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 supplemental proposed

airworthiness directive (AD), applicable to certain Canadair Model CL-

600-1A11, -2A12, and -2B16 series airplanes, that would have required a

functional check of the idle stop function of the engine throttle

quadrant; repair or replacement, if necessary; and eventual replacement

of the engine throttle quadrant. That proposal was prompted by reports

of unintentional engine shutdown on certain of these airplanes due to

problems associated with operation of the engine throttle quadrant.

This action further revises the proposed rule by adding a second type

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

levers bypass the idle stop into the shut-off position. The actions

specified by this proposed AD are intended to ensure the proper

operation of the throttle quadrant so as to prevent inadvertent

shutdown of an engine while the airplane is taxiing or in flight.

DATES: Comments must be received by November 23, 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 9:00 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, 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 supplemental notice of proposed rulemaking (NPRM) in

the Federal Register on June 28, 1994 (59 FR 33233). That supplemental

NPRM would have required a functional check of the idle stop function

of the throttle quadrant; repair or replacement of the throttle

quadrant if the check failed; and the eventual replacement of the

throttle quadrant with a new model. In addition, that supplemental NPRM

expanded the applicability of the initially-issued NPRM to include

additional airplanes that were found to be subject to the addressed

unsafe condition.

That supplemental NPRM was prompted by reports of unintentional

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

airplanes when a throttle lever over-rode the idle stop during throttle

retardation, due to a quick, sharp pull on the throttle levers, and the

throttle lever consequently moved directly to the shut-off position.

The proposed functional check (hereafter called ``the abrupt-movement

check'') was intended to ensure that such unintentional shutdowns of

engines would not occur while the airplane is taxiing or in flight. The

abrupt-movement check procedures are described in Canadair Challenger

Service Bulletins A600-0629 and A601-0410, both dated November 1, 1993.

Subsequent to the issuance of that supplemental NPRM, the FAA

became aware that a necessary requirement, which was previously

proposed in the initially-issued NPRM, was incorrectly omitted from the

supplemental NPRM. The original NPRM was published in the Federal

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

required operators to test the engine throttle quadrant to determine if

the throttle levers bypass the idle stop into the shut-off position due

to side loads on the throttle levers; quadrants that failed the test

(hereafter called ``the side-load test'') would be required to be

modified or replaced. Those actions would have been required to be

accomplished in accordance with the instructions contained in Canadair

Alert Service Bulletin A600-0615, dated June 10, 1992 (for Model CL-

600-1A11 series airplanes); or Canadair Alert Service Bulletin A601-

0374, Revision 1, dated September 30, 1992 (for Models CL-600-2A12 and

CL-600-2B16 series airplanes).

The FAA has determined that performance of this side-load test is

necessary in order to adequately address the unsafe condition presented

by the problems identified with the operation of the engine throttle

quadrant.

Operators should note that the originally-issued NPRM would have

required that throttle quadrants failing the side-load test be modified

in accordance with the Canadair service bulletins released in 1992

(referred to above). However, in accordance with the recommendations of

the Canadair service bulletins released in November 1993 (referred to

above), throttle quadrants that failed the abrupt-movement check would

be replaced with a new unit. The FAA has determined that it is not

logical to require that the throttle quadrants be modified if they fail

the side-load test and subsequently be replaced by a new unit if they

fail the abrupt-movement check. The FAA has determined, instead, that

both the side-load test and the abrupt-movement check must be

performed, and units that fail either test must be replaced in

accordance with the Canadair service bulletins dated November 1993.

(Units that pass the tests would be required eventually to be replaced

at a later time.)

Additionally, the compliance time for the proposed eventual

replacement of the engine throttle quadrant on all airplanes was

incorrectly expressed in the previous supplemental NPRM as ``1,200

flight hours.'' The compliance time for this proposed requirement

should have been specified as ``4,500 hours time-in-service.'' (The

``1,200'' figure actually represented the number of landings that is

approximately equivalent to 4,500 hours time-in-service for the

majority of the affected fleet.)

This airplane model is manufactured in Canada and is type

certificated for operation in the United States under the provisions of

Sec. 21.29 of the Federal Aviation Regulations (14 CFR 21.29) and the

applicable bilateral airworthiness agreement.

