SAIB ACE-98-05

SPECIAL

AIRWORTHINESS

INFORMATION

BULLETIN

AIRCRAFT CERTIFICATION SERVICE 800 INDEPENDENCE AVENUE, S.W.

WASHINGTON, DC 20591

U.S. Department of Transportation Federal Aviation Administration

No. ACE-98-05 November 12, 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 Model ASK-8 sailplane owners on the following:

• Examination of the canopy lock (Technical Note No. 21)

• Elevator fitting inspection (Technical Note No. 23)

• Canopy retaining cord; inspection/replacement (Technical Note No. 24)

• Rudder pedals; inspection/modification (Technical Note No. 24)

• Elevator control linkage; inspection/replacement (Technical Note No. 24)

• Inspection of fuselage tube skeleton and control linkages for corrosion (Technical Note No. 24)

• Amendment of the K8 Flight and Operations Manual (Technical Note No. 24)

• Specification of the maximum diameter for the wing attachment pins (Technical Note No. 24)

• Strengthening of the plywood web on the outer spar at aileron bell crank (Modification No. 1)

• Removing the fittings to carry the ballast weights (Modification No. 2)

• Changing the middle elevator bearing support (Modification No. 3)

Background The FAA is currently conducting an assessment of fo reign 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 a corresponding U.S. airworthiness directive on U.S.

type certificated Model ASK-8 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 ai rworthiness 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.

Examination of the canopy lock (Technical Note No. 21) Alexander Schleicher has determined that there have been service history that has shown that if the canopy locking cam is not 2 mm high, the canopy may come open in flight. To eliminate this possibility, Alexander Schleicher has issued Tec hnical Note No. 21 that requires inspection and modification of the canopy lock (if required). Fo r your information, LBA Airworthiness Directive 80-158 is enclosed as well as Alexander Schlei cher Technical Note No. 21. The FAA highly encourages you to accomplish this inspection a nd modification on your sailplane. If this inspection/modification has not been accomplished, th e manufacturer has estimated that it will take approximately one hour to conduct the inspection and one hour to accomplish the modification.

Alexander Schleicher has the parts available to accomplish this modification. The cost is approximately $50.00 U.S. dollars for the canopy locking assembly.

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Elevator fitting inspection (Technical Note No. 23) Alexander Schleicher has determined that there has been an occurrence on a Model K7 where the loss of elevator control was caused due to a disbond of a glue joint at the number 1 elevator rib.

The Models K7 and K8 are similar in design in th is area. To eliminate this possibility, Alexander Schleicher has issued Technical Note 23 that requires inspection of the glued joint between rib number 1 and the leading edge plywood and the elev ator spar respectively for adequate condition.

For your information, LBA Airworthiness Directiv e 72-7/3 is enclosed as well as Alexander Schleicher Technical Note No. 23. The FAA highly encourages you to accomplish this inspection, and modification if required, on your sailplane. If this inspection/modification has not been accomplished, the manufacturer has estimated that it will take approximately one hour to conduct the inspection and ten hours to accomplish the modi fication. Alexander Schleicher has the parts available to accomplish this modification. The cost is approximately $50.00 U.S. dollars for a set of pins. NOTE: The FAA issued AD 75-23-03 applicable to this airworthiness issue. Subsequent to the issuance of this AD, there was another occurrence of a disbonding. For this reason, Alexander Schleicher issued Technical Note 23, and the LBA issue the German AD 72-7/3 in December 1989.

Canopy retaining cord; inspection/replacement (Technical Note No. 24) Alexander Schleicher has determined through a serious accident that the canopy did not release from the retaining chord when the canopy was jettis oned. To eliminate this possibility, Alexander Schleicher has issued Technical Note 24, acti on A1, that requires checking whether the canopy retaining chord uses a snap hook as a weak li nk at the fuselage. For your information, LBA Airworthiness Directive 96-005 is enclosed as well as Alexander Schleicher Technical Note No. 24.

The FAA highly encourages you to determine if this modification has been accomplished on your sailplane. If this modification has not been accomplished, the manufacturer has estimated that it will take approximately two hours to accomplish the modification. Alexander Schleicher has stated that locally procured parts are acceptable and will cost approximately $20.00 U.S. dollars to accomplish the modification.

Rudder pedals; inspection/modification (Technical Note No. 24) Alexander Schleicher has determined that there ha ve been several occurrences where the collars of the rudder pedals have bent causing a restriction in the full deflection of the rudder pedals. To eliminate this possibility, Alexander Schleicher has issued Technical Note 24, action A2, that requires modification of the attachment collar of the rudder pedals. For your information, LBA Airworthiness Directive 96-005 is enclosed as well as Alexander Schleicher Technical Note No.

24. The FAA highly encourages you to determine if this modification has been accomplished on your sailplane. If this modification has not been accomplished, the manufacturer has estimated that it will take approximately fifteen hours to accomplis h the modification. Alexander Schleicher has the parts available to accomplish this modification. The cost is approximately $10.00 U.S. dollars.

Elevator control linkage; inspection/replacement (Technical Note No. 24) Alexander Schleicher has determined that there ha ve been five occurrences (one fatal) where the bending has occurred in the elevator push rod cont rol system that caused loss of control of the sailplane. To eliminate this possibility, Alexander Schleicher has issued Technical Note 24, action A3, that requires inspection of the elevator push rods for bending, deformation and or damage. For your information, LBA Airworthiness Directive 96-005 is enclosed as well as Alexander Schleicher Technical Note No. 24. The FAA highly encourages you to determine if this modification has been accomplished on your sailplane. If this modifica tion has not been accomplished, the manufacturer has estimated that it will take approximately tw o hours to conduct the inspection and ten hours to accomplish the modification. Alexander Schleicher has the parts available to accomplish this modification. The cost is approximately $100.00 U.S. dollars.

