### 3310 Federal Register / Vol. 81, No. 13 / Thursday, January 21, 2016 / Rules and Regulations

**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):
2016–01–15 Agusta S.p.A.: Amendment 39– 18374; Docket No. FAA–2015–1935; Directorate Identifier 2014–SW–008–AD.
(a) Applicability

This AD applies to Agusta S.p.A. Model AB139 and AW139 helicopters, serial number (S/N) 31005 through 31517 (except S/N 31007, 31415, 31431, 31491, 31500, 31508, and 31516) and S/N 41001 through 41356 (except S/N 41355), certificated in any category.
(b) Unsafe Condition

This AD defines the unsafe condition as a crack in a subfloor frame. This conditioncould result in failure of the pilot and copilot pedal support frame and subsequent loss of control of the helicopter.

(c) Effective Date

This AD becomes effective February 25,
2016. (d) Compliance

You are responsible for performing each action required by this AD within the specified compliance time unless it has already been accomplished prior to that time.
(e) Required Actions

(1) Within 30 hours time-in-service (TIS) and thereafter at intervals not to exceed 300 hours TIS, using a light, inspect all visible surfaces of the left hand subfloor frame, right hand subfloor frame, and middle subfloor frame at station (STA) 2105 for a crack as shown in Figures 10 through 13 of AgustaWestland Bollettino Tecnico No. 139– 311, Revision B, dated June 4, 2014 (BT 139– 311).

(2) If there is a crack, before further flight, install frame STA 2105 retromod part number (P/N) 3G5306P47211 by following the Compliance Instructions, Part II, paragraphs 7 through 7.10. of BT 139–311.

(3) If there are no cracks, within 1200 hours TIS, install frame STA 2105 retromod P/N 3G5306P47211 by following the Compliance Instructions, Part II, paragraphs 7 through 7.10. of BT 139–311.

(4) Installing frame STA 2105 retromod P/ N 3G5306P47211 terminates the repetitive inspection requirements in paragraph (e)(1) of this AD.
(f) Special Flight Permits

Special flight permits are prohibited.
(g) Alternative Methods of Compliance (AMOCs)

(1) The Manager, Safety Management Group, FAA, may approve AMOCs for this AD. Send your proposal to: Robert Grant, Aviation Safety Engineer, Safety Management Group, Rotorcraft Directorate, FAA, 10101 Hillwood Pkwy., Fort Worth, TX 76177; telephone (817) 222–5110; email 9-ASWFTW-AMOC-Requests@faa.gov.

(2) For operations conducted under a 14 CFR part 119 operating certificate or under 14 CFR part 91, subpart K, we suggest that you notify your principal inspector, or lacking a principal inspector, the manager of the local flight standards district office or certificate holding district office, before operating any aircraft complying with this AD through an AMOC.

(h) Additional Information

The subject of this AD is addressed in European Aviation Safety Agency (EASA) AD No. 2014–0048, dated March 4, 2014. You may view the EASA AD on the Internet at http://www.regulations.gov in Docket No.
FAA–2015–1935.
(i) Subject

Joint Aircraft Service Component (JASC) Code: 5300, Fuselage Structure (General).
(j) Material Incorporated by Reference

(1) The Director of the Federal Register approved the incorporation by reference 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) AgustaWestland Bollettino Tecnico No. 139–311, Revision B, dated June 4, 2014.

(ii) Reserved. (3) For Agusta S.p.A. service information identified in this AD, contact AgustaWestland, Product Support Engineering, Via del Gregge, 100, 21015 Lonate Pozzolo (VA) Italy, ATTN: Maurizio D’Angelo; telephone 39–0331–664757; fax
39–0331–664680; or at http://www.agustawestland.com/technicalbulletins.

(4) You may view this service information at FAA, Office of the Regional Counsel, Southwest Region, 10101 Hillwood Pkwy., Room 6N–321, Fort Worth, TX 76177. For information on the availability of this material at the FAA, call (817) 222–5110.

(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/ibrlocations.html.

