AD 2011-18-15
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Bombardier | Various | Airworthiness Directives; Bombardier, Inc. Model DHC-8-400 Series Airplanes |
| aircraft | Aviat | Various | Airworthiness Directives; Bombardier, Inc. Model DHC-8-400 Series Airplanes |
Unsafe Condition
Cracked barrel nuts at the front spar locations of the wing-to-fuselage attachment joints, and loose washers in the barrel nut assembly, could compromise the structural integrity of the wing-to-fuselage attachments.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Perform a torque check to determine if the bolt preload is correct. If the preload is correct, conduct a detailed inspection of each barrel nut and cradle for cracking, pitting, or corrosion. Repeat the torque check and inspection at intervals not exceeding 2,000 flight hours or 12 months, whichever occurs first.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
Within the specified compliance times, unless the actions have already been performed.
AI-generated summary from the source AD text. Verify against the official source before acting.
Affected Aircraft
Bombardier, Inc. Model DHC-8-400, -401, and -402 airplanes, certificated in any category, serial numbers 4001 and subsequent.
AI-generated summary from the source AD text. Verify against the official source before acting.
Federal Register Abstract
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:
Document Text
Show stored source text (verify against official source)
[Federal Register Volume 76, Number 169 (Wednesday, August 31, 2011)]
[Rules and Regulations]
[Pages 54093-54095]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2011-22013]
=======================================================================
-----------------------------------------------------------------------
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.
-----------------------------------------------------------------------
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:
<bullet> Federal eRulemaking Portal: Go to <a href="http://www.regulations.gov">http://www.regulations.gov</a>. Follow the instructions for submitting comments.
<bullet> Fax: (202) 493-2251.
<bullet> 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.
<bullet> 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 <a href="http://www.regulations.gov">http://www.regulations.gov</a>; 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 <a href="http://www.regulations.gov">http://www.regulations.gov</a>, 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 <a href="/cdn-cgi/l/email-protection#80f4e8e4aef1f3e5f2e9e5f3c0e1e5f2efaee2efede2e1f2e4e9e5f2aee3efed"><span class="__cf_email__" data-cfemail="0f7b676b217e7c6a7d666a7c4f6e6a7d60216d60626d6e7d6b666a7d216c6062">[email protected]</span></a>; Internet
<a href="http://www.bombardier.com">http://www.bombardier.com</a>.
(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: <a href="http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html">http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html</a>.
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
Source: Official FAA Source ↗
Retrieved: Apr 6, 2026
Rights: U.S. Government Public Domain
This site is not affiliated with or endorsed by the FAA. Always verify with official sources.