81 FR 13298 - Airworthiness Directives; Bombardier, Inc. Airplanes

DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration

Federal Register Volume 81, Issue 49 (March 14, 2016)

We propose to adopt a new airworthiness directive (AD) for certain Bombardier, Inc. Model DHC-8-400 airplanes. This proposed AD was prompted by one in-service report of a cracked and corroded barrel nut found at the mid-spar location of the horizontal stabilizer to vertical stabilizer attachment joint. There have also been two other reports of corroded barrel nuts found at mid-spar locations. This proposed AD would require repetitive detailed inspections of each barrel nut and cradle, a check of the bolt torque of any preload indicating washer (PLI), and corrective action if necessary. We are proposing this AD to detect and correct cracked and corroded barrel nuts. This condition could compromise the structural integrity of the vertical stabilizer attachment joints, which could lead to loss of control of the airplane.

[Federal Register Volume 81, Number 49 (Monday, March 14, 2016)]
[Proposed Rules]
[Pages 13298-13300]
From the Federal Register Online  [www.thefederalregister.org]
[FR Doc No: 2016-05607]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2016-4224; Directorate Identifier 2015-NM-170-AD]
RIN 2120-AA64


Airworthiness Directives; Bombardier, Inc. Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: We propose to adopt a new airworthiness directive (AD) for 
certain Bombardier, Inc. Model DHC-8-400 airplanes. This proposed AD 
was prompted by one in-service report of a cracked and corroded barrel 
nut found at the mid-spar location of the horizontal stabilizer to 
vertical stabilizer attachment joint. There have also been two other 
reports of corroded barrel nuts found at mid-spar locations. This 
proposed AD would require repetitive detailed inspections of each 
barrel nut and cradle, a check of the bolt torque of any preload 
indicating washer (PLI), and corrective action if necessary. We are 
proposing this AD to detect and correct cracked and corroded barrel 
nuts. This condition could compromise the structural integrity of the 
vertical stabilizer attachment joints, which could lead to loss of 
control of the airplane.

DATES: We must receive comments on this proposed AD by April 28, 2016.

ADDRESSES: You may send comments, using the procedures found in 14 CFR 
11.43 and 11.45, by any of the following methods:
     Federal eRulemaking Portal: Go to http://www.regulations.gov. Follow the instructions for submitting comments.
     Fax: 202-493-2251.
     Mail: U.S. Department of Transportation, Docket 
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New 
Jersey Avenue SE., Washington, DC 20590.
     Hand Delivery: U.S. Department of Transportation, Docket 
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New 
Jersey Avenue SE., Washington, DC, between 9 a.m. and 5 p.m., Monday 
through Friday, except Federal holidays.
    For service information identified in this proposed 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 [email protected]; 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.

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-2016-
4224; 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 proposed 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. 
Comments will be available in the AD docket shortly after receipt.

FOR FURTHER INFORMATION CONTACT: Aziz Ahmed, Aerospace Engineer, 
Airframe and Mechanical Systems Branch, ANE-171, FAA, New York Aircraft 
Certification Office (ACO), 1600 Stewart Avenue, Suite 410, Westbury, N 
Y 11590; telephone 516-228-7329; fax 516-794-5531.

SUPPLEMENTARY INFORMATION:

Comments Invited

    We invite you to send any written relevant data, views, or 
arguments about this proposed AD. Send your comments to an address 
listed under the ADDRESSES section. Include ``Docket No. FAA-2016-4224; 
Directorate Identifier 2015-NM-170-AD'' at the beginning of your 
comments. We specifically invite comments on the overall regulatory, 
economic, environmental, and energy aspects of this proposed AD. We 
will consider all comments received by the closing date and may amend 
this proposed AD based on those comments.
    We will post all comments we receive, without change, to http://www.regulations.gov, including any personal information you provide. We 
will also post a report summarizing each substantive verbal contact we 
receive about this proposed AD.

