Airworthiness Directive · Amendment 39-19189 · Propellers/propulsors
Stemme AG Gliders
This AD applies to Stemme AG Model Stemme S10-VT gliders (type certificate previously held by Stemme GmbH & Co. KG), all serial numbers, and Stemme AG Model Stemme S 12 gliders, all serial numbers, that are:
(1) Equipped with a front gearbox, part number (P/N) 11AG, with a serial number listed in table 1 to paragraph (c) of this AD; and
(2) are certificated in any category.
| 80058/0814 | 80059/0915 | 80060/0915 | 80061/1115 | 80062/1215 |
| 80063/0116 | 80064/0416 | 80065/0616 | 80066/0716 | 80067/0916 |
| 80068/1016 | 80069/0117 | 80070/0217 | 80071/0217 |
Note 1 to paragraph (c) of this AD: Page 2 of Stemme AG Service Bulletin No. P062-980010, dated April 21, 2017, provides a pictorial of where the serial number of the affected gearboxes are located.
We are superseding Airworthiness Directive (AD) 2017-10-11 for Stemme AG Model Stemme S10-VT gliders (type certificate previously held by Stemme GmbH & Co. KG). This AD results from mandatory continuing airworthiness information (MCAI) issued by an aviation authority of another country to identify and address an unsafe condition on an aviation product. The MCAI describes the unsafe condition as certain propeller front transmission gear wheels having insufficient material strength because of improper heat treatment during manufacturing. We are issuing this AD to require actions to address the unsafe condition on these products and to add Stemme AG Model Stemme S 12 gliders to the Applicability section.
Unless already done, do the following actions:
(1) For Model Stemme S10-VT gliders: Before further flight after June 15, 2017 (the effective date of AD 2017-10-11), replace the front gearbox following STEMME Procedural Specification Dok. Nr.: P320-900060, as specified in STEMME Service Bulletin Dok. Nr.: P062-980010, Issue: 01, both dated June 14, 2017.
(2) For Model Stemme S 12 gliders: Before further flight after March 20, 2018 (the effective date of this AD), replace the front gearbox following STEMME Procedural Specification Dok. Nr.: P320-900060, as specified in STEMME Service Bulletin Dok. Nr.: P062-980010, Issue: 01, both dated June 14, 2017.
(3) As of March 20, 2018 (the effective date of this AD), do not install a front gear box listed in table 1 of paragraph (c) of this AD.
(4) The service information for this AD allows the owner/operator to do certain maintenance tasks. Also, the service information specifies certain maintenance tasks be done by Stemme AG. However, for this AD, we do not allow the owner/operator to do any maintenance tasks; all maintenance tasks must be done by an appropriately certified mechanic or maintenance shop. In addition, we do not require any maintenance tasks be done specifically by Stemme AG; any appropriately certified mechanic or maintenance shop may do the tasks required by this AD.
The aircraft, engines and makers this AD names, by the model designations in its text. A model listed here may still be outside the AD's serial ranges.
