Airworthiness Directive

ID: 2017-20-07
Issue date: 2017-10-02
Effective date: 2017-11-06
Subject: Fire protection
Source: FAA
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Bombardier, Inc., Airplanes

[Federal Register Volume 82, Number 189 (Monday, October 2, 2017)]
[Rules and Regulations]
[Pages 45703-45705]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2017-20824]

––––––––––––––––––––––––––––––––––

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2017-0518; Product Identifier 2016-NM-167-AD; Amendment 39-19064; AD
2017-20-07]

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 DHC-8-400 series airplanes. This AD was prompted by the failure of the fire control amplifier
(FCA), which was likely caused by an electrical short in a discharged squib for a fire extinguishing
bottle. This AD requires replacing certain circuit breakers. We are issuing this AD to address the
unsafe condition on these products.

Dates:
This AD is effective November 6, 2017.
The Director of the Federal Register approved the incorporation by reference of a certain
publication listed in this AD as of November 6, 2017.

Addresses:
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 Standards Branch, 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-2017-0518.

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-2017-0518; or in person at the Docket Management Facility between 9
a.m. and 5 p.m., Monday through Friday, except Federal holidays. The AD docket contains this AD,
the regulatory evaluation, any comments received, and other information. The street address for the
Docket Office (telephone 800-647-5527) is Docket Management Facility, U.S. Department of

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Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New
Jersey Avenue SE., Washington, DC 20590.

FOR FURTHER INFORMATION CONTACT: Assata Dessaline, Aerospace Engineer, Avionics
and Administrative Services Section, FAA, New York ACO Branch, 1600 Stewart Avenue, Suite
410, Westbury, NY 11590; telephone 516-228-7301; 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 DHC-8-400 series airplanes. The NPRM
published in the Federal Register on June 2, 2017 (82 FR 25554) (“the NPRM”). The NPRM was
prompted by the failure of the FCA, which was likely caused by an electrical short in a discharged
squib for a fire extinguishing bottle. The NPRM proposed to require replacing certain circuit
breakers. We are issuing this AD to prevent failure of the FCA and subsequent discharge of fire
extinguishing bottles and false fire indications, leaving the flight crew with reduced firefighting
capability in the event of a fire.
Transport Canada Civil Aviation (TCCA), which is the aviation authority for Canada, has issued
Canadian Airworthiness Directive CF-2016-25, dated August 22, 2016 (referred to after this as the
Mandatory Continuing Airworthiness Information, or “the MCAI”), to correct an unsafe condition for
certain Bombardier, Inc., Model DHC-8-400 series airplanes. The MCAI states:

An operator reported having a false SMOKE warning light for the Aft Baggage
compartment, which caused the pilots to discharge the Aft Baggage compartment fire
extinguishing bottles per Aircraft Flight Manual procedures. Subsequently, there were
continuous engine and Auxiliary Power Unit (APU) fire warning lights, and the fire
extinguishing bottles for both engines (forward and aft) and the APU were
automatically discharged. Post event investigation of the Fire Control Amplifier
(FCA) revealed a burnt 2600-P2 connector. The FCA was also found to have sustained
significant thermal damage. In a separate event involving a different operator, several
fire extinguishing bottles discharged after an electrical short was introduced into the
FCA by a shorted squib tester (external ground support equipment) during
maintenance.

The FCA manufacturer has identified the most likely failure condition to be an
electrical short at the discharged squib. The squib's burst disk may have caused a short
circuit of the bridgewires, which caused the FCA's internal power wires to experience
thermal damage, consequently powering other squibs and fire alarm lines and resulting
in the uncommanded discharge of the fire extinguishing bottles and false fire
indications.

Bombardier (BA) has issued service bulletin (SB) 84-26-16 to change two 7.5 amp
circuit breakers to lower current rating 1 amp circuit breakers to prevent damage to
squib discharge circuits and the inadvertent discharge of fire extinguishing bottles.

This [Canadian] AD mandates the incorporation of [Bombardier] SB 84-26-16 to
prevent the inadvertent discharge of fire extinguishing bottles [leaving the flight crew
with reduced firefighting capability in the event of a fire].



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You may examine the MCAI in the AD docket on the Internet at http://www.regulations.gov by
searching for and locating Docket No. FAA-2017-0518.

