Document ID: FAA-2007-29235-0001
Agency: faa
Document Type: Rule
Title: Airworthiness Directives; Bombardier Model DHC-8-400 Series Airplanes
Posted Date: 2007-10-30T04:00Z

[Federal Register: October 30, 2007 (Volume 72, Number 209)]
[Rules and Regulations]               
[Page 61288-61291]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr30oc07-3]                         

=======================================================================
-----------------------------------------------------------------------

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2007-29235; Directorate Identifier 2007-NM-232-AD; 
Amendment 39-15245; AD 2007-22-09]
RIN 2120-AA64

 
Airworthiness Directives; Bombardier Model DHC-8-400 Series 
Airplanes

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

[[Page 61289]]

ACTION: Final rule; request for comments.

-----------------------------------------------------------------------

SUMMARY: The FAA is adopting a new airworthiness directive (AD) for 
certain Bombardier Model DHC-8-400 series airplanes. This AD requires 
an inspection to detect discrepancies of the main landing gear (MLG) 
system, an inspection of the jam nut of the retract actuator of the 
MLGs to ensure the wire lock is in place and the nut is secured, an 
inspection of the retract actuator for any signs of corrosion or wear, 
and applicable related investigative and corrective actions if 
necessary. This AD also requires submitting an inspection report to 
Bombardier. This AD results from two reports of collapse of MLGs within 
a few days of each other. We are issuing this AD to detect and correct 
potential failure of major components of the MLG assembly and 
attachments, which could result in the possible collapse of a MLG and 
consequent damage to the airplane and injury to people or damage to 
property on the ground.

DATES: This AD becomes effective November 14, 2007.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in the AD as of November 14, 
2007.
    We must receive comments on this AD by November 29, 2007.

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 20590, between 9 a.m. and 5 p.m., 
Monday through Friday, except Federal holidays.
    For service information identified in this AD, contact Bombardier, 
Inc., Bombardier Regional Aircraft Division, 123 Garratt Boulevard, 
Downsview, Ontario M3K 1Y5, Canada.

Examining the AD Docket

    You may examine the AD docket on the Internet at http://www.regulations.gov
; or in person at the Docket Management Facility 

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 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: Jon Hjelm, Aerospace Engineer, 
Airframe and Propulsion Branch, ANE-171, FAA, New York ACO, 1600 
Stewart Avenue, Suite 410, Westbury, New York 11590; telephone (516) 
228-7323; fax (516) 794-5531.

SUPPLEMENTARY INFORMATION:

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, 
on September 9, 2007, a main landing gear (MLG) collapsed on a 
Bombardier Model DHC-8-400 series airplane during landing, and that two 
days later on September 11, 2007, another MLG collapsed on a Bombardier 
Model DHC-8-400 series airplane during landing. It has been determined 
that the root cause of both MLG failures was a failure of the retract 
actuator during gear extension. This failure allowed the gear to fall 
unrestricted with sufficient force to break the over-center drag strut. 
The reason for the component failure was determined to be caused by 
internal corrosion of the threads at the rod end of the retract 
actuator. Potential failure of the major components of the MLG assembly 
and attachments, if not corrected, could result in the possible 
collapse of the MLG and consequent damage to the airplane and injury to 
people or damage to property on the ground.

Relevant Service Information

    Bombardier has issued DHC-8 Series 400 Maintenance Requirements 
Manual (PSM 1-84-7), Part 1 (Maintenance Review Board Report), tasks 
Z700-03E (left hand) and Z700-04E (right hand). These tasks describe 
procedures for doing a general visual inspection to detect 
discrepancies of the left- and right-hand MLG systems.
    Bombardier also has issued Repair Drawing (RD) 8/4-32-059, Issue 4, 
dated September 14, 2007. Bombardier RD 8/4-32-059 refers to Goodrich 
Service Concession Request SCR 086-07, Revision C, dated September 14, 
2007, as an additional source of service information for accomplishing 
the procedures in the RD. These documents describe procedures for doing 
an inspection of the retract actuator for any signs of corrosion or 
wear, and doing applicable corrective actions if necessary, which 
include adjusting the retracted length of the rod end, torquing the jam 
nut, installing a wire lock, and lubricating the piston if necessary. 
These documents also describe procedures for doing a detailed 
inspection of affected parts for any signs of corrosion or wear, and 
doing applicable related investigative and corrective actions if 
necessary. The related investigative actions involve visually 
inspecting the threads of the piston pin and the thread relief area for 
evidence of corrosion. The corrective actions include, but are not 
limited to, removing the wire lock, backing off the jam nut and rod end 
out of the piston, replacing any discrepant retract actuator or 
actuator assembly, coating certain parts with a corrosion inhibitor 
compound, and reworking any corroded threaded area of the piston.
    TCCA mandated the RD and Bombardier DHC-8 Series 400 Maintenance 
Requirements Manual (PSM 1-84-7), Part 1 (Maintenance Review Board 
Report), tasks Z700-03E (left hand) and Z700-04E (right hand), and 
issued Canadian airworthiness directive CF-2007-20, dated September 12, 
2007, to ensure the continued airworthiness of these airplanes in 
Canada.

