### 59093 Federal Register / Vol. 79, No. 190 / Wednesday, October 1, 2014 / Rules and Regulations

6.B.(1)(c), and the requirement to return module M01 in paragraph 6.B.(2)(b) 2 of Turbomeca S.A. MSB No. 292 72 2849, Version B, dated November 25, 2013, are not required by this AD.

(2) For all affected Turbomeca S.A. engines, during each engine shop visit after the effective date of this AD, perform a vibration check of the AGB 41/23-tooth bevel gear meshing. Guidance on performing the vibration check during an engine shop visit can be found in the service information listed in paragraph (i)(3) in the Related Information
section.

(3) If the AGB does not pass the vibration check required by paragraphs (e)(1) or (e)(2) of this AD, replace the AGB with a part eligible for installation.

(f) Credit for Previous Action

If you performed a vibration check of the AGB before the effective date of this AD using Turbomeca S.A. MSB No. 292 72 0839, Version A, dated September 9, 2013; or MSB No. 292 72 2849, Version A, dated September 9, 2013, or during an engine shop visit per paragraph (e)(2) of this AD, you met the initial inspection requirement of paragraph (e)(1) of this AD.

(g) Definition

For the purpose of this AD, an ‘‘engine shop visit’’ is the induction of an engine into the shop for maintenance involving the separation of pairs of major mating engine flanges. The separation of engine flanges solely for the purpose of transportation without subsequent engine maintenance does not constitute an engine shop visit.

(h) Alternative Methods of Compliance (AMOCs)

The Manager, Engine Certification Office, FAA, may approve AMOCs to this AD. Use the procedures found in 14 CFR 39.19 to make your request.

(i) Related Information

(1) For more information about this AD, contact Mark Riley, Aerospace Engineer, Engine Certification Office, FAA, Engine & Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803; phone: 781–238–7758; fax: 781–238–7199; email: mark.riley@faa.gov.

(2) Refer to MCAI European Aviation Safety Agency AD 2014–0036, dated February 11, 2014, for related information. You may examine the MCAI in the AD docket on the Internet at http://www.regulations.gov/#!docketDetail;D=FAA2014-0164.

(3) Turbomeca Engine Test Bed Acceptance Test Specifications CCT No. 0292009400, Version T; CCT No. 0292019400, Version R; CCT No. 0292019690, Version I; CCT No. 029201530, Version K; CCT No. 0292019610, Version K; CCT No. 0292029450, Version J; CCT No. 0292029490, Version I; CCT No. 0292029440, Version I; CCT No. 0292029480, Version K; CCT No. 0292029520, Version H; CCT No. 0292029410, Version L; CCT No. 0292029530, Version H; or Turbomeca ID No. 383952; or Turbomeca RTD No. X 292 65 327 2, which are not incorporated by reference in this AD, can be obtained from Turbomeca S.A., using the contact information in paragraph (j)(3) of this AD. This service information provides guidance on performing the vibration check during an engine shop
visit.

(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) Turbomeca S.A. Mandatory Service Bulletin (MSB) No. 292 72 0839, Version B, dated November 25, 2013.

(ii) Turbomeca S.A. MSB No. 292 72 2849, Version B, dated November 25, 2013.

(iii) Turbomeca S.A. Arriel 1 Technical Instruction (TI) No. 292 72 0839, Version E, dated February 20, 2014.

(iv) Turbomeca S.A. Arriel 1 TI No. 292 72 0840, Version A, dated November 29, 2013.

(v) Turbomeca S.A. Arriel 2 TI No. 292 72 2849, Version E, dated February 20, 2014.

(vi) Turbomeca S.A. Arriel 2 TI No. 292 72 2850, Version A, dated November 29, 2013.

(3) For Turbomeca S.A. service information identified in this AD, contact Turbomeca, S.A., 40220 Tarnos, France; phone: 33 (0)5 59 74 40 00; telex: 570 042; fax: 33 (0)5 59 74

45 15.

(4) You may view this service information at FAA, Engine & Propeller Directorate, 12 New England Executive Park, Burlington, MA. For information on the availability of this material at the FAA, call 781–238–7125.

(5) You may view this service information 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/ibrlocations.html.

Issued in Burlington, Massachusetts, on September 15, 2014.
Colleen M. D’Alessandro, Assistant Directorate Manager, Engine & Propeller Directorate, Aircraft Certification
Service.

