[Federal Register Volume 71, Number 110 (Thursday, June 8, 2006)]
[Proposed Rules]
[Pages 33270-33272]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E6-8898]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2006-24979; Directorate Identifier 2006-NM-014-AD]
RIN 2120-AA64


Airworthiness Directives; Bombardier Model DHC-8-100, DHC-8-200, 
DHC-8-300, and DHC-8-400 Series Airplanes

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

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD) 
for certain Bombardier Model DHC-8-100, DHC-8-200, DHC-8-300, and DHC-
8-400 series airplanes. This proposed AD would require inspecting the 
left and right control column torque tube assemblies to determine the 
type of rivets installed and replacing incorrect or indeterminate type 
rivets with the correct type rivets. This proposed AD results from a 
report that incorrect rivets having lower than required strength were 
installed on the control column torque tube during production. We are 
proposing this AD to prevent shear failure of control column torque 
tube rivets, which could cause unexpected decoupling of the elevators 
and large unwanted deflection of the free elevator, and consequent 
reduced controllability of the airplane.

DATES: We must receive comments on this proposed AD by July 10, 2006.

ADDRESSES: Use one of the following addresses to submit comments on 
this proposed AD.
     DOT Docket Web site: Go to http://dms.dot.gov and follow 
the instructions for sending your comments electronically.
     Government-wide rulemaking Web site: Go to http://www.regulations.gov and follow the instructions for sending your 
comments electronically.
     Mail: Docket Management Facility, U.S. Department of 
Transportation, 400 Seventh Street SW., Nassif Building, room PL-401, 
Washington, DC 20590.
     Fax: (202) 493-2251.
     Hand Delivery: Room PL-401 on the plaza level of the 
Nassif Building, 400 Seventh Street SW., Washington, DC, between 9 a.m. 
and 5 p.m., Monday through Friday, except Federal holidays.
    Contact Bombardier, Inc., Bombardier Regional Aircraft Division, 
123 Garratt Boulevard, Downsview, Ontario M3K 1Y5, Canada, for service 
information identified in this proposed AD.

FOR FURTHER INFORMATION CONTACT: Richard Beckwith, Aerospace Engineer, 
Airframe and Propulsion Branch, ANE-171, FAA, New York Aircraft 
Certification Office, 1600 Stewart Avenue, suite 410, Westbury, New 
York 11590; telephone (516) 228-7302; fax (516) 794-5531.

SUPPLEMENTARY INFORMATION:

Comments Invited

    We invite you to submit any relevant written data, views, or 
arguments regarding this proposed AD. Send your comments to an address 
listed in the ADDRESSES section. Include the docket number ``FAA-2006-
24979; Directorate Identifier 2006-NM-014-AD'' at the beginning of your 
comments. We specifically invite comments on the overall regulatory, 
economic, environmental, and energy aspects of the proposed AD. We will 
consider all comments received by the closing date and may amend the 
proposed AD in light of those comments.
    We will post all comments we receive, without change, to http://dms.dot.gov, including any personal information you provide. We will 
also post a report summarizing each substantive verbal contact with FAA 
personnel concerning this proposed AD. Using the search function of 
that Web site, anyone can find and read the comments in any of our 
dockets, including the name of the individual who sent the comment (or 
signed the comment on behalf of an association, business, labor union, 
etc.). You may review the DOT's complete Privacy Act Statement in the 
Federal Register published on April 11, 2000 (65 FR 19477-78), or you 
may visit http://dms.dot.gov.

Examining the Docket

    You may examine the AD docket on the Internet at http://dms.dot.gov, or in person at the Docket Management Facility office 
between 9 a.m. and 5 p.m., Monday through Friday, except Federal 
holidays. The Docket Management Facility office (telephone (800) 647-
5227) is located on the plaza level of the Nassif Building at the DOT 
street address stated in the ADDRESSES section. Comments will be 
available in the AD docket shortly after the Docket Management System 
receives them.

Discussion

    Transport Canada Civil Aviation (TCCA), which is the airworthiness 
authority for Canada, notified us that an unsafe condition may exist on 
certain Bombardier DHC-8-100, DHC-8-200, DHC-8-300, and DHC-8-400 
series

[[Page 33271]]

airplanes. TCCA advises that incorrect rivets having lower than 
required strength were installed on the control column torque tube 
during production. This condition, if not corrected, could result in 
shear failure of rivets in the control column torque tube during a jam 
of the pitch control circuit, when the pilot of the non-jammed pitch 
control tries to free the control by applying a large force. This type 
of rivet failure could cause unexpected decoupling of the elevators and 
large unwanted deflection of the free elevator, reducing the 
controllability of the airplane.

