ALERT SERVICE BULLETIN

MBB BK117 C-2

CHANGE INSTRUCTION NO. 2 FOR MBB BK117 C-2-64A-002

2007-08-06 PAGE 1 of 1

Date: First issue: 2006-12-21

Revision 01: 2007-07-09

Revision 02: 2007-08-06

Please replace Revision 01 of Alert Service Bulletin MBB BK117 C-2-64A-002 with Revision 02.

With Revision 02 of this Alert Service Bulletin, improved control levers including weights are

introduced. 

The control levers B642M1009102 including weights are added to the components affected for

those helicopters already retrofitted by an ECD NTO–Document (No Technical Objection

Document). The control levers B642M1009102 are not affected by the visual inspection but the

tail rotor head has either to be reidentified or the new improved control levers have to be

retrofitted.

ALERT SERVICE BULLETIN

MBB BK117 C-2

MBB BK117 C-2-64A-002

PAGE 1 of 11

2006-12-21

REVISION 02, 2007-08-06

Tail Rotor System – Control lever with weights – Replacement of the

control levers including weights

1. Planning Information

A. Effectivity

(1) Helicopters affected: MBB BK117 C-2, S/N 9075 up to and including S/N 9122

and those helicopters from S/N 9004 up to and including

S/N 9074 on which Service Bulletin 

MBB BK117 C-2-67-006 has been accomplished.

(2) Components affected: Dynamic weight 230 g B642M1011202

Control lever B642M1009103

Dynamic weight 230 g B642M1011201*

Control lever B642M1009102*

* Valid for helicopters S/N 9013, 9015, 9018, 9084, 9090, 9092, 9094,

9097, 9099, 9100, 9111, 9114, 9117, 9120, 9121 retrofitted with NTO

(No Technical Objection Document) from control lever B642M1009103

to B642M1009102.

(3) Spare Parts affected: Not applicable.

B. Concurrent Requirements

Not applicable.

C. Reason

ECD has been informed of an in–flight incident where a dynamic weight broke off the control

lever subsequently leading to considerable vibrations. A visual inspection showed that the

threaded bolt of the control lever had broken off. For this reason, this Alert Service Bulletin

has been issued to introduce a corresponding visual inspection.

With Revision 02 of this Alert Service Bulletin ECD offers an improved control lever including

dynamic weights (”chinese weights”) which renders the 8 fh visual inspection no longer

applicable.

D. Description

Replace control lever including weights, inspect control lever up to replacement.

E. Compliance

(1) If the first issue or Revision 01 of this Alert Service Bulletin has not been accomplished

yet, the visual inspection of the control levers B642M1009103 with weights

B642M1011202 i.a.w. section 3.A. must be accomplished before the next flight.

(2) Until replacement of control levers B642M1009103 i.a.w 3.B of this Alert Service

Bulletin, the visual inspection i.a.w. section 3.A. of this Alert Service Bulletin must be

repeated every 8 Fh.
ALERT SERVICE BULLETIN

MBB BK117 C-2

MBB BK117 C-2-64A-002

PAGE 2 of 11 REVISION 02, 2007-08-06

2006-12-21

(3) The control levers B642M1009103 have to be replaced i.a.w. section 3.B. of this Alert

Service Bulletin by October 31, 2007 at the latest.

(4) Control levers B642M1009102 with their asscociated weights B642M1011201 are not

affected by the visual inspection i.a.w. 3.A., however, the structural configuration which

is introduced by NTO must be documented. To do so, the following possibilities can be

applied:

a. Maintain structural configuration and reidentify tail rotor head i.a.w. 3.C. or

b. Retrofit tail rotor head to control levers with weights B642M1009104 i.a.w. 

section 3.B. of this Alert Service Bulletin.

One of these measures must be accomplished by June 30, 2008 at the latest.

F. Approval

First Issue and Revision 01:

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

EASA.21J.034.

