are issuing this AD to prevent loss of flight-critical information 
displayed to the flightcrew during a critical phase of flight, such as 
an approach or takeoff, which could result in loss of airplane control 
at an altitude insufficient for recovery, or controlled flight into 
terrain.

Clarification of Cause of Unsafe Condition

    The cause of the unsafe condition stated in the Discussion section 
of this AD is a known susceptibility of the Phase 3 DUs to RF 
transmissions inside and outside of the airplane. This susceptibility 
has been verified to exist in a range of RF spectrum (mobile satellite 
communications, cell phones, air surveillance and weather radar, and 
other systems), and is not limited to WiFi transmissions.

Comments

    We gave the public the opportunity to participate in developing 
this AD. The following presents the comments received on the proposal 
(78 FR 58487, September 24, 2013), and the FAA's response to each 
comment.

Request To Change Applicability

    Three commenters requested that we revise the applicability. A4A 
requested that we change the applicability to address only airplanes 
that have phase 3 DUs installed. Mr. Philipp Schmid requested that the 
applicability only address airplanes that have a WiFi system installed 
in the cabin. All Nippon Airways (ANA) requested that we revise 
applicability paragraph (c) of the proposed AD (78 FR 58487, September 
24, 2013) to refer to the airplanes identified in Boeing Special 
Attention Service Bulletin 737-31-1471, dated November 29, 2012; and 
Boeing Special Attention Service Bulletin 777-31-0187, dated November 
29, 2012.
    A4A stated that the FAA is making the NPRM (78 FR 58487, September 
24, 2013) applicable to all Model 737 NG and Model 777 series 
airplanes, regardless of the operator's intent to install a Wi-Fi 
system. A4A expressed that in paragraph (e) of the proposed AD, the FAA 
acknowledges that the unsafe condition is directly related to 
electromagnetic interference (EMI) characteristics exhibited at 
specific frequency ranges related to Wi-Fi transmission. A4A stated 
that the phase 3 DUs have passed all applicable certification testing 
required for approval and use on transport category airplanes, 
including the DO-160 environmental standards. A4A asserted

[[Page 59097]]

that the phase 3 display units have proven to be reliable under normal 
operating conditions. A4A also stated that the failure mode identified 
by the NPRM is specific to an additional test procedure prescribed by 
DO-294C that is required only as part of the certification requirements 
of an operator-installed Wi-Fi system.
    ANA stated that the those airplanes not specified in Boeing Special 
Attention Service Bulletin 737-31-1471, dated November 29, 2012; and 
Boeing Special Attention Service Bulletin 777-31-0187, dated November 
29, 2012; were/will be delivered with the requested changes in 
production.
    We partially agree with the commenters' requests. We recognize that 
operators will not be able to comply with the proposed replacement 
specified in paragraph (g) of the proposed AD (78 FR 58487, September 
24, 2013) if airplanes do not have any phase 3 DUs installed. 
Therefore, we have revised paragraph (g) of this AD to allow operators 
to inspect to determine if phase 3 DUs are installed and if no phase 3 
DUs are installed, no further action is necessary.
    The intent of this AD is to remove all DUs with an unsafe condition 
from all Model 737NG and Model 777 series airplanes, regardless of 
whether or not the airplanes are listed in the effectivity of Boeing 
Special Attention Service Bulletin 737-31-1471, dated November 29, 
2012; and Boeing Special Attention Service Bulletin 777-31-0187, dated 
November 29, 2012.
    DUs can be rotated among other airplanes. As noted by Boeing, the 
phase 3 DU's are interchangeable and intermixable with earlier versions 
of DU's on 737NG and 777 airplanes, and may have been installed on any 
737NG or 777 airplanes, and may be in operator spares inventory.
    In regards to A4A's comment that phase 3 DUs have proven to be 
reliable under normal operating conditions, the testing that revealed 
the DU susceptibility was verified by inspection of the phase 3 DU 
qualification test reports provided by the DU manufacturer. The intent 
of this AD is to eliminate this known susceptibility of the phase 3 DUs 
to RF transmissions, including those from sources outside the airplane. 
This susceptibility is not limited to WiFi transmissions, but has been 
verified to exist in a range of the RF spectrum used by mobile 
satellite communications, cell phones, air surveillance and weather 
radar, and other systems. The phase 3 displays that failed the test did 
so substantially below the RF immunity levels set forth in paragraph 1 
of the ``High Intensity Radiated Fields (HIRF)'' section of the 
preamble to 737 Special Condition 25-ANM-132, dated September 26, 1997; 
and paragraph 1 of the HIRF discussion in the preamble to 777 Special 
Condition 25-ANM-78, dated November 10, 1993. Under the provisions of 
paragraph (h) of this AD, we will consider requests for approval of an 
AMOC if sufficient data are submitted to substantiate that the DU 
change is not necessary. We have not changed this AD in this regard.