Relevant Service Information

    Bombardier has issued Service Bulletin 8-27-104, dated October 26, 
2004, for Model DHC-8-100, DHC-8-200, and DHC-8-300 series airplanes, 
and Service Bulletin 84-27-24, Revision A, dated September 28, 2005, 
for Model DHC-8-400 series airplanes. The service bulletins describe 
procedures for inspecting the left and right control column torque tube 
assemblies to determine the type of rivets installed and replacing 
incorrect (AD rivets) or indeterminate type rivets with the correct 
type rivets (DD or DN rivets). Accomplishing the actions specified in 
the service information is intended to adequately address the unsafe 
condition. TCCA mandated the service information and issued Canadian 
airworthiness directive CF-2005-39, dated November 21, 2005, to ensure 
the continued airworthiness of these airplanes in Canada.

FAA's Determination and Requirements of the Proposed AD

    These airplane models are manufactured in Canada and are type 
certificated for operation in the United States under the provisions of 
section 21.29 of the Federal Aviation Regulations (14 CFR 21.29) and 
the applicable bilateral airworthiness agreement. Pursuant to this 
bilateral airworthiness agreement, TCCA has kept the FAA informed of 
the situation described above. We have examined TCCA's findings, 
evaluated all pertinent information, and determined that we need to 
issue an AD for airplanes of this type design that are certificated for 
operation in the United States.
    Therefore, we are proposing this AD, which would require 
accomplishing the actions specified in the service information 
described previously, except as discussed under ``Differences Between 
the Proposed AD and the Service Information.''

Differences Between the Proposed AD and the Service Information

    Bombardier Service Bulletin 8-27-104 and Service Bulletin 84-27-24, 
Revision A, specify replacing incorrect or unidentifiable rivets with 
DN rivets. This proposed AD allows replacement with either DN or DD 
rivets. The service bulletins state no further action is necessary if 
DD rivets are found installed; this proposed AD does not require 
replacement of the rivets if either DN or DD rivets are found 
installed.

Clarification of Inspection Terminology

    The service bulletin refers only to an ``inspection'' for the type 
of rivets installed. We have determined that the procedures in the 
service bulletin should be described as a ``general visual 
inspection.'' Note 1 has been included in this AD to define this type 
of inspection.

Costs of Compliance

    The following table provides the estimated costs for U.S. operators 
to comply with this proposed AD.

                                                                     Estimated Costs
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                                                                                            Number of U.S.-
                 Action                     Work    Average labor   Parts      Cost per       registered                     Fleet cost
                                           hours    rate per hour              airplane        airplanes
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Inspection for rivet type...............        1             $80       $0             $80             162  $12,960.
Rivet replacement, if necessary.........       16              80       50           1,330             162  A maximum of $215,460.
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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 have 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 that the 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); 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 proposed AD and placed it in the AD docket. See the 
ADDRESSES section for a location to examine the regulatory evaluation.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, 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

    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]

    2. The Federal Aviation Administration (FAA) amends Sec.  39.13 by 
adding the following new airworthiness directive (AD):


[[Page 33272]]


Bombardier, Inc. (Formerly de Havilland, Inc.): Docket No. FAA-2006-
24979; Directorate Identifier 2006-NM-014-AD.

Comments Due Date

    (a) The FAA must receive comments on this AD action by July 10, 
2006.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to Bombardier airplanes identified in Table 
1 of this AD, certified in any category.

                         Table 1.--Applicability
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      Bombardier airplane model--        Affected serial numbers (S/N)--
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(1) DHC-8-102, DHC-8-103, DHC-8-106,     528 through 602 inclusive, and
 DHC-8-201, DHC-8-202, DHC-8-301, DHC-8-  606.
 311, DHC-8-314, and DHC-8-315
 airplanes.
(2) DHC-8-400, DHC-8-401, and DHC-8-402  4003, 4004, 4006, 4008 through
 airplanes.                               4080 inclusive, and 4082.
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Unsafe Condition

    (d) This AD results from a report that incorrect rivets having 
lower than required strength were installed on the control column 
torque tube during production. We are issuing this AD to prevent 
shear failure of rivets in the control column torque tube, which 
could cause unexpected decoupling of the elevators and large 
unwanted deflection of the free elevator, and consequent reduced 
controllability of the airplane.