Revision 02:

The information or instructions contained in this document refer to change no. 1158. The

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

EASA.21J.034.

G. Manpower

Inspection of the control lever: 0,75 man–hours.

Replacement of the control lever: 7 man–hours.

H. Weight and Balance

Weight: 0.030 kg

Moment: 329 kgmm

I. Electrical Load Data

Not applicable.

J. Software Accomplishment Summary

Not applicable.

K. References

AMM MBB BK117 C-2.

L. Other Publication affected

Not applicable.
ALERT SERVICE BULLETIN

MBB BK117 C-2

MBB BK117 C-2-64A-002

PAGE 3 of 11

2006-12-21

REVISION 02, 2007-08-06

M. Interchangeability of Parts

After accomplishment of this Alert Service Bulletin the control levers P/N B642M1009103

including weights B642M1011202 must no longer be used.

2. Material Information

A. Material – Price and Availability

Information on cost and availability of required retrofit kit SB-117C2-64A-002-2C will be

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

B. Support Information

Not applicable.

C. Material Necessary for Each Helicopter

Retrofit kit SB-117C2-64A-002-2C similar to design document B642M1002105.

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

1 B642M1009104 Control Lever Preassy with

Weights

− 2 A

− Control Lever Preassy without

Weights

B642M1009103 or

B642M1009102

2 C

− Weight 230 g B642M1011202 or

B642M1011201

4 C

2 MBBN3060E2BS Label MBBN3060E2BS 1 A, C

3 6TCR106 Nylstop−Nut 6TCR106 6 D, C

4 LN94−15015 Split Pin LN94−15015 6 D, C

5 LN94−30030 Split Pin LN94−30030 4 D, C

6 12TCR106 Nylstop−nut 12TCR106 2 D, C

7 MS24665−302 Cotter pin MS24665−302 2 D, C

8 8TCR106 Nylstop−nut 8TCR106 2 D, C

9 LN94−20018 Cotter pin LN94−20018 2 D, C

10 − Acetone

(CM 203)

− a.n.* B

11 − Lacquer, single−layer

(CM 425)

− a.n.* B

*a.n. = as needed

Disposition:
ALERT SERVICE BULLETIN

MBB BK117 C-2

MBB BK117 C-2-64A-002

PAGE 4 of 11 REVISION 02, 2007-08-06

2006-12-21

A = New, included in kit.

B = Consumable material, to be ordered from the Interturbine company as needed.

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

C = Part with old P/N is discarded.

Discarded parts are not taken back by ECD.

D = The retrofit kit contains no standard parts (DIN, ISO, EN etc.).

If these items are needed, a separate order has to be placed for it.

D. Material Necessary for Each Spare

Not applicable.

E. Reidentified Parts

The part number of the tail rotor head B642M1002103 or B642M1002104 with control lever

B642M1009102 will be changed to B642M1002102.

The part number of the tail rotor head B642M1002102 or B642M1002103 or

B642M1002104 with control lever B642M1009104 will be changed to B642M1002105.

With accomplishment of this Alert Service Bulletin an “A” is added to the beginning of the

serial number.

F. Special Tooling

Not applicable.

3. Accomplishment Instructions

EFFECTIVITY Control lever B642M1009103 with weights B642M1011202.

A. Visual inspection of the control lever:

(1) Mark position of weights (2, Figure 1) before removal. Remove split pins (3) and

weights (2).

(2) Perform visual inspection of the area around the split pin borehole for damage:

(a) If there are no signs of damage, proceed i.a.w. 3.A.(3).

(b) If there are only polished marks but no score marks ( , Figure 1), proceed i.a.w.

3.A.(3).

(c) If score marks, notching, scratching ( , Figure 1), cracks or similar are detected,

replace the control lever before the next flight.