[FR Doc. 2014–23353 Filed 9–30–14; 8:45 am]

**BILLING CODE 4910–13–P**

**DEPARTMENT OF TRANSPORTATION**

**Federal Aviation Administration**

**14 CFR Part 39**

**[Docket No. FAA–2014–0424; Directorate Identifier 2014–NM–003–AD; Amendment**  **39–17976; AD 2014–20–03]**

**RIN 2120–AA64**

**Airworthiness Directives; Bombardier, Inc. Airplanes** 

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

**ACTION :**  Final rule. **SUMMARY :**  We are adopting a new airworthiness directive (AD) for certain Bombardier, Inc. Model BD–700–1A10 and BD–700–1A11 airplanes. This AD was prompted by reports of an incorrectly assembled check tee fitting used in fire extinguishing (FIREEX) distribution lines. This AD requires inspecting to determine the part number and for all affected check tee fittings measuring for correct depth, and replacing if necessary. We are issuing this AD to detect and correct faulty check tee fittings, which will reduce fire extinguishing protection.

**DATES :**  This AD becomes 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 :**  You may examine the AD docket on the Internet at http:// www.regulations.gov/ #!docketDetail;D=FAA-2014-0424 or in person at the 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.

For service information identified in this AD, contact Bombardier, Inc., 400
Co

ˆ te-Vertu Road West, Dorval, Que  ́bec H4S 1Y9, Canada; telephone 514–855– 5000; fax 514–855–7401; email thd.crj@ aero.bombardier.com; Internet http:// www.bombardier.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.

**FOR FURTHER INFORMATION CONTACT :**  Cesar Gomez, Aerospace Engineer, Airframe and Mechanical Systems Branch, ANE–171, FAA, New York Aircraft Certification Office, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; telephone 516–228–7318; fax

516–794–5531.

**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 certain Bombardier, Inc. Model BD–700–1A10 and BD–700–1A11 airplanes. The NPRM published in the Federal Register on July 1, 2014 (79 FR 37246).

Transport Canada Civil Aviation (TCCA), which is the aviation authority for Canada, has issued Canadian Airworthiness Directive CF–2013–41, dated December 30, 2013 (referred to


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after this as the Mandatory Continuing Airworthiness Information, or ‘‘the MCAI’’), to correct an unsafe condition on certain Bombardier, Inc. Model BD– 700–1A10 and BD–700–1A11 airplanes. The MCAI states:

A check tee fitting used in the aeroplane fire extinguishing (FIREEX) distribution lines, was discovered by another airframe manufacturer as being incorrectly assembled. A properly assembled check tee fitting normally contains one check ball, however the affected fitting contained two check balls. The FIREEX manufacturer advised Bombardier that this condition may be present on aeroplane models BD–700–1A10 and BD–700–1A11.

Testing has verified that incorrect installation of the additional check ball in the fitting reduces the flow rate of the extinguishing agent. There are three check tee fittings installed on the BD–700–1A10 and BD–700–1A11 aeroplanes, one for each engine and one for the auxiliary power unit. Faulty fittings will reduce fire extinguishing protection at the affected locations.

Bombardier has issued several Alert Service Bulletins (ASBs) to identify, inspect and replace if required, all affected fittings. This [Canadian] AD mandates incorporation of the applicable Bombardier ASBs to rectify this problem.

You may examine the MCAI in the AD docket on the Internet at http:// www.regulations.gov/#!documentDetail;
D=FAA-2014-0424-0002.

Comments

We gave the public the opportunity to participate in developing this AD. We received no comments on the NPRM (79 FR 37246, July 1, 2014) or on the determination of the cost to the public.
‘‘Contacting the Manufacturer’’ Paragraph in This AD

Since late 2006, we have included a standard paragraph titled ‘‘Airworthy Product’’ in all MCAI ADs in which the FAA develops an AD based on a foreign authority’s AD.

We have become aware that some operators have misunderstood or misinterpreted the Airworthy Product paragraph to allow the owner/operator to use messages provided by the manufacturer as approval of deviationsduring the accomplishment of an ADmandated action. The Airworthy Product paragraph does not approve messages or other information provided by the manufacturer for deviations to the requirements of the AD-mandated actions. The Airworthy Product paragraph only addresses the requirement to contact the manufacturer for corrective actions for the identified unsafe condition and does not cover deviations from other AD requirements. However, deviations to AD-required actions are addressed in 14 CFR 39.17, and anyone may request the approval for an alternative method of compliance to the AD-required actions using the procedures found in 14 CFR 39.19.

