AD 2023-17-05 Airworthiness Directives; Schempp-Hirth Flugzeugbau GmbH Gliders

This AD applies to Schempp-Hirth Flugzeugbau GmbH (Schempp-Hirth) Model Ventus-2a and Ventus-2b gliders, all serial numbers, certificated in any category.

Comply with this AD within the compliance times specified, unless already done.

(1) Within 40 days after the effective date of this AD and thereafter at intervals not to exceed 100 hours time-in-service (TIS), do the actions in paragraphs (g)(1)(i) and (ii) of this AD. (i) Inspect the airbrake bell cranks and airbrake drive funnels for cracking at the welding seams, in accordance with Action paragraphs (1a) and (1b) in Schempp-Hirth Technical Note 349-43, dated August 9, 2022 (Schempp-Hirth TN 349-43). (ii) Inspect the clearance of the airbrake control system, in accordance with Action paragraph (1c) in Schempp-Hirth TN 349-43; and Action paragraph (1.c) in Schempp-Hirth Working Instruction for Technical Note 349-43 dated August 9, 2022 (Schempp-Hirth Working Instruction TN 349-43). Where Schempp-Hirth Working Instruction TN 349-43 specifies “if in doubt” use plasticine lines, this AD requires using plasticine lines. Note 1 to paragraph (g)(1): This service information contains German to English translation. The European Union Aviation Safety Agency (EASA) used the English translation in referencing the document from Schempp-Hirth. For enforceability purposes, the FAA will refer to the Schempp-Hirth service information in English as it appears on the document. (2) If, during any inspection required by paragraph (g)(1)(i) of this AD, any cracking at the welding seams is detected, before next flight, do the applicable corrective actions in accordance with Action paragraph(s) (2a), (2b), (2c), and (2d), in Schempp-Hirth TN 349-43; and Action paragraph(s) (2.a), (2.b), (2.c), and (2.d), in Schempp-Hirth Working Instruction TN 349-43. Where Schempp-Hirth Working Instruction TN 349-43 specifies to purchase a new mounting plate with a reinforced airbrake bell crank installed from the manufacturer or its international representative, this AD does not specify the source from which new parts should be purchased. (3) If, during any inspection required by paragraph (g)(1)(ii) of this AD, it is determined that there is interference among the components of the airbrake control system and adjustments to the airbrake control system are needed, do those adjustments in accordance with a method approved by the FAA; EASA; or Schempp-Hirth's EASA Design Organization Approval (DOA). If approved by the DOA, the approval must include the DOA-authorized signature. (4) Unless already accomplished as required by paragraph (g)(2) of this AD, within 12 months after the effective date of this AD, replace the airbrake bell cranks with reinforced airbrake bell cranks and replace the airbrake drive funnels with reinforced drive funnels, in accordance with Action paragraph (2d) in Schempp-Hirth TN 349-43; and Action paragraph(s) (2.a), (2.b), (2.c), and (2.d), in Schempp-Hirth Working Instruction TN 349-43. Where Schempp-Hirth Working Instruction TN 349-43 specifies to purchase a new mounting plate with a reinforced airbrake bell crank installed from the manufacturer or its international representative, this AD does not specify the source from which new parts should be purchased. (5) Replacement on a glider of each airbrake bell crank and airbrake drive funnel with a reinforced airbrake bell crank and a reinforced airbrake drive funnel, as required by paragraph (g)(2) or paragraph (g)(4) of this AD, constitutes terminating action for the repetitive inspections required by paragraph (g)(1) of this AD for that glider. The initial inspection is required for all gliders.

This AD is prompted by reports of uncommanded extraction of the airbrakes on one or both wings, possibly resulting in reduced control of the glider. The FAA is issuing this AD to address this condition. The unsafe condition, if not addressed, could result in reduced control of the glider.

None.