Comments

We gave the public the opportunity to participate in developing this AD. We received no
comments on the NPRM or on the determination of the cost to the public.

Conclusion

We reviewed the relevant data and determined that air safety and the public interest require
adopting this AD as proposed except for minor editorial changes. We have determined that these
minor changes:
• Are consistent with the intent that was proposed in the NPRM for correcting the unsafe
condition; and
• Do not add any additional burden upon the public than was already proposed in the NPRM.

Related Service Information Under 1 CFR Part 51

Bombardier, Inc., has issued Service Bulletin 84-26-16, Revision A, dated February 12, 2016.
This service information describes procedures for locating and replacing certain 7.5-amp circuit
breakers with 1-amp circuit breakers. 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 53 airplanes of U.S. registry.
We estimate the following costs to comply with this AD:

Estimated Costs
Action Labor cost Parts Cost per Cost on U.S.
cost product operators
Replacement of circuit 3 work-hours × $85 per $0 $255 $13,515
breakers 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.
This AD is issued in accordance with authority delegated by the Executive Director, Aircraft
Certification Service, as authorized by FAA Order 8000.51C. In accordance with that order, issuance
of ADs is normally a function of the Compliance and Airworthiness Division, but during this

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transition period, the Executive Director has delegated the authority to issue ADs applicable to
transport category airplanes to the Director of the System Oversight Division.

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.

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):




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AIRWORTHINESS
FAA DIRECTIVE
Aviation Safety
www.faa.gov/aircraft/safety/alerts/
www.gpoaccess.gov/fr/advanced.html


2017-20-07 Bombardier, Inc.: Amendment 39-19064; Docket No. FAA-2017-0518; Product
Identifier 2016-NM-167-AD.

(a) Effective Date

This AD is effective November 6, 2017.

(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 4003 through 4504 inclusive.

(d) Subject

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

(e) Reason

This AD was prompted by the failure of the fire control amplifier (FCA), which was likely
caused by an electrical short in a discharged squib for a fire extinguishing bottle. We are issuing this
AD to prevent failure of the FCA and subsequent discharge of fire extinguishing bottles and false fire
indications, leaving the flight crew with reduced firefighting capability in the event of a fire.

(f) Compliance

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

(g) Replacement of Affected Circuit Breakers

Within 6,000 flight hours or 3 years, whichever occurs first, after the effective date of this AD:
Replace the 7.5-amp circuit breakers specified in Bombardier Service Bulletin 84-26-16, Revision A,
dated February 12, 2016, with 1-amp circuit breakers having part number MS3320-1, in accordance
with the Accomplishment Instructions of Bombardier Service Bulletin 84-26-16, Revision A, dated
February 12, 2016.

(h) Credit for Previous Actions

This paragraph provides credit for actions required by paragraph (g) of this AD, if those actions
were performed before the effective date of this AD using Bombardier Service Bulletin 84-26-16,
dated August 14, 2015.

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(i) Other FAA AD Provisions

The following provisions also apply to this AD:
(1) Alternative Methods of Compliance (AMOCs): The Manager, New York ACO Branch, 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
certification office, send it to ATTN: Program Manager, Continuing Operational Safety, FAA, New
York ACO Branch, 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.
(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 Branch, 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.

(j) Related Information

(1) Refer to Mandatory Continuing Airworthiness Information (MCAI) Canadian Airworthiness
Directive CF-2016-25, dated August 22, 2016, for related information. This MCAI may be found in
the AD docket on the Internet at http://www.regulations.gov by searching for and locating Docket
No. FAA-2017-0518.
(2) For more information about this AD, contact Assata Dessaline, Aerospace Engineer,
Avionics and Administrative Services Section, FAA, New York ACO Branch, 1600 Stewart Avenue,
Suite 410, Westbury, NY 11590; telephone 516-228-7301; fax 516-794-5531.
(3) Service information identified in this AD that is not incorporated by reference is available at
the addresses specified in paragraphs (k)(3) and (k)(4) of this AD.

(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 Service Bulletin 84-26-16, Revision A, dated February 12, 2016.
(ii) Reserved.
(3) For 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) You may view this service information at the FAA, Transport Standards Branch, 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 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 20, 2017.
Dionne Palermo,
Acting Director, System Oversight Division,

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Aircraft Certification Service.




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This is a partial extract of the full document - please refer to the actual report for full information.
Sources as credited.