Federal Aviation Administration, DOT.
Notice of proposed rulemaking (NPRM).
This document proposes the supersedure of an existing airworthiness directive (AD) for Eurocopter Deutschland Model EC135 P1 and T1 helicopters that currently requires visual and dye-penetrant inspections for a cracked stator blade of the fenestron tail rotor (tail rotor). That AD also requires either stop drilling a cracked blade or, as necessary, replacing an unairworthy stator blade with an airworthy stator blade. This action would require replacing the existing stator blade assembly with a new stator blade assembly that incorporates a reinforced base and modified riveting and limits the applicability to certain serial numbered tail booms. This proposal is prompted by additional reports of cracked stator blades of the tail rotor. The actions specified by the proposed AD are intended to prevent failure of the tail rotor and subsequent loss of control of the helicopter.
Comments must be received on or before November 17, 2000.
Submit comments in triplicate to the Federal Aviation Administration (FAA), Office of the Regional Counsel, Southwest Region, Attention: Rules Docket No. 2000-SW-19-AD, 2601 Meacham Blvd., Room 663, Fort Worth, Texas 76137. You may also send comments electronically to the Rules Docket at the following address: email@example.com. Comments may be inspected at the Office of the Federal Register between 9 a.m. and 3 p.m., Monday through Friday, except Federal holidays.Start Further Info
FOR FURTHER INFORMATION CONTACT:
Richard Monschke, Aviation Safety Engineer, FAA, Rotorcraft Directorate, Rotorcraft Standards Staff, 2601 Meacham Blvd., Fort Worth, Texas 76137, telephone (817) 222-5116, fax (817) 222-5961.End Further Info End Preamble Start Supplemental Information
Interested persons are invited to participate in the making of the Start Printed Page 56277proposed rule by submitting such written data, views, or arguments as they may desire. Communications should 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 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 mailed comments submitted in response to this notice must submit a self-addressed, stamped postcard on which the following statement is made: “Comments to Docket No. 2000-SW-19-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, Office of the Regional Counsel, Southwest Region, Attention: Rules Docket No. 2000-SW-19-AD, 2601 Meacham Blvd., Room 663, Fort Worth, Texas 76137.
On December 2, 1997, the FAA issued AD 97-20-13, Amendment 39-10240; (62 FR 65198, dated December 11, 1997), to require visual and dye-penetrant inspections for a cracked stator blade of the tail rotor. That AD also requires that a cracked stator blade be stop-drilled or replaced with an airworthy stator blade if the crack is 15mm or longer or if more than three stator blades are affected. That action was prompted by the discovery of cracks on the stator blades of the fenestron tail rotor. The requirements of that AD are intended to prevent failure of the tail rotor and subsequent loss of control of the helicopter.
Since the issuance of that AD, additional cracks have been reported on the stator blades of the fenestron tail rotor. The manufacturer has developed a stator blade assembly that incorporates a reinforced base and modified riveting.
We have identified an unsafe condition that is likely to exist or develop on other Eurocopter Deutschland Model EC135 P1 and T1 helicopters of the same type design. The proposed AD would supersede AD 97-20-13 to require replacing any stator blade assembly, part number (P/N) L 535A4201 052, with a stator blade assembly, P/N L 535A4201 053, that incorporates a reinforced base and modified riveting. The proposed AD would also limit the applicability to certain serial numbered tail booms.
The FAA estimates that 25 helicopters of U.S. registry would be affected by this proposed AD, that it would take approximately 12 work hours per helicopter to accomplish the proposed actions, and that the average labor rate is $60 per work hour. The manufacturer states in its service bulletin that parts and labor will be furnished at no cost. Based on that information, there would be no cost impact from the proposed AD on U.S. operators.
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.Start List of Subjects
List of Subjects in 14 CFR Part 39
- Air transportation
- Aviation 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:Start Part
PART 39—AIRWORTHINESS DIRECTIVES
1. The authority citation for part 39 continues to read as follows:
2. Section 39.13 is amended by removing Amendment 39-10240 (62 FR 65198, dated December 11, 1997), and by adding a new airworthiness directive (AD) to read as follows:
Eurocopter Deutschland: Docket No. 2000-SW-19-AD. Supersedes AD 97-20-13, Amendment 39-10240, Docket No. 97-SW-46-AD.
Applicability: Model EC135 P1 and T1 helicopters, with tail boom serial number EVL 001 through EVL 045, installed, certificated in any category.
This AD applies to each helicopter identified in the preceding applicability provision, regardless of whether it has been otherwise modified, altered, or repaired in the area subject to the requirements of this AD. For helicopters 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 (b) 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 within 90 days, unless accomplished previously.
To prevent failure of the stator blades of the fenestron tail rotor and subsequent loss of control of the helicopter, accomplish the following:
(a) Replace stator blade assembly, part number (P/N) L 535A4201 052, with stator blade assembly, P/N L 535A4201 053.
(b) 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, Regulations Group, Rotorcraft Directorate. Operators shall submit their requests through an FAA Principal Maintenance Inspector, who may concur or comment and then send it to the Manager, Regulations Group.
Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Regulations Group.
(c) Special flight permits may be issued in accordance with §§ 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 and 21.199) to operate the helicopter to a location where the requirements of this AD can be accomplished.
Issued in Fort Worth, Texas, on September 11, 2000.
Acting Manager, Rotorcraft Directorate, Aircraft Certification Service.
[FR Doc. 00-23863 Filed 9-15-00; 8:45 am]
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