Discussion

    Transport Canada Civil Aviation (TCCA), which is the aviation 
authority for Canada, has issued Canadian Airworthiness Directive CF-
2015-13, dated June 25, 2015 (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 
airplanes. The MCAI states:

    There has been one in-service report of a cracked and corroded 
barrel nut, part number (P/N) DSC228-12, found at the mid-spar 
location of the horizontal stabilizer to vertical stabilizer 
attachment joint. There have also been two other reports of corroded 
barrel nuts found at mid-spar locations.
    Preliminary investigation determined that the cracking is 
initiated by corrosion. The corrosion may have been caused by 
inadequate cadmium plating on the barrel nut. Failure of the barrel 
nuts could compromise the structural integrity of the joint and 
could lead to loss of control of the aeroplane.
    This [Canadian] AD mandates initial and repetitive inspections 
of the barrel nuts [and cradles for cracks and corrosion] at each 
horizontal stabilizer to vertical stabilizer attachment joints.

    Required actions include a bolt preload check of any PLI washers 
and applicable corrective actions (retorque of the bolts and 
replacement of the barrel nut), a detailed inspection of cracked or 
broken barrel nuts for damaged bores of the fittings, replacement of 
barrel nuts, and repair of damage and corrosion.
    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-2016-
4224.

Related Service Information Under 1 CFR Part 51

    Bombardier, Inc. has issued Alert Service Bulletin A84-55-04, 
Revision A, dated June 2, 2015. The service information describes 
procedures for a detailed inspection of the barrel nuts and cradles for 
cracks and corrosion, a bolt preload check of any PLI washers and 
applicable corrective actions, a detailed inspection for corrosion and 
damage of the bores of the fittings, replacement of the barrel nuts, 
and repair of damage and corrosion.
    Bombardier has issued Bombardier Repair Drawing (RD) 8/4-55-1143, 
Issue 1, dated May 21, 2015. The service information describes 
procedures for repairing corrosion and damage of the bore of the 
fitting.
    This service information is reasonably available because the 
interested parties have access to it through their normal

[[Page 13299]]

course of business or by the means identified in the ADDRESSES section.

FAA's Determination and Requirements of This Proposed AD

    This product has been approved by the aviation authority of another 
country, and is approved for operation in the United States. Pursuant 
to our bilateral agreement with the State of Design Authority, we have 
been notified of the unsafe condition described in the MCAI and service 
information referenced above. We are proposing this AD because we 
evaluated all pertinent information and determined an unsafe condition 
exists and is likely to exist or develop on other products of the same 
type design.

Costs of Compliance

    We estimate that this proposed AD affects 76 airplanes of U.S. 
registry.
    We also estimate that it would take about 6 work-hours per product 
to comply with the basic requirements of this proposed AD and 1 work-
hour per product for reporting. 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 proposed AD on U.S. operators to 
be $45,220, or $595 per product.
    In addition, we estimate that any necessary follow-on actions would 
take about 4 work-hours, and require parts costing $8,881, for a cost 
of $9,221 per product. We have no way of determining the number of 
aircraft that might need this action.

Paperwork Reduction Act

    A federal agency may not conduct or sponsor, and a person is not 
required to respond to, nor shall a person be subject to penalty for 
failure to comply with a collection of information subject to the 
requirements of the Paperwork Reduction Act unless that collection of 
information displays a current valid OMB control number. The control 
number for the collection of information required by this proposed AD 
is 2120-0056. The paperwork cost associated with this proposed AD has 
been detailed in the Costs of Compliance section of this document and 
includes time for reviewing instructions, as well as completing and 
reviewing the collection of information. Therefore, all reporting 
associated with this proposed AD is mandatory. Comments concerning the 
accuracy of this burden and suggestions for reducing the burden should 
be directed to the FAA at 800 Independence Ave. SW., Washington, DC 
20591, ATTN: Information Collection Clearance Officer, AES-200.

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 proposed AD would not have federalism 
implications under Executive Order 13132. This proposed AD would 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 this proposed 
regulation:
    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.

The Proposed Amendment

    Accordingly, under the authority delegated to me by the 
Administrator, the FAA proposes to amend 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):

Bombardier, Inc.: Docket No. FAA-2016-4224; Directorate Identifier 
2015-NM-170-AD.

