AD 2002-08-05

[Federal Register Volume 67, Number 75 (Thursday, April 18, 2002)]
[Rules and Regulations]
[Pages 19101-19104]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 02-9391]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2002-NM-35-AD; Amendment 39-12713; AD 2002-08-05]
RIN 2120-AA64


Airworthiness Directives; Bombardier Model DHC-8-400, -401, and -
402 Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule; request for comments.

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SUMMARY: This amendment adopts a new airworthiness directive (AD) that 
is applicable to certain Bombardier Model DHC-8-400, -401, and -402 
series airplanes. This action requires revising the Airplane Flight 
Manual to advise the flight crew of appropriate procedures to follow in 
the event that a main landing gear (MLG) fails to extend following a 
gear-down selection. This action also requires 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 action is 
necessary to ensure that the flight crew 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: Effective April 23, 2002.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of April 23, 2002.
    Comments for inclusion in the Rules Docket must be received on or 
before May 20, 2002.

[[Page 19102]]


ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 2002-NM-35-AD, 1601 Lind Avenue, SW., 
Renton, Washington 98055-4056. Comments may be inspected at this 
location between 9:00 a.m. and 3:00 p.m., Monday through Friday, except 
Federal holidays. Comments may be submitted via fax to (425) 227-1232. 
Comments may also be sent via the Internet using the following address: 
<a href="/cdn-cgi/l/email-protection#3e07135f505313575f4c5d5153535b504a7e585f5f10595148"><span class="__cf_email__" data-cfemail="1920347877743470786b7a7674747c776d597f7878377e766f">[email&#160;protected]</span></a>. Comments sent via the Internet must contain 
``Docket No. 2002-NM-35-AD'' in the subject line and need not be 
submitted in triplicate. Comments sent via fax or the Internet as 
attached electronic files must be formatted in Microsoft Word 97 for 
Windows or ASCII text.
    The service information referenced in this AD may be obtained from 
Bombardier, Inc., Bombardier Regional Aircraft Division, 123 Garratt 
Boulevard, Downsview, Ontario M3K 1Y5, Canada. This information may be 
examined at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, 
SW., Renton, Washington; or at the FAA, New York Aircraft Certification 
Office, 10 Fifth Street, Third Floor, Valley Stream, New York; or at 
the Office of the Federal Register, 800 North Capitol Street, NW., 
suite 700, Washington, DC.

FOR FURTHER INFORMATION CONTACT: Ezra Sasson, Aerospace Engineer, 
Systems and Flight Test Branch, ANE-172, FAA, New York Aircraft 
Certification Office, 10 Fifth Street, Third Floor, Valley Stream, New 
York 11581; telephone (516) 256-7520; fax (516) 568-2716.

SUPPLEMENTARY INFORMATION: Transport Canada Civil Aviation (TCCA), 
which is the airworthiness authority for Canada, recently notified the 
FAA that an unsafe condition may exist on certain Bombardier Model DHC-
8-400, -401, and -402 series airplanes. TCCA advises that the flight 
crew of a Bombardier Model DHC-8-400 series airplane experienced 
difficulties in extending the right main landing gear (MLG) following a 
gear-down selection. During that event, when subsequent use of the 
alternate landing gear extension procedure failed to extend the 
affected gear, the MLG was retracted and a second alternate gear 
extension was performed. This resulted in the MLG successfully 
extending to the down and locked position.
    Inspection of the MLG revealed a groove in the lower jaw of the 
uplock hook on the MLG uplock assembly due to premature wear. Findings 
indicate that excessive wear to the uplock hook could prevent release 
of the roller, and the inability to extend the MLG with either the 
normal, or alternate, landing gear extension procedure. Findings also 
indicate that the low friction (black-colored) liner of the uplock 
rollers was omitted on a batch lot of uplock rollers, including the 
subject airplane.
    Conditions that could cause failure of the MLG to extend, following 
a gear-down selection, include the absence of an uplock roller, absence 
of an approved liner, or presence of an unapproved or damaged uplock 
roller. These conditions, if not corrected, could result in the 
inability of the flight crew to extend the MLG, which could result in a 
gear-up landing and possible injury to passengers and crew.

