[Federal Register Volume 70, Number 60 (Wednesday, March 30, 2005)]
[Proposed Rules]
[Pages 16170-16173]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 05-6248]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2005-20727; Directorate Identifier 2004-NM-148-AD]
RIN 2120-AA64


Airworthiness Directives; Bombardier Model DHC-8-400, -401, and -
402 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-8-400, -401, and -402 airplanes. This 
proposed AD would require repetitive inspections to detect 
discrepancies of the attachment fittings of the outboard flap front 
spar at flap track Number 4 and Number 5 locations, and corrective 
actions if necessary. This proposed AD also would require eventual 
replacement of the attachment fittings as terminating action for the 
repetitive inspections. This proposed AD is prompted by the discovery 
of several airplanes that have loose flap front spar attachment 
fittings at flap track Number 4 and Number 5 locations. We are 
proposing this AD to prevent the attachment fittings from becoming 
detached, and consequent loss of control of the airplane.

DATES: We must receive comments on this proposed AD by April 29, 2005.

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.
     By 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.
    For service information identified in this proposed AD, contact 
Bombardier, Inc., Bombardier Regional Aircraft Division, 123 Garratt 
Boulevard, Downsview, Ontario M3K 1Y5, Canada.
    You can examine the contents of this AD docket on the Internet at 
http://dms.dot.gov, or at the Docket Management Facility, U.S. 
Department of Transportation, 400 Seventh Street, SW., room PL-401, on 
the plaza level of the Nassif Building, Washington, DC. This docket 
number is FAA-2005-20727; the directorate identifier for this docket is 
2004-NM-148-AD.

FOR FURTHER INFORMATION CONTACT: David A. Lawson, 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) 228-7327; fax (516) 794-5531.

SUPPLEMENTARY INFORMATION:

Comments Invited

    We invite you to submit any written relevant data, views, or 
arguments regarding this proposed AD. Send your comments to an address 
listed under ADDRESSES. Include ``Docket No. FAA-2005-20727; 
Directorate Identifier 2004-NM-148-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 submitted 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 our 
docket Web site, anyone can find and read the comments in any of our 
dockets, including the name of the individual

[[Page 16171]]

who sent the comment (or signed the comment on behalf of an 
association, business, labor union, etc.). You can review the DOT's 
complete Privacy Act Statement in the Federal Register published on 
April 11, 2000 (65 FR 19477-78), or you can visit http://dms.dot.gov.

Examining the Docket

    You can 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 DMS 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 Model DHC-8-400, -401, and -402 airplanes. TCCA 
advises that, during inspections and flap modifications, several 
airplanes were found to have loose flap front spar attachment fittings 
at flap track Number 4 and Number 5 locations. When the fittings were 
removed, it was discovered that the fittings and the flap front spar 
web to which they were mounted had elongated attachment holes. In 
addition, the lugs of certain attachment fittings were found to be 
chafing with flap track Number 4. Loose fittings can damage the front 
spar web and result in the fitting becoming detached, and consequent 
loss of control of the airplane.