Request To Withdraw the NPRM (78 FR 58487, September 24, 2013)

    Virgin Australia (VOZ), Air France (AFA), Ryanair, Airlines for 
America (A4A), and Honeywell requested that we withdraw or review the 
need for the NPRM (78 FR 58487, September 24, 2013).
    VOZ stated that during testing of the WiFi inflight entertainment 
system on the VOZ Model 737NG fleet, it noted that the DU blanking 
occurred only when the WiFi radiated power source (set-up in the flight 
deck) was increased to a high level. VOZ also stated that under normal 
operating conditions of the WiFi radiated power, there was no blanking 
of the DU, but interference was present only at a certain frequency. 
VOZ commented that as part of the WiFi supplemental type certificate 
(STC), a decal is installed in the flight deck that states that WiFi is 
not to be used when airplane engines are running for the purpose of 
flight, and flight operation procedures also restrict transmitting 
devices in the flight deck. We infer that VOZ requested that we 
withdraw the NPRM (78 FR 58487, September 24, 2013).
    AFA stated that since April 2013, AFA and Koninklijke Luchtvaart 
Maatschappij N.V.(KLM) have operated two Model 777 airplanes equipped 
with WiFi that have had no DU problems. AFA commented that the WiFi 
signal is available on the flight deck, but its use is prohibited. AFA 
suggested that it is likely that the WiFi signal level is too low to 
cause the DU blanking problems that led to the NPRM (78 FR 58487, 
September 24, 2013). AFA also stated that on its other Model 777 
airplanes (85 airplanes equipped with phase 2 or 3 DUs with no WiFi), 
neither AFA nor KLM, have experienced DU problems. AFA stated that the 
DU discrepancies are caused by WiFi interference directly associated 
with design defects of the phase 3 DU, and since replacement cost is at 
customer expense, estimated more than $2,000 per DU, the cost to comply 
with the NPRM for the quantity of phase 3 DUs in service in both fleets 
is not reasonable or justified.
    Ryanair and Honeywell commented that testing performed on the phase 
3 DUs concluded that a Federal Communications Commission (FCC) 
compliant WiFi radiating device does not result in interference on the 
phase 3 DU unless the transmitting device is within 1 meter of the DU. 
Ryanair and Honeywell stated that is not possible for FCC compliant 
WiFi devices to cause interference to the DUs from outside the airplane 
during flight and that intentional emitting devices by passengers are 
prohibited from use on an airplane, and in any case will always be more 
than the required 1 meter distance from the DU, and consequently cannot 
cause interference to the DUs. Ryanair and Honeywell also stated that 
the installation and operation of any intentional emitting devices in 
the cockpit during flight is subject to regulatory approval and such 
regulatory approval process includes electromagnetic interference 
testing at WiFi frequencies. Ryanair asserted that requiring the NPRM 
(78 FR 58487, September 24, 2013) actions on all airplanes, 
irrespective of the installation or operation of WiFi systems in the 
cockpit, is imposing a high, and unnecessary, financial burden on 
operators.
    Honeywell stated that instead of requiring all phase 3 DUs to be 
replaced or modified, as proposed by the NPRM (78 FR 58487, September 
24, 2013), the need for modifying the DUs should only be considered in 
the process for authorizing the use of WiFi devices in the cockpit. 
Honeywell explained that since the cockpit is a controlled environment, 
the airline has the opportunity to select acceptable devices and 
establish procedures for their use and storage that can mitigate any 
interference risk. Honeywell stated that Delta Airlines has been safely 
operating WiFi-enabled Apple iPads in its flight decks, including those 
with phase 3 DUs, based on a waiver granted by the FAA.
    Honeywell also stated that they have performed an assessment of 
continued operational safety (COS) risk to an external high intensity 
radiated field (HIRF) condition using the methods defined in the 
Transport Airplane Risk Assessment Methodology (TARAM) Handbook 
published by the FAA, Transport Airplane Directorate, and that its 
TARAM analysis concluded that the COS risk from external HIRF condition 
falls well within the FAA's acceptable risk zone.
    A4A requested that we withdraw the NPRM (78 FR 58487, September 24, 
2013) because it believes that the risk is not adequately 
substantiated, and that

