ALERT SERVICE BULLETIN

MBB BK117 C-2

MBB BK117 C-2-67A-010

PAGE 1 of 14

2008-04-28

REVISION 03, 2010-02-08

Rotor Flight Control – Tail Rotor- and Lateral Control – Check bearings

for correct attachment and retrofit of bushings

1. Planning Information

A. Effectivity

(1) Helicopters affected: All MBB BK117 C-2.

(2) Components affected: Tail rotor control:

RH lever assy B672M1007101

RH lever B672M1002202

LH lever assy B672M1807101

LH lever L672M2802205

Lateral control: 

Lever assy B670M1008101

(3) Spare parts affected: Tail rotor control:

RH lever assy B672M1007101

RH lever B672M1002202

LH lever assy B672M1807101

LH lever L672M2802205

Lateral control: 

Lever assy B670M1008101

B. Concurrent Requirements

Not applicable.

C. Reason

During inspection of a helicopter, bearings have been detected which were not correctly

bonded and staked. In one case, the bonding of such a bearing had become loose. In

another case, bearings have been detected which were not or not properly staked. Not

properly attached bearings may cause the lever to shift in the axial direction. Under

unfavorable circumstances, the levers might get into contact with the helicopter structure

and thus impair the controls’ freedom of movement.

Therefore, with this Alert Service Bulletin the affected bearings must be checked for correct

attachment.

Further on, the retrofit of bushings is prescribed to prevent moving of the bearings in axial

direction.

D. Description

Check attachment of bearings. If necessary, rebond bearings or replace levers and inform

ECD customer service. Retrofit of the bushings.

This document is available on the internet: www.eurocopter.com/techpub
ALERT SERVICE BULLETIN

MBB BK117 C-2

MBB BK117 C-2-67A-010

PAGE 2 of 14 REVISION 03, 2010-02-08

2008-04-28

E. Compliance

(1) For the First Issue and the Revision 01 the following duration for accomplishment was

valid:

EFFECTIVITY RH lever assy B672M1007101 and LH lever assy B672M1807101.

(a) The inspection and the possibly necessary replacement or repair of the levers

i.a.w. Section 3.B. must be accomplished within the next 50 fh after receipt of this

Alert Service Bulletin, but by 31.05.2008 at the latest.

EFFECTIVITY RH lever B672M1002202 and LH lever L672M2802205.

(b) The inspection and the possibly necessary replacement or repair of the levers

i.a.w. Section 3.B. must be accomplished within the next 50 fh after receipt of this

Alert Service Bulletin, but by 31.07.2008 at the latest.

EFFECTIVITY MBB BK117 C-2 S/N 9004 up to and including S/N 9310 before

retrofit of the bushings i.a.w. 3.C.

(c) The check of the levers i.a.w. Section 3.B. must be repeated together with the

periodical inspection or with the 12-month inspection (whatever comes first).

(2) For Revision 02 of this Alert Service Bulletin, the following is added:

EFFECTIVITY MBB BK117 C-2 S/N 9004 up to and including S/N 9310.

(a) The retrofit of the bushings must be accomplished within the next 12 months after

receipt of this Alert Service Bulletin, Revision 02 (2009-12-16) i.a.w. 3.C.

EFFECTIVITY MBB BK117 C-2 with additional bushings i.a.w. 3.C.

(b) The check of the bushings must be repeated together with the periodical inspection

at 600 FH or 24 months (whatever comes first).

EFFECTIVITY Levers given in Section 1.A.(3) delivered before receipt of

Revision 02 (2009-12-16).

(c) Installed levers must be inspected i.a.w. Section 3.B not later than 50 fh after

receipt of this Alert Service Bulletin, Revision 03.

(d) Not installed levers should be returned to ECD or, if the levers are to be installed,

they must be inspected i.a.w. Section 3.B not before 10 fh have been reached but

not later than 50 fh after their installation.

F. Approval

The information or instruction contained in this document refer to change no. 1787. The

technical content of this document is approved under the authority of DOA No.

 EASA.21J.034.
ALERT SERVICE BULLETIN

MBB BK117 C-2

MBB BK117 C-2-67A-010

PAGE 3 of 14

2008-04-28

REVISION 03, 2010-02-08

G. Manpower

Approx. 1 man-hour for the check.

Approx. 32 man-hours for the retrofit of the bushings.

H. Weight and Balance

Not applicable.

I. Electrical Load Data

Not applicable.

J. Software Accomplishment Summary

Not applicable.

K. References

AMM MBB BK117 C-2.

L. Other publications affected

The required changes to the AMM MBB BK117 C-2, IPC MBB BK117 C-2 and

MSM MBB BK117 C-2 which are a result of this Alert Service Bulletin will be incorporated

with one of the next revisions.