Explanation of Relevant Service Information

    Bombardier has issued DHC-8 Alert Service Bulletin A84-32-15, dated 
February 4, 2002, which describes procedures for a one-time inspection 
of the inside surface of the uplock roller on the shock strut of the 
MLG for the presence of an inner low friction (black-colored) liner, 
and corrective actions if necessary. If a low friction liner is 
present, operators may reinstall the existing uplock roller, or replace 
the uplock roller with a new uplock roller having a low friction liner. 
If the bore of the uplock roller has a bright metal finish, indicating 
the absence of a liner, operators must replace the existing uplock 
roller with a new uplock roller having a low friction liner. In 
addition, the alert service bulletin references Chapter 32-11-01, dated 
January 5, 2001, of Bombardier Series 400 Aircraft Maintenance Manual 
(AMM), PSM 1-84-2, as a secondary source of service information for 
replacing the MLG uplock roller with a new roller having a low friction 
liner.
    Chapter 32-31-21, dated January 5, 2001, of Bombardier Series 400 
AMM, PSM 1-84-2, describes procedures for replacing existing MLG uplock 
assemblies with new assemblies.
    Transport Canada Civil Aviation (TCCA), which is the airworthiness 
authority for Canada, has issued Canadian airworthiness directive CF-
2002-13, dated February 4, 2002, to assure the continued airworthiness 
of these airplanes in Canada. That airworthiness directive specifies 
procedures for revising the Airplane Flight Manual (AFM); replacing the 
left and right MLG uplock assemblies with new assemblies per Chapter 
32-31-21 of Bombardier Series 400 AMM, PSM 1-84-2; and inspecting the 
uplock roller, and taking corrective action if necessary.

FAA's Conclusions

    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, the TCCA has kept the FAA informed 
of the situation described above. The FAA has determined that the 
primary cause of the failure of the right MLG to extend and the uplock 
assembly to disengage, following a gear-down selection, is the design 
of the uplock assembly. However, we also consider that the uplock 
roller, which involves a quality control problem, may have contributed 
to such failure. The FAA has examined the findings of the TCCA, 
reviewed all available information, and determined that AD action is 
necessary for products of this type design that are certificated for 
operation in the United States.

Explanation of Requirements of Rule

    Since an unsafe condition has been identified that is likely to 
exist or develop on other airplanes of the same type design registered 
in the United States, this AD is being issued to require a revision to 
the Limitations section, and certain paragraphs of the Normal and 
Alternate Extension Procedures, of the FAA-approved AFM, to advise the 
flight crew of appropriate procedures to follow in the event that an 
MLG fails to extend following a gear-down selection; replacement of the 
left and right MLG uplock assemblies; and a one-time inspection of the 
left and right MLG uplock rollers for the presence of an inner low 
friction liner, and corrective actions if necessary. The actions 
required by this AD must be accomplished per the alert service bulletin 
and the AMM, except as described below.

Differences Between Alert Service Bulletin, and the Canadian 
Airworthiness Directive and This AD

    The Bombardier alert service bulletin specifies procedures only for 
an inspection of the left and right MLG uplock rollers, and corrective 
actions if necessary. However, in addition to that procedure, the 
Canadian airworthiness directive and this AD also specify procedures 
for revising the AFM and replacing the MLG uplock assemblies.