[[Page 59098]]

conflicting data exists questioning the susceptibility of the DUs to 
WiFi interference. A4A also commented that the economic impact of the 
NPRM actions is far greater than the cost estimate stated in the NPRM 
and should be acknowledged and weighed against what it characterized as 
questionable risk.
    We do not agree with the commenters' request to withdraw the NPRM 
(78 FR 58487, September 24, 2013). The testing that revealed the DU 
susceptibility to WiFi interference was verified by inspection of the 
phase 3 DU qualification test reports provided by the DU manufacturer. 
The intent of this final rule is to eliminate this known susceptibility 
of the phase 3 DUs to radio frequency (RF) transmissions, including 
those from sources outside the airplane. The phase 3 displays that 
failed testing did so substantially below the RF immunity levels set 
forth in paragraph 1 of the HIRF section of the preamble to 737 Special 
Condition 25-ANM-132, dated September 26, 1997 (http://www.gpo.gov/fdsys/pkg/FR-2009-09-03/pdf/E9-21299.pdf); and paragraph 1. of the HIRF 
discussion in the preamble to 777 Special Condition 25-ANM-78, dated 
November 10, 1993 (http://www.gpo.gov/fdsys/pkg/FR-2004-11-08/pdf/04-24847.pdf).
    As part of our assessment of the safety issue in accordance with 
our established safety process, the FAA also performed a TARAM analysis 
of the issue with the assistance of the airplane manufacturer. This 
analysis did not agree with Honeywell's assessment. The FAA issued an 
operating rule exemption to Delta Airlines for use of iPads on the 
flight deck because it was in the public interest to do so in order to 
enable testing and evaluation of other aviation safety-enhancing 
technology the FAA was researching. The FAA's exemption was granted to 
Delta based on extensive testing and supporting data, use of specially 
trained flight crews, and establishment of appropriate operating 
procedures to ensure safe flight operations during the time period of 
the exemption. The NPRM (78 FR 58487, September 24, 2013) will not be 
withdrawn because it meets the intent of correcting the unsafe 
condition listed in the SUMMARY section. Under the provisions of 
paragraph (h) of this AD, we will consider requests for approval of an 
alternative method of compliance (AMOC) if sufficient data are 
submitted to substantiate that the DU change is not necessary. We have 
not changed this AD in this regard.

Request To Disclose Underlying Data in Support of the NPRM (78 FR 
58487, September 24, 2013)

