Airworthiness Directives; Canadair Model Turboprop CL-215-6B11 Series Airplanes

DEPARTMENT OF TRANSPORTATION

14 CFR Part 39

[Docket No. 93-NM-135-AD; Amendment 39-8820, AD 94-04-02]

Airworthiness Directives; Canadair Model Turboprop CL-215-6B11

Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment adopts a new airworthiness directive (AD),

applicable to certain Canadair Model CL-215-6B11 series airplanes, that

requires inspections to detect cracking in the rear engine mount

struts, and replacement of struts with new struts, if necessary; and

the eventual replacement of all struts with new struts. This amendment

is prompted by reports of failures of these rear engine mount struts

due to cracking that was caused by rosette welds on the shank of the

struts not achieving full weld penetration during manufacture. The

actions specified by this AD are intended to prevent failure of the

rear engine mount struts, which could subsequently result in reduced

structural integrity of the nacelle and engine support structure.

DATES: Effective April 4, 1994.

The incorporation by reference of certain publications listed in

the regulations is approved by the Director of the Federal Register as

of April 4, 1994.

ADDRESSES: The service information referenced in this AD 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 Federal Aviation Administration (FAA), Transport

Airplane Directorate, Rules Docket, 1601 Lind Avenue, SW., Renton,

Washington; or at the FAA, Engine and Propeller Directorate, New York

Aircraft Certification Office, 181 South Franklin Avenue, room 202,

Valley Stream, New York.; or at the Office of the Federal Register, 800

North Capitol Street, NW., suite 700, Washington, DC.

FOR FURTHER INFORMATION CONTACT: Jeff Casale, Aerospace Engineer,

Airframe Branch, ANE-172, FAA, Engine and Propeller Directorate, New

York Aircraft Certification Office, 181 South Franklin Avenue, room

202, Valley Stream, New York 11581; telephone (516) 791-6220; fax (516)

791-9024.

SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal

Aviation Regulations to include an airworthiness directive (AD) that is

applicable to certain Canadair Model CL-215-6B11 series airplanes was

published in the Federal Register on October 13, 1993 (58 FR 52931).

That action proposed to require repetitive visual inspections to detect

cracking in the rear engine mount struts, and replacement of struts

with new struts, if necessary. That action also proposed to require the

eventual replacement of all struts with new struts; such replacement

would constitute terminating action for the visual inspections.

Interested persons have been afforded an opportunity to participate

in the making of this amendment. No comments were submitted in response

to the proposal or the FAA's determination of the cost to the public.

The FAA has determined that air safety and the public interest require

the adoption of the rule as proposed.

Currently, there are no Canadair Model CL-215-6B11 series airplanes

on the U.S. Register. However, should an affected airplane be imported

and placed on the U.S. Register in the future, it would take

approximately 10 work hours per airplane to accomplish the required

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

parts will be provided by the manufacturer at no cost to the operators.

Based on these figures, the total cost impact of the AD will be $550

per airplane.

The regulations adopted herein will 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 final

rule does not have sufficient federalism implications to warrant the

preparation of a Federalism Assessment.

For the reasons discussed above, I certify that this action (1) is

not a ``significant regulatory action'' under Executive Order 12866;

(2) is not a ``significant rule'' under DOT Regulatory Policies and

Procedures (44 FR 11034, February 26, 1979); and (3) 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 final evaluation has been prepared for this action

and it is contained in the Rules Docket. A copy of it may be obtained

from the Rules Docket at the location provided under the caption

ADDRESSES.

List of Subjects in 14 CFR Part 39

Air transportation, Aircraft, Aviation safety, Incorporation by

reference, Safety.

Adoption of the Amendment

Accordingly, pursuant to the authority delegated to me by the

Administrator, the Federal Aviation Administration amends 14 CFR part

39 of the Federal Aviation Regulations 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:

94-04-02 Canadair: Amendment 39-8820. Docket 93-NM-135-AD.

Applicability: Model CL-215-6B11 series airplanes, serial

numbers 1057, 1061, 1080, 1113 through 1115 inclusive, 1121, 1122,

1124, and 1125; turboprop versions only; certificated in any

category.

Compliance: Required as indicated, unless accomplished

previously.

To prevent failure of the rear engine mount struts, which could

subsequently result in reduced structural integrity of the nacelle

and engine support structure, accomplish the following:

(a) Within 50 hours time-in-service after the effective date of

this AD, perform a visual inspection to detect cracking in the rear

engine mount struts, part number (P/N) 87110016-003, in accordance

with Canadair Alert Service Bulletin 215-A3040, dated September 2,

1992.

(1) If no cracking is detected, repeat the visual inspection

thereafter at intervals not to exceed 50 hours time-in-service,

until the requirements of paragraph (b) of this AD are accomplished.

(2) If any cracking is detected, prior to further flight,

replace the engine rear mount strut with a new strut, P/N 87110016-

009 or -011, in accordance with the service bulletin.

(b) Within 2 years after the effective date of this AD, replace

all engine rear mount struts, with new struts, P/N 87110016-009 or -

011, in accordance with Canadair Alert Service Bulletin 215-A3040,

dated September 2, 1992. Such replacement constitutes terminating

action for the inspections required by this AD.

(c) As of the effective date of this AD, no person shall install

a rear engine mount strut, P/N 87110016-003, on any airplane.

(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: Information concerning the existence of approved

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

obtained from the New York ACO.

(e) Special flight permits may be issued in accordance with

Federal Aviation Regulations (FAR) 21.197 and 21.199 to operate the

airplane to a location where the requirements of this AD can be

accomplished.

(f) The inspections and replacement shall be done in accordance

with Canadair Alert Service Bulletin 215-A3040 dated September 2,

1992. This incorporation by reference was approved by the Director

of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR

Part 51. Copies may be obtained from Bombardier, Inc., Canadair,

Aerospace Group, P.O. Box 6087 Station A, Montreal, Quebec H3C 3G9,

Canada. Copies may be inspected 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, room 202, Valley

Stream, New York; or at the Office of the Federal Register, 800

North Capitol Street, NW., suite 700, Washington, DC.

(g) This amendment becomes effective on April 4, 1994.

Issued in Renton, Washington, on February 4, 1994.

N.B. Martenson,

Acting Manager, Transport Airplane Directorate, Aircraft Certification

Service.

[FR Doc. 94-3104 Filed 3-3-94; 8:45 am]

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