EASA AD No.: 2010-0107

EASA Form 110 Page 1/3 

## EASA AIRWORTHINESS DIRECTIVE

AD No.: 2010-0107

Date: 11 June 2010

Note: This Airworthiness Directive (AD) is issued b y EASA, acting in accordance with Regulation (EC) No 216/2008 on behalf of the European Communit y, its Member States and of the European third countries that participate in the activities of EASA under Article 66 of that Regulation.

This AD is issued in accordance with EC 1702/2003, Part 21A.3B. In accordance with EC 2042/2003 Annex I, Part M.A.301, the continuing airworthiness of an aircraft shall be en sured by accomplishing any applicable ADs. Conseque ntly, no person may operate an aircraft to which an AD applies, except in accordan ce with the requirements of that AD, unless otherwi se specified by the Agency [EC 2042/2003 Annex I, Part M.A.303] or agreed with the Authority of the State of Registry [EC 216/2008, A rticle 14(4) exemption]. 

### Type Approval Holder’s Name:

GROB AIRCRAFT AG Type/Model designation(s):
G 103 C Twin III SL Powered Sailplanes

Approval Number: Germany No. 869

Foreign AD: Not applicable

Supersedure: None



### ATA 61 Propellers - Propeller Assembly – Inspection / Repair

Manufacturer(s): Grob Aircraft AG (formerly Grob Ae rospace GmbH, Grob Luft- & Raumfahrt GmbH)
Applicability: G 103 C Twin III SL powered sailplanes, all serial numbers.

Reason: The in-flight loss of a propeller and pulley wheel from the engine of a Grob G 103 C Twin III SL powered sailplane has been repo rted.
Grob Aircraft AG suspects that the possible reasons for this loss can be due to an incorrect propeller track (the play at the prope ller tip) and/or to a damaged propeller nut securing plate.
Those conditions, if not corrected, could also resu lt in loosening of parts and, consequently could result in damage to the sailplan e and possible injury to persons on the ground.
For the reasons stated above, this AD requires to i nspect the propeller assembly attachment, to verify that the propeller track is w ithin the allowable tolerances and, depending on findings, to accomplish the relev ant corrective actions.

Effective Date: 25 June 2010EASA AD No.: 2010-0107

EASA Form 110 Page 2/3 Required Action(s) and Compliance Time(s): Required as indicated, unless accomplished previous ly: (1) Within 30 days after the effective date of this AD, accomplish the following actions concurrently: (1.1) Update the aircraft documentation (Flight Man ual and Maintenance Manual) in accordance with Grob Aircraft Service Bu lletin (SB) No. MSB 869-24/1. (1.2) Inspect for cracks the bent area of the engag ed tooth of the propeller nut securing plate. (1.3) Verify that the propeller track (the play at the propeller tip) is within the allowable tolerances in accordance with the updated technical documentation (the list of documentation instructio ns is provided in the Grob Aircraft Service Letter (SL) No. SL-869-01).
Note 1 : The torque values and tolerances of the propeller assembly attachment nut have been standardised in the Flight and Mainte nance Manuals. (2) If the bent area of the engaged tooth of the pr opeller nut securing plate has no crack but the propeller track value measured is not within the allowable tolerances, before next flight, readjust the torque of the propeller attachment nut in accordance with the updated aircraft technic al documentation (the list of documentation instructions is provided in the Gr ob Aircraft SL No. SL-869-01). (3) If any crack is found in the bent area of the e ngaged tooth of the propeller nut securing plate, before next flight, accomplish the following actions concurrently: (3.1) Remove the propeller attachment nut and there after bend another tooth (not an already bent tooth) of the securing p late to secure the propeller nut. It is not allowed to bend an already bent tooth. I f all teeth of the securing plate have been already bent, replace the securing plate with a serviceable one. (3.2) Screw back the propeller attachment nut (and its securing plate) and tighten it, applying the torque as defined in the u pdated aircraft technical documentation (the list of documentation instructions is provided in the Grob Aircraft SL No. SL-869-01) and verify accordingly that the propeller track is within the allowable to lerances.
Note 2 : The action required by paragraph (1) of this AD m ay also be accomplished by a Part-66 qualified person in accor dance with M.A. 801 (b)2.

Ref. Publications: Grob Aircraft AG Service Bulleti n No. MSB-869-24/1 dated 20 July 2009.
Grob Aircraft AG Service Letter No. SL-869-01 dated 9 June 2009. The use of later approved revisions of these docume nts is acceptable for compliance with the requirements of this AD.

Remarks: 1. If requested and appropriately substantiated, EA SA can approve Alternative Methods of Compliance for this AD.
2. The required actions and the risk allowance have granted the issuance of a Final AD with Request for Comments, postponing the public consultation process after publication.
3. Enquiries regarding this AD should be referred t o the Airworthiness Directives, Safety Management & Research Section, C ertification Directorate, EASA. E-mail ADs@easa.europa.eu

.EASA AD No.: 2010-0107

EASA Form 110 Page 3/3 4. For any question concerning the technical conten t of the requirements in this AD, please contact: Grob Aircraft AG; Lettenb achstr. 9; TussenhausenMattsies; Head of Customer Service & Support, Germa ny Telephone: +49 (0) 8268 998 139, Fax: +49 (0) 8268 998 200 E-mail: productsupport@grob-aircraft.com , Website: www.grob-aircraft.com and/or www.firecmm.com

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