    A4A requested that we fully present our underlying data in support 
of the NPRM (78 FR 58487, September 24, 2013) risk allegation. Mr. 
Philipp Schmid stated that WiFi operational limitations should be 
considered in the risk assessment and that to his knowledge, WiFi 
systems must be disabled during the critical phases of flight such as 
an approach or take-off.
    A4A stated that the FAA does not disclose in the NPRM (78 FR 58487, 
September 24, 2013), the nature of DU testing conducted nor its source, 
and that a rulemaking of this magnitude must be supported in 
incontrovertible data from appropriate and reliable sources.
    A4A submitted information from Southwest Airlines (SWA) that stated 
that SWA collected data from both certified lab and engineering 
designed airplane ground tests indicating that the Honeywell phase 3 
DUs are not susceptible at or below the energy levels required for 
certification. SWA also stated that it has performed extensive testing 
with respect to susceptibility of the Honeywell phase 3 DUs in the WiFi 
bands outlined in the NPRM (78 FR 58487, September 24, 2013) and that 
this testing indicated that significant safety margins are available; 
and that there are no threat susceptibilities recorded at or below the 
WiFi certification levels. SWA also commented that it has flown 
2,375,481 hours with 435 airplanes since WiFi system installation with 
no un-attributable DU blanking or blinking defects that would be a 
consideration under the NPRM. SWA concluded that ``this experience 
indicates a negligible level of risk.''
    A4A submitted information from United Airlines (UAL). UAL explained 
that an alternate means of assuring an equivalent level of safety while 
a replacement program is undertaken has been accepted by FAA at UAL. 
UAL stated that it has been granted certification limitations which 
allow operation of the WiFi system provided that the flight deck is 
placarded to disallow use of transmitting portable electronic devices 
(TPED) when engines are operating for purposes of flight. UAL stated it 
believes such limitations are the appropriate means to address the 
unsafe condition because they apply directly to the certification of 
airplane with an operator-installed WiFi system. A4A stated that it 
agrees with UAL that such a restriction provides an equivalent level of 
safety, for if it did not, it would not have been approved by the FAA.
    We do not agree with the commenters' requests. We do not agree to 
share the underlying data in the AD. An AD is not an appropriate 
vehicle for sharing proprietary data.
    The susceptibility of phase 3 DUs to RF transmissions was initially 
identified during a WiFi STC installation by an operator and a WiFi 
vendor and reported to the FAA. As a result of this discovery, we 
performed a risk assessment for in-service airplanes equipped with 
phase 3 DUs using our established COS process, which determined that an 
AD action was warranted for this issue. In addition, Boeing did an 
independent safety review and also determined that the DU blanking was 
a safety issue using its own risk assessment process.
    Although various entities (operators, vendors, etc.) may have done 
testing which may seem to contradict our findings, the WiFi tests 
conducted during the above referenced STC project failed to meet RF 
immunity level requirements. The testing that revealed the DU 
susceptibility was further verified by inspection of the phase 3 DU 
qualification test reports provided to the FAA by the DU manufacturer.
    The intent of this AD is to eliminate this known susceptibility of 
the phase 3 DUs to RF transmissions, including those from sources 
outside the airplane. The phase 3 displays that failed testing did so 
substantially below the RF immunity levels set forth in paragraph l of 
the ``High Intensity Radiated Fields (HIRF)'' section of the preamble 
to 737 Special Condition 25-ANM-132, dated September 26, 1997; and 
paragraph l. of the HIRF discussion in the preamble to 777 Special 
Condition 25-ANM-78, dated November 10, 1993.
    We do not agree that no problems have occurred on in-service 
airplanes, since the WiFi STC testing that disclosed this 
susceptibility was conducted on an in-service airplane equipped with 
phase 3 DUs. With respect to operational limitations providing an 
acceptable level of safety, we approved certain STCs with such 
limitations as a means of compliance until a permanent solution was 
available. However, we intended those limitations as interim action 
until permanent corrective actions for the unsafe condition became 
available for the baseline airplanes. We do not consider it adequate to 
leave those operating limitations in place permanently as the sole 
corrective action for the unsafe condition.
    Under the provisions of paragraph (h) of this AD, we will consider 
requests for

[[Page 59099]]

approval of an AMOC if sufficient data are submitted to substantiate 
that the DU change is not necessary. We have not changed this final 
rule in this regard.