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Inspection of fuselage tube sk eleton and control linkages for corrosion (Technical Note No.

24) Alexander Schleicher has determined that there ha ve been several occurrences where moisture has entered the structural tubing and caused internal corrosion. To eliminate this possibility, Alexander Schleicher has issued Technical Note 24, action A4, that requires inspection of the fuselage structural tubing and control linkages for corrosion, and if necessary, replace concerned parts. For your information, LBA Airworthiness Directive 96-005 is enclosed as well as Alexander Schleicher Technical Note No. 24. The FAA highly encourages you to determine if this inspection has been accomplished on your sailplane. If this inspecti on has not been accomplished, the manufacturer has estimated that it will take approximately fifteen hours. The time required to accomplish any repairs is dependent on the problems found. Alexander Schleich er has the parts available for this sailplane.

Prices for affected parts may be obtained from the manufacturer.

Amendment of the K8 Flight and Operations Manual (Technical Note No. 24) Alexander Schleicher has determined that Technical Note No. 24 must be inserted into the Flight and Maintenance Manual K8 as an annex to “Attach ments” and the insertion must be certified in the Manual.

Specification of the maximum diameter for the wing attachment pins (Technical Note No. 24) Alexander Schleicher has determined that there have been several occurrences where the wing to fuselage fittings have become loose. This condition can cause premature fatigue and control problems (possibility of flutter). To eliminate th is possibility, Alexander Schleicher has issued Technical Note 24, action B2, that requires insp ection for play between the wing to fuselage attachment. For your information, LBA Airworth iness Directive 96-005 is enclosed as well as Alexander Schleicher Technical Note No. 24. The FAA highly encourages you to accomplish this inspection, and modification if required, on your sailp lane. If this inspection/modification has not been accomplished, the manufacturer has estimated that it will take approximately one hour to conduct the inspection and ten hours to accomplish th e modification. Alexander Schleicher has the parts available to accomplish this modification. Th e cost is approximately $50.00 U.S. dollars for a set of pins.

Strengthening of the plywood web on the outer spar at aileron bell crank (Modification No. 1) Alexander Schleicher has determined that there ha ve been several occurrences of spar web damage when the aileron bellcrank was disconnected. To eliminate this possibility, Alexander Schleicher has issued Modification No. 1 that requires stre ngthening the plywood web on the outer spar at the aileron bellcrank. For your information, Modifica tion No. 1 has been 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 one hour to conduct the inspection and six hours to accomplish the modification. Alexander Schleicher has specified that locally procured parts are acceptable and should cost approximately $20.00 U.S. dollars.

Removing the fittings to carry the ballast weights (Modification No. 2) Alexander Schleicher has determined that there has been one occurrence where the rudder pedal has been caught on the front fitting of the balance we ights. This condition can cause loss of rudder control. To eliminate this possibility, Alexande r Schleicher has issued Modification No. 2 that requires removal of the fittings that carry the ballast weight. For your information, Alexander Schleicher Modification No. 2 is enclosed. Th e FAA highly encourages you to accomplish this modification on your sailplane. If this modifi cation has not been accomplished, the manufacturer has estimated that it will take approximately three hours to accomplish.

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Changing the middle elevator bearing support (Modification No. 3) Alexander Schleicher has determined that there have been several occurrences where the middle elevator bearing support may crack as a result of the welds on the ground plane being ground to thin. This condition can cause limited elevator c ontrol. To eliminate this possibility, Alexander Schleicher has issued Modification No. 3 that requires and inspection and replacement of the ground plate. For your information, Alexander Sc hleicher Modification No. 3 is enclosed. The FAA highly encourages you to accomplish this insp ection and modification on your sailplane. If this inspection/modification has not been accomplis hed, the manufacturer has estimated that it will take approximately one hour to conduct the inspection and ten hours to accomplish the modification. Alexander Schleicher has the parts available to accomplish this modification. The cost is approximately $50.00 U.S. dollars.

Additional Information The FAA has issued the following Airworthiness Directives (AD) on the Alexander Schleicher Model ASK-8. This information is provided to you for your information only.

• AD 64-07-05; To preclude elevator control failu res due to deflection of the long unsupported section of the push-pull control system (Modification No. 7).

• AD 64-09-06; Cracks and faulty welds in the airbrake push-pull rod (Modication No. 9).

• AD 75-19-01; To prevent the failure of the airb rake bellcrank inboard bearing brackets to the main fuselage attachment welds (Modificati on No. 10). NOTE: AD 64-09-06 was superseded by AD 75-19-01.

• AD 75-23-03; To prevent structural failure of the elevator and loss of control of the elevator control. It is necessary to read, “ Elevator fitting inspection (Technical Note No. 23)” in the text above.

For Further Information Contact:

Alexander Schleicher GmbH & Co. Segelf lugzeugbau, Postfach 60, D-36161 Poppenhausen, Germany; Telephone 49.6658.8920; Facsimile 49.6658.8940 or 49.6658.8923.

John Murrey, Eastern Sailplanes, United States Al exander 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.

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FOR ATTACHMENTS, CONTACT: MIKE KIESOV OR BRIAN HANCOCK AT (816) 426-6934.