Issued in Fort Worth, Texas, on January 6,

2016. Bruce E. Cain, Acting Manager, Rotorcraft Directorate, Aircraft Certification Service.
[FR Doc. 2016–00659 Filed 1–20–16; 8:45 am]

**BILLING CODE 4910–13–P DEPARTMENT OF TRANSPORTATION** 

**Federal Aviation Administration**

**14 CFR Part 39**

**[Docket No. FAA–2014–0577; Directorate Identifier 2013–SW–042–AD; Amendment**  **39–18375; AD 2015–12–09 R1]**

**RIN 2120–AA64**

**Airworthiness Directives; Airbus Helicopters Deutschland GmbH**  **(Previously Eurocopter Deutschland GmbH) (Airbus Helicopters)** 

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

**ACTION :**  Final rule.

**SUMMARY :**  We are revising airworthiness directive (AD) 2015–12–09 for Airbus Helicopters Model EC135P1, EC135T1, EC135P2, EC135T2, EC135P2+, EC135T2+, and MBB–BK 117 C–2 helicopters. AD 2015–12–09 required inspecting certain washers for movement and making the appropriate repairs if the washers move. As published, AD 2015–12–09 referenced an incorrect date for the service information in the Credit for Previous Actions section. This AD corrects the error while retaining the requirements of AD 2015–12–09. These actions are intended to prevent loss of concerned control axis and subsequent loss of control of the helicopter.

**DATES :**  This AD is effective February 25,
2016.

The Director of the Federal Register approved the incorporation by reference of certain documents listed in this AD as of July 23, 2015 (80 FR 34831, June 18, 2015).

**ADDRESSES :**  For service information identified in this final rule, contact Airbus Helicopters, Inc., 2701 N. Forum Drive, Grand Prairie, TX 75052; telephone (972) 641–0000 or (800) 232– 0323; fax (972) 641–3775; or at http:// www.airbushelicopters.com/techpub

. You may review the referenced service information at the FAA, Office of the Regional Counsel, Southwest Region, Room 6N–321, 10101 Hillwood Pkwy, Fort Worth, TX 76177. 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–2014– 0577; 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 European Aviation Safety Agency (EASA) AD, any


### 3311 Federal Register / Vol. 81, No. 13 / Thursday, January 21, 2016 / Rules and Regulations

incorporated-by-reference information, the economic evaluation, any comments received, and other information. The address for the Docket Office (phone: 800–647–5527) is Document 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 :**  Matt Wilbanks, Aviation Safety Engineer, Regulations and Policy Group, Rotorcraft Directorate, Rotorcraft Directorate, FAA, 10101 Hillwood Pkwy, Fort Worth, TX 76177; telephone (817) 222–5110; email matt.wilbanks@ faa.gov

. **SUPPLEMENTARY INFORMATION :** 

Discussion

On July 24, 2015, we issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 to revise AD 2015–12–09, Amendment 39–18184 (80 FR 34831, June 18, 2015), which applied to Airbus Helicopters Model EC135P1, EC135T1, EC135P2, EC135T2, EC135P2+, EC135T2+, and MBB–BK 117 C–2 helicopters. The NPRM published in the Federal Register on August 3, 2015 (80 FR 45900). The NPRM was prompted by the discovery of an incorrectly dated Alert Service Bulletin (ASB) in the Credit for Previous Actions section of AD 2015–12–09. The NPRM proposed to retain the actions required by AD 2015–12–09 and correct the ASB date and revise other information throughout the AD.

AD 2015–12–09 was prompted by AD No. 2013–0176, dated August 7, 2013, issued by EASA, which is the Technical Agent for the Member States of the European Union, to correct an unsafe condition for Eurocopter Deutschland GmbH Model EC 135 P1 (CDS), EC 135 P1 (CPDS), EC 135 P2+, EC 135 P2 (CPDS), EC 135 T1 (CDS), EC 135 T1 (CPDS), EC 135 T2+, EC 135 T2 (CPDS), EC 635 P2+, EC 635 T1 (CPDS), EC 635 T2+, and MBB–BK 117 C–2 helicopters. EASA advises that during installation work on a helicopter, it was discovered that it was not possible to install attachment hardware on a threaded blind borehole between the Smart Electro Mechanical Actuator (SEMA) and the control rod without play. EASA advises that this condition, if not detected and corrected, could lead to loss of the concerned control axis, possibly resulting in loss of helicopter control. For these reasons, EASA AD No. 2013–0176 requires a one-time inspection of the affected SEMA attachment hardware to detect improper connection and play and, depending on the findings, replacement of the affected hardware. After the issuance of EASA AD No. 2013–0176, Eurocopter Deutschland GmbH changed its name to Airbus Helicopters Deutschland GmbH.

When AD 2015–12–09 was published, an incorrect reference to the date of Eurocopter ASB EC135–22A–015, Revision 0, dated May 13, 2008, appeared in the text of the rule. Specifically, AD 2015–12–09 includes the following under paragraph (f), Credit for Previous Actions: ‘‘If you performed the actions in Eurocopter Alert Service Bulletin EC135–22A–015, Revision 0, dated May 13, 2018, or Eurocopter Alert Service Bulletin MBB BK117 C–2–22A– 009, Revision 0, May 13, 2008, before the effective date of this AD, you met the requirements of this AD.’’ As published, the reference to May 13, 2018, is incorrect. The correct date for Eurocopter ASB EC135–22A–015, Revision 0, is May 13, 2008.