Request To Change Compliance Time

    A4A requested that we revise the compliance time in the proposed AD 
(78 FR 58487, September 24, 2013) from 60 months to 72 months, and that 
we recognize system redundancy when considering its compliance time 
request.
    A4A stated that multiple redundancies associated with the display 
system are designed to assure the flight crew always has access to 
critical information, and even in the event three DUs become 
inoperative, all normal primary flight display, navigation display, 
terrain guidance, and engine instrument information will still be 
displayed to the pilot. A4A also stated that there are vastly more 
affected units than were identified by the proposed AD (78 FR 58487, 
September 24, 2013). A4A stated that two of its largest operators alone 
account for over one thousand affected DUs. A4A contends that a 72-
month compliance time is a reasonable time to comply with the NPRM and 
is an appropriate time given the risk.
    We partially agree with the commenter. We agree with the 
commenter's statement that there are more units and airplanes affected 
than those listed in the proposed AD (78 FR 58487, September 24, 2013) 
because this has now been verified with the manufacturer's service 
information and comments to the NPRM. We disagree with extending the 
compliance time beyond 60 months. Our risk assessment considered system 
redundancy. However, along with DU susceptibility to RF transmissions, 
we have also considered other risk factors such as human factors, pilot 
workload, and phase of flight, etc. It is possible for all primary 
flight display units to fail at once during a critical phase of flight 
such as a takeoff or approach and landing. This could lead to loss of 
control of the airplane at an altitude insufficient for recovery, or 
controlled flight into terrain or obstacles, the availability of 
standby instruments in such a situation notwithstanding.
    Our compliance time is based on a detailed and in-depth risk 
assessment by the FAA and Boeing that has determined that the 
requirements of this AD must be accomplished within 60 months to 
mitigate the unsafe condition in the interest of the safety of the 
flying public. We recognize that in some cases, it may be necessary to 
accomplish the AD requirements outside normal scheduled maintenance 
cycles, and that some level of additional cost and/or lost revenue may 
result in such cases. However, the risk assessment indicates 60 months 
is an appropriate compliance time that will ensure an acceptable level 
of continued operational safety for the Model 737NG and Model 777 
series airplane fleets. However, according to the provisions of 
paragraph (h) of this AD, we may consider requests to adjust the 
compliance time if the request includes data that prove that the new 
compliance time would provide an acceptable level of safety. We have 
not changed this AD in this regard.

Request To Change Compliance Method

    Boeing requested that we remove Boeing Special Attention Service 
Bulletin 737-31-1471, dated November 29, 2012; and Boeing Special 
Attention Service Bulletin 777-31-0187, dated November 29, 2012; from 
the terminating action, since terminating action should include 
alternate part number DUs. Or, alternatively, Boeing recommended that 
operators be allowed to replace at a minimum, the phase 3 DUs and 
corresponding database software with earlier or newer certified units 
installed in the left outboard, right outboard and upper center DU 
positions. Boeing stated that earlier versions of intermixable/
interchangeable DUs also do not exhibit HIRF susceptibility, so the 
terminating action could include replacement of phase 3 DU's with 
earlier certified units.
    Boeing also requested that we revise the language in the NPRM (78 
FR 58487, September 24, 2013) to specify that terminating action is to 
remove phase 3 DUs from Model 737NG and Model 777 series airplanes, 
with replacement of any other DU certified for the Model 737NG and 
Model 777 series airplanes. Boeing stated that the NPRM should not 
require the installation of the phase 3A DUs, but instead only require 
that the phase 3 DUs be replaced or not installed on any airplane.
    We partially agree with the commenter's requests. We agree that 
terminating action is to replace all phase 3 DUs with certain other DUs 
certified for the Model 737NG and Model 777 series airplanes. We have 
revised this final rule so that it does not require the installation of 
phase 3A DUs, but instead only requires that the phase 3 DUs be 
replaced with the following approved DU part numbers that do not have 
the unsafe condition: Phase 1, phase 2, and phase 3A DUs. Phase 1 and 
phase 2 DUs do not have the RF susceptibility that has been identified 
in the phase 3 DUs, are intermixable and interchangeable with the phase 
3 DUs, and therefore, are an acceptable option for replacement of the 
phase 3 DUs to correct the unsafe condition. The intent of this AD is 
to remove all DUs with an unsafe condition and replace them with an 
acceptable alternative.
    We disagree with the request to remove the references to Boeing 
Special Attention Service Bulletin 737-31-1471, dated November 29, 
2012; and Boeing Special Attention Service Bulletin 777-31-0187, dated 
November 29, 2012; from the terminating action. Installing phase 3A DUs 
as specified in these service bulletins is an acceptable option for 
correcting the identified unsafe condition.
    We have revised paragraph (g) of this AD to require replacing phase 
3 DUs with phase 1, phase 2, or phase 3A DUs.