To address this misunderstanding and misinterpretation of the Airworthy Product paragraph, we have changed the paragraph and retitled it ‘‘Contacting the Manufacturer.’’ This paragraph now clarifies that for any requirement in this AD to obtain corrective actions from a manufacturer, the actions must be accomplished using a method approved by the FAA, TCCA, or Bombardier, Inc.’s TCCA Design Approval Organization (DAO).

The Contacting the Manufacturer paragraph also clarifies that, if approved by the DAO, the approval must include the DAO-authorized signature. The DAO signature indicates that the data and information contained in the documentare TCCA-approved, which is also FAAapproved. Messages and other information provided by the manufacturer that do not contain the DAO-authorized signature approval are not TCCA-approved, unless TCCA directly approves the manufacturer’s message or other information.

This clarification does not remove flexibility previously afforded by the Airworthy Product paragraph. Consistent with long-standing FAA policy, such flexibility was never intended for required actions. This is also consistent with the recommendation of the Airworthiness Directive Implementation Aviation Rulemaking Committee to increase flexibility in complying with ADs by identifying those actions in manufacturers’ service instructions that are ‘‘Required for Compliance’’ with ADs. We continue to work with manufacturers to implement this recommendation. But once we determine that an action is required, any deviation from the requirement must be approved as an alternative method of compliance.

We also have decided not to include a generic reference to either the ‘‘delegated agent’’ or ‘‘design approval holder (DAH) with State of Design Authority design organization approval,’’ but instead we have provided the specific delegation approval granted by the State of Design Authority for the DAH.

Conclusion

We reviewed the relevant data 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: • Are consistent with the intent that was proposed in the NPRM (79 FR 37246, July 1, 2014) for correcting the unsafe condition; and

• Do not add any additional burden upon the public than was already proposed in the NPRM (79 FR 37246, July 1, 2014).

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 57 airplanes of U.S. registry.

We also estimate that it would take about 1 work-hour per product to comply with the basic requirements of this AD. The average labor rate is $85 per work hour. Required parts would cost about $0 per product. Based on these figures, we estimate the cost of this AD on U.S. operators to be $4,845, or $85 per product.

In addition, we estimate that any necessary follow-on actions would take about 1 work-hour, for a cost of $85 per tee fitting. We have no way of determining the number of aircraft that might need this action.

According to the manufacturer, some of the costs of this 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 AD will not have federalism implications under Executive Order 13132. This AD will


### 59095 Federal Register / Vol. 79, No. 190 / Wednesday, October 1, 2014 / Rules and Regulations

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 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.
Examining the AD Docket

You may examine the AD docket on the Internet at http:// www.regulations.gov/ #!docketDetail;D=FAA-2014-0424; 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 Operations office (telephone 800–647–5527) is in the **ADDRESSES** section.
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** 

■ 1. The authority citation for part 39 continues to read as follows:

Authority: 49 U.S.C. 106(g), 40113, 44701.

**§ 39.13 [Amended]**

■ 2. The FAA amends § 39.13 by adding the following new airworthiness directive (AD):

2014–20–03 Bombardier, Inc.: Amendment 39–17976. Docket No. FAA–2014–0424; Directorate Identifier 2014–NM–003–AD.

(a) Effective Date

This AD becomes effective November 5,

2014.

(b) Affected ADs

None. (c) Applicability This AD applies to Bombardier, Inc. Model BD–700–1A10 and BD–700–1A11 airplanes, certificated in any category, serial numbers 9002 through 9500 inclusive, and 9998.

(d) Subject

Air Transport Association (ATA) of America Code 26, Fire Protection.

(e) Reason

This AD was prompted by reports of an incorrectly assembled check tee fitting used in fire extinguishing (FIREEX) distribution lines. We are issuing this AD to detect and correct faulty check tee fittings, which will reduce fire extinguishing protection.

(f) Compliance

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

(g) Part Number Identification

Within 100 flight hours or 180 days, whichever occurs first after the effective date of this AD, inspect to determine the part number (P/N) of the FIREEX check tee fitting, in accordance with the Accomplishment Instructions of the applicable service bulletin identified in paragraph (g)(1), (g)(2), (g)(3), or (g)(4) of this AD.

