[Federal Register Volume 69, Number 89 (Friday, May 7, 2004)]
[Proposed Rules]
[Pages 25503-25505]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 04-10384]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2002-NM-234-AD]
RIN 2120-AA64


Airworthiness Directives; Bombardier Model DHC-8-400 Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes the supersedure of an existing 
airworthiness directive (AD), applicable to certain Bombardier Model 
DHC-8-400 airplanes. That AD currently requires revising the Normal and 
Abnormal sections of the airplane flight manual (AFM) to include 
procedures that enable the flightcrew to determine if the main landing 
gear (MLG) is extended before landing, and to take appropriate actions 
if necessary. This new action would add an airplane to the 
applicability, and require replacing the existing MLG downlock 
proximity sensors with new, improved sensors. After the replacement, 
this action would also require removing from the AFM the revision to 
the Normal and Abnormal sections require by the existing AD. The 
actions specified by the proposed AD are intended to prevent failure of 
the MLG downlock proximity sensors on the same MLG at the same time, 
which could result in the MLG's failure to extend during landing, and 
cause injury to flightcrew and passengers.

DATES: Comments must be received by June 7, 2004.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 2002-NM-234-AD, 1601 Lind Avenue, SW., 
Renton, Washington 98055-4056. Comments may be inspected at this 
location between 9 a.m. and 3 p.m., Monday through Friday, except 
Federal holidays. Commments may be submitted via fax to (425) 227-1232. 
Comments may also be sent via the Internet using the following address: 
[email protected]. Comments sent via fax or the Internet must 
contain ``Docket No. 2002-NM-234-AD'' in the subject line and need not 
be submitted in triplicate. Comments sent via the Internet as attached 
electronic files must be formatted in Microsoft Word 97 for Windows or 
ASCII text.
    The service information referenced in the proposed rule 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, 1600 Stewart Avenue, Westbury, New York 
11590.

FOR FURTHER INFORMATION CONTACT: Dan Parillo, Aerospace Engineer, 
Systems and Flight Test Branch, ANE-172, FAA, New York Aircraft 
Certification Office, 1600 Stewart Avenue, Westbury, New York 11590; 
telephone (516) 228-7305; fax (516) 794-5531.

SUPPLEMENTARY INFORMATION: 

Comments Invited

    Interested persons are invited to participate in the making of the 
proposed 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 above. All 
communications received on or before the closing date for comments, 
specified above, will be considered before taking action on the 
proposed rule. The proposals contained in this action may be changed in 
light of the comments received.
    Submit comments using the following format:
     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.
     For each issue, state what specific change to the proposed 
AD is being requested.
     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 proposed 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 summarizing each FAA-public contact concerned with 
the substance of this proposal will be filed in the Rules Docket.
    Commenters wishing the FAA to acknowledge receipt of their comments 
submitted in response to this action must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 2002-NM-234-AD.'' The postcard will be date stamped 
and returned to the commenter.

Availability of NPRMs

    Any person may obtain a copy of this NPRM by submitting a request 
to the FAA, Transport Airplane Directorate, ANM-114, Attention: Rules 
Docket No. 2002-NM-234-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    On May 25, 2001, the FAA issued AD 2001-11-10, amendment 39-12253 
(66 FR 30305, June 6, 2001), applicable to certain Bombardier Model 
DHC-8-400 series airplanes, to require revising the Normal and Abnormal 
sections of the airplane flight manual (AFM) to include procedures that 
enable the flightcrew to determine if the main landing gear (MLG) is 
extended before landing and to take appropriate actions if necessary. 
That action was prompted by notification from Transport Canada Civil 
Aviation (TCCA), which is the airworthiness authority for Canada, that 
MLG downlock proximity sensors may fail concurrently on the same gear. 
The requirements of that AD are intended to ensure that the flightcrew 
is advised of a potential gear-up landing due to misleading indications 
for the MLG extension, and has the procedures necessary to address that 
potential condition.

