SAIB ACE-98-13 —

No. ACE-98-13 November 24, 1997

Published by: FAA, AFS-610, P.O. Box 26460, Oklahoma City, OK 73125 This is issued for informational purposes only and any recommendation for corrective action is not mandatory.

The purpose of this Special Airworthiness Information Bulletin (SAIB) is to provide safety information to Alexander Schleicher Models ASW-19 and ASW-19B sailplane owners on the following:

• Stiffening of the Rudder Surface Panels (Technical Note No. 2) [See Note 1] (ASW-19) • Inspection Panel Jamming Aileron and Flap Controls (Technical Note No. 7) [See Note 1] (ASW-19) • Inadvertent Tow Release (Technical Note No. 18) (ASW-19 and ASW-19B) • Possible Aileron Hinge Shaft Not Correctly Secured (LBA AD 81-74/2) (ASW-19 and ASW-19B) • Increase Service Life/Maintenance Manual Revision (Technical Note No. 25) (ASW-19 and ASW-19B) NOTE 1: Possible Airworthiness Directive actions are currently being evaluated for these selected service difficulty issues.

Background The FAA is currently conducting an assessment of foreign airworthiness directives that have been issued by the German Luftfahrt-Bundesamt (LBA) on German type certificated sailplanes. The LBA has issued German airworthiness directives on the service difficulty issues listed above. The FAA is currently assessing the need to issue corresponding U.S. airworthiness directives on U.S. type certificated Models ASW-19 and ASW-19B sailplanes. In the interim, the FAA is using this Special Airworthiness Information Bulletin to inform U.S. owners of this model sailplane of the service difficulties reported by the manufacturer. If an airworthiness directive is determined to be appropriate, a Notice of Proposed Rulemaking will be issued. The following is a brief description of the main areas of each issue.

Stiffening of the Rudder Surface Panels (Technical Note No. 2) Alexander Schleicher has determined that there has been service history showing that rudder surface panels can flutter near maximum speed on hot days. To eliminate this possibility, Alexander Schleicher has issued Technical Note No. 2 that requires the installation of two additional stringers in the rudder panels. For your information, Alexander Schleicher Technical Note No. 2 is enclosed with drawing number 190.38.S1 (place pages 1 through 4 and 5 through 8 per hand written number alignments for complete drawing). The FAA highly encourages you to ensure that this modification has been accomplished on your sailplane. If this modification has not been accomplished, the manufacturer has estimated that it will take approximately ten hours to accomplish. Alexander Schleicher has the parts available to accomplish this modification. The cost is approximately $50.00 U.S. dollars.

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Inspection Panel Jamming Aileron and Flap Controls (Technical Note No. 7) Alexander Schleicher has determined that an inspection hole cover on the fuselage was pulled into the fuselage by negative pressure and temporarily jammed the ailerons and flap controls. To eliminate this possibility, Alexander Schleicher has issued Technical Note No. 7 that requires modification of the inspection hole. For your information, Alexander Schleicher Technical Note No. 7 and the associated drawings are enclosed. The FAA highly encourages you to accomplish this modification, on your sailplane. If this modification has not been accomplished, the manufacturer has estimated that it will take approximately two hours to accomplish (with the kit provided by Alexander Schleicher). Alexander Schleicher has the parts available to accomplish this modification. The cost is approximately $40.00 U.S. dollars.

Inadvertent Tow Release (Technical Note No. 18) Alexander Schleicher has determined that there have been several occurrences where inadvertent tow hook releases have resulted from an incorrect mounting of the tow release cable guides. To eliminate this possibility, Alexander Schleicher has issued Technical Note No. 18 that requires inspection of the tow release system and modifications as required. For your information, LBA Airworthiness Directive (AD) 84-115 is enclosed as well as Alexander Schleicher Technical Note No. 18. The FAA highly encourages you to determine if this inspection/modification has been accomplished on your sailplane. If this modification has not been accomplished, the manufacturer has estimated that it will take approximately one hour to conduct the inspection and two hours to accomplish the modification. Alexander Schleicher has the parts available to accomplish this modification. The cost is approximately $20.00 U.S. dollars.

Possible Aileron Hinge Shaft Not Correctly Secured (LBA AD 81-74/2) Alexander Schleicher has determined that there has been an occurrence where the aileron hinge was found unsecured. To resolve this potential problem, the LBA has issued AD 81-74/2 that requires inspection of the aileron hinge shaft. For your information, LBA AD 81-74/2 is enclosed. The FAA highly encourages you to determine if the aileron hinges are properly secured on your sailplane. If this aileron hinge is not properly secured, the manufacturer has estimated that it will take approximately one hour to accomplish the modification.

Increase Service Life/Maintenance Manual Revision (Technical Note No. 25) Alexander Schleicher has developed Technical Note No. 25 that increases the service life of the ASK-19 to 12,000 hours. For your information, LBA AD 97-010 is enclosed as well as Alexander Schleicher Technical Note No. 25, with the applicable maintenance manual revisions.

Note: Extension of service life is not considered AD material by the FAA. This information is presented for your information.

Additional Information The FAA has issued the following Airworthiness Directive (AD) on the Alexander Schleicher Models ASW-19 and ASW-19B. This information is provided to you for your information only. • AD 84-13-04; Accomplish Technical Note No. 17 to prevent the occurrence of horizontal tailplane flutter. A copy of this AD is enclosed for your information.

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Further Information Contact: Alexander Schleicher GmbH & Co. Segelflugzeugbau, Postfach 60, D-36161 Poppenhausen, Germany; Telephone 49.6658.8920; Facsimile 49.6658.8940 or 49.6658.8923.

John Murray, Eastern Sailplanes, United States Alexander Schleicher Dealer, 398 Miami Street, Post Office Box 753, Waynesville, OH 45068; Telephone (513) 897-5667; Facsimile (513) 897-5909.

Mike Kiesov, Aerospace Engineer/Pilot, FAA, Small Airplane Directorate, 1201 Walnut, Kansas City, Missouri, 64106; telephone (816) 426-6934; Facsimile (816) 426-2169.