MSB1121-144 

Page 1 of4 

14 July 2014 

Replaces Issue: AI RCR A FT 

SERVICE BULLETIN NO. MSB1121-144 

I. TECHNICAL DETAILS 

1.1 Category: 

Mandatory 

Note: GROB issues Service Bulletins of category Mandatory (MSBs), if the information or 

instructions have a safety intent either related to design or conformity and to 

publish revisions of manuals (AFM, AMM, IPC). However, according to Article 20 

(1) of Regulation (EC) No. 216/2008, only EASA may issue mandatory information, 

in the form of an Airworthiness Directive (AD), in order to react to a given safety 

problem. Service Bulletins classified Mandatory issued by GROB's design 

organisation do not have a legally mandatory character equivalent to an AD, 

cannot have enforcement implications and, therefore, serve as information or 

instruction by GROB only. This also applies to cases where a Service Bulletin is 

published in anticipation of an AD. 

Note: This service bulletin is issued in anticipation of an AD. Issue of an AD will not 

necessarily lead to revision of this service bulletin. 

1.2 Airplanes affected: 

G 120A all SIN 

G 120A-I all SIN 

1.3 Time of Compliance: 

Part A: Before next IFR or VFR Night flight, or within next 50FH, whichever comes first. 

1.4 Subject: 

AT A-Code: 80-00 Starting 

Inspection of starter solenoid 

1.5 Reason: 

Grob received a report about a total loss of electrical power in IMC on a G 115E aircraft. Root 

cause was found to be a defect starter solenoid. The starter solenoid had an internal defect 

causing a short circuit. The defect cannot be detected by visual inspection. The installation is 

similar to the installation on G120 aircraft. 

This Service Bulletin is intended to prevent an unsafe condition. The configuration of the aircraft 

is not affected by this Service Bulletin. 

1.6 Concurrent documents: 

Corresponding AMM 

1. 7 Approval Note: 

The technical content of this document is approved under the authority of EASA Design 

Organization Approval No. EASA21J.030. 

1121 ·144 M$8, Inspection of start., solencid G 120A, A-1 

Grob Aircraft AG, Lettenbachstrasse 9, D-8687 4 Tussenhausen-Mattsies 
MSB1121-144 

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14 July 2014 

Replaces Issue: 

1.8 Accomplishment/Instructions 

Part A One-time Inspection 

1.8.1 Disconnect the aircraft battery, refer to AMM Chapter 24-31. 

1.8.2 Remove the Engine Cowlings, refer to AMM Chapter 71 -10. 

AIRCRAFT 

1.8.3 Visually inspect the starter. Make sure that the power connection bolts have the same 

length, refer to Figure 1 for defective item and Figure 2 for correct installation. 

Figure 1: Incorrect connection bolts Figure 2: Correct installation 

1.8.4 Release the two bolts on the starter solenoid. Carefully pull the solenoid away from the 

starter housing until the dead stop. Make sure that the solenoid plunger is still attached, 

refer to Figure 3. Attach the solenoid to the starter with the two bolts. 

Figure 3: Starter solenoid at dead stop 

1.8.5 If the starter is OK, do step 1.8.7. 

1.8.6 If the starter is not OK or in case of doubt, replace the Starter. 

G 120A, A-1 

Grob Aircraft AG, Lettenbachstrasse 9, D-86874 Tussenhausen-Mattsies 
MSB1121-144 

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14 July 2014 

Replaces Issue: 

1.8.7 Install the Engine Cowlings, refer to AMM Chapter 71 -10. 

1. 8. 8 Connect the aircraft battery, refer to AM M Chapter 24-31 . 

A IR CRAFT 

1.8.9 Release aircraft into service according to national requirements. 

PartS 

Reserved for the terminating action 

1.9 Repetitive Actions 

none 

II. PLANNING INFORMATION 

2.1 Weight and CG 

N/A 

2.2 Material and Availability 

N/A 

2.3 Special Tools 

N/A 

2.4 Labor costs 

N/A 

2.5 Reference documents 

Corresponding AMM and IPC 

2.6 Credit 

N/A 

1121-144 M$8, Inspection olslalter solenoid G 120A, A-1 

Grob Aircraft AG, Lettenbachstrasse 9, D-8687 4 Tussenhausen-Mattsies 
MSB1121-144 

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14 July 2014 

Replaces Issue: 

Ill. REMARKS 

0 

AIRCRAFT 

The instructions in paragraph 1.8 have to be accomplished and certified in the logbook by 

authorized staff: 

- in EASA countries according to Article 5 VO EG 2042/03 (VO EG 1 056/2008) Appendix Ill -

Part 66 

- in non-EASA countries according to national regulations with respect to maintenance. 

If you have sold your aircraft in the meantime, we kindly ask you to forward this information to 

the new owner and to provide us with the name and address of the new owner as well as with 

the respective serial number. 

For questions and assistance please contact: 

phone: 

fax: 

e-mail: 

1121·144 MS8. 1nspeetion of starter soleno:d 

Product Support, 

+49 8268 998105 

+49 8268 998200 

productsupport@grob-aircraft. com 

G 120A, A-1 

Grob Aircraft AG, Lettenbachstrasse 9, D-86874 Tussenhausen-Mattsies