(a) Comments Due Date

    We must receive comments by April 28, 2016.

(b) Affected ADs

    None.

(c) Applicability

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

(d) Subject

    Air Transport Association (ATA) of America Code 55, Stablizers.

(e) Reason

    This AD was prompted by one in-service report of a cracked and 
corroded barrel nut, part number DSC228-12, found at the mid-spar 
location of the horizontal stabilizer to vertical stabilizer 
attachment joint. There have also been two other reports of corroded 
barrel nuts found at mid-spar locations. We are issuing this AD to 
detect and correct cracked and corroded barrel nuts. This condition 
could compromise the structural integrity of the vertical stabilizer 
attachment joints, which could lead to loss of control of the 
airplane.

(f) Compliance

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

(g) Detailed Inspection of Barrel Nuts for Cracks and Corrosion

    (1) For airplanes that have accumulated 5,400 flight hours or 
more, or have been in service 32 months or more since the date of 
issuance of the original certificate of airworthiness or the date of 
issuance of the original export certificate of airworthiness as of 
the effective date of this AD: Within 600 flight hours or 4 months, 
whichever occurs first, after the effective date of this AD, do a 
detailed visual inspection for signs of cracks and corrosion of the 
barrel nut and cradle, in accordance with the Accomplishment 
Instructions of Bombardier Alert Service Bulletin A84-55-04, 
Revision A, dated June 2, 2015.
    (2) For airplanes that have less than 5,400 flight hours, and 
have been in-service for less than 32 months since the date of 
issuance of the original certificate of airworthiness or the date of 
issuance of the original export certificate of airworthiness as of 
the effective date of this AD: Before the accumulation of 6,000 
total flight hours or 36 months since the date of issuance of the 
original certificate of airworthiness or the date of issuance of the 
original export certificate of airworthiness, whichever occurs 
first, do a detailed visual inspection of the barrel nut for signs 
of cracks and corrosion of the barrel nut and cradle, in

[[Page 13300]]

accordance with the Accomplishment Instructions of Bombardier Alert 
Service Bulletin A84-55-04, Revision A, dated June 2, 2015.

(h) Corrective Actions, Detailed Inspection, and Repetitive Inspections

    Depending on the findings of any inspection required by 
paragraphs (g) and (j) of this AD, do the applicable actions in 
paragraphs (h)(1), (h)(2), and (h)(3) of this AD.
    (1) If any barrel nut or cradle is found cracked or broken, 
before further flight, replace the barrel nut and associated 
hardware, in accordance with the Accomplishment Instructions of 
Bombardier Alert Service Bulletin A84-55-04, Revision A, dated June 
2, 2015.
    (i) Concurrently with the replacement of any barrel nut, do a 
detailed inspection for corrosion and damage of the bore of the 
fitting, in accordance with the Accomplishment Instructions of 
Bombardier Alert Service Bulletin A84-55-04, Revision A, dated June 
2, 2015, and, before further flight, repair all corrosion and 
damage, in accordance with Bombardier Repair Drawing (RD) RD 8/4-55-
1143, Issue 1, dated May 21, 2015. If the bore of the fitting cannot 
be repaired in accordance with Bombardier RD 8/4-55-1143, Issue 1, 
dated May 21, 2015, repair before further flight 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).
    (ii) Within 600 flight hours or 4 months, whichever occurs 
first, after the replacement of a cracked barrel nut, replace the 
remaining barrel nuts and their associated hardware at the 
horizontal stabilizer to vertical stabilizer attachment joints, in 
accordance with the Accomplishment Instructions of Bombardier Alert 
Service Bulletin A84-55-04, Revision A, dated June 2, 2015.
    (2) If any corrosion is found on any barrel nut on the front or 
rear-spar joints, before further flight, replace the barrel nut 
using a method approved by the Manager, New York ACO, ANE-170, FAA; 
or TCCA; or Bombardier, Inc.'s TCCA DAO.
    (3) If any corrosion above level 1, as defined in Bombardier 
Alert Service Bulletin A84-55-04, Revision A, dated June 2, 2015, is 
found on a barrel nut at the mid-spar joint, before further flight, 
replace the barrel nut using a method approved by the Manager, New 
York ACO, ANE-170, FAA; or TCCA; or Bombardier, Inc.'s TCCA DAO.
    (4) If all corrosion found is at level 1 or below, as defined in 
Bombardier Service Bulletin A84-55-04, Revision A, dated June 2, 
2015, on a barrel nut at the mid-spar joint, repeat the inspection 
specified in paragraph (g) of this AD at intervals not to exceed 600 
flight hours or 4 months, whichever occurs first, until completion 
of the actions required by paragraph (k) of this AD.