M. Interchangeability of Parts

(1) With accomplishment of this Alert Service Bulletin the following part numbers are

changing:

– Guidance unit RH from B672M1002103 to B672M1002104

– Guidance unit LH from B672M1805101 to B672M1805102

– Guidance unit LAT from B670M1002102 to B670M1002103

(2) If a lever B670M1008101 is replaced, it is possible to install a lever B670M1008101

after modification of the lever i.a.w. Section 3.C.(9)(d) of this Alert Service Bulletin or to

use a lever B670M1008102 without any modification.

2. Material Information

A. Material – Price and Availability

Information on cost and availability of required retrofit kit SB-117C2-67A-010-2C-1 will be

provided by ECD, Dept. Spares Order Administration on request.

B. Support Information

Not applicable.
ALERT SERVICE BULLETIN

MBB BK117 C-2

MBB BK117 C-2-67A-010

PAGE 4 of 14 REVISION 03, 2010-02-08

2008-04-28

C. Material Necessary for Each Helicopter

EFFECTIVITY MBB BK117 C-2 S/N 9004 up to and including S/N 9310.

Retrofit kit SB-117C2-67A-010-2C-1 similar to design documents B670M1008102,

B672M1002104 and B672M1805102.

No. New P/N Keyword Old P/N Qty Disposition

1 L672M1012260 Bushing − 2 A

B670M1008208 Bushing − 1 A

2 − B670M1013201

or

B670M1008207

B

3 MBBN312906D Castle Nut

lf l ki

− 3 A

− self locking MBBN312906D B

4 LN9415018 Split Pin LN9415018 2 A

5 EN236714010 Split Pin EN236714010 1 A

6 − Cleaner

(CM 2001)

− a.n.* C

7 − Corrosion Preventive Paste

(CM 518)

− a.n.* C

8 − Lacquer, singlelayer

(CM 421)

− a.n.* C

*a.n. = as needed

Disposition:

A = New, included in kit.

B = Part with old P/N is discarded.

Discarded parts are not taken back by ECD.

C = Consumable material, to be ordered as required from the Interturbine company.

CM item number i.a.w. list of consumable materials in the AMM.

D. Material Necessary for Each Spare

Not applicable.

E. Reidentified Parts

Not applicable.

F. Special Tooling

Not applicable.
ALERT SERVICE BULLETIN

MBB BK117 C-2

MBB BK117 C-2-67A-010

PAGE 5 of 14

2008-04-28

REVISION 03, 2010-02-08

3. Accomplishment Instructions

A. Preliminary work steps:

(1) De–energize helicopter electrical system i.a.w. AMM, 24-00-00, 2-1.

(2) Remove bottom access cover i.a.w. AMM, 52-40-00, 4-2.

B. Check bearings for correct attachment:

CAUTION BEFORE STARTING WORK, AFFIX A PLACARD IN THE COCKPIT

WHICH SAYS THAT THE CONTROLS MUST NOT BE MOVED.

OPERATING THE CONTROLS DURING THE CHECK MAY CAUSE

SERIOUS INJURIES.

NOTE The check requires a flashlight and a mirror.

(1) Check bearing in RH guidance unit (Detail B, Figure 2) for correct attachment.

(a) Check, whether bearings (1, 2, Figure 2) are correctly installed in lever (3) as

shown in Section B–B.

(b) Manually check, whether bearings (1) and (2) are tightly fitted in lever (3). To do

so, manually try to move lever in axial direction . After this, manually try to move

the forked end in axial direction .

(c) If a loose bearing is detected, copy reply form sheet on page 14, fill out and send

to ECD customer support. Replace lever (3) or rebond bearing i.a.w. AMM,

20-00-00, 2-23.

(2) Check bearing in LH guidance unit (Detail C, Figure 2) for correct attachment.

(a) Check, whether bearing (1, Figure 2) is correctly installed in lever (4) as shown in

Section C–C.

(b) Manually check, whether bearing (1, Figure 2) is tightly fitted in lever (4). To do so,

manually try to move lever (4) in axial direction .

(c) If a loose bearing is detected, copy reply form sheet on page 14, fill out and send

to ECD customer support. Replace lever (4) or rebond bearing i.a.w. AMM,

20-00-00, 2-23.

(3) Check bearing in guidance unit of lateral control (Detail D, Figure 3) for correct

attachment.

(a) Check, whether bearing (1, Figure 3) is correctly installed in lever (3) as shown in

Section D–D.

(b) Manually check, whether bearings (1, Figure 3) are tightly fitted in lever (3). To do

so, manually try to move lever in axial direction .

