[Federal Register Volume 68, Number 243 (Thursday, December 18, 2003)]
[Proposed Rules]
[Pages 70469-70473]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 03-31183]



[[Page 70469]]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2002-NM-126-AD]
RIN 2120-AA64


Airworthiness Directives; Bombardier Model DHC-8-101, -102, -103, 
-106, -201, -202, -301, -311, and -315 Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes the adoption of a new airworthiness 
directive (AD) that is applicable to all Bombardier Model DHC-8-101, -
102, -103, -106, -201, -202, -301, -311, and -315 airplanes. This 
proposal would require a detailed inspection of the wing leading edge 
de-icer boots to determine if they comply with the patch size and/or 
patch number limits in the critical zone as defined in the Aircraft 
Maintenance Manual; and corrective action, if necessary. This action is 
necessary to prevent reduced aerodynamic smoothness of the wing leading 
edge de-icer boots and possible reduced stall margin, which could 
result in a significant increase in stall speeds, leading to a possible 
stall prior to activation of the stall warning. This action is intended 
to address the identified unsafe condition.

DATES: Comments must be received by January 20, 2004.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 2002-NM-126-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. Comments 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-126-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 or 2000 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, 10 Fifth Street, Third Floor, Valley 
Stream, New York.

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:

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:
    [sbull] 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.
    [sbull] For each issue, state what specific change to the proposed 
AD is being requested.
    [sbull] 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-126-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-126-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    Transport Canada Civil Aviation (TCCA), which is the airworthiness 
authority for Canada, notified the FAA that an unsafe condition may 
exist on certain Bombardier Model DHC-8-101, -102, -103, -106, -201, -
202, -301, -311, and -315 airplanes. The manufacturer has revised the 
Aircraft Maintenance Manual (AMM) to tighten the limit on the size and 
number of repair patches on the de-icer boots in the wing critical zone 
to avoid any adverse effect to the aerodynamic stall margins. The new 
limits are based on the airplane aerodynamic characteristics and the 
smoothness of the boots. Reduced aerodynamic smoothness of the wing 
leading edge de-icer boots, and possible reduced stall margin, if not 
corrected, could result in a significant increase in stall speeds, 
leading to a possible stall prior to activation of the stall warning.

Explanation of Relevant Service Information

    Bombardier has issued revisions to the AMM, listed in the following 
table, which describe procedures for a detailed inspection of the wing 
leading edge de-icer boots for damage and to determine if they comply 
with the patch size and/or patch number limits in the critical zone as 
defined in the AMM. The AMM revisions also describe procedures for 
replacement of non-compliant de-icer boots with new de-icer boots, if 
necessary.

[[Page 70470]]



                                              Table--AMM Revisions
----------------------------------------------------------------------------------------------------------------
                                                       Program
                                                       support
            Model--                     AMM--          manual     Chapter--  Revision--          Dated--
                                                       (PSM)--
----------------------------------------------------------------------------------------------------------------
DHC-8-101, -102, -103, and -106  Series 100........       1-8-2    30-10-48          49  October 3, 2001.
DHC-8-201, and -202............  Series 200........      1-82-2    30-12-00          11  October 19, 2001.
DHC-8-301, -311, and -315......  Series 300........      1-83-2    30-10-48  ..........  October 30, 2001.
----------------------------------------------------------------------------------------------------------------
1 Temporary Revision (TR) 30-21.

    Accomplishment of the actions specified in the applicable AMM 
revision is intended to adequately address the identified unsafe 
condition.
    TCCA classified these actions as mandatory and issued Canadian 
airworthiness directive CF-2001-43, dated November 23, 2001, to ensure 
the continued airworthiness of these airplanes in Canada.

FAA's Conclusions

    These airplane models 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, the TCCA has kept us informed of the 
situation described above. We have 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 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 require accomplishment of 
the actions specified in the Canadian airworthiness directive described 
previously, and corrective actions, if necessary. The corrective 
actions involve the temporary revision of the Aircraft Flight Manual 
(AFM) to specify operating limitations, and eventual replacement of the 
de-icer boots with new boots.