Relevant Service Information

    Bombardier has issued Alert Service Bulletin (ASB) A84-57-06, 
Revision ``B'' dated March 9, 2004. That ASB describes procedures for 
repetitive visual inspections to detect discrepancies of the attachment 
fittings of the outboard flap front spar, track Number 4 and Number 5. 
For flap track Number 4, discrepancies include damage caused by fouling 
with a flap track, loose fittings, and nonconforming blind fasteners. 
For flap track Number 5, discrepancies include loose fittings, a gap 
between any fitting and the front spar web that exceeds 0.002 inches, 
and nonconforming blind fasteners.
    The alert service bulletin refers to the following Bombardier 
Repair Drawings (RD) as additional sources of service information for 
doing corrective actions/temporary repairs/terminating action:
     8/4-57-226, Issue 2, dated November 11, 2003.
     8/4-57-228, Issue 1, dated October 27, 2003.
     8/4-57-220, Issue 2, dated October 15, 2003.
    The temporary repair procedures involve opening up the holes on 
original centers in both the brackets and front spar to allow for 
installation of oversize fasteners, inspecting the areas around the 
holes for cracks and/or other signs of damage, installing oversize Hi-
Lite Pins with corresponding collars in lieu of original standard MS-
type blind bolts at all repair locations, and applying corrosion 
inhibiting compounds as required.
    The alert service bulletin also refers to Modification Summary 
Package IS4Q5750002, Revision D, released December 1, 2003, as an 
additional source of service information for doing a permanent repair. 
The permanent repair involves replacing four blind bolts with certain 
oversize fasteners having certain collars, and installing a repair 
patch and solid shim. Accomplishing the permanent repair eliminates the 
need for the repetitive inspections described previously.
    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-
2004-11, dated June 28, 2004, 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 
Sec.  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 AD action is 
necessary for products of this type design that are certificated for 
operation in the United States.
    Therefore, we are proposing this AD, which would require repetitive 
inspections to detect discrepancies of the attachment fittings of the 
outboard flap front spar at flap track Number 4 and Number 5 locations, 
and corrective actions if necessary. This proposed AD also would 
require eventual replacement of the attachment fittings as terminating 
action for the repetitive inspections. The proposed AD would require 
you to use the service information described previously to perform 
these actions, except as discussed below.

Differences Between Proposed Rule and Alert Service Bulletin

    The alert service bulletin specifies that you may contact the 
manufacturer for instructions on how to repair certain conditions, but 
this proposed AD would require you to repair those conditions using a 
method that we or TCAA (or its delegated agent) approve. In light of 
the type of repair that would be required to address the unsafe 
condition, and consistent with existing bilateral airworthiness 
agreements, we have determined that, for this proposed AD, a repair we 
or TCAA approve would be acceptable for compliance with this proposed 
AD Operators should note that, although the Accomplishment Instructions 
of the alert service bulletin describe procedures for submitting 
inspection results to the manufacturer, this proposed AD would not 
require that action.

Costs of Compliance

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

                                                 Estimated Costs
----------------------------------------------------------------------------------------------------------------
                                                                                         Number of
                                                Average                    Cost per        U.S.-
            Action              Work hours    labor rate       Parts       airplane     registered    Fleet cost
                                               per hour                                  airplanes
----------------------------------------------------------------------------------------------------------------
Inspections (per inspection               1           $65            $0           $65            22   \1\ $1,430
 cycle)......................
Permanent repair.............            20            65             0         1,300            22      28,600
----------------------------------------------------------------------------------------------------------------
\1\ Per inspection cycle.


[[Page 16172]]

Authority for This Rulemaking

    The FAA's authority to issue rules regarding aviation safety is 
found in Title 49 of the United States Code. 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.
    This rulemaking is promulgated 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. 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 FAA amends Sec.  39.13 by adding the following new 
airworthiness directive (AD):

Bombardier, Inc. (Formerly de Havilland, Inc.): Docket No. FAA-2005-
20727; Directorate Identifier 2004-NM-148-AD.

Comments Due Date

    (a) The Federal Aviation Administration must receive comments on 
this AD action by April 29, 2005.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to Bombardier Model DHC-8-400, -401 and -402 
airplanes, certificated in any category; serial numbers 4001 and 
4003 through 4093 inclusive.

Unsafe Condition

    (d) This AD is prompted by the discovery of several airplanes 
that have loose flap front spar attachment fittings at flap track 
Number 4 and Number 5 locations. We are issuing this AD to prevent 
the attachment fittings from becoming detached, and consequent loss 
of control 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.

Service Bulletin Reference

    (f) The term ``service bulletin,'' as used in this AD, means the 
Accomplishment Instructions of Bombardier Alert Service Bulletin 
A84-57-06, Revision `B,' dated March 9, 2004.

