
[Federal Register Volume 76, Number 169 (Wednesday, August 31, 2011)]
[Rules and Regulations]
[Pages 54093-54095]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2011-22013]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2011-0910; Directorate Identifier 2011-NM-151-AD; 
Amendment 39-16797; AD 2011-18-15]
RIN 2120-AA64


Airworthiness Directives; Bombardier, Inc. Model DHC-8-400 Series 
Airplanes

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

ACTION: Final rule; request for comments.

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SUMMARY: We are adopting a new airworthiness directive (AD) for the 
products listed above. This AD results from mandatory continuing 
airworthiness information (MCAI) originated by an aviation authority of 
another country to identify and correct an unsafe condition on an 
aviation product. The MCAI describes the unsafe condition as:

    There have been three in-service reports of cracked barrel nuts 
found at the front spar locations of the wing-to-fuselage attachment 
joints. Additionally, three operators have reported finding a loose 
washer in the barrel nut assembly. Failure of the barrel nuts could 
compromise the structural integrity of the wing-to-fuselage 
attachments.
* * * * *
The unsafe condition could result in separation of the wing from the 
airplane during flight. This AD requires actions that are intended to 
address the unsafe condition described in the MCAI.

DATES: This AD becomes effective September 15, 2011.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in the AD as of September 15, 
2011.
    We must receive comments on this AD by October 17, 2011.

ADDRESSES: You may send comments 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.

Examining the AD Docket

    You may examine the AD docket on the Internet at http://www.regulations.gov; or in person at the Docket Operations office 
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. 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, 1600 Stewart Avenue, Suite 410, Westbury, New 
York 11590; telephone (516) 228-7329; fax (516) 794-5531.

SUPPLEMENTARY INFORMATION: 

Discussion

    Transport Canada Civil Aviation (TCCA), which is the aviation 
authority for Canada, has issued Canadian Emergency Airworthiness 
Directive CF-2011-24, dated July 21, 2011 (referred to after this as 
``the MCAI''), to correct an unsafe condition for the specified 
products. The MCAI states:

    There have been three in-service reports of cracked barrel nuts 
found at the front spar locations of the wing-to-fuselage attachment 
joints. Additionally, three operators have reported finding a loose 
washer in the barrel nut assembly. Failure of the barrel nuts could 
compromise the structural integrity of the wing-to-fuselage 
attachments.
    Preliminary investigation determined that these cracks are due 
to hydrogen embrittlement.
    This [TCCA airworthiness] directive mandates an initial and 
repetitive [torque checks to determine if the bolt pre-load is 
correct and, if necessary], detailed inspection of the barrel nuts 
[and cradle for cracking, pitting, and corrosion; and replacement of 
hardware if necessary].

The unsafe condition could result in separation of the wing from the 
airplane during flight.

Relevant Service Information

    Bombardier has issued Alert Service Bulletin A84-57-25, dated July 
20, 2011. The actions described in this service information are 
intended to correct the unsafe condition identified in the MCAI.

FAA's Determination and Requirements of This 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 issuing this AD because we 
evaluated all pertinent information and determined the unsafe condition 
exists and is likely to exist or develop on other products of the same 
type design.

Differences Between the AD and the MCAI or Service Information

    We have reviewed the MCAI and related service information and, in 
general, agree with their substance. But we might have found it 
necessary to use different words from those in the MCAI to ensure the 
AD is clear for U.S. operators and is enforceable. In making these 
changes, we do not intend to differ substantively from the information 
provided in the MCAI and related service information.
    We might also have required different actions in this AD from those 
in the MCAI in order to follow FAA policies. Any such differences are 
highlighted in a Note within the AD.

FAA's Determination of the Effective Date

    An unsafe condition exists that requires the immediate adoption of 
this AD. The FAA has found that the risk to the flying public justifies 
waiving notice and comment prior to adoption of this rule because 
failure of the wing-to-fuselage attachments could result in separation 
of the wing from the airplane during flight. Therefore, we determined 
that notice and opportunity for public

[[Page 54094]]

comment before issuing this AD are impracticable and that good cause 
exists for making this amendment effective in fewer than 30 days.