(c) If the staked bearing is loose, replace lever (3). Copy reply form sheet on page 14,

fill out and send together with lever to ECD customer support.
ALERT SERVICE BULLETIN

MBB BK117 C-2

MBB BK117 C-2-67A-010

PAGE 6 of 14 REVISION 03, 2010-02-08

2008-04-28

C. Retrofit of the bushings:

EFFECTIVITY MBB BK117 C-2 S/N 9004 up to and including S/N 9310.

(1) Remove the right hand Guidance Unit i.a.w. AMM, 67-20-00, 4-3.

(2) Disassemble the right hand Guidance Unit i.a.w. AMM, 67-20-00, 4-4.

(3) Assemble the right hand Guidance Unit i.a.w. AMM, 67-20-00, 4-4. While you do so,

other than the given details of the AMM, attach the bushing (3) between the lever (1)

and the bracket (2) (see detail B, figure 4).

(4) Install the right hand Guidance Unit i.a.w. AMM, 67-20-00, 4-3.

(5) Remove the left hand Guidance Unit i.a.w. AMM, 67-20-00, 4-3.

(6) Disassemble the left hand Guidance Unit i.a.w. AMM, 67-20-00, 4-4.

(7) Assemble the left hand Guidance Unit i.a.w. AMM, 67-20-00, 4-4. While you do so, other

than the given details of the AMM, attach the bushing (3) between the lever (5) and the

bracket (4) (see detail C, figure 4).

(8) Install the right hand Guidance Unit i.a.w. AMM, 67-20-00, 4-3.

(9) Remove the lateral control lever (13, figure 5) as follows:

(a) Remove the split pin (3), the nut (2), the washer (4) and the screw (15) from the

control rod (1). Discard the split pin (3) and the nut (2).

(b) Remove the split pin (18), the nut (17), the washer (16) and the screw (14) from

the flex ball (19). Discard the split pin (18) and the nut (17).

(c) Remove the split pin (7), the nut (6), the washers (5, 9) and the screw (10) from the

bracket (8) and remove the lever (13) with the bushings (11, 12) from the

bracket (8). Discard the split pin (7) and the nut (6).

(d) Remove the ball bearing (2, figure 3) and the bushing (4) from the lever (3).

Discard bushing (4).

(e) Clean the lever (3) with cleaner (CM 2001).

(f) Install the new bushing (2, figure 6) and the ball bearing (4) at the lever (1).

(g) After installation, check that the ball bearing (4, figure 6) is correctly fitted in the

lever (1) (see detail D, figure 6).

(h) Identification of the lever assy:

1 Using a permanent marking pen, write the number of this Alert Service

Bulletin on the lever (1) and protect it by means of lacquer, single-layer

(CM 421).
ALERT SERVICE BULLETIN

MBB BK117 C-2

MBB BK117 C-2-67A-010

PAGE 7 of 14

2008-04-28

REVISION 03, 2010-02-08

WARNING CORROSION PREVENTIVE PASTE IS A POISONOUS MATERIAL.

IT CAN CAUSE CANCER. ONLY USE IN AN AREA THAT IS OPEN

TO A FLOW OF CLEAN AIR. DO NOT BREATHE THE FUMES. DO

NOT LET IT TOUCH YOUR SKIN OR YOUR EYES. IF IT TOUCHES

YOU, FLUSH IMMEDIATELY WITH A LARGE QUANTITY OF

CLEAN WATER AND SOAP. USE EQUIPMENT TO BREATHE,

GOGGLES AND GLOVES WHEN YOU USE IT. IT IS FLAMMABLE.

KEEP IT AWAY FROM FLAMES AND SPARKS.

(i) Apply Corrosion Preventive Paste (CM 518) on the shank of the screw 

(10, figure 5) and install the lever (13) with the bushings (11, 12), the screw (10),

the washers (5, 9) and the new nut (6) at the bracket (8). Tighten the nut (6)

(torque load 4–5 Nm) and secure the nut (6) with a new split pin (7).

(j) Apply Corrosion Preventive Paste (CM 518) on the shank of the screw (15) and

install the control rod (1) with the screw (15), the washer (4) and the new nut (2)

at the lever (13). Tighten the nut (2) (torque load 3–4 Nm) and secure the nut (2)

with a new split pin (3).

(k) Apply Corrosion Preventive Paste (CM 518) on the shank of the screw (14) and

install the flex ball (19) with the screw (14), the washer (16) and the new nut (17)

at the lever (13). Tighten the nut (17) (torque load 3–4 Nm) and secure the nut (17)

with a new split pin (18).

D. Conclusive work:

(1) Accomplish inspection for foreign objects and for foreign matter.

(2) Install bottom access cover i.a.w. AMM, 52-40-00, 4-2.

E. Confirm accomplishment of this Alert Service Bulletin by an entry in the historical record of

the helicopter.