Request To Allow DU Upgrade

    Honeywell requested that we allow for phase 3 DUs to be upgraded to 
phase 3A DUs, rather than replacing with new phase 3A DUs. Honeywell 
stated that phase 3 DUs can be upgraded to phase 3A DUs via a 
modification kit and rework process defined in service information that 
has previously been provided to operators.
    We agree with the commenter's request to allow for phase 3 DUs to 
be upgraded to phase 3A DUs. We have removed the requirement in 
paragraph (g) of this AD to replace phase 3 DUs with ``new'' phase 3A 
DUs. Either new or modified phase 3A DUs may be installed.

Request To Revise Cost Estimate

    Several commenters requested that we revise the cost estimate in 
the NPRM (78 FR 58487, September 24, 2013). A4A requested that we 
revise the cost analysis to include all affected airplanes and DUs in 
the U.S. registry, and increase the per-airplane replacement time to 
three hours. A4A stated that the FAA states that the NPRM affects 157 
airplanes of U.S. registry, encompassing 942 DUs. A4A commented that 
UAL alone operates 150 such airplanes, exposing a significant error in 
estimation. A4A also stated that Honeywell indicates there are 10,100 
in-service phase 3 DUs affected; and that using the NPRM figure of 
$1,700 parts cost per DU ($10,200/six units per airplane), the parts 
cost alone rises to $17,170,000, or more than ten times the stated 
total cost of compliance. A4A also commented that while the NPRM 
estimates two hours per airplane for DU replacement, one carrier 
estimates three hours, a 50 percent increase in labor hours.
    Ryanair requested that we review the cost of compliance. Ryanair 
stated that

[[Page 59100]]

the estimated cost of compliance for the U.S. carriers seems to be a 
gross underestimate of the actual figure. Ryanair explained that it has 
707 phase 3 DUs in its fleet of 737-800s. This is approximately the 
same number the FAA is assuming for the entire US fleet of Model 737NG 
series airplanes.
    Boeing requested that we review the estimated costs table for the 
number of affected airplanes for both Model 737 and Model 777 series 
airplanes; and that we include the cost of updating phase 3 DUs which 
may have been installed on airplanes not delivered with phase 3 DUs as 
replacement units for failed DUs, and spare phase 3 DUs provided to 
airlines. Boeing explained that phase 3 DUs are interchangeable and 
intermixable with earlier versions of DUs on Model 737NG and Model 777 
series airplanes, and may have been installed on any Model 737NG and 
Model 777 series airplane, and may be in operator spares inventory. 
Boeing also stated that a review of Boeing Special Attention Service 
Bulletin 737-31-1471, dated November 29, 2012; and Boeing Special 
Attention Service Bulletin 777-31-0187, dated November 29, 2012; shows 
an effectivity of 1,326 U.S. registered airplanes.
    We partially agree with the commenters' requests. We agree with 
revising the estimated U.S. fleet size in the Cost of Compliance 
section in this final rule. Boeing has indicated in its comments that 
the number of affected U.S. airplanes is greater than the number of 
airplanes estimated in the NPRM (78 FR 58487, September 24, 2013). We 
disagree with revising the estimated labor hours. The labor hour 
estimate has been provided by the manufacturer. A4A's comment indicates 
that only one operator estimates that the labor hour estimate should be 
increased. We do not account for individual operator differences in the 
calculation of total labor hour estimates. We also disagree with 
considering airplanes that may have had phase 3 DUs installed after 
production as we have no way of estimating how many airplanes may have 
had this modification. We have changed the cost estimate in this final 
rule to reflect 1,149 Model 737 airplanes and 177 Model 777 airplanes.

