[Federal Register Volume 71, Number 69 (Tuesday, April 11, 2006)]
[Proposed Rules]
[Pages 18239-18242]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 06-3439]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2006-24365; Directorate Identifier 2006-NM-022-AD]
RIN 2120-AA64


Airworthiness Directives; Bombardier Model 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-8-400 series airplanes. This proposed 
AD would require repetitive inspections for cracks of the first fuel 
access panel outboard of the nacelle on the left- and right-hand wings, 
and related investigative/corrective actions if necessary. This 
proposed AD also would require eventual replacement of each access 
panel with a new access panel having a new part number. The replacement 
would terminate the repetitive inspection requirements. This proposed 
AD results from reports of cracks of the fuel access panels. We are 
proposing this AD to detect and correct cracked fuel access panels, 
which could lead to arcing and ignition of fuel vapor during a 
lightning strike, and result in fuel tank explosions and consequent 
loss of the airplane.

DATES: We must receive comments on this proposed AD by May 11, 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.

[[Page 18240]]


FOR FURTHER INFORMATION CONTACT: George Duckett, Aerospace Engineer, 
Airframe and Propulsion Branch, ANE-171, New York Aircraft 
Certification Office, FAA, 1600 Stewart Avenue, suite 410, Westbury, 
New York 11590; telephone (516) 228-7325; 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-
24365; Directorate Identifier 2006-NM-022-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 Model DHC-8-400 series airplanes. TCCA advises that 
there have been a number of reports of cracks of the first fuel access 
panel outboard of the nacelle. Operators found the cracks, some up to 4 
inches long, during routine checks. Investigation showed that certain 
fuel access panels were manufactured with seal grooves that have sharp 
corner radii. This condition, if not corrected, could lead to arcing 
and ignition of fuel vapor during a lightning strike, and result in 
fuel tank explosions and consequent loss of the airplane.

Relevant Service Information

    Bombardier has issued Service Bulletin 84-57-13, dated August 17, 
2005. The service bulletin describes procedures for an ultrasonic 
inspection for cracks of the first fuel access panel outboard of the 
nacelle on the left- and right-hand wings, and doing the following 
related investigative and corrective actions, as applicable, before 
further flight after the inspection:
    1. If there is no crack, the service bulletin describes procedures 
for an ultrasonic inspection to see if there is a radius in the seal 
groove, and the service bulletin describes procedures for one of the 
following actions, as applicable:
     If there is a radius in all locations inspected, doing a 
detailed visual inspection for cracks of the external surface of the 
panel, and repeating the detailed visual inspection thereafter at 
intervals not to exceed 1,200 flight hours.
     If a radius is not present in all locations, repeating the 
ultrasonic inspection for cracks thereafter at intervals not to exceed 
1,200 flight hours.
     If any crack is found during any inspection, replacing the 
panel in accordance with paragraph 2 or 3 below, as applicable.
    2. If there is a crack or cracks, and all cracks are inside certain 
limits specified in the service bulletin, the service bulletin 
describes procedures for doing one of the following actions: Doing a 
temporary repair of the crack, and, within 1,000 flight hours after the 
temporary repair, replacing the cracked access panel with a new panel 
having one of two new part numbers (P/N) as identified in the service 
bulletin; or replacing the cracked panel with a new panel having the 
same P/N that has had an ultrasonic inspection to determine that it has 
no crack, and doing the ultrasonic inspection and applicable repetitive 
inspection as described in paragraph 1 above.
    3. If there is a crack or cracks, and any crack is outside certain 
limits specified in the service bulletin, the service bulletin 
describes procedures for installing a new access panel having a new P/N 
before further flight.
    The service bulletin states that replacing the fuel access panel 
with a new panel that has a new P/N is terminating action for the 
repetitive inspections for the replaced fuel access panel; replacing 
both fuel access panels terminates all repetitive inspections specified 
in the service bulletin. The service bulletin specifies that both 
access panels be replaced within 6,000 flight hours after doing the 
initial ultrasonic inspection.
    The service bulletin also describes procedures for reporting the 
results of the ultrasonic inspections to the manufacturer.
    Accomplishing the actions specified in the service information is 
intended to adequately address the unsafe condition.
    The service bulletin refers to Bombardier Repair Drawing (RD) 8/4-
57-451, dated February 2005, as an additional source of service 
information for doing the temporary repair.
    TCCA mandated the service information and issued Canadian 
airworthiness directive CF-2005-37, dated October 11, 2005, to ensure 
the continued airworthiness of these airplanes in Canada.