(i) Preload Indicating (PLI) Washers Check

    For airplanes with PLI washers installed at the front and rear 
spar joints, before further flight after accomplishing any 
inspection required by (g) of this AD and all applicable corrective 
actions required by paragraph (h) of this AD, check the bolt 
preload, and do all applicable corrective actions, in accordance 
with the Accomplishment Instructions of Bombardier Alert Service 
Bulletin A84-55-04, Revision A, dated June 2, 2015. Do all 
applicable corrective actions before further flight.

(j) Repetitive Inspection Interval

    Repeat the inspection and preload check required by paragraphs 
(g) and (i) of this AD at intervals not to exceed 3,600 flight hours 
or 18 months, whichever occurs first, except as provided by 
paragraph (k) of this AD.

(k) Optional Barrel Nut Replacement

    Inspection and replacement of all barrel nuts at the horizontal 
stabilizer to vertical stabilizer attachment joints, in accordance 
with the Accomplishment Instructions of Bombardier Alert Service 
Bulletin A84-55-04, Revision A, dated June 2, 2015, extends the next 
inspection required by paragraph (j) of this AD to within 6,000 
flight hours or 36 months, whichever occurs first, after 
accomplishing the replacement.

(l) Reporting Requirements

    At the applicable time specified in paragraph (l)(1) or (l)(2) 
of this AD, submit a report of the findings (both positive and 
negative) of each inspection required by this AD to Technical Help 
Desk--Qseries, telephone: 416-375-4000, fax: 416-375-4539, email: 
[email protected], using the inspection form in 
Bombardier Alert Service Bulletin A84-55-04, Revision A, dated June 
2, 2015.
    (1) If the inspection was done on or after the effective date of 
this AD: Submit the report within 30 days after the inspection.
    (2) If the inspection was done before the effective date of this 
AD: Submit the report within 30 days after the effective date of 
this AD.

(m) 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 Alert Service Bulletin A84-55-04, 
dated May 21, 2015, which is not incorporated by reference in this 
AD.

(n) Other FAA AD Provisions

    The following provisions also apply to this AD:
    (1) Alternative Methods of Compliance (AMOCs): The Manager, New 
York 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 TCCA; or Bombardier, Inc.'s TCCA DAO. If approved 
by the DAO, the approval must include the DAO-authorized signature.
    (3) Reporting Requirements: A federal agency may not conduct or 
sponsor, and a person is not required to respond to, nor shall a 
person be subject to a penalty for failure to comply with a 
collection of information subject to the requirements of the 
Paperwork Reduction Act unless that collection of information 
displays a current valid OMB Control Number. The OMB Control Number 
for this information collection is 2120-0056. Public reporting for 
this collection of information is estimated to be approximately 5 
minutes per response, including the time for reviewing instructions, 
completing and reviewing the collection of information. All 
responses to this collection of information are mandatory. Comments 
concerning the accuracy of this burden and suggestions for reducing 
the burden should be directed to the FAA at: 800 Independence Ave. 
SW., Washington, DC 20591, Attn: Information Collection Clearance 
Officer, AES-200.

(o) Related Information

    (1) Refer to Mandatory Continuing Airworthiness Information 
(MCAI) Canadian Airworthiness Directive CF-2015-13, dated June 25, 
2015, 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-2016-4224.
    (2) 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 [email protected]; Internet 
http://www.bombardier.com. 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.

    Issued in Renton, Washington, on March 3, 2016.
Michael Kaszycki,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2016-05607 Filed 3-11-16; 8:45 am]
 BILLING CODE 4910-13-P