SAIB CE-03-58

No. CE-03-58 September 26, 2003 We post SAIBs on the internet at www.airweb.faa.gov This is information only. Recommendations are not mandatory.

Introduction This Special Airworthiness Information Bulletin (SAIB) alerts you, an owner or operator of DG FLUGZEUGBAU Model DG-500MB series sailplanes, of a possible safety issue concerning the Warner LA10 engine extension/retraction spindle drive. The affected gliders include all serial numbers up to 5E220B15. Applicability for serial numbers 5E236B16 and 5E237B17 is considered optional based on the initial issue of the manufacturer’s Technical Note No. 843/18.

Background The FAA has received several safety recommendations from the field to address two separate occurrences of possible fatigue failure of the designated spindle drive. During activation and operation, this unit has a potential for rupture. Failure of this mechanism could result in an unstable engine pylon assembly during flight. DG Flugzeugbau GmbH issued the LBA-approved Technical Note No. 843/18; Issue 2, which specifies replacement of the Warner LA10 unit with a Stross BSA 10 unit, a modification in the electrical system, and a change in the maintenance manual. The LBA has not issued an Airworthiness Directive, but has plans to do so in the near future.

Recommendation The FAA strongly recommends an immediate inspection of the Warner LA10 spindle drive and subsequent inspections prior to each flight until the unit is replaced. Failure to replace the spindle drive could result in a failure in the extension/retraction mechanism. It is not sufficient to inspect only the areas that are readily visible, but to inspect the areas hidden by the actuator sleeve assembly. If you find any defects, we recommend that you replace the unit per Technical Note No. 843/18, Issue 2, prior to next flight.

For Further Information Contact Gregory Davison, Aerospace Engineer, FAA, Small Airplane Directorate, Room 301, 901 Locust, Kansas City, Missouri 64106; phone: (816) 329-4130; fax: (816) 329-4090; email: [email protected]

For copies of Technical Note 843/18, Issue 2, go to the Internet at: http://www.dg-flugzeugbau.de/ or contact DG Flugzeugbau at: Otto Lilienthal Weg 2 / AM Flugplatz, D-76646 Bruchsal; phone: 49 7251 3020-0; fax: 49 7251 3020-200.