Airworthiness Directives; Alexander Schleicher GmbH & Co. Model ASK 21 Gliders

[Federal Register Volume 60, Number 11 (Wednesday, January 18, 1995)] [Proposed Rules] [Pages 3579-3580] From the Federal Register Online via the Government Publishing Office [www.gpo.gov] [FR Doc No: 95-1128]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 91-CE-25-AD]

Airworthiness Directives; Alexander Schleicher GmbH & Co. Model ASK 21 Gliders

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes to adopt a new airworthiness directive (AD) that would apply to Alexander Schleicher GmbH & Co. (Alexander Schleicher) Model ASK 21 gliders. The proposed action would require replacing the parallel rocker with a part of improved design, and incorporating flight manual revisions. Two incidents of the parallel rocker breaking at the elevator connection on the affected gliders prompted the proposed action. The actions specified by the proposed AD are intended to prevent possible loss of elevator control that could result from a broken parallel rocker.

DATES: Comments must be received on or before March 27, 1995.

ADDRESSES: Submit comments in triplicate to the Federal Aviation Administration (FAA), Central Region, Office of the Assistant Chief Counsel, Attention: Rules Docket No. 91-CE-25-AD, Room 1558, 601 E. 12th Street, Kansas City, Missouri 64106. Comments may be inspected at this location between 8 a.m. and 4 p.m., Monday through Friday, holidays excepted. Service information that applies to the proposed AD may be obtained from Alexander Schleicher GmbH & Company, D-36163, Popppenhausen- Wasserkuppe, Germany; or Eastern Sailplane, Heath Stage Route Shelburne Falls, Massachusetts 01370; telephone (413) 625-6059. This information also may be examined at the Rules Docket at the address above.

FOR FURTHER INFORMATION CONTACT: Mr. Herman C. Belderok, Project Officer, Sailplanes, Small Airplane Directorate, Aircraft Certification Service, FAA, 1201 Walnut, suite 900, Kansas City, Missouri 64106; telephone (816) 426-6932; facsimile (816) 426-2169.

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 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, both before and after the closing date for comments, in the Rules Docket for examination by interested persons. A report that summarizes 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 No. 91-CE-25-AD.'' The postcard will be date stamped and returned to the commenter. [[Page 3580]]

Availability of NPRMs

Any person may obtain a copy of this NPRM by submitting a request to the FAA, Central Region, Office of the Assistant Chief Counsel, Attention: Rules Docket No. 91-CE-25-AD, Room 1558, 601 E. 12th Street, Kansas City, Missouri 64106.

Discussion

The Luftfahrt-Bundesamt (LBA), which is the airworthiness authority for Germany, recently notified the FAA that an unsafe condition may exist on Alexander Schleicher Model ASK 21 gliders. The LBA advises that there have been two instances where the parallel rocker has broken at the elevator connection on the affected gliders. A broken parallel rocker, if not detected and corrected, could result in loss of elevator control. Alexander Schleicher has issued ASK 21 Technical Note (TN) No. 22, dated November 26, 1990, which specifies procedures for replacing the parallel rocker. The LBA has approved this technical note, and issued LBA AD 90-350 to assure the continued airworthiness of these gliders in Germany. This glider model is manufactured in Germany 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, the LBA has kept the FAA informed of the situation described above. The FAA has examined the findings of the LBA, 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 in other Alexander Schleicher Model ASK 21 gliders of the same type design, this proposed AD would require replacing the parallel rocker at the automatic elevator connection with a part of improved design, and incorporating flight manual revisions. The proposed action would be accomplished in accordance with the service information referenced above. The compliance time of the proposed AD is in calendar time instead of hours time-in-service (TIS). The average monthly usage of the affected gliders ranges throughout the fleet. For example, one owner may operate the glider 25 hours TIS in one week, while another operator may operate the glider 25 hours in one year. For this reason, the FAA has determined that, in order to ensure that all of the affected gliders have parallel rockers of improved design installed, a calendar compliance time is proposed. The FAA estimates that 35 gliders in the U.S. registry would be affected by the proposed AD, that it would take approximately 1 workhour per airplane to accomplish the proposed action, and that the average labor rate is approximately $60 an hour. Parts cost approximately $45 per airplane. Based on these figures, the total cost impact of the proposed AD on U.S. operators is estimated to be $3,990. This figure is based on the assumption that no affected glider owner/ operator has accomplished the proposed replacement. Alexander Schleicher has informed the FAA that improved design parallel rockers have been distributed for all 35 affected gliders. Assuming that each of these parts is installed on one of the affected gliders, the proposed action would not impose any cost impact upon U.S. operators. 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 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) 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 has been placed 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 a new AD to read as follows:

Alexander Schleicher GMBH & Co.: Docket No. 91-CE-25-AD.

Applicability: Model ASK 21 gliders (all serial numbers), certificated in any category. Compliance: Required within the next 30 calendar days after the effective date of this AD, unless already accomplished. To prevent possible loss of elevator control that could result from a broken parallel rocker, accomplish the following: (a) Replace the parallel rocker with an improved and stronger part (part number 99.000.4940 with modification status 1) in accordance with the instructions in Alexander Schleicher ASK 21 Technical Note No. 22, dated November 26, 1991. (b) Incorporate the flight manual revisions included with the technical note referenced above. (c) 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 glider to a location where the requirements of this AD can be accomplished. (d) An alternative method of compliance or adjustment of the compliance time that provides an equivalent level of safety may be approved by the Manager, Small Airplane Directorate, FAA, 1201 Walnut, suite 900, Kansas City, Missouri 64106. The request should be forwarded through an appropriate FAA Maintenance Inspector, who may add comments and then send it to the Manager, Small Airplane Directorate.

Note: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Small Airplane Directorate.

(e) All persons affected by this directive may obtain copies of the document referred to herein upon request to Alexander Schleicher GmbH & Company, D-36163, Popppenhausen-Wasserkuppe, Germany; or Eastern Sailplane, Heath Stage Route Shelburne Falls, Massachusetts 01370; telephone (413) 625-6059; or may examine this document at the FAA, Central Region, Office of the Assistant Chief Counsel, Room 1558, 601 E. 12th Street, Kansas City, Missouri 64106.

Issued in Kansas City, Missouri, on January 10, 1995. Barry D. Clements, Manager, Small Airplane Directorate, Aircraft Certification Service. [FR Doc. 95-1128 Filed 1-17-95; 8:45 am] BILLING CODE 4910-13-U