[Federal Register Volume 72, Number 16 (Thursday, January 25, 2007)]
[Rules and Regulations]
[Pages 3347-3350]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E7-909]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2006-26050; Directorate Identifier 2006-NM-078-AD; 
Amendment 39-14890; AD 2007-02-03]
RIN 2120-AA64


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

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

ACTION: Final rule.

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SUMMARY: The FAA is superseding an existing airworthiness directive 
(AD), which applies to certain Bombardier Model DHC-8-400 series 
airplanes. That AD currently requires revising the airplane flight 
manual (AFM) to advise the flightcrew of appropriate procedures to 
follow in the event that a main landing gear (MLG) fails to extend 
following a gear-down selection. That AD also currently requires 
repetitive replacement of the left and right MLG uplock assemblies with 
new assemblies; and an inspection of the left and right MLG uplock 
rollers for the presence of an inner low friction liner, and corrective 
actions if necessary. This new AD revises the requirement for replacing 
the left and right MLG uplock assemblies by allowing replacement with 
alternative parts. For a certain MLG uplock assembly, this new AD 
requires repetitive inspections of the uplock hatch lower jaw for the 
presence of a wear groove and replacement with an improved part if 
necessary. For a certain MLG uplock assembly, this new AD requires 
repetitive inspections of the uplock roller to ensure that it rotates 
freely and replacement with a new part if necessary. This new AD allows 
optional replacement of the left and right MLG uplock assemblies with 
improved parts, which ends the requirements of the AFM revision and 
repetitive replacement and inspections. This new AD removes airplanes 
from the applicability. This AD results from development of a 
terminating action. We are issuing this AD to ensure that the 
flightcrew has the procedures necessary to address failure of an MLG to 
extend following a gear-down selection; and to detect and correct such 
failure, which could result in a gear-up landing and possible injury to 
passengers and crew.

DATES: This AD becomes effective March 1, 2007.
    The Director of the Federal Register approved the incorporation by 
reference of certain publications listed in the AD as of March 1, 2007.
    On April 23, 2002 (67 FR 19101, April 18, 2002), the Director of 
the Federal Register approved the incorporation by reference of 
Bombardier DHC-8 Alert Service Bulletin A84-32-15, dated February 4, 
2002.

ADDRESSES: You may examine the AD docket on the Internet at http://dms.dot.gov or in person at the Docket Management Facility, U.S. 
Department of Transportation, 400 Seventh Street, SW., Nassif Building, 
Room PL-401, Washington, DC.
    Contact Bombardier, Inc., Bombardier Regional Aircraft Division, 
123 Garratt Boulevard, Downsview, Ontario M3K 1Y5, Canada, for service 
information identified in this AD.

FOR FURTHER INFORMATION CONTACT: Ezra Sasson, Aerospace Engineer, 
Systems and Flight Test Branch, ANE-172, FAA, New York Aircraft 
Certification Office, 1600 Stewart Avenue, Suite 410, Westbury, New 
York 11590; telephone (516) 228-7320; fax (516) 794-5531.

SUPPLEMENTARY INFORMATION:

Examining the Docket

    You may examine the airworthiness directive (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 street address stated in the ADDRESSES section.

Discussion

    The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 
CFR part 39 to include an AD that supersedes AD 2002-08-05, amendment 
39-12713 (67 FR 19101, April 18, 2002). The existing AD applies to 
certain Bombardier Model DHC-8-400 series airplanes. That NPRM was 
published in the Federal Register on October 13, 2006 (71 FR 60450). 
That NPRM proposed to continue to require revising the airplane flight 
manual (AFM) to advise the flightcrew of appropriate procedures to 
follow in the event that a main landing gear (MLG) fails to extend 
following a gear-down selection. That NPRM also proposed to continue to 
require repetitive replacement of the left and right MLG uplock 
assemblies with new assemblies; and an inspection of the left and right 
MLG uplock rollers for the presence of an inner low friction liner, and 
corrective actions if necessary. That NPRM also proposed to revise the 
requirement for replacing the

[[Page 3348]]

left and right MLG uplock assemblies by allowing replacement with 
alternative parts. For a certain MLG uplock assembly, that NPRM also 
proposed to require repetitive inspections of the uplock hatch lower 
jaw for the presence of a wear groove and replacement with an improved 
part if necessary. For a certain MLG uplock assembly, that NPRM also 
proposed to require repetitive inspections of the uplock roller to 
ensure that it rotates freely and replacement with a new part if 
necessary. That NPRM also proposed to allow optional replacement of the 
left and right MLG uplock assemblies with improved parts, which would 
end the requirements of the AFM revision and repetitive replacements 
and inspections. That NPRM also proposed to remove airplanes from the 
applicability.

Comments

    We provided the public the opportunity to participate in the 
development of this AD. We have considered the one comment that has 
been received on the NPRM.

Request To Provide Additional Terminating Action

    Horizon Air requests that we revise paragraph (k) of the NPRM to 
provide an additional terminating action by allowing replacement with a 
new or overhauled uplock assembly having part number (P/N) 46500-9. 
Paragraph (k) of the NPRM proposed only to allow replacement of uplock 
assemblies having P/N 46500-3 or -5 with new or overhauled uplock 
assemblies having P/N 46500-7. As justification, the commenter states 
that P/N 46500-9 is the latest version of the uplock assembly. The 
commenter also points out that Bombardier DHC-8 Service Bulletin 84-32-
46, dated July 4, 2006, provides instructions for modifying an uplock 
assembly having P/N 46500-7 and reidentifying it as P/N 46500-9.
    We agree to revise paragraph (k) of this AD to provide P/N 46500-9 
as a terminating action. We have also revised paragraphs (g) and (i)(1) 
of this AD to allow replacement with P/N 46500-9. Bombardier DHC-8 
Service Bulletin 84-32-46 modifies an uplock assembly having P/N 46500-
7 by improving retention of the proximity sensor target. Therefore, we 
have determined that a new or overhauled uplock assembly having P/N 
46500-9 is also adequate for addressing the unsafe condition of this 
AD.

Conclusion

    We have carefully reviewed the available data, including the 
comment that has been received, and determined that air safety and the 
public interest require adopting the AD with the changes described 
previously. We have determined that these changes will neither increase 
the economic burden on any operator nor increase the scope of the AD.

Costs of Compliance

    The following table provides the estimated costs, at an average 
labor rate of $80 per work hour, for U.S. operators to comply with this 
AD.

                                                 Estimated Costs
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                                                                                Number of
                                      Work                                        U.S.-
              Action                  hours     Parts    Cost per  airplane    registered        Fleet cost
                                                                                airplanes
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AFM revision (required by AD 2002-         1      None  $80.................            21  $1,680.
 08-05).
Replacement of uplock assemblies           4    \1\ $0  $320, per                       21  $6,720 per
 (required by AD 2002-08-05).                            replacement cycle.                  replacement cycle.
Inspection of uplock rollers               1      None  $80.................            21  $1,680.
 (required by AD 2002-08-05).
Inspections of uplock assemblies           5      None  $400................            21  $8,400.
 and uplock rollers (new action).
Terminating action (new action)...         4    \1\ $0  $320................            21  $6,720.
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\1\ The parts manufacturer states that it will supply required parts to operators at no cost.

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 this AD:
    (1) Is not a ``significant regulatory action'' under Executive 
Order 12866;
    (2) Is not a ``significant rule'' under 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:


[[Page 3349]]


    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 
removing amendment 39-12713 (67 FR 19101, April 18, 2002) and by adding 
the following new airworthiness directive (AD):

2007-02-03 Bombardier, Inc. (Formerly de Havilland, Inc.): Amendment 
39-14890. Docket No. FAA-2006-26050; Directorate Identifier 2006-NM-
078-AD.

Effective Date

    (a) This AD becomes effective March 1, 2007.