Comment Regarding Certification Process

    Mr. Philipp Schmid commented that in today's world with more and 
more transmitters in the cabin and on the ground, the FAA should have 
more carefully taken into account the design and system integrations of 
line replaceable units for immunity to EMI.
    We acknowledge the commenter's concern. We make efforts to ensure 
that systems and equipment are immune to EMI effects during 
certification. We recently published rules with compliance requirements 
for HIRF immunity (e.g. section 25.1317 of Title 14, Code of Federal 
Regulations (14 CFR 25.1317)) (http://www.gpo.gov/fdsys/pkg/CFR-2011-title14-vol1/pdf/CFR-2011-title14-vol1-sec25-1317.pdf). However, we 
continue to conduct monitoring and surveillance of approved designs in 
service and require accomplishment of corrective actions for unsafe 
conditions when needed to ensure continued operational safety. This AD 
accomplishes continued operational safety by addressing an identified 
unsafe condition. The commenter did not request any changes to the NPRM 
(78 FR 58487, September 24, 2013). We have not changed this AD in this 
regard.

Clarification Regarding the Installation of Winglets

    Aviation Partners Boeing (APB) stated that the installation of 
winglets per Supplemental Type Certificate (STC) ST00830SE (http://
rgl.faa.gov/RegulatoryandGuidanceLibrary/
rgstc.nsf/0/
E3615811C4A7D87B86257C1C00720D67?OpenDocument&Highlight=st00830se) does 
not affect the accomplishment of the manufacturer's service 
instructions.
    We agree with APB's statement that the installation of winglets as 
specified in STC ST00830SE (http://rgl.faa.gov/
RegulatoryandGuidanceLibrary/rgstc.nsf/0/
E3615811C4A7D87B86257C1C00720D67?OpenDocument&Highlight=st00830se) does 
not affect accomplishment of the requirements of this AD, and for 
airplanes on which STC ST00830SE is installed, an alternative method of 
compliance (AMOC) approval request to account for the installation of 
that STC is not necessary to comply with the requirements of section 
39.17 of the Federal Aviation Regulations (14 CFR 39.17).

Conclusion

    We reviewed the relevant data, considered the comments received, 
and determined that air safety and the public interest require adopting 
this AD with the changes described previously and minor editorial 
changes. We have determined that these minor changes:
     [Agr]re consistent with the intent that was proposed in 
the NPRM (78 FR 58487, September 24, 2013) for correcting the unsafe 
condition; and
     Do not add any additional burden upon the public than was 
already proposed in the the NPRM (78 FR 58487, September 24, 2013).
    We also determined that these changes will not increase the 
economic burden on any operator or increase the scope of this AD.

Costs of Compliance

    We estimate that this AD affects 1,326 airplanes of U.S. registry.
    We estimate the following costs to comply with this AD:

                                                 Estimated Costs
----------------------------------------------------------------------------------------------------------------
                                                                                     Cost per      Cost on U.S.
                Action                         Labor cost           Parts cost        product        operators
----------------------------------------------------------------------------------------------------------------
Replacement (1,149 Model 737            2 work-hours x $85 per           $10,200         $10,370     $11,915,130
 airplanes).                             hour = $170.
Replacement (177 Model 777 airplanes).  3 work-hours x $85 per            10,200          10,455       1,850,535
                                         hour = $255.
----------------------------------------------------------------------------------------------------------------

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.

[[Page 59101]]

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):

2014-20-06 The Boeing Company: Amendment 39-17979; Docket No. FAA-
2013-0792; Directorate Identifier 2013-NM-118-AD.

(a) Effective Date

    This AD is effective November 5, 2014.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to The Boeing Company airplanes, certificated in 
any category, as identified in paragraphs (c)(1) and (c)(2) of this 
AD.
    (1) Model 737-600, -700, -700C, -800, -900, and -900ER series 
airplanes.
    (2) Model 777-200, 777-200LR, 777-300, 777-300ER, and 777F 
series airplanes.