Accordingly, we are revising AD 2015–12–09 to correct the date for Eurocopter ASB EC135–22A–015, Revision 0. Further, we updated the physical address of the FAA Southwest Regional Office throughout this AD and the email address for requesting an Alternative Method of Compliance (AMOC). We did not change any other part of the preamble or regulatory information. The final rule is reprinted in its entirety for the convenience of affected operators.

Comments

We gave the public the opportunity to participate in developing this AD, but we received no comments on the NPRM (80 FR 45900, August 3, 2015).

FAA’s Determination

These helicopters have been approved by the aviation authority of Germany and are approved for operation in the United States. Pursuant to our bilateral agreement with Germany, EASA, its technical representative, has notified us of the unsafe condition described in the EASA AD. We are issuing this AD because we evaluated all information provided by EASA and determined the unsafe condition exists and is likely to exist or develop on other helicopters of these same type designs.

Related Service Information Under 1 CFR Part 51

Eurocopter reported in ASBs EC135– 22A–015, Revision 1, dated January 28, 2013, and MBB BK117 C–2–22A–009, Revision 1, dated August 3, 2009, that it was discovered during the installation work on a helicopter that it was not possible to establish attachment hardware on a threaded blind borehole between the SEMA and the control rod without play. The ASBs state that ‘‘unfavourable adding of the tolerances’’ of the individual attachment hardware elements caused the screw to push against the bottom of the threaded blind borehole on the SEMA, preventing any clamping force on the screw head. The ASBs call for inspecting the SEMA attachment hardware connected to their respective control rods for play and making the proper adjustments to eliminate any play. This service information is reasonably available because the interested parties have access to it through their normal course of business or by the means identified in the **ADDRESSES** section. Costs of Compliance

We estimate that this AD affects 385 helicopters of U.S. Registry and that labor costs average $85 per work-hour. Based on these estimates, we expect the following costs:

• Inspecting for movement of the washers requires 1.5 work-hours for a labor cost of $128 per helicopter and $49,280 for the U.S. fleet.

• Replacing the screws and relatedwork requires an additional 0.5 workhours for a labor cost of $43. Screws cost $4 each while washers cost $10 each. We estimate the cost at $79 per repair. 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 have determined that 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


### 3312 Federal Register / Vol. 81, No. 13 / Thursday, January 21, 2016 / Rules and Regulations

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** 

■ 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 removing Airworthiness Directive (AD) 2015–12–09, Amendment 39–18184 (80 FR 34831, June 18, 2015), and adding the following new AD: 2015–12–09 R1 Airbus Helicopters Deutschland GmbH (Previously Eurocopter Deutschland GmbH) (Airbus Helicopters): Amendment 39–18375; Docket No. FAA–2014–0577; Directorate Identifier 2013–SW–042–AD.

(a) Applicability

This AD applies to Airbus Helicopters Model EC135P1, EC135T1, EC135P2, EC135T2, EC135P2+, EC135T2+, and MBB– BK 117 C–2 helicopters, certificated in any category.
(b) Unsafe Condition

This AD defines the unsafe condition as loose attachment hardware between the Smart Electro Mechanical Actuator (SEMA) and a control rod. This condition could result in loss of the control axis and subsequent loss of control of the helicopter.
(c) Effective Date

This AD becomes effective February 25,
2016. (d) Compliance

You are responsible for performing each action required by this AD within the specified compliance time unless it has already been accomplished prior to that time. (e) Required Actions (1) Within 50 hours time-in-service (TIS), for Model EC135P1, EC135T1, EC135P2, EC135T2, EC135P2+, and EC135T2+ helicopters, do the following:

(i) Using Figure 1 and Figure 2 of Eurocopter Alert Service Bulletin EC135– 22A–015, Revision 1, dated January 28, 2013 (ASB EC135–22A–015) as reference, inspect the attachment hardware between the SEMA and the longitudinal actuator control rod to determine whether any of the washers can be moved.

(A) If no washer can be moved, no further action is needed.

(B) If a washer can be moved, replace the four screws and install two additional washers, part number (P/N) EN2139–05016, to connect the SEMA with the control rod. Torque-tighten each screw to 5–6 Nm.

(ii) Using Figure 1 and Figure 2 of ASB EC135–22A–015 as reference, inspect the attachment hardware between the SEMA and the lateral actuator control rod to determine whether any of the washers can be moved.

