Airworthiness Directives; Canadair Model CL-600-1A11, -2A12, and -2B16 Series Airplanes

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 93-NM-207-AD]

Airworthiness Directives; Canadair Model CL-600-1A11, -2A12, and

-2B16 Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Supplemental notice of proposed rulemaking; reopening of

comment period.

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SUMMARY: This document revises an earlier proposed airworthiness

directive (AD), applicable to certain Canadair Model CL-600-1A11, -

2A12, and -2B16 series airplanes, that would have required a test of

the engine throttle quadrant to determine if the throttle lever

bypasses the idle stop into the shut-off position, and modification of

the throttle quadrant or replacement of the throttle quadrant with a

modified unit. That proposal was prompted by reports of unintentional

engine shutdown on certain of these airplanes. This action revises the

proposed rule by requiring a different test and eventual replacement of

the throttle quadrant. The actions specified by this proposed AD are

intended to prevent inadvertent shutdown of an engine while the

airplane is taxiing or in flight.

DATES: Comments must be received by August 2, 1994.

ADDRESSES: Submit comments in triplicate to the Federal Aviation

Administration (FAA), Transport Airplane Directorate, ANM-103,

Attention: Rules Docket No. 93-NM-207-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.

The service information referenced in the proposed rule may be

obtained from Bombardier, Inc., Canadair, Aerospace Group, P.O. Box

6087, Station A, 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, 181 South Franklin

Avenue, Valley Stream, New York.

FOR FURTHER INFORMATION CONTACT: Raymond J. O'Neill, Aerospace

Engineer, Propulsion Branch, ANE-174, FAA, Engine and Propeller

Directorate, New York Aircraft Certification Office, 181 South Franklin

Avenue, Room 202, Valley Stream, New York 11581; telephone (516) 791-

7421; fax (516) 791-9024.

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 93-NM-207-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-103, Attention: Rules

Docket No. 93-NM-207-AD, 1601 Lind Avenue, SW., Renton, Washington

98055-4056. Discussion

A proposal to amend part 39 of the Federal Aviation Regulations (14

CFR part 39) to add an airworthiness directive (AD), applicable to

certain Canadair Model CL-600-1A11, -2A12, and -2B16 series airplanes,

was published as a notice of proposed rulemaking (NPRM) in the Federal

Register on February 9, 1994 (59 FR 5966). That NPRM would have

required a test of the engine throttle quadrant to determine if the

throttle lever bypasses the idle stop into the shut-off position, and

modification of the throttle quadrant or replacement of the throttle

quadrant with a modified unit. That NPRM was prompted by reports of

unintentional engine shutdown on Model CL-600-2A12 and -2B16 series

airplanes. That condition, if not corrected, could result in

inadvertent shutdown of an engine while the airplane is taxiing or in

flight.

Subsequent to the issuance of that NPRM, Transport Canada Aviation,

which is the airworthiness authority for Canada, advised the FAA of an

additional unsafe condition that may exist on these, and additional,

airplanes. While performing a test of the engine throttle quadrant, one

operator discovered that a quick, sharp pull of the throttle lever,

combined with contamination of the surfaces of the idle stop plate and

pawl, could result in inadvertent run-through of the lever past the

idle stop and through the shut-off position. If this were to occur

while the airplane was in flight or while taxiing, it could result in

the inadvertent shutdown of the engines.

Canadair has issued Challenger Service Bulletins 600-0629 (for

Model CL-600-1A11 series airplanes) and 601-0410 (for Model CL-601-2A12

and -2B16 series airplanes), both dated November 1, 1993. These service

bulletins contain new procedures for conducting a check of the idle

stop function of the throttle quadrant and procedures for cleaning,

retesting, and/or replacement of the throttle quadrant, if necessary.

These service bulletins also contain instructions for installing a

modified throttle quadrant. Operators that have previously accomplished

the check and/or modification of the throttle quadrants in accordance

with Canadair Challenger Service Bulletin A600-0615, dated June 10,

1992 (for Model CL-600-1A11 series airplanes), and Service Bulletin

A601-0374 (for Model CL-600-2A12 and -2B16 series airplanes), Revision

1, dated September 30, 1992, must re-check and replace in accordance

with the new service bulletins. The new service bulletins list part

numbers of additional affected throttle quadrants, and serial numbers

of additional (Model CL-600-2B16) airplanes that may also be subject to

the addressed unsafe condition.

Transport Canada Aviation classified these service bulletins as

mandatory and issued Canadian Airworthiness Directive CF-92-23R1, dated

March 31, 1994, in order to assure the continued airworthiness of these

airplanes in Canada.