(d) Subject

    Air Transport Association (ATA) of America Code 31, Instruments.

(e) Unsafe Condition

    This AD was prompted by testing reports on certain Honeywell 
phase 3 display units (DUs). These DUs exhibited susceptibility to 
radio frequency emissions in WiFi frequency bands at radiated power 
levels below the levels that the displays are required to tolerate 
for certification of WiFi system installations. The phase 3 DUs 
provide primary flight information, including airspeed, altitude, 
pitch and roll attitude, heading, and navigation information, to the 
flightcrew. We are issuing this AD to prevent loss of flight-
critical information displayed to the flightcrew during a critical 
phase of flight, such as an approach or takeoff, which could result 
in loss of airplane control at an altitude insufficient for 
recovery, or controlled flight into terrain.

(f) Compliance

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

(g) Inspection, Software Installation, and DU Installation

    Within 60 months after the effective date of this AD: Inspect to 
determine if any phase 3 DUs are installed. If any phase 3 DUs are 
installed, within 60 months after the effective date of this AD, do 
the applicable actions required by paragraph (g)(1) or (g)(2) of 
this AD. A review of airplane maintenance records is acceptable in 
lieu of this inspection if the phase number of the DUs can be 
conclusively determined from that review.
    (1) For Model 737 airplanes: Remove all phase 3 common display 
system (CDS) DUs and replace with phase 1, phase 2, or phase 3A CDS 
DUs. If any phase 3 CDS DUs are replaced with phase 3A CDS DUs, 
replace the phase 3 CDS DUs and install new database software into 
the display electronics units, in accordance with the Accomplishment 
Instructions of Boeing Special Attention Service Bulletin 737-31-
1471, dated November 29, 2012.
    (2) For Model 777 airplanes: Remove all phase 3 DUs and replace 
with phase 1, phase 2, or phase 3A DUs. If any phase 3 DUs are 
replaced with phase 3A DUs, replace the phase 3 DUs and install the 
DU database software into the left and right airplane information 
management system core processor module/graphics generator, in 
accordance with the Accomplishment Instructions of Boeing Special 
Attention Service Bulletin 777-31-0187, dated November 29, 2012.

(h) 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: 9-ANM-Seattle-ACO-AMOC-Requests@faa.gov.
    (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 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.

(i) Related Information

    For more information about this AD, contact Jeffrey W. Palmer, 
Aerospace Engineer, Systems and Equipment Branch, ANM-130S, Seattle 
Aircraft Certification Office, FAA, 1601 Lind Avenue SW., Renton, WA 
98057-3356; phone: 425-917-6472; fax: 425-917-6590; email: 
jeffrey.w.palmer@faa.gov.

(j) Material Incorporated by Reference

    (1) The Director of the Federal Register approved the 
incorporation by reference (IBR) of the service information listed 
in this paragraph under 5 U.S.C. 552(a) and 1 CFR part 51.
    (2) You must use this service information as applicable to do 
the actions required by this AD, unless the AD specifies otherwise.
    (i) Boeing Special Attention Service Bulletin 737-31-1471, dated 
November 29, 2012.
    (ii) Boeing Special Attention Service Bulletin 777-31-0187, 
dated November 29, 2012.
    (3) For Boeing 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.
    (4) You may view this service information at FAA Transport 
Airplane Directorate, 1601 Lind Avenue SW., Renton, Washington. For 
information on the availability of this material at the FAA, call 
425-227-1221.
    (5) You may view this service information that is incorporated 
by reference at the National Archives and Records Administration 
(NARA). For information on the availability of this material at 
NARA, call 202-741-6030, or go to: http://www.archives.gov/federal-register/cfr/ibr-locations.html.

    Issued in Renton, Washington, on September 19, 2014.
Jeffrey E. Duven,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2014-23231 Filed 9-30-14; 8:45 am]
BILLING CODE 4910-13-P