AD 98-12-04 Airworthiness Directives; Glaser-Dirks Flugzeugbau GmbH Model DG- 500M Gliders

Model DG-500M gliders, all serial numbers, certificated in any category. Note 1: This AD applies to each glider identified in the preceding applicability provision, regardless of whether it has been modified, altered, or repaired in the area subject to the requirements of this AD. For gliders 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 (d) 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.

Required within the next 3 calendar months after the effective date of this AD, unless already accomplished. To prevent rudder vibrations caused by flow separation at the rudder gap, which could result in flutter with consequent loss of rudder control, accomplish the following: (a) Install a rudder gap seal in accordance with the instructions in the maintenance manual, as referenced in Glaser- Dirks Technical Note (TN) No. 843/5, dated November 30, 1992. (b) Modify the cooling liquid reservoir mount in accordance with Glaser-Dirks Working Instruction No. 1 for TN 843/5, dated November 5, 1992, as referenced in Glaser-Dirks TN No. 843/5, dated November 30, 1992. (c) Special flight permits may be issued in accordance with Secs. 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 shall be forwarded through an appropriate FAA Maintenance Inspector, who may add comments and then send it to the Manager, Small Airplane Directorate. Note 2: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Small Airplane Directorate. (e) Questions or technical information related to Glaser-Dirks Technical Note No. 843/5, dated November 30, 1992, should be directed to DG Flugzeugbau GmbH, Postfach 4120, D-76625 Bruchsal 4, Germany; telephone: +49 7257-89-0; facsimile: +49 7257-8922. This service information may be examined at the FAA, Central Region, Office of the Regional Counsel, Room 1558, 601 E. 12th Street, Kansas City, Missouri 64106. (f) The modification required by this AD shall be done in accordance with Glaser-Dirks Working Instruction No. 1 for Technical Note 843/5, dated November 5, 1992, as referenced in Glaser-Dirks Technical Note No. 843/5, dated November 30, 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 DG Flugzeugbau GmbH, Postfach 4120, D-76625 Bruchsal 4, Germany. Copies may be inspected at the FAA, Central Region, Office of the Regional Counsel, Room 1558, 601 E. 12th Street, Kansas City, Missouri, or at the Office of the Federal Register, 800 North Capitol Street, NW, suite 700, Washington, DC. Note 3: The subject of this AD is addressed in German AD 93-010, dated January 5, 1993. (g) This amendment becomes effective on July 21, 1998. Issued in Kansas City, Missouri, on May 26, 1998. Michael Gallagher, Manager, Small Airplane Directorate, Aircraft Certification Service. [FR Doc. 98-14618 Filed 6-3-98; 8:45 am] BILLING CODE 4910-13-U