4. Appendix

Not applicable.
ALERT SERVICE BULLETIN

MBB BK117 C-2

MBB BK117 C-2-67A-010

PAGE 8 of 14 REVISION 03, 2010-02-08

2008-04-28

Tail Rotor and Lateral Control

Figure 1

1 LH guidance unit

2 RH guidance unit

3 Guidance unit of lateral control

1

3

View A

B

C

D

Detail B, C see Figure 2

Detail D see Figure 3

2

A
ALERT SERVICE BULLETIN

MBB BK117 C-2

MBB BK117 C-2-67A-010

PAGE 9 of 14

2008-04-28

REVISION 03, 2010-02-08

Detail B and C of Figure 1

Figure 2

1 Double grooved ball bearing (bonded) AG12EG81

2 Roller bearing (bonded) EN2015BN06E

3 RH lever assy B672M1007101

RH lever B672M1002202

4 LH lever assy B672M1807101

LH lever L672M2802205

1 2

Lever must be free of play in axial direction.

Forked lever must be free of play in axial direction.

3

Detail B (overview see figure 1) before modification

1

4

B

B

Section

B–B

Section

C–C C

C

Detail C (overview see figure 1) before modification
ALERT SERVICE BULLETIN

MBB BK117 C-2

MBB BK117 C-2-67A-010

PAGE 10 of 14 REVISION 03, 2010-02-08

2008-04-28

Detail D of Figure 1 and removal of bushing

Figure 3

1 Ball bearing (staked) EN3047A08E

2 Ball bearing (loose) EN3047A08E

3 Lever assy B670M1008101

4 Bushing B670M1013201 or

B670M1008207

3

Lever must be free of play in axial direction.

1 2

Section D–D

Detail D (overview see figure 1) before modification

FLIGHT DIRECTION

D

D

4
ALERT SERVICE BULLETIN

MBB BK117 C-2

MBB BK117 C-2-67A-010

PAGE 11 of 14

2008-04-28

REVISION 03, 2010-02-08

Detail B and C of Figure 1

Figure 4

1 RH lever assy B672M1007101

RH lever B672M1002202

2 Bracket

3 Bushing L672M1012260

4 Bracket

5 LH lever assy B672M1807101

LH lever L672M2802205

1

2

After modification.

3

Detail B (overview see figure 1) after modification

Section C–C

Detail C (overview see figure 1) after modification

Section B–B

3

4

5
ALERT SERVICE BULLETIN

MBB BK117 C-2

MBB BK117 C-2-67A-010

PAGE 12 of 14 REVISION 03, 2010-02-08

2008-04-28

Removal / Installation of Lever Assy

Figure 5

A

1 Control rod

2 Nut

3 Split pin LN94-15018

4 Washer

5 Washer

6 Castle nut

7 Split pin EN2367-14010

8 Bracket

9 Washer

10 Screw

11 Bushing

12 Bushing

13 Lever B670M1008101

B670M1008102

Before modification.

After modification.

3 Discard after removal.

3

FLIGHT DIRECTION

1

2

3 4

5

6

7

8

9

10

12 11

13

14

15

16 17

18

19

14 Screw

15 Screw

16 Washer

17 Castle nut

18 Split pin

19 Flex ball

3

The lever can be installed inverted due to its symmetry.

4–5 Nm

3–4 Nm

3–4 Nm
ALERT SERVICE BULLETIN

MBB BK117 C-2

MBB BK117 C-2-67A-010

PAGE 13 of 14

2008-04-28

REVISION 03, 2010-02-08

Detail D of Figure 1 and installation of bushing

Figure 6

1 Lever assy B670M1008101

B670M1008102

2 Bushing B670M1008208

3 Ball bearing (staked)

4 Ball bearing (loose)

Before modification.

After modification.

2

1

Section D–D

Detail D (overview see figure 1) after modification

3

FLIGHT DIRECTION

D

D

4
ALERT SERVICE BULLETIN

MBB BK117 C-2

MBB BK117 C-2-67A-010

PAGE 14 of 14 REVISION 03, 2010-02-08

2008-04-28

Telefax

To

Eurocopter Deutschland GmbH

Customer Support

FAX 0049 906 714111 or

e-mail:

Vehicle.ecd.technical-support@eurocopter .com

Address of operator:

Reply form sheet for ASB MBB BK117 C-2-67A-010 ”Check bearings for correct

attachment”

Please completely fill out reply form sheet and send to the given FAX No.

Date:__________ Signature:___________________

Helicopter P/N*

S/N:

1

2

3

4

Important data regarding lever

Production

order number** TT (Fh)

Please copy page! Original page remains in Alert Service Bulletin!

Remarks:

B672M1007101 S01 ECD500

10001397284 07.09.05

*

** Example