
[Federal Register Volume 81, Number 13 (Thursday, January 21, 2016)]
[Rules and Regulations]
[Pages 3313-3316]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2016-00378]


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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.

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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

[[Page 3314]]

assemblies within their fleet for repair, and replace them relatively 
quickly to minimize airplane downtime. In these cases, there may be a 
lag between the removal and replacement action and updating the records 
typically used to conduct a records review. In coordination with TCCA, 
we have determined that airplane records may not reliably reflect the 
serial numbers of all airstair door step assemblies present on the 
affected airplanes. However, under the provisions of paragraph (j)(1) 
of this AD, we will consider requests for approval of an alternative 
method of compliance for determining serial numbers, if sufficient data 
are submitted to substantiate that the new method would provide an 
acceptable level of safety. We have not changed this final rule 
regarding this issue.

Request To Allow Maintenance Manual Tasks for Airstair Replacement

    Horizon Air requested that we revise paragraph (g)(1)(ii) of the 
proposed AD (79 FR 41661, July 17, 2014), which would conditionally 
require replacing the airstair door step assembly in accordance with 
Bombardier Service Bulletin 84-52-77, Revision B, dated October 31, 
2013. For this action, Horizon Air requested that we also allow the 
replacement to be done using maintenance manual tasks 52-11-01-000-801 
and 52-11-01-400-801. Horizon Air stated that the service information 
specified in the NPRM does not include any actions beyond those 
specified in the maintenance manual tasks.
    We disagree with the request. Part 3, ``Procedure,'' of the 
Accomplishment Instructions of Bombardier Service Bulletin 84-52-77, 
Revision C, dated June 5, 2014, does, in fact, specify additional tasks 
not included in the maintenance manual tasks referenced by the 
commenter. The additional tasks include verification of the serial 
number of the new airstair door step assembly before installation, and 
adjustment and a functional check of the new door. We have not changed 
this AD regarding this issue.

Request To Limit Requirements to Steps That Correct the Unsafe 
Condition

    Horizon Air requested that we revise the NPRM (79 FR 41661, July 
17, 2014) to require only the section of the Accomplishment 
Instructions of Bombardier Service Bulletin 84-52-77, Revision C, dated 
June 5, 2014, that directly corrects the unsafe condition: paragraph 
3.B., ``Procedure.'' Horizon Air stated that the unsafe condition is 
not directly corrected by accomplishment of the actions specified in 
paragraph 3.A., ``Job Set-up,'' and paragraph 3.C., ``Close Out,'' of 
the Accomplishment Instructions of Bombardier Service Bulletin 84-52-
77, Revision C, dated June 5, 2014. Horizon Air added that 
incorporating the Job Set-up and Close Out as a requirement of the AD 
would restrict an operator's ability to perform other maintenance in 
conjunction with the incorporation of the service information.
    We agree with the request and the commenter's rationale. We have 
revised paragraph (g) of this AD accordingly.

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:
     Are consistent with the intent that was proposed in the 
NPRM (79 FR 41661, July 17, 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 41661, July 17, 2014).
    We also determined that these changes will not increase the 
economic burden on any operator or increase the scope of this AD.

Related Service Information Under 1 CFR Part 51

    Bombardier has issued Service Bulletin 84-52-77, Revision C, dated 
June 5, 2014, including Appendix A, and with the attached Short 
Brothers Service Bulletin D8400-52-0011, Revision C, dated February 26, 
2014. The service information describes procedures for determining the 
airstair door step assembly serial number, doing an electronic tap 
test, and reidentifying and replacing the assembly. This service 
information is reasonably available because the interested parties have 
access to it through their normal course of business or by means 
identified in the ADDRESSES section of this AD.

Costs of Compliance

    We estimate that this AD affects 76 airplanes of U.S. registry. We 
also estimate that it will 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 
$6,460, or $85 per product.
    In addition, we estimate that any necessary follow-on actions would 
take up to 9 work-hours and require parts costing $206,175, for a cost 
of $206,940 per product. We have no way of determining the number of 
aircraft that might need these actions.

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 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-2014-0447; 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

[[Page 3315]]

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

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):

2016-01-09 Bombardier, Inc.: Amendment 39-18368. Docket No. FAA-
2014-0447; Directorate Identifier 2014-NM-019-AD.

(a) Effective Date

    This AD becomes effective February 25, 2016.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to Bombardier, Inc. Model DHC-8-400, -401, and -
402 airplanes, certificated in any category, serial numbers 4001 and 
subsequent.

(d) Subject

    Air Transport Association (ATA) of America Code 52, Doors.

(e) Reason

    This AD was prompted by a report of several cracks found on the 
forward passenger airstair door step assembly. We are issuing this 
AD to detect and correct cracks in the forward passenger airstair 
door step assembly, which 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.