[[Page 25504]]

Actions Since Issuance of Previous Rule

    The preamble to AD 2001-11-10 explains that we considered the 
requirements of that AD ``interim action'' and were considering further 
rulemaking. We now have determined that further rulemaking is indeed 
necessary, and this proposed AD follows from that determination.
    We also have revised the applicability of the existing AD to 
include an additional airplane that was inadvertently omitted from the 
applicability of Canadian airworthiness directive CF-2001-16, dated 
April 11, 2001, which was used as a source of applicability information 
for AD 2001-11-10. Canadian airworthiness directive CF-2001-16R1, dated 
June 3, 2002, has since been issued to include the additional airplane 
and is used as a source for applicability information in this proposed 
AD.

Explanation of Relevant Service Information

    Bombardier has issued Service Bulletin 84-32-09, Revision A, dated 
November 20, 2001, which describes procedures for replacing the 
existing MLG downlock proximity sensors with new, improved proximity 
sensors, and rigging the new sensors in accordance with the airplane 
maintenance manual. Accomplishment of the actions specified in the 
service bulletin is intended to adequately address the identified 
unsafe condition.
    TCCA classified this service bulletin as mandatory and issued 
Canadian airworthiness directive CF-2001-16R1, dated June 3, 2002, to 
ensure the continued airworthiness of these airplanes in Canada.
    The Bombardier service bulletin references Menasco Aerospace 
Service Bulletin 46400-32-09, dated May 15, 2001, as an additional 
source of service information for accomplishment of the replacement. 
The Menasco service bulletin is included in the Bombardier service 
bulletin.

FAA's Conclusions

    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. The FAA has examined the findings of 
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 Proposed 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, the proposed AD would supersede AD 2001-11-10 to 
continue to require revising the Normal and Abnormal sections of the 
AFM to include procedures that enable the flightcrew to determine if 
the MLG is extended before landing, and to take appropriate actions if 
necessary. This new action would add an airplane to the applicability. 
This new action also would require replacing the existing MLG downlock 
proximity sensors with new, improved proximity sensors and rigging the 
new sensors in accordance with the airplane maintenance manual. After 
the replacement, this new action would also require removing from the 
AFM the revision to the Normal and Abnormal sections required by the 
existing AD. The actions would be required to be accomplished in 
accordance with the service bulletin described previously, except as 
discussed below.

Differences Between the Proposed AD and the Menasco Service Bulletin

    Operators should note that, although the Menasco service bulletin 
contains procedures for returning certain parts to the manufacturer (BF 
Goodrich), this proposed AD would not include this requirement.

Changes to 14 CFR Part 39/Effect on the Proposed AD

    On July 10, 2002, the FAA issued a new version of 14 CFR part 39 
(67 FR 47997, July 22, 2002), which governs the FAA's airworthiness 
directives system. The regulation now includes material that relates to 
altered products, special flight permits, and alternative methods of 
compliance. Because we have now included this material in part 39, we 
no longer need to include it in each individual AD; therefore, 
paragraphs (b) and (c) and Note 1 of AD 2001-11-10 are not included in 
this proposed AD. However, this proposed AD identifies the office 
authorized to approve alternative methods of compliance.

Cost Impact

    There are approximately 15 airplanes of U.S. registry that would 
affected by this proposed AD.
    The revision of the AFM that is currently required by AD 2001-11-10 
takes approximately 1 work hour per airplane to accomplish, at an 
average labor rate of $65 per work hour. Based on these figures, the 
cost impact of the currently required actions on U.S. operators is 
estimated to be $975, or $65 per airplane.
    The replacement that is proposed in this AD action would take 
approximately 4 work hours per airplane to accomplish, at an average 
labor rate of $65 per work hour. Required parts would be provided free 
of charge. Based on these figures, the cost impact of the proposed 
requirements of this AD on U.S. operators is estimated to be $3,900, or 
$260 per airplane.
    The cost impact figures discussed above are based on assumptions 
that no operator has yet accomplished any of the current or proposed 
requirements of this AD action, and that no operator would accomplish 
those actions in the future if this AD were not adopted.

Regulatory Impact

    The regulations proposed herein 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. Therefore, it 
is determined that this proposal would not have federalism implications 
under Executive Order 13132.
    For the reasons discussed above, I certify that this 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) if promulgated, 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. A copy of the draft 
regulatory evaluation prepared for this action is contained in the 
Rules Docket. A copy of it may be obtained by contacting the Rules 
Docket at the location provided under the caption ADDRESSES.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Safety.