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, this supplemental NPRM would require:

1. A one-time test of the engine throttle quadrant to determine if

side loads on the throttles will cause the throttle levers to bypass

the idle stop into the shut-off position, and replacement of the

throttle quadrant if it fails this test;

2. A one-time functional check of the engine throttle quadrant to

determine if a quick, sharp pull on the throttles will cause the

throttle levers to bypass the idle stop into the shut-off position, and

replacement of the throttle quadrant if it fails this functional check;

and

3. Replacement of the throttle quadrant as terminating action for

the requirements of this AD.

Additionally, paragraph (e) of this supplemental NPRM indicates the

corrected compliance time of ``4,500 hours time-in-service'' for

replacement of the throttle quadrant. Expressing this compliance time

in terms of ``hours time-in-service'' makes it consistent with the

compliance terms for the other requirements of this proposed AD.

Since certain of these changes expand the scope of the previously

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

the comment period to provide additional opportunity for public

comment.

Cost Impact

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

affected by this proposed AD.

The proposed side-loads test of the engine throttle quadrant would

take approximately 17 work hours per airplane to accomplish the

proposed actions, and that the average labor rate is $55 per work hour.

Based on these figures, the total cost impact of this proposed

requirement on U.S. operators is estimated to be $140,250, or $935 per

airplane.

The proposed abrupt-movement check of the idle stop function 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 $231,000, or $1,540

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.

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. 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 50 hours time-in-service after the effective date of

this AD, perform a test of the engine throttle quadrant to determine

if the throttle levers bypass the idle stop into the shut-off

position, in accordance with Canadair Alert Service Bulletin A600-

0615, dated June 10, 1992 (for Model CL-600-1A11 series airplanes);

or Canadair Alert Service Bulletin A601-0374, Revision 1, dated

September 30, 1992 (for Models CL-600-2A12 and CL-600-2B16 series

airplanes), as applicable.

Note 1: Canadair Alert Service Bulletins A600-0615 and A601-0374

reference Sargent Aerospace Service Bulletins 43058-76-03 (for Model

CL-600-1A11 series airplanes) and 43068-76-05 (for Model CL-600-2A12

and -2B16 series airplanes), both dated April 13, 1992, for

additional service information.

(b) If the test required by paragraph (a) of this AD indicates

that either throttle lever bypasses the idle stop into the shut-off

position, prior to further flight, replace the throttle quadrant in

accordance with Part B of the Accomplishment Instructions of

Canadair Challenger Service Bulletin A600-0629, dated November 1,

1993 (for Model CL-600-1A11 series airplanes); or Canadair

Challenger Service Bulletin A601-0410, dated November 1, 1993 (for

Models CL-600-2A12 and -2B16 series airplanes); as applicable.

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

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

throttle quadrant in accordance with Part A of the Accomplishment

Instructions of Canadair Challenger Service Bulletin A600-0629,

dated November 1, 1993 (for Model CL-600-1A11 series airplanes); or

Canadair Challenger Service Bulletin A601-0410, dated November 1,

1993 (for Models CL-600-2A12 and -2B16 series airplanes); as

applicable.

Note 2: Canadair Challenger Service Bulletins A600-0629 and

A601-0410 reference Sargent Aerospace Service Bulletins 43058-76-04

(for Model CL-600-1A11 series airplanes) and 43068-76-06 (for Model

CL-600-2A12 and -2B16 series airplanes), both dated March 24, 1993,

for additional service information.

(d) If the functional check required by paragraph (c) of this AD

indicates that the idle stop function of the throttle quadrant

fails, prior to further flight, replace the throttle quadrant in

accordance with Part B of the Accomplishment Instructions of

Canadair Challenger Service Bulletin A600-0629 or A601-0410, both

dated November 1, 1993, as applicable.

(e) Within 4,500 hours time-in-service after the effective date

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

of the Accomplishment Instructions of Canadair Challenger Service

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

series airplanes); or Canadair Challenger Service Bulletin A601-

0410, dated November 1, 1993 (for Models CL-600-2A12 and CL-600-2B16

series airplanes); as applicable. Such replacement constitutes

terminating action for the requirements of this AD.

(f) 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 3: Information concerning the existence of approved

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

obtained from the Standardization Branch, ANM-113.

(g) 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 October 13, 1994.

Darrell M. Pederson,

Acting Manager, Transport Airplane Directorate, Aircraft Certification

Service.

[FR Doc. 94-25845 Filed 10-18-94; 8:45 am]

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