Inspections of Flap Track Number 4

    (g) For any front spar attachment fitting at the flap track 
Number 4 location on which Bombardier Repair Drawing (RD) 8/4-57-
228, Issue 1, dated October 27, 2003; in combination with RD 8/4-57-
173, Issue 2, dated June 17, 2003, or RD 8/4-57-180, Issue 2, dated 
September 22, 2003, or RD 8/4-57-226, Issue 2, dated November 11, 
2003; has not been done prior to the effective date of this AD: 
Within 400 flight hours after the effective date of this AD, do a 
general visual inspection to detect discrepancies of the front spar 
attachment fittings at the flap track Number 4 location on both the 
left and right outboard flap assemblies. Do the inspection in 
accordance with the service bulletin. Repeat the inspection 
thereafter at intervals not to exceed 800 flight hours until the 
terminating action required by paragraph (j) of this AD is done.

    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.''

Inspections of Flap Track Number 5

    (h) Within 400 flight hours after the effective date of this AD, 
do a general visual inspection to detect discrepancies of the front 
spar attachment fittings at the flap track Number 5 location on both 
the left and right outboard flap assemblies. Do the inspection in 
accordance with the service bulletin. Repeat the inspection 
thereafter at intervals not to exceed 800 flight hours until the 
terminating action required by paragraph (j) of this AD is done.

Corrective Actions

    (i) If any discrepancy is found during any inspection required 
by paragraph (g) or (h) of this AD, before further flight, repair 
the discrepancy in accordance with the service bulletin. Where the 
service bulletin says to contact the manufacturer for repair 
instructions, before further flight, repair in accordance with a 
method approved by either the Manager, New York Aircraft 
Certification Office (ACO), FAA; or Transport Canada Civil Aviation 
(TCCA) (or its delegated agent).

Terminating Action--Permanent Repair

    (j) Within 4,000 flight hours after the effective date of this 
AD, do the permanent repair required by paragraphs (j)(1) and (j)(2) 
of this AD. Completing the permanent repair constitutes terminating 
action for the requirements of this AD.
    (1) Modify the attachment of the front fittings of flap track 
Number 4 on both the left and right outboard flap assemblies in 
accordance with Bombardier Repair Drawing (RD) 8/4-57-226, Issue 2, 
dated November 11, 2003. Fittings on which the repairs specified in 
RD 8/4-57-173, Issue 2, dated June 17, 2003, or RD 8/14-57-180, 
Issue 2, dated September 22, 2003, have been done do not require 
that RD 8/4-57-226 be incorporated at those fitting locations.
    (2) Modify the attachment of the front fittings of flap track 
Number 5 on both the left and right outboard flap assemblies in 
accordance with Bombardier Modification Summary Package IS4Q5750002, 
Revision D, dated December 1, 2003.

Inspections Accomplished According to Previous Issue of Service 
Bulletin

    (k) Inspections accomplished before the effective date of this 
AD in accordance with Bombardier Alert Service Bulletin A84-57-06, 
dated November 5, 2003; or Revision `A,' dated December 16, 2003; 
are acceptable for compliance with the inspections required by this 
AD.

No Reporting Requirement

    (l) Although the service bulletin specifies to submit certain 
information to the manufacturer, this AD does not include that 
requirement.

[[Page 16173]]

Alternative Methods of Compliance (AMOCs)

    (m) The Manager, New York Aircraft Certification Office, FAA, 
has the authority to approve AMOCs for this AD, if requested in 
accordance with the procedures found in 14 CFR 39.19.

Related Information

    (n) Canadian airworthiness directive CF-2004-11, dated June 28, 
2004, also addresses the subject of this AD.

    Issued in Renton, Washington, on March 18, 2005.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 05-6248 Filed 3-29-05; 8:45 am]
BILLING CODE 4910-13-P