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CFR Citation: 14 CFR Part 39

Docket ID: [Docket No. 2003-NM-139-AD]

RIN ID: RIN 2120-AA64

NOTICE: PROPOSED RULES

ACTION: Airworthiness directives:

DOCUMENT ACTION: Notice of proposed rulemaking (NPRM).

SUBJECT CATEGORY: Airworthiness Directives; Bombardier Model CL-215-1A10 and CL- 215-6B11 Series Airplanes

DATES: Comments must be received by January 5, 2004.

DOCUMENT SUMMARY: This document proposes the supersedure of an existing airworthiness directive (AD), applicable to certain Bombardier Model CL2151A10 and CL2156B11 series airplanes, that currently requires repetitive inspections to detect cracking of main landing gear (MLG) axles that have been reworked by chromium plating, and replacement of cracked axles with serviceable axles. This action would add a dimensional check and followon corrective actions, mandate terminating action for certain airplanes, and add three airplanes to the applicability in the existing AD. The actions specified by the proposed AD are intended to prevent cracking of the inner bearing surface of the MLG axles, which could result in failure of an axle, subsequent separation of the wheel from the airplane, and consequent reduced controllability of the airplane during takeoff or landing. This action is intended to address the identified unsafe condition.

SUMMARY: Bombardier,

SUPPLEMENTAL INFORMATION

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 action may be changed in light of the comments received.

Submit comments using the following format:
[sbull] Organize comments issuebyissue. For example, discuss a request to change the compliance time and a request to change the service bulletin reference as two separate issues.
[sbull] For each issue, state what specific change to the proposed AD is being requested.
[sbull] Include justification (e.g., reasons or data) for each request.

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 FAApublic 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 action must submit a selfaddressed, stamped postcard on which the following statement is made: ``Comments to Docket Number 2003NM139AD.'' 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, ANM114, Attention: Rules Docket No. 2003NM139AD, 1601 Lind Avenue, SW., Renton, Washington 980554056.

Discussion

On October 16, 1995, the FAA issued AD 952204, amendment 399411 (60 FR 54421, October 24, 1995), applicable to certain Canadair Model CL2151A10 and CL2156B11 series airplanes, to require inspections to detect cracking of main landing gear (MLG) axles that have been reworked by chromium plating, and replacement of cracked axles with serviceable axles. That action was prompted by reports of fatigue cracking found on several MLG wheel axes that had been chromiumplated during rework. The requirements of that AD are intended to prevent such cracking, which can result in failure of the axle, separation of the wheel from the aircraft, and consequent reduced controllability of the airplane during takeoff or landing.

Actions Since Issuance of Previous AD

Since the issuance of AD 952204, Transport Canada Civil Aviation (TCCA), which is the airworthiness authority for Canada, issued Canadian airworthiness directive CF199308R3, dated March 30, 2000; applicable to certain Bombardier Model CL2151A10 and CL2156B11 series airplanes. The Canadian airworthiness directive was issued to require eventual
[[Page 67972]]
replacement of the MLG axles following an evaluation of the service history that showed the maximum number of allowable landings that could be accumulated on the MLG axles before replacement is necessary. Explanation of Relevant Service Information

Bombardier has issued Service Bulletin 215A462, Revision 3, dated January 17, 2000 (Canadair Alert Service Bulletin 215A462, dated June 2, 1993, was referenced for accomplishment of the actions specified in the existing AD). Revision 3 contains the same inspection procedures as those in the original issue of the service bulletin, but a new dimensional check is added to determine whether the MLG axle has been reworked outside the dimensions specified in the Overhaul Manual. If the axle has been reworked outside those dimensions, has unknown rework dimensions, or has an unknown service life, repetitive ultrasonic inspections (as specified in the existing AD) are recommended until the MLG axle is replaced with a serviceable axle. Revision 3 also recommends replacement of the MLG axles after accumulation of the maximum number of allowable landings on the axles. The replacement eliminates the need for the repetitive inspections. TCCA classified this service bulletin as mandatory and issued Canadian airworthiness directive CF199308R3, dated March 30, 2000, to ensure 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 Sec. 21.29 of the Federal Aviation Regulations (14 CFR 21.29) and the applicable bilateral airworthiness agreement. Pursuant to this bilateral airworthiness agreement, TCCA has kept the FAA informed of the situation described above. We have examined the findings of TCCA, 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 AD

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 supersede AD 952204 to continue to require repetitive inspections to detect cracking of MLG axles that have been reworked by chromium plating, and replacement of cracked axles with serviceable axles. The proposed AD would add a dimensional check and followon corrective actions, mandate terminating action for certain airplanes, add three airplanes to the applicability in the existing AD, and remove the reporting requirement. The actions would be required to be accomplished in accordance with the service bulletin described previously, except as discussed below.

Difference Between Service Bulletin and Proposed AD

The service bulletin referenced in this proposed AD specifies to submit certain inspection findings to the manufacturer; however, this proposed AD does not include such a requirement.

Revised Labor Rate

After the existing AD was issued, we reviewed the figures we use to calculate the labor rate to do the required actions. To account for various inflationary costs in the airline industry, we find it appropriate to increase the labor rate used in these calculations from $60 per work hour to $65 per work hour. The economic impact information, below, has been revised to reflect this increase in the specified hourly labor rate.

Cost Impact

There are approximately 3 airplanes of U.S. registry that would be affected by this proposed AD.

The inspections that are currently required by AD 952204 take about 2 work hours per airplane to accomplish, at an average labor rate of $65 per work hour. Based on these figures, the cost impact of the currently required inspections on U.S. operators is estimated to be $390, or $130 per airplane, per inspection cycle.