FAA's Determination and Requirements of this AD

    These airplanes 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 products of this type design that are certificated for 
operation in the United States.
    Therefore, we are issuing this AD to detect and correct potential 
failure of major components of the MLG assembly and attachments, which 
could result in the possible collapse of a MLG and consequent damage to 
the airplane and injury to people or damage to property on the ground. 
This AD requires doing a general visual inspection to detect 
discrepancies of the left- and right-hand MLG systems, doing a general 
visual inspection of the jam nut of the retract actuator of the left- 
and right-hand MLGs to ensure the wire lock is in place and the nut is 
secured, doing a detailed

[[Page 61290]]

inspection of the retract actuator for any signs of corrosion or wear, 
and doing applicable related investigative and corrective actions if 
necessary. This AD also requires reporting the inspection results to 
Bombardier.

Interim Action

    We consider this AD interim action. The inspection reports that are 
required by this AD will enable the manufacturer to obtain better 
insight into the nature, cause, and extent of the problem, and 
eventually to develop final action to address the unsafe condition. 
Once final action has been identified, we might consider further 
rulemaking.

FAA's Determination of the Effective Date

    An unsafe condition exists that requires the immediate adoption of 
this AD; therefore, providing notice and opportunity for public comment 
before the AD is issued is impracticable, and good cause exists to make 
this AD effective in less than 30 days.

Comments Invited

    This AD is a final rule that involves requirements affecting flight 
safety, and we did not provide you with notice and an opportunity to 
provide your comments before it becomes effective. However, we invite 
you to send any written data, views, or arguments about this AD. Send 
your comments to an address listed under the ADDRESSES section. Include 
``Docket No. FAA-2007-29235; Directorate Identifier 2007-NM-232-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 have 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 that the 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 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, Incorporation by 
reference, Safety.

Adoption of the Amendment

0
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 Federal Aviation Administration (FAA) amends Sec.  39.13 by 
adding the following new airworthiness directive (AD):

2007-22-09 Bombardier, Inc. (Formerly de Havilland, Inc.): Amendment 
39-15245. Docket No. FAA-2007-29235; Directorate Identifier 2007-NM-
232-AD.

Effective Date

    (a) This AD becomes effective November 14, 2007.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to Bombardier Model DHC-8-400 series 
airplanes, certificated in any category; serial number 003 and 
subsequent.

Unsafe Condition

    (d) This AD results from two reports of collapse of the main 
landing gear (MLG) within a few days of each other. We are issuing 
this AD to detect and correct potential failure of major components 
of the MLG assembly and attachments, which could result in the 
possible collapse of the MLG and consequent damage to the airplane 
and injury to people or damage to property on the ground.

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.

General Visual Inspection of MLG System and Corrective Actions

    (f) Before further flight, do a general visual inspection to 
detect discrepancies of the left- and right-hand MLG system and do 
all applicable corrective actions, in accordance with a method 
approved by the Manager, New York Aircraft Certification Office 
(ACO), FAA; or the Transport Canada Civil Aviation (TCCA) (or its 
delegated agent). Bombardier DHC-8 Series 400 Maintenance 
Requirements Manual (PSM 1-84-7), Part 1 (Maintenance Review Board 
Report), tasks Z700-03E (left hand) and Z700-04E (right hand), is 
one approved method for accomplishing the general visual inspection.

    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.''

General Visual Inspection of the Jam Nut of the Retract Actuator of the 
MLG and Corrective Actions

    (g) Before further flight, do a general visual inspection of the 
jam nut of the retract actuator of the left- and right-hand MLG to 
ensure the wire lock is in place and the nut is secured. If the wire 
lock is not in place or if the jam nut is not secured, before 
further flight, adjust the retracted length of the rod end, torque 
the jam nut, install a wire lock, and lubricate the piston, as 
applicable, in

[[Page 61291]]

accordance with Bombardier Repair Drawing (RD) 8/4-32-059, Issue 4, 
dated September 14, 2007.

    Note 2: Bombardier Repair Drawing 8/4-32-059 refers to Goodrich 
Service Concession Request SCR 086-07, Revision C, dated September 
14, 2007 (specifically item 14), as an additional source of service 
information for adjusting the retracted length of the rod end, 
torquing the jam nut, installing a wire lock, and lubricating the 
piston if necessary, as required by paragraph (g) of this AD.

Detailed Inspection of the Retract Actuator of the MLG

    (h) For airplanes on which the retract actuator of the MLG, part 
number 46550-7 or 46550-9, has accumulated 8,000 or more total 
landings or has been in-service 4 or more years since new as of the 
effective date of this AD: Before further flight, do a detailed 
inspection of affected parts for any signs of corrosion or wear, and 
applicable related investigative and corrective actions, in 
accordance with Bombardier Repair Drawing 8/4-32-059, Issue 4, dated 
September 14, 2007.

    Note 3: 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.''

    (i) For airplanes other than those identified in paragraph (h) 
of this AD with a retract actuator of the MLG, part number 46550-7 
or 46550-9: Do a detailed inspection of affected parts for any signs 
of corrosion or wear, and applicable related investigative and 
corrective actions, in accordance with Bombardier RD 8/4-32-059, 
Issue 4, dated September 14, 2007; at the later of the times 
specified in paragraphs (i)(1) and (i)(2) of this AD.
    (1) Before the accumulation of 4,000 total landings or 2 years 
since new, whichever occurs first.
    (2) Within 500 flight hours after the effective date of this AD.

    Note 4: Bombardier Repair Drawing 8/4-32-059 refers to Goodrich 
Service Concession Request SCR 086-07, Revision C, dated September 
14, 2007, as an additional source of service information for 
accomplishing the applicable related investigative and corrective 
actions required by paragraphs (h) and (i) of this AD.

Actions Done in Accordance with Previous Issues of Service Information

    (j) Actions done before the effective date of this AD in 
accordance with Bombardier Repair Drawing 8/4-32-059, Issue 1, dated 
September 12, 2007; Issue 2, dated September 13, 2007; or Issue 3, 
dated September 13, 2007; are acceptable for compliance with the 
corresponding actions specified in paragraphs (g) through (i) of 
this AD.

Reporting Requirement

    (k) Submit a report of any discrepancy found during any 
inspection required by this AD to the Bombardier Technical Help 
Desk, at the applicable time specified in paragraph (k)(1) or (k)(2) 
of this AD; telephone (416) 375-4000; fax (416) 375-4539; e-mail: 
thd.qseries@aero.bombardier.com. Under the provisions of the 

Paperwork Reduction Act (44 U.S.C. 3501 et seq.), the Office of 
Management and Budget (OMB) has approved the information collection 
requirements contained in this AD and has assigned OMB Control 
Number 2120-0056.
    (1) If the inspection was done after the effective date of this 
AD: Submit the report within 7 days after the inspection.
    (2) If the inspection was done before the effective date of this 
AD: Submit the report within 7 days after the effective date of this 
AD.

Special Flight Permit

    (l) Special flight permits may be issued in accordance with 
sections 21.197 and 21.199 of the Federal Aviation Regulations (14 
CFR 21.197 and 21.199) to operate the airplane to a location where 
the airplane can be inspected (if the operator elects to do so), 
provided that the procedures and limitations in paragraphs (l)(1) 
and (l)(2) of this AD are adhered to.
    (1) Flight Crew Limitations and Procedures:
    (i) Ferry flight with gear extended and pinned.
    (ii) Landing to be conducted at a minimum descent rate.
    (iii) Minimize braking on landing.
    (iv) Flight to be conducted in accordance with Section 4.8 of 
the Aircraft Operating Manual (AOM).
    (v) Essential crew only on board.
    (vi) Flight in known or forecast icing condition is prohibited.
    (2) Maintenance Procedures:
    (i) Do the general visual inspection required by paragraph (g) 
of this AD.
    (ii) Do the general visual inspections of the stabilizer stay 
and the hinge points of the MLG for general condition and security, 
in accordance with Bombardier Q400 All Operator Message 236A, dated 
September 11, 2007.
    (iii) If no discrepancy is detected during the inspections 
required by paragraph (l)(2)(i) and (l)(2)(ii) of this AD, before 
further flight, insert the ground lock pins and a wire lock of the 
MLG in place.
    (iv) Ensure the ground lock of the nose landing gear is engaged.

Alternative Methods of Compliance (AMOCs)

    (m)(1) The Manager, New York ACO, has the authority to approve 
AMOCs for this AD, if requested in accordance with the procedures 
found in 14 CFR 39.19.
    (2) To request a different method of compliance or a different 
compliance time for this AD, follow the procedures in 14 CFR 39.19. 
Before using any approved AMOC on any airplane to which the AMOC 
applies, notify your appropriate principal inspector (PI) in the FAA 
Flight Standards District Office (FSDO), or lacking a PI, your local 
FSDO.

Related Information

    (n) Canadian airworthiness directive CF-2007-20, dated September 
12, 2007, also addresses the subject of this AD.

Material Incorporated by Reference

    (o) You must use Bombardier Repair Drawing 8/4-32-059, Issue 4, 
dated September 14, 2007, to perform the actions that are required 
by this AD, unless the AD specifies otherwise. The Director of the 
Federal Register approved the incorporation by reference of this 
document in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. 
Contact Bombardier, Inc., Bombardier Regional Aircraft Division, 123 
Garratt Boulevard, Downsview, Ontario M3K 1Y5, Canada, for a copy of 
this service information. You may review copies at the FAA, 
Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, 
Washington; or 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/cfr/ibr-locations.html
.

    Issued in Renton, Washington, on October 19, 2007.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. E7-21178 Filed 10-29-07; 8:45 am]

BILLING CODE 4910-13-P