[Federal Register Volume 64, Number 119 (Tuesday, June 22, 1999)]
[Proposed Rules]
[Pages 33232-33234]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-15773]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 99-NM-55-AD]
RIN 2120-AA64


Airworthiness Directives; Bombardier Model DHC-8 Series 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 certain Bombardier Model DHC-8 
series airplanes. This proposal would require a one-time inspection of 
the spring assemblies located in the rudder control feel unit to verify 
that dual rate configuration springs are installed; and revising the 
Airplane Flight Manual to prohibit airplane operation from runways less 
than 75 feet wide, if necessary. This proposal also would require 
eventual replacement of any single rate configuration springs with dual 
rate configuration springs, which would terminate the requirement for 
the AFM revision. This proposal is prompted by issuance of mandatory 
continuing airworthiness information by a foreign civil airworthiness 
authority. The actions specified by the proposed AD are intended to 
prevent an asymmetric rudder force condition, which could result in 
reduced controllability of the airplane and consequent potential for 
center line deviation.

DATES: Comments must be received by July 22, 1999.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 99-NM-55-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.
    The service information referenced in the proposed rule may be 
obtained from Bombardier, Inc., Bombardier Regional Aircraft Division, 
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, Engine and Propeller 
Directorate, New York Aircraft Certification Office, 10 Fifth Street, 
Third Floor, Valley Stream, New York.

FOR FURTHER INFORMATION CONTACT: James E. Delisio, Aerospace Engineer, 
Airframe and Propulsion Branch, ANE-171, FAA, Engine and Propeller 
Directorate, New York Aircraft Certification Office, 10 Fifth Street, 
Third Floor, Valley Stream, New York 11581; telephone (516) 256-7521; 
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 notice may be changed in 
light of the comments received.
    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 notice must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 99-NM-55-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. 99-NM-55-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

[[Page 33233]]

Discussion

    Transport Canada Aviation (TCA), which is the airworthiness 
authority for Canada, notified the FAA that an unsafe condition may 
exist on certain Bombardier Model DHC-8 series airplanes. TCA indicated 
that during production of these airplanes, single rate configuration 
springs were inadvertently installed in the rudder control feel units. 
The installation of single rate configuration springs in lieu of the 
correct dual rate configuration springs could require heavier than 
normal rudder pedal forces, causing the pilot to exert extreme pressure 
on the rudder pedal during takeoff or landing resulting in an 
asymmetric rudder force condition. Such conditions could result in 
reduced controllability of the airplane and consequent potential for 
center line deviation.

Explanation of Relevant Service Information

    The manufacturer has issued Bombardier Alert Service Bulletin S.B. 
A8-27-82, dated July 10, 1998, which describes procedures for a one-
time inspection of the spring assemblies located in the rudder control 
feel unit to verify that dual rate configuration springs are installed, 
and replacement of any single rate configuration springs with dual rate 
configuration springs. Accomplishment of the actions specified in the 
alert service bulletin is intended to adequately address the identified 
unsafe condition. TCA classified this alert service bulletin as 
mandatory and issued Canadian airworthiness directives CF-98-39, dated 
October 23, 1998, and CF-98-39R1, dated December 31, 1998; in order to 
assure the continued airworthiness of these airplanes in Canada.

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, TCA has kept the FAA informed of the 
situation described above. The FAA has examined the findings of TCA, 
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 alert service bulletin described 
previously.

Differences Between Proposed Rule and Foreign AD

    The proposed AD would differ from the parallel Canadian 
airworthiness directive in that it would require a revision to the 
operator's Airplane Flight Manual (AFM). The AFM revision would specify 
that operation from runways less than 75 feet wide is prohibited for 
airplanes operating with single rate configuration springs. Operators 
currently follow the procedures specified in deHavilland Supplement No. 
54, ``Operation from Narrow Runways,'' which has not been FAA-approved 
for U.S.-registered airplanes. This supplement allows a minimum runway 
width of 59 feet for airplanes operating with single rate configuration 
springs. The FAA has examined the charts included in the supplement, 
crew training issues, and feedback from U.S. operators, and has 
determined that accomplishment of the AFM revision described previously 
is necessary in order to address the unsafe condition. This is based on 
the FAA's determination that this would not impose an unnecessary 
burden on U.S. operators, and would allow affected airplanes to 
continue to operate without compromising safety.

Cost Impact

    The FAA estimates that 235 airplanes of U.S. registry would be 
affected by this proposed AD.
    It would take approximately 1 work hour per airplane to accomplish 
the proposed inspection, at an average labor rate of $60 per work hour. 
Based on these figures, the cost impact of the inspection proposed by 
this AD on U.S. operators is estimated to be $14,100, or $60 per 
airplane.
    It would take approximately 10 work hours per airplane to 
accomplish the proposed replacement, at an average labor rate of $60 
per work hour. Required parts would be provided by the manufacturer at 
no cost to the operators. Based on these figures, the cost impact of 
the replacement proposed by this AD on U.S. operators is estimated to 
be $141,000, or $600 per airplane.
    If accomplished, it would take approximately 1 work hour per 
airplane to accomplish the AFM revision, at an average labor rate of 
$60 per work hour. Based on these figures, the cost impact of the AFM 
revision on U.S. operators, if accomplished, is estimated to be 
$14,100, or $60 per airplane.
    The cost impact figures discussed above are 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.

Regulatory Impact

    The regulations proposed herein would not have substantial direct 
effects 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, in 
accordance with Executive Order 12612, it is determined that this 
proposal would not have sufficient federalism implications to warrant 
the preparation of a Federalism Assessment.
    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 99-NM-55-AD.

    Applicability: Model DHC-8 series airplanes, as listed in 
Bombardier Alert

[[Page 33234]]

Service Bulletin S.B. A8-27-82, dated July 10, 1998; 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 prevent an asymmetric rudder force condition, which could 
result in reduced controllability of the airplane and consequent 
potential for center line deviation, accomplish the following:

General Visual Inspection

    (a) Within 100 flight hours or 14 days after the effective date 
of this AD, whichever occurs later: Perform a one-time visual 
inspection of the spring assemblies located in the rudder control 
feel unit to verify that dual rate configuration springs are 
installed, in accordance with Bombardier Alert Service Bulletin S.B. 
A8-27-82, dated July 10, 1998.
    (1) If dual rate configuration springs are installed, no further 
action is required by this AD.

AFM Revision

    (2) If any single rate configuration springs are installed, 
prior to further flight: Revise the Limitations Section of the de 
Havilland Dash 8 Airplane Flight Manual (AFM) to include the 
following statement. This action may be accomplished by inserting a 
copy of this AD into the AFM.
``OPERATION FROM RUNWAYS LESS THAN 75 FEET WIDE IS PROHIBITED.''

Terminating Action

    (b) At the next scheduled maintenance visit, but no later than 
36 months after the effective date of this AD: Replace any single 
rate configuration springs located in the rudder control feel unit 
with dual rate configuration springs, in accordance with Part C 
through Part H inclusive, of the Accomplishment Instructions of 
Bombardier Alert Service Bulletin S.B. A8-27-82, dated July 10, 
1998. Such replacement constitutes terminating action for the 
requirements of this AD. After the replacement has been 
accomplished, the AFM limitation required by paragraph (a)(2) of 
this AD may be removed from the AFM.

Spares Paragraph

    (c) As of the effective date of this AD, no person shall install 
any spring assembly having part number 82760050-003 on any airplane.

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, Engine and Propeller Directorate. 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 2: 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 
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 requirements of this AD can be accomplished.

    Note 3: The subject of this AD is addressed in Canadian 
airworthiness directives CF-98-39, dated October 23, 1998, and CF-
98-39R1, dated December 31, 1998.

    Issued in Renton, Washington, on June 15, 1999.
Dorenda D. Baker,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 99-15773 Filed 6-21-99; 8:45 am]
BILLING CODE 4910-13-P