(A) If no washer can be moved, no further action is needed.

(B) If a washer can be moved, replace the four screws and install two additional washers, P/N EN2139–05016, to connect the SEMA with the control rod. Torque-tighten each screw to 5–6 Nm.

(iii) Using Figure 1, Figure 3, and Figure 4 of ASB EC135–22A–015 as reference, inspect the attachment hardware between the SEMA and the yaw actuator control rod to determine whether any of the washers can be moved.

(A) If no washer can be moved, no further action is needed.

(B) If a washer can be moved, replace the four screws and install two additional washers, P/N EN2139–05016, to connect the SEMA with the control rod. Torque-tighten each screw to 5–6 Nm.

(2) Within 50 hours TIS, for Model MBB BK117 C–2 helicopters, using Figure 1 of Eurocopter Alert Service Bulletin MBB BK117 C–2–22A–009, Revision 1, dated August 3, 2009, as reference, inspect theattachment hardware between the YawSEMA and the Yaw-SEMA control rod to determine whether any of the washers can be moved.

(i) If no washer can be moved, no further action is needed.

(ii) If a washer can be moved, replace the four screws and install two additional washers, P/N EN2139–05016, to connect the SEMA with the control rod. Torque-tighten each screw to 5–6 Nm and apply polyurethane lacquer onto the attachment hardware.
(f) Affected ADs

This AD revises AD 2015–12–09, Amendment 39–18184 (80 FR 34831, June 18, 2015).
(g) Credit for Previous Actions

If you performed the actions in Eurocopter Alert Service Bulletin EC135–22A–015, Revision 0, dated May 13, 2008, or Eurocopter Alert Service Bulletin MBB BK117 C–2–22A–009, Revision 0, May 13, 2008, before the effective date of this AD, you met the requirements of this AD. (h) Alternative Methods of Compliance (AMOCs)

(1) The Manager, Safety Management Group, FAA, may approve AMOCs for this AD. Send your proposal to: Matt Wilbanks, Aviation Safety Engineer, Regulations and Policy Group, Rotorcraft Directorate, FAA, 10101 Hillwood Pkwy, Fort Worth, TX 76177; telephone (817) 222–5110; email 9- SW-FTW-AMOC-Requests@faa.gov.

(2) For operations conducted under a 14 CFR part 119 operating certificate or under 14 CFR part 91, subpart K, we suggest that you notify your principal inspector, or lacking a principal inspector, the manager of the local flight standards district office or certificate holding district office before operating any aircraft complying with this AD through an AMOC.

(i) Additional Information

The subject of this AD is addressed in the European Aviation Safety Agency (EASA) AD No. 2013–0176, dated August 7, 2013. You may view the EASA AD on the Internet at http://www.regulations.gov in Docket No.
FAA 2014–0577.
(j) Subject

Joint Aircraft Service Component (JASC) Code: 2213, Flight Controller.
(k) Material Incorporated by Reference

(1) The Director of the Federal Register approved the incorporation by reference 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.

(3) The following service information was approved for IBR on July 23, 2015, (80 FR 34831, June 18, 2015).

(i) Eurocopter Alert Service Bulletin EC135–22A–015, Revision 1, dated January 28, 2013.

(ii) Eurocopter Alert Service Bulletin MBB BK117 C–2–22A–009, Revision 1, dated August 3, 2009.

(4) For Airbus Helicopters service information identified in this final rule, contact Airbus Helicopters, Inc., 2701 N. Forum Drive, Grand Prairie, TX 75052; telephone (972) 641–0000 or (800) 232–0323; fax (972) 641–3775; or at http:// www.airbushelicopters.com/techpub.

(5) You may view this service information at FAA, Office of the Regional Counsel, Southwest Region, Room 6N–321, 10101 Hillwood Pkwy, Fort Worth, TX 76177. For information on the availability of this material at the FAA, call (817) 222–5110.

(6) 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/ibrlocations.html.


### 3313 Federal Register / Vol. 81, No. 13 / Thursday, January 21, 2016 / Rules and Regulations

Issued in Fort Worth, Texas, on January 6,
2016. Bruce E. Cain, Acting Manager, Rotorcraft Directorate, Aircraft Certification Service.
[FR Doc. 2016–00664 Filed 1–20–16; 8:45 am]

**BILLING CODE 4910–13–P**

**DEPARTMENT OF TRANSPORTATION**

**Federal Aviation Administration**

**14 CFR Part 39**

**[Docket No. FAA–2014–0447; Directorate Identifier 2014–NM–019–AD; Amendment**  **39–18368; AD 2016–01–09]**

**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 Model DHC–8–400 series airplanes. This AD was prompted by a report of several cracks found on the forward passenger airstair door step assembly. This AD requires an inspection to determine the serial number of the airstair door step assembly, and if necessary, an electronic tap test, reidentification of the airstair door step assembly, and replacement of the airstair door step assembly. We are issuing this AD to detect and correct cracks in the forward passenger airstair door step assembly; such cracking could propagate and result in the structural failure of the steps and impede the evacuation of passengers in the event of an emergency egress situation.