Comments Invited

    This AD is a final rule that involves requirements affecting flight 
safety, and we did not precede it by notice and opportunity for public 
comment. We invite you to send any written relevant data, views, or 
arguments about this AD. Send your comments to an address listed under 
the ADDRESSES section. Include ``Docket No. FAA-2011-0910; Directorate 
Identifier 2011-NM-151-AD'' at the beginning of your comments. We 
specifically invite comments on the overall regulatory, economic, 
environmental, and energy aspects of this AD. We will consider all 
comments received by the closing date and may amend this AD because of 
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 AD.

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 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); and
    3. 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.
    We prepared a regulatory evaluation of the estimated costs to 
comply with this AD and placed it in the AD docket.

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 AD:

2011-18-15 Bombardier, Inc.: Amendment 39-16797. Docket No. FAA-
2011-0910; Directorate Identifier 2011-NM-151-AD.

Effective Date

    (a) This airworthiness directive (AD) becomes effective 
September 15, 2011.

Affected ADs

    (b) None.

Applicability

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

Subject

    (d) Air Transport Association (ATA) of America Code 57: Wings.

Reason

    (e) The mandatory continued airworthiness information (MCAI) 
states:

    There have been three in-service reports of cracked barrel nuts 
found at the front spar locations of the wing-to-fuselage attachment 
joints. Additionally, three operators have reported finding a loose 
washer in the barrel nut assembly. Failure of the barrel nuts could 
compromise the structural integrity of the wing-to-fuselage 
attachments.

The unsafe condition could result in separation of the wing from the 
airplane during flight.

Compliance

    (f) You are responsible for having the actions required by this 
AD performed within the compliance times specified, unless the 
actions have already been done.

Initial and Repetitive Inspections

    (g) At the applicable time specified in paragraph (g)(1) or 
(g)(2) of this AD: Do a torque check to determine if the bolt 
preload is correct, and if the preload is correct, before further 
flight, do a detailed inspection of each barrel nut and cradle for 
cracking, pitting or corrosion, in accordance with paragraph 3.B., 
part A, of the Accomplishment Instructions of Bombardier Alert 
Service Bulletin A84-57-25, dated July 20, 2011. Repeat the torque 
check and, as applicable, the inspection thereafter at intervals not 
to exceed 2,000 flight hours or 12 months, whichever occurs first.
    (1) For airplanes that have accumulated 1,900 or more total 
flight hours as of the effective date of this AD, or for which it 
has been 12 months or more since the date of issuance of the 
original Canadian airworthiness certificate or the date of issuance 
of the original Canadian export certificate of airworthiness as of 
the effective date of this AD: Within 100 flight hours or 10 days 
after the effective date of this AD, whichever occurs first.
    (2) For airplanes that have accumulated less than 1,900 total 
flight hours as of the effective date of this AD, and for which it 
has been less than 12 months since the date of issuance of the 
original Canadian airworthiness certificate or the date of issuance 
of the original Canadian export certificate of airworthiness as of 
the effective date of this AD: Prior to the accumulation of 2,000 
total flight hours or within 12 months since the date of issuance of 
the original Canadian standard airworthiness certificate or the date 
of issuance of the original Canadian export certificate of 
airworthiness, whichever occurs first.

Corrective Actions

    (h) If any bolt preload is found to be incorrect (i.e., the ring 
can be rotated during any torque check required by this AD), before 
further flight, replace all hardware at that location (except the 
saddle washer and retainer) in accordance with paragraph 3.B., part 
B, of the Accomplishment Instructions of Bombardier Alert Service 
Bulletin A84-57-25, dated July 20, 2011.
    (i) If any crack, pitting, or corrosion of the barrel nut or 
cradle is found during any inspection required by this AD, before 
further flight, replace all hardware at that location (except the 
saddle washer and retainer) in accordance with paragraph 3.B., part 
B, of the Accomplishment Instructions of Bombardier Alert Service 
Bulletin A84-57-25, dated July 20, 2011.