(3) Screw weights (2, Figure 1) onto control lever (1) until stop is reached. Then screw back

weights to such an extent that split pins (3) can be inserted and secured. For your

control, measure clearance between the end faces of both weights: Specified

clearance: 216 mm +/– 0.25 mm.
ALERT SERVICE BULLETIN

MBB BK117 C-2

MBB BK117 C-2-64A-002

PAGE 5 of 11

2006-12-21

REVISION 02, 2007-08-06

(4) Confirm the first accomplishment of this Alert Service Bulletin by an entry in the log card

of the tail rotor head.

EFFECTIVITY All helicopters.

B. Replacement of the control levers with weights:

(1) Disconnect the pitch links (10, Figure 2) i.a.w. AMM, 67-20-00, 4-9.

(2) Remove the blade mounting forks (1, Figure 2) i.a.w. AMM, 64-20-00, 4-2.

(3) Discard the control levers (4, Figure 2) with weights (9) used up to now.

(4) Install control lever (4, Figure 2) and weights (9) contained in the material kit i.a.w. AMM,

64-20-00, 4-2. Adjust the weights (9) symetrical and flush with the bolt of the control

lever (4).

(5) Install the blade mounting forks (1, Figure 2) i.a.w. AMM, 64-20-00, 4-2.

(6) Connect the pitch links (10, Figure 2) i.a.w. AMM, 67-20-00, 4-9.

(7) Balance the tail rotor i.a.w. AMM, 18-10-00, 5-6 or AMM, 18-10-00, 5-5.

(8) Reidentification of tail rotor head, change of P/N of tail rotor head assy and tail rotor

drive system:

NOTE In order that the modified tail rotor head can still be identified at any

later date, an ”A” has to be added to the beginning of the S/N which

has been valid before modification.

(a) Mark new label (2, Figure 3) with the P/N B642M1002105 and with the serial

number of the tail rotor head. Add an A at the beginning of the serial number.

(b) Enter new part number of the tail rotor head:

Keyword old P/N new P/N

Tail rotor head B642M1002102 or

B642M1002103 or

B642M1002104

B642M1002105

in the

– log card of the tail rotor head

– list of life–limited parts

– list of all log cards.
ALERT SERVICE BULLETIN

MBB BK117 C-2

MBB BK117 C-2-64A-002

PAGE 6 of 11 REVISION 02, 2007-08-06

2006-12-21

NOTE The part number of the “Tail rotor head assy” and “Tail rotor drive

system” are changed as follows:

Keyword old P/N new P/N

Tail rotor head assy B642M1001103 or

B642M1001104 or

B642M1001105

B642M1001106

Tail rotor drive system B650M0001102 or

B650M0001103 or

B650M0001104

B650M0001105

(9) Inform ECD about the replacement of the control levers with weights using the reply

form sheet on page 11. This piece of information is very important. Therefore, we ask

you to always return the filled–out reply form sheet. Thank you very much for your

assistance!

(10) Confirm the accomplishment of section 3.B. of this Alert Service Bulletin by an entry in

the log card of the tail rotor head.

EFFECTIVITY Tail rotor heads retrofitted with NTO.

C. Reidentification of tail rotor heads retrofitted with NTO:

(1) Enter new part number of the tail rotor head:

Keyword old P/N new P/N

Tail rotor head B642M1002103 or

B642M1002104

B642M1002102

in the

– log card of the tail rotor head

– list of life–limited parts

– list of all log cards.

NOTE The part number of the “Tail rotor head assy” and “Tail rotor drive

system” are changed as follows:

Keyword old P/N new P/N

Tail rotor head assy B642M1001104 or

B642M1001105

B642M1001103

Tail rotor drive system B650M0001103 or

B650M0001104

B650M0001102
ALERT SERVICE BULLETIN

MBB BK117 C-2

MBB BK117 C-2-64A-002

PAGE 7 of 11

2006-12-21

REVISION 02, 2007-08-06

EFFECTIVITY All helicopters.

(2) Remove existing label from the inner sleeve (2, Figure 3) and clean the bonding surface

on the inner sleeve with acetone (CM 203). Bond new label to inner sleeve and protect

label by applying lacquer single layer (CM 425).