Cost Impact

    We estimate that 200 airplanes of U.S. registry would be affected 
by this proposed AD, that it would take approximately 2 work hours per 
airplane to accomplish the proposed inspection, and that the average 
labor rate is $65 per work hour. Based on these figures, the cost 
impact of the proposed AD on U.S. operators is estimated to be $26,000, 
or $130 per airplane.
    The cost impact figure discussed above is based on assumptions that 
no operator has yet accomplished any of the proposed requirements of 
this AD action, and that no operator would accomplish those actions in 
the future if this AD were not adopted. The cost impact figures 
discussed in AD rulemaking actions represent only the time necessary to 
perform the specific actions actually required by the AD. These figures 
typically do not include incidental costs, such as the time required to 
gain access and close up, planning time, or time necessitated by other 
administrative actions.

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 me by the 
Administrator, the Federal Aviation Administration proposes to amend 
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:

Bombardier, Inc. (Formerly de Havilland, Inc.): Docket 2002-NM-126-
AD.

    Applicability: All Model DHC-8-101, -102, -103, -106, -201, -
202, -301, -311, and -315 airplanes; certificated in any category.
    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent reduced aerodynamic smoothness of the wing leading 
edge de-icer boots and possible reduced stall margin, which could 
result in a significant increase in stall speeds, leading to a 
possible stall prior to activation of the stall warning; accomplish 
the following:

Maintenance Manual Reference

    (a) The term ``Aircraft Maintenance Manual,'' or the acronym 
``AMM,'' as used in this AD, means the chapter of the Bombardier 
Aircraft Maintenance Manuals listed in Table 1 of this AD, as 
applicable:

[[Page 70471]]



                                             Table 1.--AMM Reference
----------------------------------------------------------------------------------------------------------------
                                                       Program
                                                       support
            Model--                     AMM--          manual     Chapter--  Revision--          Dated--
                                                       (PSM)--
----------------------------------------------------------------------------------------------------------------
DHC-8-101, -102, -103, and -106  Series 100........       1-8-2    30-10-48          49  October 3, 2001.
DHC-8-201, and -202............  Series 200........      1-82-2    30-12-00          11  October 19, 2001.
DHC-8-301, -311, and -315......  Series 300........      1-83-2    30-10-48       (\1\)  October 30, 2001.
----------------------------------------------------------------------------------------------------------------
1 Temporary Revision (TR) 30-12.

Detailed Inspection

    (b) Within 60 days after the effective date of this AD: Perform 
a detailed inspection of the wing leading edge de-icer boots to 
determine if the de-icer boots comply with the patch size and/or 
patch number limits in the critical zone as defined in the AMM.

    Note 1: For the purposes of this AD, a detailed inspection is 
defined as: ``An intensive visual examination of a specific 
structural area, system, installation, or assembly to detect damage, 
failure, or irregularity. Available lighting is normally 
supplemented with a direct source of good lighting at intensity 
deemed appropriate by the inspector. Inspection aids such as mirror, 
magnifying lenses, etc., may be used. Surface cleaning and elaborate 
access procedures may be required.''

    (1) If all de-icer boots are within the patch size and/or patch 
number limits in the critical zone as defined in the AMM, no further 
action is required by this paragraph.
    (2) If any de-icer boot exceeds the patch size and/or patch 
number limits in the critical zone as defined in the AMM, accomplish 
the corrective actions required by paragraph (c) of this AD.

Corrective Actions

    (c) For de-icer boots that require the corrective actions 
described in paragraph (b)(2) of this AD, accomplish the following 
corrective actions:
    (1) Before further flight, insert the contents of Table 2 of 
this AD in the Limitations Section of the Aircraft Flight Manual 
(AFM) and advise flight crews to comply with the performance 
penalties detailed in Table 2 of this AD.
    (2) Within 24 months after the effective date of this AD, 
replace all wing de-icer boots that exceed the patch size and/or 
patch number limits in the critical zone as defined in the AMM, with 
new de-icer boots, in accordance with the applicable AMM referenced 
in Table 1 of this AD. Remove the contents of Table 2 of this AD 
from the AFM, and terminate the requirements to comply with the 
performance penalties after all replacements are accomplished.