Compliance

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

Inspection and Replacement of Incorrect Rivets

    (f) At the applicable times specified in Table 2 of this AD: Do 
the applicable actions in accordance with the applicable service 
bulletin identified in Table 2 of this AD. If all rivets identified 
during the inspection specified in paragraphs (f)(1)(i) or (f)(2)(i) 
of this AD are of the correct type (DD or DN rivets), no further 
action is required by this AD.

    Note 1: For the purposes of this AD, a general visual inspection 
is: ``A visual examination of an interior or exterior area, 
installation, or assembly to detect obvious damage, failure, or 
irregularity. This level of inspection is made from within touching 
distance unless otherwise specified. A mirror may be necessary to 
ensure visual access to all surfaces in the inspection area. This 
level of inspection is made under normally available lighting 
conditions such as daylight, hangar lighting, flashlight, or 
droplight and may require removal or opening of access panels or 
doors. Stands, ladders, or platforms may be required to gain 
proximity to the area being checked.''


                            Table 2.--Inspection and Replacement of Incorrect Rivets
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               Model--                    Compliance time--             Action--           In accordance with--
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(1) Model DHC-8-102, DHC-8-103, DHC-8- (i) Within 5,500 flight  Do a general visual      Part A of the
 106, DHC-8-201, DHC-8-202, DHC-8-      hours after the          inspection of the left   Accomplishment
 301, DHC-8-311, DHC-8-314, and DHC-8-  effective date of this   and right control        Instructions of
 315 airplanes.                         AD.                      column torque tube       Bombardier Service
                                                                 assemblies to            Bulletin 8-27-104,
                                                                 determine the types of   dated October 26,
                                                                 rivets installed.        2004.
                                       (ii) Before further      Replace any rivet of an  Part B of the
                                        flight.                  incorrect type (AD       Accomplishment
                                                                 rivets) or of a type     Instructions of
                                                                 that cannot be           Bombardier Service
                                                                 determined with          Bulletin 8-27-104,
                                                                 correct type rivets      dated October 26,
                                                                 (DD or DN rivets).       2004.
(2) Model DHC-8-400, DHC-8-401, and    (i) Within 5,500 flight  Do a general visual      Part A of the
 DHC-8-402 airplanes.                   hours after the          inspection of the left   Accomplishment
                                        effective date of the    and right control        Instructions of
                                        AD.                      column torque tube       Bombardier Service
                                                                 assemblies to            Bulletin 84-27-24,
                                                                 determine the type of    Revision A, dated
                                                                 rivets installed.        September 28, 2005.
                                       (ii) Before further      Replace any rivet of an  Part B of the
                                        flight.                  incorrect type (AD       Accomplishment
                                                                 rivets) or of a type     Instructions of
                                                                 that cannot be           Bombardier Service
                                                                 determined with          Bulletin 84-27-24,
                                                                 correct type rivets      Revision A, dated
                                                                 (DD or DN rivets).       September 28, 2005.
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Actions Accomplished According to Previous Issue of Service Bulletin

    (g) For Model DHC-8-400, DHC-8-401 and DHC-8-402 airplanes: 
Inspections and rivet replacements done before the effective date of 
this AD according to Bombardier Service Bulletin 84-27-24, dated 
September 20, 2004, are considered acceptable for compliance with 
the corresponding actions specified in this AD.

Alternative Methods of Compliance (AMOCs)

    (h)(1) The Manager, New York Aircraft Certification Office 
(ACO), FAA, has the authority to approve AMOCs for this AD, if 
requested in accordance with the procedures found in 14 CFR 39.19.
    (2) Before using any AMOC approved in accordance with Sec.  
39.19 on any airplane to which the AMOC applies, notify the 
appropriate principal inspector in the FAA Flight Standards 
Certificate Holding District Office.

Related Information

    (i) Canadian airworthiness directive CF-2005-39, dated November 
21, 2005, also addresses the subject of this AD.

    Issued in Renton, Washington, on May 31, 2006.
Jeffrey E. Duven,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. E6-8898 Filed 6-7-06; 8:45 am]
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