Affected ADs

    (b) This AD supersedes AD 2002-08-05.

Applicability

    (c) This AD applies to Bombardier Model DHC-8-400 series 
airplanes, certificated in any category; serial numbers 4001 and 
4003 through 4087 inclusive; equipped with main landing gear (MLG) 
uplock assembly part numbers (P/Ns) 46500-3 and -5.

Unsafe Condition

    (d) This AD results from development of a terminating action. We 
are issuing this AD to ensure that the flightcrew has the procedures 
necessary to address failure of an MLG to extend following a gear-
down selection; and to detect and correct such failure, which could 
result in a gear-up landing and possible injury to passengers and 
crew.

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.

Requirements of AD 2002-08-05

Revision of FAA-Approved Airplane Flight Manual (AFM)

    (f) Within 3 days after April 23, 2002 (the effective date of AD 
2002-08-05), amend all copies of the FAA-approved Bombardier Series 
400 AFM, PSM 1-84-1A (for Models 400, 401, and 402), by adding the 
following procedure to the Limitations section of the AFM and 
opposite page 4-21-1 of the AFM; and advise all flightcrew members 
of these changes. (The revision may be accomplished by inserting a 
copy of this AD into the Limitations section of the AFM and affected 
paragraphs of the AFM.):
    ``If ONE main landing gear fails to extend after performing 
landing gear extension per normal procedures given in paragraph 
4.3.7 and alternate extension procedures per paragraph 4.21.1 of the 
AFM:
    1. Visually confirm that the affected gear has not extended and 
that the associated doors have opened.
    2. Ensure No. 2 hydraulic system pressure and quantity are 
normal and the following landing gear advisory lights are 
illuminated: selector lever amber, gear green locked down (nose and 
non-affected main gear), red gear unlocked (affected main gear) and 
all amber doors open.
    3. NOSE L/G RELEASE handle--Return to the stowed position.
    4. LANDING GEAR ALTERNATE EXTENSION door--Close fully.
    5. MAIN L/G RELEASE handle--Return to the stowed position.
    6. LANDING GEAR ALTERNATE RELEASE door--Close fully.
    7. LANDING GEAR lever--DN.
    8. L/G DOWN SELECT INHIBIT SW--Normal and guarded. Check amber 
doors open advisory lights out (nose and non-affected main gear) and 
LDG GEAR INOP caution light out.
    9. LANDING GEAR lever--UP Check all gear, door and LANDING GEAR 
lever advisory lights out.
    10. With minimum delay, LANDING GEAR lever--DN. Check 3 green 
gear locked down advisory lights illuminate, all amber doors open, 
red gear unlocked and selector lever amber advisory lights out.
    11. Items 9 and 10 may be repeated in an effort to achieve 3 
gear down and locked.

CAUTION

    Should the LDG GEAR INOP caution light illuminate, or loss of 
no. 2 hydraulic system pressure or quantity, or any abnormality in 
landing gear system indication other than those associated with the 
affected main landing gear be experienced, see paragraph 4.21.1 
ALTERNATE LANDING GEAR EXTENSION.''
    Accomplishing the actions specified in paragraph (k) of this AD 
terminates the requirements of this paragraph, and after the 
replacement has been done, the AFM limitation may be removed from 
the AFM.