(1) Bombardier Alert Service Bulletin A700–1A11–26–003, dated April 18, 2013 (for Model BD–700–1A11 (BD–700) airplanes having S/Ns 9127 through 9383 inclusive; 9389 through 9400 inclusive, 9404 through 9431 inclusive, and 9998).

(2) Bombardier Alert Service Bulletin A700–26–010, dated April 18, 2013 (for Model BD–700–1A10 (BD–700) airplanes having S/Ns 9002 through 9312 inclusive, 9314 through 9380 inclusive, and 9384 through 9429 inclusive).

(3) Bombardier Alert Service Bulletin A700–26–5002, dated April 18, 2013 (for Model BD–700–1A11 (BD–700) airplanes having S/Ns 9386, 9401, and 9445 through 9498 inclusive).

(4) Bombardier Alert Service Bulletin A700–26–6002, dated April 18, 2013 (for Model BD–700–1A10 (BD–700) airplanes having S/Ns 9313, 9381, and 9432 through 9500 inclusive).

(h) Measurement and Replacement

If any inspection specified in paragraph (g) of this AD reveals any check tee fitting having P/N 446651 and S/N 062 through 070 inclusive, 117 through 133 inclusive, 3728 through 3731 inclusive, 3733 through 3760 inclusive, or 3762 through 3776 inclusive: Within 100 flight hours or 180 days, whichever occurs first after the effective date of this AD, measure the depth of the inlet fitting of the check tee, in accordance with the Accomplishment Instructions of the applicable service bulletin identified in paragraph (g)(1), (g)(2), (g)(3), or (g)(4) of this AD. If the check tee depth is less than 1.70 inches (4.32 cm), before further flight, replace the check tee in accordance with the Accomplishment Instructions of the applicable service bulletin identified in paragraph (g)(1), (g)(2), (g)(3), or (g)(4) of this
AD. (i) Other FAA AD Provisions The following provisions also apply to this
AD:

(1) Alternative Methods of Compliance (AMOCs): The Manager, New York Aircraft Certification Office (ACO), ANE–170, 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 ACO, send it to ATTN: Program Manager, Continuing Operational Safety, FAA, New York ACO, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; telephone 516–228–7300; fax 516–794–5531. 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. The AMOC approval letter must specifically reference this AD.

(2) Contacting the Manufacturer: For any requirement in this AD to obtain corrective actions from a manufacturer, the action must be accomplished using a method approved by the Manager, New York ACO, ANE–170, Engine and Propeller Directorate, FAA; or Transport Canada Civil Aviation (TCCA); or Bombardier, Inc.’s TCCA Design Approval Organization (DAO). If approved by the DAO,the approval must include the DAOauthorized signature.

(j) Related Information

Refer to Mandatory Continuing Airworthiness Information (MCAI) Canadian Airworthiness Directive CF–2013–41, dated December 30, 2013, for related information. This MCAI may be found in the AD docket on the Internet at http:// www.regulations.gov/ #!documentDetail;D=FAA-2014-0424-0002.

(k) 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 this AD specifies otherwise.

(i) Bombardier Alert Service Bulletin A700–1A11–26–003, dated April 18, 2013.

(ii) Bombardier Alert Service Bulletin A700–26–010, dated April 18, 2013.

(iii) Bombardier Alert Service Bulletin A700–26–5002, dated April 18, 2013.

(iv) Bombardier Alert Service Bulletin A700–26–6002, dated April 18, 2013.

(3) For service information identified in this AD, contact Bombardier, Inc., 400 Co ˆ teVertu Road West, Dorval, Que  ́bec H4S 1Y9, Canada; telephone 514–855–5000; fax 514– 855–7401; email thd.crj@ aero.bombardier.com; Internet http:// www.bombardier.com.

(4) 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.

(5) You may view this service information that is incorporated by reference at the


### 59096 Federal Register / Vol. 79, No. 190 / Wednesday, October 1, 2014 / Rules and Regulations

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/ibrlocations.html.

Issued in Renton, Washington, on September 19, 2014. Michael Kaszycki, Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.

[FR Doc. 2014–22978 Filed 9–30–14; 8:45 am]

**BILLING CODE 4910–13–P**

**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.

**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