AD 2020-19-12 Concerns Jamming Between The Double Two-Ring End Of The Towing Cable And The Deflector Angles Of The C.G. Release Mechanism

The FAA is superseding Airworthiness Directive (AD) 2018-21-04 for Glasflugel Models Club Libelle 205, H 301 “Libelle,” H 301B “Libelle,” Kestrel, Mosquito, Standard “Libelle,” and Standard Libelle-201B gliders.

This AD results from 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 jamming between the double two-ring end of the towing cable and the deflector angles of the center of gravity (C.G.) release mechanism. The FAA is issuing this AD to address the unsafe condition on these products. This AD is effective October 22, 2020.

Supplementary Information: The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 by removing AD 2018-21-04, Amendment 39-19462 (83 FR 53573, October 24, 2018) (“AD 2018-21-04”) and adding a new AD. AD 2018-21-04 applied to Glasflugel Models Club Libelle 205, H 301 “Libelle,” H 301B “Libelle,” Kestrel, Mosquito, Standard “Libelle,” and Standard Libelle-201B gliders and required inspecting the distance between the deflector-angles of the C.G. release mechanism and revising the operations section of the sailplane flight manual (SFM) before the next winch launch. The NPRM published in the Federal Register on August 5, 2019 (84 FR 37974).

AD 2018-21-04 was based on MCAI originated by the European Aviation Safety Agency (EASA), which is the Technical Agent for the Member States of the European Community. EASA issued Emergency AD No. 2018-0143-E, dated July 6, 2018 (referred to after this as “the MCAI”), to correct an unsafe condition for the specified products. The MCAI states:
Jamming between the double two ring end of the towing cable and the deflector angles of the C.G. release mechanism was reported. Subsequent investigation identified incorrect geometry of the deflector angles of the affected part as likely cause of the jamming.

This condition, if not detected and corrected, could lead to failure to disconnect the towing cable, possibly resulting in reduced or loss of control of the sailplane.

To address this potential unsafe condition, Glasfaser Flugzeug-Service GmbH issued the TN [Technical Note] to provide inspection instructions and corrective action. For the reasons described above, this [EASA] AD requires repetitive inspections of the affected part, and, depending on findings, accomplishment of applicable corrective action(s). This [EASA] AD also requires amendment of the sailplane Aircraft Flight Manual (AFM).

The FAA issued AD 2018-21-04 as an interim action to address the immediate need for the initial inspection of the distance between the deflector-angles of the C.G. release mechanism, any necessary corrective action, and the revision of the flying operations section of the SFM. In the NPRM, the FAA proposed to supersede AD 2018-21-04 to address the long-term need to repeat the inspection of the C.G. release mechanism for the distance between the deflector-angles at intervals not to exceed 12 months.

FMI: www.regulations.gov