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, Transport Canada Aviation has kept

the FAA informed of the situation described above. The FAA has examined

the findings of Transport Canada Aviation, 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.

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 a check of the idle

stop function of the throttle quadrant, and repair or replacement of

the throttle quadrant if the check fails. In addition, this proposed AD

would require the eventual replacement of the throttle quadrant with a

new model. The proposed actions would be required to be accomplished in

accordance with the new service bulletins described previously.

Additionally, the applicability of the proposed rule would be expanded

to include additional airplanes that are subject to the addressed

unsafe condition.

Since these changes expand the scope of the originally proposed

rule, the FAA has determined that it is necessary to reopen the comment

period to provide additional opportunity for public comment.

The FAA estimates that 150 airplanes of U.S. registry would be

affected by this proposed AD.

The proposed functional check of the throttle quadrant would take

approximately 1 work hour per airplane to accomplish, at an average

labor rate of $55 per work hour. Based on these figures, the total cost

impact of the proposed functional check on U.S. operators is estimated

to be $8,250, or $55 per airplane.

The proposed installation of a modified throttle quadrant would

take approximately 10 work hours per airplane to accomplish, at an

average labor rate of $55 per work hour. Required parts would be

provided by the manufacturer at no cost to operators. Based on these

figures, the total cost impact of the proposed installation on U.S.

operators is estimated to be $82,500, or $550 per airplane.

Based on the figures discussed above, the total cost impact of this

proposed AD on U.S. operators is estimated to be $90,750, or $605 per

airplane. This total cost impact figure 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 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. App. 1354(a), 1421 and 1423; 49 U.S.C.

106(g); and 14 CFR 11.89.

Sec. 39.13 [Amended]

2. Section 39.13 is amended by adding the following new

airworthiness directive:

CANADAIR: Docket 93-NM-207-AD.

Applicability: Model CL-600-1A11 series airplanes, serial

numbers 1004 through 1085, inclusive, equipped with throttle

quadrant part numbers 600-90601-69, -71,, -73, -75, -77, and -79;

Model CL-600-2A12 series airplanes, serial numbers 3001 through

3066, inclusive, equipped with throttle quadrant part numbers 600-

90601-983, -987, -989, -1013, -1015, -1017, -1019, -1021, -1023,

1025, and -1027; and Model CL-600-2B16 series airplanes, serial

numbers 5001 through 5139, inclusive, equipped with throttle

quadrant part numbers 600-90601-983, -987, -989, -1013, -1015, -

1017, -1019, -1021, -1023, -1025, and -1027; certificated in any

category.

Compliance: Required as indicated, unless accomplished

previously.

To prevent inadvertent shutdown of an engine while the airplane

is taxiing or in flight, accomplish the following:

(a) Within 150 hours time-in-service after the effective date of

this AD, perform a functional test (check) of the idle stop function

of the throttle quadrant in accordance with Part A of the

Accomplishment Instructions of Canadair Challenger Service Bulletins

A600-0629, dated November 1, 1993 (for Model CL-600-1A11 series

airplanes), or A601-0410, dated November 1, 1993 (for Model CL-600-

2A12 and -2B16 series airplanes), as applicable. If the idle stop

functional test fails, prior to further flight, repair or replace

the throttle quadrant in accordance with the applicable service

bulletin.

(b) Within 1,200 flight hours after the effective date of this

AD, replace the throttle quadrant in accordance with Part B of the

Accomplishment Instructions of Canadair Challenger Service Bulletins

A600-0629, dated November 1, 1993 (for Model CL-600-1A11 series

airplanes), or A601-0410, dated November 1, 1993 (for Model CL-600-

2A12 and -2B16 series airplanes), as applicable.

(c) Replacement of the throttle quadrant in accordance with Part

B of the Accomplishment Instructions of Canadair Challenger Service

Bulletins A600-0629, dated November 1, 1993 (for Model CL-600-1A11

series airplanes), or A601-0410, dated November 1, 1993 (for Model

CL-600-2A12 and -2B16 series airplanes), as applicable, constitutes

terminating action for the requirements of this AD.

(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, Standardization Branch, ANM-113,

FAA, Transport Airplane Directorate. Operators shall submit their

requests through an appropriate FAA Principal Maintenance Inspector,

who may add comments and then send it to the Manager,

Standardization Branch, ANM-113.

Note: Information concerning the existence of approved

alternative methods of compliance with this AD, if any, may be

obtained from the Standardization Branch, ANM-113.

(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.

Issued in Renton, Washington, on June 22, 1994. Original signed

by:

S.R. Miller,

Acting Manager, Transport Airplane Directorate, Aircraft Certification

Service.

[FR Doc. 94-15595 Filed 6-27-94; 8:45 am]

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