**DATES :**  This AD becomes effective February 25, 2016.

The Director of the Federal Register approved the incorporation by reference of a certain publication listed in this AD as of February 25, 2016.

**ADDRESSES :**  You may examine the AD docket on the Internet at http:// www.regulations.gov/ #!docketDetail;D=FAA-2014-0447; 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 final rule, contact Bombardier, Inc., Q-Series Technical Help Desk, 123 Garratt Boulevard, Toronto, Ontario M3K 1Y5, Canada; telephone 416–375– 4000; fax 416–375–4539; email thd.qseries@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. It is also available on the Internet at http:// www.regulations.gov by searching for and locating Docket No. FAA–2014–
0447.

**FOR FURTHER INFORMATION CONTACT :**  Jeffrey Zimmer, Aerospace Engineer, Airframe and Mechanical Systems Branch, ANE–171, FAA, New York Aircraft Certification Office, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; telephone 516–228–7306; 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 Model DHC–8–400 series airplanes. The NPRM published in the Federal Register on July 17, 2014 (79 FR 41661). The NPRM was prompted by a report of several cracks found on the forward passenger airstair door step assembly. The NPRM proposed to require an inspection to determine the serial number of the airstair door step assembly, and if necessary, an electronic tap test, reidentification of the airstair door step assembly, and replacement of the airstair door step assembly. We are issuing this AD to detect and correct cracks in the forward passenger airstair door step assembly; such cracking could propagate and result in the structural failure of the steps and impede the evacuation of passengers in the event of an emergency egress situation.

Transport Canada Civil Aviation (TCCA), which is the aviation authority for Canada, has issued Canadian Airworthiness Directive CF–2013–20R1, dated December 30, 2013 (referred to after this as the Mandatory Continuing Airworthiness Information, or ‘‘the MCAI’’), to correct an unsafe condition for the specified products. The MCAI
states:

There has been one in-service report of several cracks being found on the forward passenger airstair door step assembly between the steps and the sidewall panels. The investigation revealed that the application of potting compound may have been omitted during the bonding at the joint of the airstair door steps and the sidewalls. The omission of potting compound could cause the bonding sealant to crack. The cracks, if not detected, could propagate to result in the structural failure of the steps.

In the event of an emergency egress situation, the failure of the airstair step assembly could impede the evacuation of
passengers.

This [Canadian] AD mandates the replacement of the affected forward passenger airstair step assembly with a new or reworked step assembly.

Revision 1 of this [Canadian] AD provides additional instructions for performing an electronic tap test of the airstair step assembly if the Serial Number (S/N) of the airstair step assembly cannot be found.

Required actions include an inspection to determine the serial number of the airstair door step assembly, and if necessary, an electronic tap test and reidentification and replacement of the assembly. You may examine the MCAI in the AD docket on the Internet at http:// www.regulations.gov/ #!documentDetail;D=FAA-2014-0447-
0004

. Comments

We gave the public the opportunity to participate in developing this AD. The following presents the comments received on the NPRM (79 FR 41661, July 17, 2014) and the FAA’s response to each comment. Request To Refer to Latest Service Information

Republic Airlines and Horizon Air requested that we revise the NPRM (79 FR 41661, July 17, 2014) to refer to the latest service information.

We agree with the request. The revised service information, Bombardier Service Bulletin 84–52–77, Revision C, dated June 5, 2014, provides minor wording changes but does not change the procedures or add any airplanes. We have revised paragraphs (g) and (h) in this AD to refer to the new service information, and added Bombardier Service Bulletin 84–52–77, Revision B, dated October 31, 2013, to paragraph (i) of this AD, to provide credit for previous actions done before the effective date of this AD. Request To Allow Records Review

Horizon Air requested that we revise paragraph (g) of the proposed AD (79 FR 41661, July 17, 2014) to allow a review of aircraft records, in addition to a physical inspection, as a way to determine the serial number of the airstair door step assembly.

We disagree with the request. A review of aircraft records may provide an appropriate means to determine serial numbers. For the airstair door step assembly, however, we understand that operators may remove and exchange the