(f) Compliance

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

(g) Inspection, Electronic Tap Test, Reidentification, and Replacement 
of the Airstair Door Step Assembly

    For airplanes having serial numbers 4001 through 4393: Within 
320 days after the effective date of this AD, do an inspection to 
determine the serial number of the airstair door step assembly, in 
accordance with paragraph 3.B., ``Procedure,'' of the Accomplishment 
Instructions of Bombardier Service Bulletin 84-52-77, Revision C, 
dated June 5, 2014, including Appendix A, and with the attached 
Short Brothers Service Bulletin D8400-52-0011, Revision C, dated 
February 26, 2014.
    (1) If the serial number of the airstair door step assembly 
cannot be found, or if the serial number is illegible: Before 
further flight, do an electronic tap test to determine the existence 
of epoxy compound, in accordance with paragraph 3.B., ``Procedure,'' 
of the Accomplishment Instructions of Bombardier Service Bulletin 
84-52-77, Revision C, dated June 5, 2014, including Appendix A, and 
with the attached Short Brothers Service Bulletin D8400-52-0011, 
Revision C, dated February 26, 2014.
    (i) If the existence of epoxy compound is confirmed, before 
further flight, reidentify the airstair door step assembly, in 
accordance with paragraph 3.B., ``Procedure,'' of the Accomplishment 
Instructions of Bombardier Service Bulletin 84-52-77, Revision C, 
dated June 5, 2014, including Appendix A, and with the attached 
Short Brothers Service Bulletin D8400-52-0011, Revision C, dated 
February 26, 2014.
    (ii) If the existence of epoxy compound is not confirmed: Within 
6,000 flight hours after the effective date of this AD, replace the 
airstair door step assembly, in accordance with paragraph 3.B., 
``Procedure,'' of the Accomplishment Instructions of Bombardier 
Service Bulletin 84-52-77, Revision C, dated June 5, 2014, including 
Appendix A, and with the attached Short Brothers Service Bulletin 
D8400-52-0011, Revision C, dated February 26, 2014.
    (2) If the serial number of the airstair door step assembly is 
in the affected range specified in paragraph 1.A., ``Effectivity,'' 
of Bombardier Service Bulletin 84-52-77, Revision C, dated June 5, 
2014: Within 6,000 flight hours after the effective date of this AD, 
replace the airstair door step assembly, in accordance with 
paragraph 3.B., ``Procedure,'' of the Accomplishment Instructions of 
Bombardier Service Bulletin 84-52-77, Revision C, dated June 5, 
2014, including Appendix A, and with the attached Short Brothers 
Service Bulletin D8400-52-0011, Revision C, dated February 26, 2014.

(h) Parts Installation Prohibition

    As of the effective date of this AD, no person may install on 
any airplane an airstair door step assembly with part number 
85217008-001 containing a serial number in the affected range 
specified in paragraph 1.A., ``Effectivity,'' of Bombardier Service 
Bulletin 84-52-77, Revision C, dated June 5, 2014, including 
Appendix A, and with the attached Short Brothers Service Bulletin 
D8400-52-0011, Revision C, dated February 26, 2014.

(i) Credit for Previous Actions

    This paragraph provides credit for actions required by paragraph 
(g) of this AD if the serial number is known, and if those actions 
were performed before the effective date of this AD using Bombardier 
Service Bulletin 84-52-77, Revision A, dated April 24, 2013; or 
Bombardier Service Bulletin 84-52-77, Revision B, dated October 31, 
2013. This service information is not incorporated by reference in 
this AD.

(j) 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, 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 DAO-authorized 
signature.

(k) Related Information

    (1) Refer to Mandatory Continuing Airworthiness Information 
(MCAI) Canadian Airworthiness Directive CF-2013-20R1, 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-2014-0447-0004.
    (2) Service information identified in this AD that is not 
incorporated by reference is available at the addresses specified in 
paragraphs (l)(3) and (l)(5) of this AD.

(l) 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 Service Bulletin 84-52-77, Revision C, dated June 
5, 2014, including Appendix A, which is undated, and attached Short 
Brothers Service Bulletin D8400-52-0011, Revision C, dated February 
26, 2014.
    (ii) Reserved.
    (3) For Bombardier service information identified in this AD, 
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.
    (4) For Short Brothers service information identified in this 
AD, contact Short Brothers PLC, Airworthiness, P.O. Box 241, Airport 
Road, Belfast, BT3 9DZ Northern Ireland;

[[Page 3316]]

telephone +44(0)2890-462469; fax +44(0)2890 468444; email 
michael.mulholland@aero.bombardier.com; Internet http://www.bombardier.com.
    (5) 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.
    (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/ibr-locations.html.

    Issued in Renton, Washington, on January 4, 2016.
Victor Wicklund,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2016-00378 Filed 1-20-16; 8:45 am]
 BILLING CODE 4910-13-P