Differences Between the Canadian Airworthiness Directive and This 
AD

    The Canadian airworthiness directive specifies inspection/
replacement of the left and right MLG uplock rollers per Bombardier 
DHC-8 Alert Service

[[Page 19103]]

Bulletin A84-32-15, dated February 4, 2002, ``or later revisions of the 
alert service bulletin.'' However, paragraph (c) of this AD requires 
accomplishment of the one-time inspection of the MLG uplock rollers, 
and corrective actions if necessary, per the alert service bulletin, 
dated February 4, 2002. Where a specific service bulletin is referenced 
in an AD, the use of the phrase ``or later revisions of the service 
bulletin,'' violates Office of the Federal Register regulations 
regarding approval of materials that are incorporated by reference, 
and, therefore may not be specified in this AD.

Interim Action

    This is considered to be interim action. Bombardier has advised 
that it is currently evaluating a possible modification to the uplock 
assembly to minimize wear to the uplock hook and to ensure a more 
positive uplock release, which will positively address the unsafe 
condition addressed by this AD. Once this modification is developed, 
approved, and available, the FAA may consider additional rulemaking.

Determination of Rule's Effective Date

    Since a situation exists that requires the immediate adoption of 
this regulation, it is found that notice and opportunity for prior 
public comment hereon are impracticable, and that good cause exists for 
making this amendment effective in less than 30 days.

Comments Invited

    Although this action is in the form of a final rule that involves 
requirements affecting flight safety and, thus, was not preceded by 
notice and an opportunity for public comment, comments are invited on 
this rule. Interested persons are invited to comment on this rule by 
submitting such written data, views, or arguments as they may desire. 
Communications shall identify the Rules Docket number and be submitted 
in triplicate to the address specified under the caption ADDRESSES. All 
communications received on or before the closing date for comments will 
be considered, and this rule may be amended in light of the comments 
received. Factual information that supports the commenter's ideas and 
suggestions is extremely helpful in evaluating the effectiveness of the 
AD action and determining whether additional rulemaking action would be 
needed.
    Submit comments using the following format:
    <bullet> Organize comments issue-by-issue. For example, discuss a 
request to change the compliance time and a request to change the 
service bulletin reference as two separate issues.
    <bullet> For each issue, state what specific change to the AD is 
being requested.
    <bullet> Include justification (e.g., reasons or data) for each 
request.
    Comments are specifically invited on the overall regulatory, 
economic, environmental, and energy aspects of the rule that might 
suggest a need to modify the rule. All comments submitted will be 
available, both before and after the closing date for comments, in the 
Rules Docket for examination by interested persons. A report that 
summarizes each FAA-public contact concerned with the substance of this 
AD will be filed in the Rules Docket.
    Commenters wishing the FAA to acknowledge receipt of their comments 
submitted in response to this rule must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 2002-NM-35-AD.'' The postcard will be date stamped and 
returned to the commenter.

Regulatory Impact

    The regulations adopted herein 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. Therefore, it 
is determined that this final rule does not have federalism 
implications under Executive Order 13132.
    The FAA has determined that this regulation is an emergency 
regulation that must be issued immediately to correct an unsafe 
condition in aircraft, and that it is not a ``significant regulatory 
action'' under Executive Order 12866. It has been determined further 
that this action involves an emergency regulation under DOT Regulatory 
Policies and Procedures (44 FR 11034, February 26, 1979). If it is 
determined that this emergency regulation otherwise would be 
significant under DOT Regulatory Policies and Procedures, a final 
regulatory evaluation will be prepared and placed in the Rules Docket. 
A copy of it, if filed, may be obtained from the Rules Docket at the 
location provided under the caption ADDRESSES.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

Adoption of the Amendment

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration amends part 39 of 
the Federal Aviation Regulations (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. Section 39.13 is amended by adding the following new 
airworthiness directive:

2002-08-05  Bombardier, Inc: Amendment 39-12713. Docket 2002-NM-35-
AD.

    Applicability: Model DHC-8-400, -401, and -402 series airplanes; 
serial numbers 4001 and subsequent; certificated in any category.