The Proposed Amendment

    Accordingly, pursuant to the authority delegated to my be the 
Administrator, the Federal Administration proposes to amend part 39 of 
the Federal Aviation Regulations (14 CFR part 39) as follows:

[[Page 25505]]

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 removing amendment 39-12253 (66 FR 
30305, June 6, 2001), and by adding a new airworthiness directive (AD), 
to read as follows:

Bombardier, Inc. (Formerly de Havilland, Inc.): Docket 2002-NM-234-
AD. Supersedes AD 2001-11-10, Amendment 39-12253.

    Applicability: Model DHC 8-400 airplanes, serial numbers 4001 
through 4055 inclusive; certified in any category.
    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent failure of the main landing gear (MLG) downlock 
proximity sensors on the same MLG at the same time, which could 
result in the MLG's failure to extent during landing, and cause 
injury to flightcrew and passengers, accomplish the following:

Restatement of the Requirements of AD 2001-11-10

Airplane Flight Manual (AFM) Revision

    (a) Within 14 days after June 21, 2001 (the effective date of AD 
2001-11-10, amendment 39-12253), revise the Normal and Abnormal 
sections of the airplane flight manual (AFM) by inserting the 
following into Section 4.21, opposite page 4.21.1. This may be 
accomplished by inserting a copy of this AD in the AFM.

``CAUTION

    If illumination of LEFT gear safe (green), and LEFT gear unsafe 
(red), and landing gear handle (amber) advisory lights with the 
landing gear handle in the up position.

 Or

    Illumination of RIGHT gear safe (green), and RIGHT gear unsafe 
(red), and landing gear handle (amber) advisory lights with the 
landing gear handling in the up position.
     1. Perform an Alternative Landing Gear extension, See paragraph 
4.21.

WARNING

    Selection of the gear down without following the Alternate 
Landing Gear Extension procedure may result in the affected gear 
being trapped inside the nacelle.
    2.Visually inspect Main Landing Gear to confirm that it has been 
extended.

WARNING

    A down and locked indication of the affected main landing gear 
is not a valid indication of the gear position.
    3. Insert hydraulic pump handle in socket and operate for a 
minimum of 12 full strokes and ensure resistance to pump handle 
movement.
    4. Observe the LEFT gear safe (green) and RIGHT gear safe 
(green) advisory lights are illuminated and the LEFT gear unsafe 
(red) and RIGHT gear unsafe (red) and the landing handle (amber) 
advisory lights are extinguished.''

New Requirements of This AD

Replacement

    (b) Within 6 months after the effective date of this AD, replace 
the left-hand and right-hand MLG downlock proximity sensors with 
new, improved sensors having new part numbers, per the 
Accomplishment Instructions of Bombardier Service Bulletin 84-32-09, 
Revision A, dated November 20, 2001. Once the sensors have been 
replaced, the AFM revision required by paragraph (a) of this AD must 
be removed from the AFM.

    Note: Bombardier Service Bulletin 84-32-09 references Menasco 
Aerospace Service Bulletin 46400-32-09, dated May 15, 2001, as an 
additional source of service information for accomplishment of the 
replacement. The Mensacso service bulletin is included in the 
Bombardier service bombardier service bulletin.

Replacements Accomplished Per Previous Issue of Service Bulletin

    (c) Replacements accomplished before the effective date of this 
AD per Bombardier Service Bulletin 84-32-09, dated May 18, 2001, are 
considered acceptable for compliance with the corresponding action 
specified in this AD.

Alternative Methods of Compliance

    (d) In accordance with 14 CFR 39.19, the Manager, New York 
Aircraft Certification Office (ACO), FAA, is authorized to approve 
alternative methods of compliance (AMOCS) for this AD.

    Note 2: The subject of this AD is addressed in Canadian 
airworthiness directive CF-2001-16R1, dated June 3, 2002.


    Issued in Renton, Washington, on April 27, 2004.
Kevin M. Mullin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 04-10384 Filed 5-6-04; 8:45 am]
BILLING CODE 4910-13-M