Credit for Actions Accomplished in Accordance With Previous Service 
Information

    (j) Accomplishment of torque checks, initial inspections, or 
replacements before the effective date of this AD, in accordance 
with Bombardier Alert Service Bulletin A84-57-19, dated February 1, 
2008; Revision A,

[[Page 54095]]

dated February 6, 2008; Revision B, dated March 6, 2008; or Revision 
C, dated August 20, 2008; is acceptable for compliance with the 
corresponding requirements of paragraphs (g) and (h) of this AD. 
However, the repetitive inspections required by paragraph (g) of 
this AD must be continued at the time specified.

FAA AD Differences

    Note 1:  This AD differs from the MCAI and/or service 
information as follows: No differences.

Special Flight Permits

    (k) Special flight permits, as described in Section 21.197 and 
Section 21.199 of the Federal Aviation Regulations (14 CFR 21.197 
and 21.199), may be issued to operate the airplane to a location 
where the requirements of this AD can be accomplished, but 
concurrence by the Manager, New York Aircraft Certification Office 
(ACO), FAA, is required prior to issuance of the special flight 
permit. Before using any approved special flight permits, notify 
your principal maintenance inspector (PMI) or principal avionics 
inspector (PAI), as appropriate, or lacking a principal inspector, 
your local Flight Standards District Office (FSDO). Operators must 
request a repair drawing from Bombardier which provides 
recommendations for a one-time special flight permit. The repair 
drawing will be applicable to the operator's aircraft serial number 
only. Special flight permits may be permitted provided that the 
conditions specified in paragraphs (k)(1), (k)(2), (k)(3), (k)(4), 
and (k)(5) of this AD are met.
    (1) Only one barrel nut out of four is cracked, one cradle is 
cracked, or one washer is loose; all other strut bolt locations must 
be free of damage.
    (2) The airplane must operate with reduced airspeed not to 
exceed 180 KIAS [knots indicated air speed]. No passengers and no 
cargo are onboard.
    (3) The airplane must not operate in known or forecast 
turbulence, other than light turbulence.
    (4) The airplane descent rate on landing flare-out is not to 
exceed 5 feet per second.
    (5) Heavy braking or hard turning of the airplane upon landing 
is to be avoided if possible.

Other FAA AD Provisions

    (l) The following provisions also apply to this AD:
    (1) Alternative Methods of Compliance (AMOCs): The Manager, ANE-
170, New York Aircraft Certification Office (ACO), 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, New York 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) Airworthy Product: For any requirement in this AD to obtain 
corrective actions from a manufacturer or other source, use these 
actions if they are FAA-approved. Corrective actions are considered 
FAA-approved if they are approved by the State of Design Authority 
(or their delegated agent). You are required to assure the product 
is airworthy before it is returned to service.

Related Information

    (m) Refer to MCAI Canadian Emergency Airworthiness Directive CF-
2011-24, dated July 21, 2011; and Bombardier Alert Service Bulletin 
A84-57-25, dated July 20, 2011; for related information.

Material Incorporated by Reference

    (n) You must use Bombardier Alert Service Bulletin A84-57-25, 
dated July 20, 2011, to do the actions required by this AD, unless 
the AD specifies otherwise.
    (1) The Director of the Federal Register approved the 
incorporation by reference of this service information under 5 
U.S.C. 552(a) and 1 CFR part 51.
    (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; e-mail thd.qseries@aero.bombardier.com; Internet 
http://www.bombardier.com.
    (3) You may review copies of the service information at the FAA, 
Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, 
Washington. For information on the availability of this material at 
the FAA, call 425-227-1221.
    (4) You may also review copies of the 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/code_of_federal_regulations/ibr_locations.html.

    Issued in Renton, Washington, on August 19, 2011.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2011-22013 Filed 8-30-11; 8:45 am]
BILLING CODE 4910-13-P


