AD 2015-20-11 Airworthiness Directives; Schempp-Hirth Flugzeugbau GmbH Gliders

This AD applies to Schempp-Hirth Flugzeugbau GmbH Model Duo Discus gliders, serial numbers 1 through 639, and Model Duo Discus T gliders, serial numbers 1 through 110 and 112 through 247, certificated in any category.

Unless already done, do the actions in paragraph (f)(1) through (f)(5) of this AD. (1) Within 40 days after November 18, 2015 (the effective date of this AD) and repetitively thereafter at intervals not to exceed 100 hours time-in-service until the terminating replacement action required in paragraphs (f)(2) and (f)(3) of this AD (as applicable) is done, inspect the airbrake bell crank, the airbrake drive funnels, and the airbrake control system. (i) Inspect the airbrake bell crank and the airbrake drive funnels for cracks and damage following Action 1 in Schempp-Hirth Flugzeugbau GmbH Technical Note No. 380 -2/396-17/868-22/890-14, Revision 1, issued July 13, 2015 (published as a single document). (ii) Inspect the airbrake control system for proper clearance following Paragraph 2.d. of Schempp-Hirth Flugzeugbau GmbH Working instruction for Technical Note No. 380-2/396-17/868-22/890-14, Ausgabe (English translation: issue) 1, Datum (English translation: dated) May 11, 2015. (2) If cracks or damage is found on the airbrake bell cranks or the airbrake drive funnels during any inspection required in paragraph (f)(1) of this AD, before further flight, replace each cracked or damaged part with a reinforced part. Installing a reinforced part terminates the repetitive inspections required in paragraph (f)(1) of this AD for that part. (i) For replacement of the airbrake bell cranks, follow Picture 2: Reinforced version of airbrake bell crank according to HS 11-50.016, Revision a or later, in Schempp-Hirth Flugzeugbau GmbH Working instruction for Technical Note No. 380-2/396-17/868-22/890-14, Ausgabe (English translation: issue) 1, Datum (English translation: dated) May 11, 2015. (ii) For replacement of the airbrake drive funnels, follow Picture 5: Airbrake drive funnel in fuselage “Reinforcement of airbrake drive funnel according to drawing S14RB703, Revision a, in Schempp-Hirth Flugzeugbau GmbH Working instruction for Technical Note No. 380-2/396-17/868-22/890-14, Ausgabe (English translation: issue) 1, Datum (English translation: dated) May 11, 2015. (3) If no cracks or damage were found on the airbrake bell cranks or the airbrake drive funnels during any inspection required in paragraph (f)(1) of this AD, within 12 months after November 18, 2015 (the effective date of this AD), replace each of the airbrake bell cranks and airbrake drive funnels with a reinforced part. These replacements terminate the repetitive inspections required in paragraph (f)(1) of this AD. (i) For replacement of the airbrake bell cranks, follow Picture 2: Reinforced version of airbrake bell crank according to HS 11-50.016, Revision a or later, in Schempp-Hirth Flugzeugbau GmbH Working instruction for Technical Note No. 380-2/396-17/868-22/890-14, Ausgabe (English translation: issue) 1, Datum (English translation: dated) May 11, 2015. (ii) For replacement of the airbrake drive funnels, follow Picture 5: Airbrake drive funnel in fuselage, “Reinforcement of airbrake drive funnel according to drawing S14RB703, Revision a,” in Schempp-Hirth Flugzeugbau GmbH Working instruction for Technical Note No. 380-2/396-17/868-22/890-14, Ausgabe (English translation: issue) 1, Datum (English translation: dated) May 11, 2015. (4) If the airbrake control system is found to not have proper clearance during the inspection required in paragraph (f)(1) of this AD, before further flight, make all necessary corrective adjustments following Paragraph 2.d. of Schempp-Hirth Flugzeugbau GmbH Working instruction for Technical Note No. 380-2/396-17/868-22/890-14, Ausgabe (English translation: issue) 1, Datum (English translation: dated) May 11, 2015. (5) As of November 18, 2015 (the effective date of this AD), only install an airbrake bell crank or an airbrake drive funnel that corresponds to Picture 2: Reinforced version of airbrake bell crank according to HS 11-50.016, Revision a or later, and Picture 5: Airbrake drive funnel in fuselage, “Reinforcement of airbrake drive funnel according to drawing S14RB703, Revision a,” in Schempp-Hirth Flugzeugbau GmbH Working instruction for Technical Note No. 380-2/396-17/868-22/890-14, Ausgabe (English translation: issue) 1, Datum (English translation: dated) May 11, 2015, as applicable.

The following provisions also apply to this AD: (1) Alternative Methods of Compliance (AMOCs): The Manager, Standards Office, FAA, has the authority to approve AMOCs for this AD, if requested using the procedures found in 14 CFR 39.19. Send information to ATTN: Jim Rutherford, Aerospace Engineer, FAA, Small Airplane Directorate, 901 Locust, Room 301, Kansas City, Missouri 64106; telephone: (816) 329-4165; fax: (816) 329-4090; email: jim.rutherford@faa.gov. Before using any approved AMOC on any glider to which the AMOC applies, notify your appropriate principal inspector (PI) in the FAA Flight Standards District Office (FSDO), or lacking a PI, your local FSDO. (2) Airworthy Product: For any requirement in this AD to obtain corrective actions from a manufacturer or other source, use these actions if they are FAA-approved. Corrective actions are considered FAA-approved if they are approved by the State of Design Authority (or their delegated agent). You are required to assure the product is airworthy before it is returned to service.

This AD was prompted by mandatory continuing airworthiness information (MCAI) originated by an aviation authority of another country to identify and correct an unsafe condition on an aviation product. The MCAI describes the unsafe condition as excessive load on the air brake system. We are issuing this AD to prevent uncontrolled actuation of the air brakes (symmetric or asymmetric), which could result in reduced control.

None.