FAA's Determination and Requirements of the Proposed AD

    This airplane model is manufactured in Canada and is 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.

Clarification of Inspection Terminology

    In this proposed AD, the ``detailed visual inspection'' specified 
in the Canadian airworthiness directive and the service bulletin is 
referred to as a ``detailed inspection'' in the proposed AD. We have 
included the definition for a detailed inspection in a note in the 
proposed AD.

[[Page 18241]]

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
                                                          Average                                    Cost per      U.S.-
                  Action                    Work hours   labor rate              Parts               airplane    registered           Fleet cost
                                                          per hour                                               airplanes
--------------------------------------------------------------------------------------------------------------------------------------------------------
Inspection, per inspection cycle.........            1          $80  None........................          $80            5  $400, per inspection cycle.
Replacement (for both wings).............            4           80  $8,200......................        8,520            5  42,600.
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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):

Bombardier, Inc. (Formerly de Havilland, Inc.): Docket No. FAA-2006-
24365; Directorate Identifier 2006-NM-022-AD.

Comments Due Date

    (a) The FAA must receive comments on this AD action by May 11, 
2006.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to Bombardier Model DHC-8-400, DHC-8-401, 
and DHC-8-402 airplanes, certificated in any category; serial 
numbers 4001, and 4003 through 4106 inclusive.

Unsafe Condition

    (d) This AD results from reports of cracks of the fuel access 
panels. We are issuing this AD to detect and correct cracked fuel 
access panels, which could lead to arcing and ignition of fuel vapor 
during a lightning strike, and result in fuel tank explosions and 
consequent loss 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 Related Investigative and Corrective Actions

    (f) Within 400 flight hours after the effective date of this AD: 
Do an ultrasonic inspection for cracks of the first fuel access 
panel, part number (P/N) 85714230-001, outboard of the nacelle, on 
the left- and right-hand wings, by doing all of the actions 
specified in the Accomplishment Instructions of Bombardier Service 
Bulletin 84-57-13, dated August 17, 2005, except as provided by 
paragraph (i) of this AD. Do all applicable related investigative 
and corrective actions before further flight in accordance with the 
service bulletin. Repeat the applicable inspection, including the 
detailed inspection, thereafter at intervals not to exceed 1,200 
flight hours.

    Note 1: Bombardier Service Bulletin 84-57-13, refers to 
Bombardier Repair Drawing (RD) 8/4-57-451, dated February 2005, as 
an additional source of service information for doing certain 
corrective actions.


    Note 2: For the purposes of this AD, a detailed inspection is: 
``An intensive examination of a specific item, installation, or 
assembly to detect damage, failure, or irregularity. Available 
lighting is normally supplemented with a direct source of good 
lighting at an intensity deemed appropriate. Inspection aids such as 
mirror, magnifying lenses, etc., may be necessary. Surface cleaning 
and elaborate procedures may be required.''

Terminating Action--Replacement

    (g) Within 6,000 flight hours after the initial inspection done 
in accordance with paragraph (f) of this AD: Replace any access 
panel P/N 85714230-001, with a new panel P/N 85714230-003 or P/N 
85714230-005. Do the replacement in accordance with the 
Accomplishment Instructions of Bombardier Service Bulletin 84-57-13, 
dated August 17, 2005. Replacing one access panel terminates the 
repetitive inspection requirements of this AD for that panel only. 
Replacing both access panels terminates all repetitive inspection 
requirements of this AD.

[[Page 18242]]

Parts Installation

    (h) As of the effective date of this AD, no person may install a 
fuel access panel, P/N 85714230-001, on any airplane unless the 
panel has been inspected, and all applicable related investigative 
and corrective actions have been accomplished, in accordance with 
paragraph (f) of this AD.

No Report Required

    (i) Although the Accomplishment Instructions of Bombardier 
Service Bulletin 84-57-13, dated August 17, 2005, specify to report 
certain information to the manufacturer, this AD does not include 
that requirement.

Alternative Methods of Compliance (AMOCs)

    (j)(1) 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.
    (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

    (k) Canadian airworthiness directive CF-2005-37, dated October 
11, 2005, also addresses the subject of this AD.

    Issued in Renton, Washington, on March 31, 2006.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 06-3439 Filed 4-10-06; 8:45 am]
BILLING CODE 4910-13-P