Prepared: Verified: Complies:

Fiberglas-Technik Service Bulletin (SB-G05) Grob Page 1 of 1

Rudolf Lindner „Control cable pulleys 42 mm“ Sailplanes

EASA AP.161 EASA.A.250 Edition 17.01.2014

Subject: Exchange of the control cable pulleys diameter 42 mm

Effectivity: Grob Sailplanes (data sheet TCDS EASA.A.250)

GROB G 103 TWIN II Serial no. 3501 – 3729 (*)

Serial no. 3730 – 3878

Serial no. 33879 – 34078

GROB G 103A TWIN II ACRO Serial no. 3544 – 3729 (with letter „K“) (*)

Serial no. 3730 – 3878 (with letter „K“)

Serial no. 33879 – 34078 (with letter „K“)

GROB G 103C TWIN III ACRO Serial no. 34101 – 34203 (**)

GROB G 103C TWIN III Serial no. 36001 – 36014 (**)

GROB G 103SL Twin III SL Serial no. 35002 – 35051 (**)

GROB G 102 Standard Astir III Serial no. 5502 – 5652 (with letter „S“)

GROB G 102 Club Astir III Serial no. 5501 – 5652 (with letter „C“)

GROB G 102 Club Astir IIIb Serial no. 5501 – 5652 (with letter „Cb“)

(*) Serial numbers of „Twin II“ and „Twin II Acro“ below 3730 are not affected 

regarding the pulleys in the pedal units.

(**) All „Twin III“, „Twin III Acro“ and „Twin III SL“ have closed cable cages in the 

pedal units and regarding other time limits.

Priority: Replacement of the plastic control cable pulleys with 42 mm diameter has to be 

accomplished

• in case of open cable cages until 31.03.2014

• in case of closed cable cages until 31.05.2014

Replacement of the plastic control cable pulleys with 42 mm diameter in the cable 

circuits of the pedal adjustment / tow hook controls is optional – no time limit.

Reason: “Instructions for the replacement of the control cable pulleys 42 mm (A/I-G05)” are 

provided.

The control cable pulleys in the rudder pedal units of models „Twin II“ and „Twin II 

Acro“ starting at serial no. 3730 and models „Twin III“, „Twin III Acro” and “Twin III 

SL“ (always for the front seat), and also models „ Standard Astir III“, „Club Astir III“ 

and „Club Astir III b“ made fromplastic materials have been installed partly in the 

above mentioned models.

Because these pulley may break thereby reducing the controllability of the 

sailplane, such pulleys need to be replaced against pulleys made from Aluminum. 

Such Aluminum pulleys have been partly already installed during production or 

during maintenance.

Also eventually installed plastic pulleys with 42 mm diameter in the cable controls 

of the pedal adjustment / tow hook controls may be also replaced if needed or 

need replacement when damaged.

Instructions and 

material:

The “Instructions for the replacement of the control cable pulleys 42 mm (A/I-G05)”

have to be added to the technical documentation of the sailplane / motor-glider as 

supplement.

Those instructions have to be followed during the installation process.

The required materials may be ordered at Fiberglas-Technik R.Lindner GmbH & 

Co.KG.

Weight and Balance: The change of weight and balance due to the described change is negligible.

Remarks: The aircraft owner may add the instructions into the maintenance manual.

The correct execution of all further instructions and of the installation has to be 

signed by approved certifying staff personnel in the aircraft logs.

EASA-approved: EASA-approved on 24.01.2014 under No. 10047863