The dimensional check and ultrasonic inspection proposed in this AD action would take about 2 work hours per airplane to accomplish, at an average labor rate of $65 per work hour. Based on these figures, the cost impact of these checks and inspections on U.S. operators is estimated to be $390, or $130 per airplane, per inspection cycle.

The replacement proposed in this AD action, if done, would take about 8 work hours per airplane to accomplish, at an average labor rate of $65 per work hour. Required parts would cost approximately $13,000 per assembly (two per airplane). Based on these figures, the cost impact of the replacement proposed by this AD on U.S. operators is estimated to be $26,520 per airplane.

The cost impact figures discussed above are based on assumptions that no operator has yet accomplished any of the current or proposed requirements of this AD action, and that no operator would accomplish those actions in the future if this AD were not adopted. The cost impact figures discussed in AD rulemaking actions represent only the time necessary to perform the specific actions actually required by the AD. These figures typically do not include incidental costs, such as the time required to gain access and close up, planning time, or time necessitated by other administrative actions.

Regulatory Impact

The regulations proposed herein would not have a substantial direct effect 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, it is determined that this proposal would not have federalism implications under Executive Order 13132.

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 39AIRWORTHINESS 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 removing amendment 399411 (60 FR [[Page 67973]]
54421, October 24, 1995), and by adding a new airworthiness directive (AD), to read as follows:
Bombardier, Inc. (Formerly Canadair): Docket 2003NM139AD.

Supersedes AD 952204, Amendment 399411.

Applicability: Model CL2151A10 (piston) and CL2156B11 (turboprop) series airplanes, having serial numbers 1001 through 1125 inclusive, certificated in any category.

Compliance: Required as indicated, unless accomplished previously.

To prevent cracking in the inner bearing surface of the main landing gear (MLG) axles, which could result in failure of an axle, subsequent separation of the wheel from the airplane, and consequent reduced controllability of the airplane during takeoff or landing, accomplish the following:
Restatement of Certain Requirements of AD 952204
Repetitive Inspections/Corrective Action
(a) Within 60 days after November 8, 1995 (the effective date of AD 952204, amendment 399411), perform either an eddy current inspection or a chemical inspection of the inner bearing surface area of the left and right MLG axles to determine if they have been reworked using chromium plating, in accordance with Bombardier Service Bulletin 215A462, dated June 2, 1993, or Revision 3, dated January 17, 2000. If the inner bearing surface of the MLG axle has not been reworked using chromium plating, no further action is required by this paragraph for that axle only.
(b) If the inner bearing surface of the MLG axle has been reworked using chromium plating, prior to further flight, perform an ultrasonic inspection to detect cracking in the axle, in accordance with Bombardier Service Bulletin 215A462, dated June 2, 1993, or Revision 3, dated January 17, 2000.
(1) If no crack is detected during this inspection, repeat the ultrasonic inspection at intervals not to exceed 150 landings. (2) If any crack is detected during this inspection, prior to further flight, remove the cracked axle and replace it with a serviceable axle that does not have an inner bearing surface that has been reworked using chromium plating, in accordance with the service bulletin.
New Requirements of This AD
Dimensional Check/Followon Corrective Actions
(c) Within 150 landings after the effective date of this AD: Do a dimensional check by measuring the diameter of the left and right MLG axles to determine if they have been reworked outside the dimensions specified in Canadair CL215 Overhaul Manual PSP 298, or if the axle has unknown rework dimensions or the service life of that axle cannot be determined, in accordance with Bombardier Service Bulletin 215A462, Revision 3, dated January 17, 2000. (1) If any axle has been reworked outside the specified dimensions, or has unknown rework dimensions, or if the service life of that axle cannot be determined: Prior to further flight, do an ultrasonic inspection to detect cracking of the axle, in accordance with the service bulletin, and replace the axle with a serviceable axle before the accumulation of 1,050 total landings, in accordance with the service bulletin. Such replacement ends the repetitive inspections for that axle only.
(i) If no cracking is detected during the inspection required by paragraph (c)(1) of this AD, repeat the inspection at intervals not to exceed 150 landings, and replace with a serviceable axle before the accumulation of 1,050 total landings.
(ii) If any cracking is detected during the inspection required by paragraph (c)(1) of this AD, prior to further flight, replace the axle with a serviceable axle per the service bulletin.
(2) If the service life of the axle is known, and the axle has not been reworked outside the specified dimensions, no further action is required by this AD for that axle only.
Actions Done Per Previous Issues of Service Bulletin
(d) Inspections and replacements done before the effective date of this AD in accordance with Canadair Alert Service Bulletin 215 A462, dated June 2, 1993; or Bombardier Service Bulletin 215A462, Revision 1, dated August 26, 1996; or Revision 2, dated March 3, 1999; are considered acceptable for compliance with the applicable actions specified in this AD.
Alternative Methods of Compliance
(e) In accordance with 14 CFR 39.19, the Manager, New York Aircraft Certification Office, FAA, is authorized to approve alternative methods of compliance for this AD.

Note 1: The subject of this AD is addressed in Canadian airworthiness directive CF199308R3, dated March 30, 2000.

Issued in Renton, Washington, on November 28, 2003. Kevin Mullin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.
[FR Doc. 0330221 Filed 12403; 8:45 am]
BILLING CODE 491013P

FOR FURTHER INFORMATION CONTACT David Lawson, Aerospace Engineer, Airframe and Propulsion Branch, ANE171, FAA, New York Aircraft Certification Office, 10 Fifth Street, Third Floor, Valley Stream, New York 11581; telephone (516) 2564227; fax (516) 5682716.