    Note 1: This AD applies to each airplane identified in the 
preceding applicability provision, regardless of whether it has been 
modified, altered, or repaired in the area subject to the 
requirements of this AD. For airplanes that have been modified, 
altered, or repaired so that the performance of the requirements of 
this AD is affected, the owner/operator must request approval for an 
alternative method of compliance in accordance with paragraph (d) of 
this AD. The request should include an assessment of the effect of 
the modification, alteration, or repair on the unsafe condition 
addressed by this AD; and, if the unsafe condition has not been 
eliminated, the request should include specific proposed actions to 
address it.

    Compliance: Required as indicated, unless accomplished 
previously.
    To ensure that the flight crew has the procedures necessary to 
address failure of the main landing gears (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; accomplish the following:

Revision of FAA-Approved Airplane Flight Manual (AFM)

    (a) Within 3 days after the effective date of this AD, 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 flight crew 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:

[[Page 19104]]

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.''

Replacement of Uplock Assembly

    (b) At the later of the times specified in paragraph (b)(1) or 
(b)(2) of this AD: Replace the left and right MLG uplock assemblies, 
part number (P/N) 46500-3, with new uplock assemblies, P/N 46500-3, 
per Chapter 32-31-21, dated January 5, 2001, of Bombardier Series 
400 Aircraft Maintenance Manual, PSM 1-84-2. Do the replacement 
thereafter at intervals not to exceed 2,500 flight hours or 3,000 
flight cycles, whichever occurs earlier.
    (1) Before the accumulation of 2,500 total flight hours or 3,000 
total flight cycles, whichever occurs earlier; or
    (2) Within 14 days after the effective date of this AD.

    Note 2: Bombardier DHC-8 Alert Service Bulletin A84-32-15, dated 
February 4, 2002, references Chapter 32-11-01, dated January 5, 
2001, of Bombardier Series 400 AMM, PSM 1-84-2, as an additional 
source of service information for procedures to replace an MLG 
uplock roller.

One-Time Inspection of MLG Uplock Rollers

    (c) Within 30 days after the effective date of this AD, inspect 
the left and right MLG uplock rollers for the presence of an inner 
low friction (black-colored) liner, per 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 (c)(1) or (c)(2) of this AD.

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; per the alert 
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; per the alert service 
bulletin.

Alternative Methods of Compliance

    (d) An alternative method of compliance or adjustment of the 
compliance time that provides an acceptable level of safety may be 
used if approved by the Manager, New York Aircraft Certification 
Office (ACO), FAA. Operators shall submit their requests through an 
appropriate FAA Principal Maintenance Inspector, who may add 
comments and then send it to the Manager, New York ACO.

    Note 3: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the New York ACO.

Special Flight Permits

    (e) Special flight permits may be issued in accordance with 
Secs. 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 
requirements of this AD can be accomplished.

Incorporation by Reference

    (f) The inspection of the uplock rollers and corrective actions 
shall be done per Bombardier DHC-8 Alert Service Bulletin A84-32-15, 
dated February 4, 2002. (The manufacturer's name is listed only on 
the first page of the document; no other page contains this 
information.) This incorporation by reference was approved by the 
Director of the Federal Register in accordance with 5 U.S.C. 552(a) 
and 1 CFR part 51. Copies may be obtained from Bombardier, Inc., 
Bombardier Regional Aircraft Division, 123 Garratt Boulevard, 
Downsview, Ontario M3K 1Y5, Canada. Copies may be inspected at the 
FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, 
Washington; or at the FAA, New York Aircraft Certification Office, 
10 Fifth Street, Third Floor, Valley Stream, New York; or at the 
Office of the Federal Register, 800 North Capitol Street, NW., suite 
700, Washington, DC.

    Note 4: The subject of this AD is addressed in Canadian 
airworthiness directive CF-2002-13, dated February 4, 2002.

Effective Date

    (g) This amendment becomes effective on April 23, 2002.

    Issued in Renton, Washington, on April 11, 2002.
Vi L. Lipski,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 02-9391 Filed 4-17-02; 8:45 am]
BILLING CODE 4910-13-U