Replacement of Uplock Assembly With New Replacement Parts and 
Requirements

    (g) At the later of the times specified in paragraph (g)(1) or 
(g)(2) of this AD: Replace the left and right MLG uplock assemblies, 
P/N 46500-3, with new or overhauled uplock assemblies having P/N 
46500-3, -5, -7, or -9 according to a method approved by either the 
Manager, New York Aircraft Certification Office (ACO), FAA; or 
Transport Canada Civil Aviation (TCCA) (or its delegated agent). 
Using Tasks 32-31-21-000-801 and 32-31-21-400-801 of Chapter 32-31-
21 of Bombardier Q400 Dash 8 Aircraft Maintenance Manual (AMM), PSM 
1-84-2, is one approved method. For any uplock assembly having P/N 
46500-3, repeat the replacement thereafter at intervals not to 
exceed 2,500 flight hours or 3,000 flight cycles, whichever occurs 
earlier. For any uplock assembly having P/N 46500-5, do the actions 
required by paragraph (i) of this AD. Replacing an uplock assembly 
with a new or overhauled uplock assembly having P/N 46500-7 or -9 
terminates the requirements of this paragraph, for that uplock 
assembly only.
    (1) Before the accumulation of 2,500 total flight hours or 3,000 
total flight cycles on an uplock assembly, whichever occurs earlier; 
or
    (2) Within 14 days after April 23, 2002.

One-Time Inspection of MLG Uplock Rollers With Added Inspection 
Definition

    (h) Within 30 days after April 23, 2002, do a general visual 
inspection of the left and right MLG uplock rollers for the presence 
of an inner low friction (black-colored) liner, in accordance with 
the Accomplishment Instructions of Bombardier DHC-8 Alert Service 
Bulletin A84-32-15, dated February 4, 2002; and, before further 
flight, do the actions required by paragraph (h)(1) or (h)(2) of 
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.''

Corrective Actions

    (1) If a low friction liner is present, reinstall the existing 
uplock roller; or install a new uplock roller, P/N 46575-1, having a 
low friction liner; on the shock strut of the MLG in accordance with 
the service bulletin.
    (2) If a low friction liner is not present, replace the existing 
uplock roller with a new uplock roller, P/N 46575-1, having a low 
friction liner, on the shock strut of the MLG in accordance with the 
service bulletin. After the effective date of this AD, if the low 
friction liner is not present, replace the uplock roller in 
accordance with paragraph (i)(2) of this AD.

    Note 2: Bombardier DHC-8 Alert Service Bulletin A84-32-15, dated 
February 4, 2002, references Chapter 32-11-01 of Bombardier Q400 
Dash 8 AMM, PSM 1-84-2, as an additional source of service 
information for procedures to replace an MLG uplock roller.

New Requirements of This AD

Repetitive Inspections and Replacement if Necessary of a Certain 
Uplock Assembly

    (i) For any MLG uplock assembly having P/N 46500-5, do the 
inspections specified in paragraphs (i)(1) and (i)(2) of this AD at 
the later of the following compliance times: Before the accumulation 
of 2,500 total flight hours or 3,000 total flight cycles on the 
uplock assembly, whichever occurs first; or within 90 days after the 
effective date of this AD. Repeat the inspections thereafter at 
intervals not to exceed 400 flight hours or 480 flight cycles, 
whichever occurs first. Replacement of an uplock assembly in 
accordance with paragraph (i)(1) of this AD terminates the 
repetitive inspections of paragraphs (i)(1) and (i)(2) of this AD, 
for that uplock assembly only.
    (1) Do a detailed dimensional inspection of the surface of the 
uplock hatch lower jaw for the presence of a wear groove and measure 
the wear groove depth to an accuracy of 0.001 inch, according to a 
method approved by either the Manager, New York ACO; or TCCA (or its 
delegated agent). Using Task 32-31-21-220-801 of the Bombardier Q400 
Dash 8 AMM, PSM 1-84-2, is one approved

[[Page 3350]]

method. If the groove depth exceeds 0.007 inch, before further 
flight, replace the uplock assembly with a new or serviceable uplock 
assembly, P/N 46500-7 or -9, according to a method approved by 
either the Manager, New York ACO; or TCCA (or its delegated agent). 
Using Tasks 32-31-21-000-801 and 32-31-21-400-801 of Chapter 32-31-
21 of the Bombardier Q400 Dash 8 AMM, PSM 1-84-2, is one approved 
method.
    (2) Do a general visual inspection of the uplock roller, P/N 
46575-1, of the MLG uplock assembly to ensure that it rotates 
freely. If the uplock roller does not rotate freely, before further 
flight, replace the uplock roller with a new uplock roller, P/N 
46575-1, in accordance with Bombardier Temporary Revision (TR) 32-
191 and Bombardier TR 32-192, both dated May 29, 2006, both to 
Bombardier Q400 Dash 8 AMM.
    (j) When the information in Bombardier TR 32-191 and Bombardier 
TR 32-192, both dated May 29, 2006, is included in the AMM, the AMM 
is approved as an acceptable method of compliance for the 
replacement specified in paragraph (i)(2) of this AD.

Optional Terminating Action for AFM Revision, Repetitive 
Replacements, and Repetitive Inspections

    (k) Replacing the left and right MLG uplock assemblies having P/
N 46500-3 or -5 with new or overhauled uplock assemblies having P/N 
46500-7 or -9 according to a method approved by either the Manager, 
New York Aircraft Certification Office (ACO), FAA; or Transport 
Canada Civil Aviation (TCCA) (or its delegated agent); terminates 
the requirements of paragraphs (f), (g), (h), and (i) of this AD, as 
applicable. Using Tasks 32-31-21-000-801 and 32-31-21-400-801 of 
Chapter 32-31-21 of Bombardier Q400 Dash 8 Aircraft Maintenance 
Manual (AMM), PSM 1-84-2, is one approved method. After the 
replacements have been done, the AFM limitation required by 
paragraph (f) of this AD may be removed from the AFM.

Alternative Methods of Compliance (AMOCs)

    (l)(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) 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.
    (3) AMOCs approved previously in accordance with AD 2002-08-05, 
are approved as AMOCs for the corresponding provisions of this AD.

Related Information

    (m) Canadian airworthiness directive CF-2002-13R2, dated May 19, 
2005, also addresses the subject of this AD.

Material Incorporated by Reference

    (n) You must use the service information listed in Table 1 of 
this AD to perform the actions that are required by this AD, unless 
the AD specifies otherwise.

                                  Table 1.--Material Incorporated by Reference
----------------------------------------------------------------------------------------------------------------
          Service information                       Revision level                           Date
----------------------------------------------------------------------------------------------------------------
Bombardier DHC-8 Alert Service Bulletin  Original...........................  February 4, 2002.
 A84-32-15.
Bombardier Temporary Revision 32-191 to  Original...........................  May 29, 2006.
 the Bombardier Q400 Dash 8 Aircraft
 Maintenance Manual.
Bombardier Temporary Revision 32-192 to  Original...........................  May 29, 2006.
 the Bombardier Q400 Dash 8 Aircraft
 Maintenance Manual.
----------------------------------------------------------------------------------------------------------------

    (1) The Director of the Federal Register approved the 
incorporation by reference of Bombardier Temporary Revision 32-191, 
dated May 29, 2006, to the Bombardier Q400 Dash 8 Aircraft 
Maintenance Manual; and Bombardier Temporary Revision 32-192, dated 
May 29, 2006, to the Bombardier Q400 Dash 8 Aircraft Maintenance 
Manual; in accordance with 5 U.S.C. 552(a) and 1 CFR part 51.
    (2) On April 23, 2002 (67 FR 19101, April 18, 2002), the 
Director of the Federal Register approved the incorporation by 
reference of Bombardier DHC-8 Alert Service Bulletin A84-32-15, 
dated February 4, 2002.
    (3) 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 
Docket Management Facility, U.S. Department of Transportation, 400 
Seventh Street, SW., Room PL-401, Nassif Building, Washington, DC; 
on the Internet at http://dms.dot.gov; or at the National Archives 
and Records Administration (NARA). For information on the 
availability of this material at the NARA, call (202) 741-6030, or 
go to http://www.archives.gov/federal_register/code_of--
federal--regulations/ibr--locations.html.

    Issued in Renton, Washington, on January 5, 2007.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. E7-909 Filed 1-24-07; 8:45 am]
BILLING CODE 4910-13-P