                     Table 2.--Performance Penalties
------------------------------------------------------------------------
                                    AFM limits with de-ice boot  patch
          AFM sections           limits exceeded  Note: Flap settings as
                                       applicable to aircraft model
------------------------------------------------------------------------
T/O Speed: Sub-Section 5-2
    V1, Vr & V2................  Add:
                                 5 kt (flap 0[deg])
                                 5 kt (flap 5[deg])
                                 5 kt (flap 10[deg])
                                 5 kt (flap 15[deg])
    Final T/O Climb Speed......  Add:
                                 5 kt (flap 0[deg])
--------------------------------
T/O WAT Limit: Sub-Section 5-3
    Note: Weight reduction not   Subtract:
     required when limited by    18 kg, 400 lb. (flap 0[deg])
     maximum structural weight.  90 kg, 200 lb. (flap 5[deg])
                                 No change (flap 10[deg])
                                 No change (flap 15[deg])
--------------------------------
T/O Climb: Sub-Section 5-4
    1st Seg. Gradient..........  Subtract:
                                 0.008 (flap 0[deg])
                                 0.004 (flap 5[deg])
                                 0.004 (flap 10[deg])
                                 0.004 (flap 15[deg])
    2nd Seg. Gradient..........  Subtract:
                                 0.005 (flap 0[deg])
                                 0.002 (flap 5[deg])
                                 0.002 (flap 10[deg])
                                 0.002 (flap 15[deg])
    Final Seg. Gradient........  Subtract:
                                 0.009 (flap 0[deg])
--------------------------------
T/O Field Length: Sub-Section 5-
 5

[[Page 70472]]

 
    TOR, TOD & ASD.............  Add:
                                 16% (flap 0[deg])
                                 16% (flap 5[deg])
                                 16% (flap 10[deg])
                                 16% (flap 15[deg])
--------------------------------
Net T/O Flight Path: Sub-
 Section 5-6
    Ref Gradient...............  Subtract
                                 0.005 (flap 0[deg])
                                 0.002 (flap 5[deg])
                                 0.002 (flap 10[deg])
                                 0.002 (flap 15[deg])
    4th Seg. Net Gradient......  Subtract:
                                 0.012 (flap 0[deg])
    Flap Retraction Initiation   Add:
     Speed.                      5 kt (flap 5[deg])
                                 5 kt (flap 10[deg])
                                 5 kt (flap 15[deg])
--------------------------------
Enroute Climb Data: Sub-Section
 5-7
    Enroute Climb Speed........  Add:
                                 5 kt
    Net Climb Gradient.........  Subtract:
                                 0.004
    OEI-Climb Ceiling..........  Subtract:
                                 1,200 ft
Landing Speed: Sub-Section 5-8
    Approach, Go-around & Vref.  Add:
                                 5 kt (flap 5[deg])
                                 5 kt (flap 10[deg])
                                 5 kt (flap 15[deg])
                                 5 kt (flap 35[deg])
--------------------------------
Landing WAT Limit: Sub-Section
 5-9
    Note: Weight reduction not   Subtract:
     required when limited by    860 kg, 1900 lb.(flap 10[deg])
     maximum structural weight.  225 kg, 500 lb. (flap 15[deg])
                                 180 kg, 400 lb. (flap 35[deg])
--------------------------------
Landing Climb Data: Sub-Section
 5-10
    Approach Gross Climb         Subtract:
     Gradient.                   0.010 (flap 5[deg])
                                 0.003 (flap 10[deg])
                                 0.002 (flap 15[deg])
    Balked Landing Gross Climb   Subtract:
     Gradient.                   0.035 (flap 10[deg])
                                 0.017 (flap 15[deg])
                                 0.016 (flap 35[deg])
--------------------------------
Landing Field Length: Sub-       Add:
 Section 5-11                    23% (flap 10[deg])
                                 16% (flap 15[deg])
                                 10% (flap 35[deg])
--------------------------------
Brake Energy: Sub-Section 5-12
    Accel/Stop B.E.............  Add
                                 7% (flap 0[deg])
                                 7% (flap 5[deg])
                                 7% (flap 10[deg])
                                 7% (flap 15[deg])
    Landing B.E................  Add:
                                 30% (flap 10[deg])
                                 20% (flap 15[deg])
                                 8% (flap 35[deg])
------------------------------------------------------------------------


[[Page 70473]]

Parts Installation

    (d) As of the effective date of this AD, no person may install--
on any airplane--a de-icer boot patch in the critical zone of the 
wing de-icer boots that exceeds the AMM limits referenced in 
paragraph (b) of this AD.

Alternative Methods of Compliance

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

    Note 2: The subject of this AD is addressed in Canadian 
airworthiness directive CF-2001-43, dated November 23, 2001.


    Issued in Renton, Washington, on December 10, 2003.
Kevin Mullin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 03-31183 Filed 12-17-03; 8:45 am]
BILLING CODE 4910-13-P