(3) Confirm the accomplishment of section 3.C. of this Alert Service Bulletin by an entry in

the log card of the tail rotor head.

4. Appendix

Not applicable.
ALERT SERVICE BULLETIN

MBB BK117 C-2

MBB BK117 C-2-64A-002

PAGE 8 of 11 REVISION 02, 2007-08-06

2006-12-21

1

2

3

Control lever

Figure 1

1 Control lever B642M1009103

2 Weight B642M1011202

3 Split pin LN94-30030

Polished area (allowed)

Scratching (not allowed)
ALERT SERVICE BULLETIN

MBB BK117 C-2

MBB BK117 C-2-64A-002

PAGE 9 of 11

2006-12-21

REVISION 02, 2007-08-06

Tail rotor head

Figure 2

1

2

3

2

3

4

4

5

5

6

6

7

7

8

8

9

9

Before Modification

After Modification

1 Before Modification

2 After Modification

1 Blade mounting fork B642M1003102

2 Bolt 1121–31712.16

3 Washer LN9016–06K

4 Control lever B642M1009104

B642M1009103

5 Angle 105–317391.09

6 Nylstop–nut 6TCR106

7 Split pin LN94–15015

8 Split pin LN94–30030

9 Weight 225 g B642M1011203

Weight 230 g B642M1011202

10 Pitch link

11 Label MBBNN3060E2BS

12 Inner sleeve

13 Nylstop–nut 12TCR106

14 Cotter pin MS24665–302

15 Nylstop–nut 8TCR106

16 Cotter pin LN94–20018

3

3

10

11

12

x2

x3

x2 x2

x3

x3

x3

14 13

16

15
ALERT SERVICE BULLETIN

MBB BK117 C-2

MBB BK117 C-2-64A-002

PAGE 10 of 11 REVISION 02, 2007-08-06

2006-12-21

Reidentification of tail rotor head

Figure 3

1 Tail rotor head B642M1002102

B642M1002103

B642M1002104

B642M1002105

2 Label MBBNN3060E2BS

3 The part number of the Tail rotor head B642M1002103 or B642M1002104 with

control lever B642M1009102 will be changed to B642M1002102. With

accomplishment of this Alert Service Bulletin an “A” is added to the beginning of

the serial number.

4 The part number of the Tail rotor head B642M1002102 or B642M1002103 or

B642M1002104 with control lever B642M1009104 will be changed to

B642M1002105. With accomplishment of this Alert Service Bulletin an “A” is added

to the beginning of the serial number.

1 2
ALERT SERVICE BULLETIN

MBB BK117 C-2

MBB BK117 C-2-64A-002

PAGE 11 of 11

2006-12-21

REVISION 02, 2007-08-06

Telefax

To

Eurocopter Deutschland GmbH

Kundendienst / Customer support

FAX 0049 906 714111

Operator’s address:

Helicopter S/N

Date:___________ Signature:___________________

Please make a copy of this page! The original of this formsheet is to remain in the ASB!

Reply form sheet

Please notify ECD of the replacement of the control levers and weights i.a.w. 3.B. of 

ASB MBB BK117 C-2-64A-002.

Tail rotor S/N

The control levers including weights were replaced:

ALERT SERVICE BULLETIN

MBB BK117 C-2

MBB BK117 C-2-64A-002

PAGE 11 of 11

2006-12-21

REVISION 02, 2007-08-06

Telefax

To

Eurocopter Deutschland GmbH

Kundendienst / Customer support

FAX 0049 906 714111

Operator’s address:

Helicopter S/N

Date:___________ Signature:___________________

Please make a copy of this page! The original of this formsheet is to remain in the ASB!

Reply form sheet

Please notify ECD of the replacement of the control levers and weights i.a.w. 3.B. of 

ASB MBB BK117 C-2-64A-002.

Tail rotor S/N

The control levers including weights were replaced: