[Federal Register Volume 63, Number 109 (Monday, June 8, 1998)]
[Proposed Rules]
[Pages 31140-31141]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-15136]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-NM-134-AD]
RIN 2120-AA64


Airworthiness Directives; Bombardier Model CL-600-2B19 (Regional 
Jet Series 100) 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 CL-600-
2B19 (Regional Jet Series 100) airplanes. This proposal would require 
repetitive inspections of the inboard and outboard flap actuators to 
measure the rotational freedom of the actuator ball screw adjacent to 
the actuator housing, and replacement of the flap actuators with new or 
serviceable actuators, if necessary. 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 premature wear of the internal gears on the 
flap actuators, which could result in complete disconnection of the 
actuator gear set and a mechanical jam of the flap system. This 
condition could cause structural damage and/or significant twist of a 
flap panel, which could lead to reduced controllability of the 
airplane.

DATES: Comments must be received by July 8, 1998.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 98-NM-134-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., Canadair, Aerospace Group, P.O. Box 
6087, Station Centre-ville, Montreal, Quebec H3C 3G9, 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: Anthony E. Gallo, Aerospace Engineer, 
Systems and Flight Test Branch, ANE-172, FAA, Engine and Propeller 
Directorate, New York Aircraft Certification Office, 10 Fifth Street, 
Third Floor, Valley Stream, New York 11581; telephone (516) 256-7510; 
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 98-NM-134-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. 98-NM-134-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

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 CL-600-2B19 (Regional Jet Series 100) 
airplanes. TCA advises that there have been several in-service reports 
of premature wear of the internal gears on the inboard and outboard 
flap actuators on airplanes returned from service. Such deterioration 
could result in complete disconnection of the actuator gear set and a 
mechanical jam of the flap system, which could cause structural damage 
and/or significant twist of a flap panel, and result in reduced 
controllability of the airplane.

Explanation of Relevant Service Information

    EEMCO has issued Service Bulletin 852D100-27-03, Revision A, dated 
February 27, 1997, including Appendices 1 and 2. This service bulletin 
describes procedures for repetitive inspections of the inboard and 
outboard flap actuators to measure the rotational freedom of the 
actuator ball screw adjacent to the actuator housing to determine the 
allowable intervals for backlash measurement; and replacement of the 
flap actuators with new or serviceable actuators, if necessary. 
Accomplishment of the actions specified in the service bulletin is 
intended to adequately address the identified unsafe condition. TCA 
classified this service bulletin as mandatory and issued Canadian 
airworthiness directive CF-97-05, dated May 5, 1997, in order to assure 
the continued airworthiness of these airplanes in Canada.

[[Page 31141]]

    Bombardier has issued Canadair Regional Jet Alert Service Bulletin 
S.B. A601R-27-069, Revision B, dated March 13, 1997, as an additional 
source of service information for accomplishment of the inspection and 
measurement procedures described in the EEMCO 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, 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 service bulletins described previously.

Cost Impact

    The FAA estimates that 81 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 $60 per work hour. Based on these figures, the 
cost impact of the proposed AD on U.S. operators is estimated to be 
$9,720, or $120 per airplane, per inspection cycle.
    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.

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 Canadair): Docket 98-NM-134-AD.

    Applicability: Model CL-600-2B19 (Regional Jet Series 100) 
airplanes, serial numbers 7003 through 7999 inclusive; 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 (c) 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 premature wear of the internal gears on the flap 
actuators, which could result in complete disconnection of the 
actuator gear set, a mechanical jam of the flap system, significant 
twist of a flap panel leading to structural damage, and consequent 
reduced controllability of the airplane; accomplish the following:
    (a) Prior to the accumulation of 1,000 total flight cycles, or 
within 400 flight cycles after the effective date of this AD, 
whichever occurs later: Inspect the inboard and outboard flap 
actuators to measure the rotational freedom of the actuator ball 
screw adjacent to the actuator housing to determine the allowable 
intervals for backlash measurement, in accordance with EEMCO Service 
Bulletin 852D100-27-03, Revision A, dated February 27, 1997, 
including Appendices 1 and 2. Repeat the inspections thereafter at 
the earliest applicable interval specified in Section 3.A., 
``Inspection Interval Criteria,'' Table I or Table II of the 
Accomplishment Instructions of the service bulletin, as applicable.
    (b) If, during any inspection required by paragraph (a) of this 
AD, the measured backlash exceeds the allowable limit specified in 
Section 3.B., ``Removal Criteria,'' and Table I or Table II of the 
Accomplishment Instructions of the service bulletin, as applicable: 
Prior to further flight, replace the actuator with a new or 
serviceable actuator, in accordance with the times and procedures 
specified in EEMCO Service Bulletin 852D100-27-03, Revision A, dated 
February 27, 1997, including Appendices 1 and 2. Thereafter, repeat 
the inspections in accordance with paragraph (a) of this AD.

    Note 2: Canadair Regional Jet Alert Service Bulletin S.B. A601R-
27-069, Revision B, dated March 13, 1997, is an additional source of 
service information for accomplishment of the inspection and 
measurement procedures described in the EEMCO service bulletin.

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

    (d) 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 4: The subject of this AD is addressed in Canadian 
airworthiness directive CF-97-05, dated May 5, 1997.

    Issued in Renton, Washington, on June 2, 1998.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 98-15136 Filed 6-5-98; 8:45 am]
BILLING CODE 4910-13-U