ALERT SERVICE BULLETIN

EC135

EC135-67A-012

PAGE 1 of 14

2006-09-04

REVISION 01, 2006-10-18

Rotor Flight Control – Tail Rotor Controls – Inspection of linear

transducer (LVDT COLLECTIVE) bearing and modification of rod and

floor

1. Planning Information

A. Effectivity

(1) Helicopters affected: EC135, all models.

(2) Components affected: Bearing LN9367GE6N2

Rod L671M5040205

Lever L671M5040101

Floor L533M1014101 or

L533M1014102 or

L533M1014103 or

L533M1014104 or

L533M1014105 or

L533M1014106

(3) Spare Parts affected: Rod L671M5040205

Lever L671M5040101

Floor L533M1014101 or

L533M1014102 or

L533M1014103 or

L533M1014104 or

L533M1014105 or

L533M1014106

B. Concurrent Requirements

Not applicable.

C. Reason

ECD was informed of an incident in which an impaired controllability of the tail rotor was

detected. Examinations have shown that the bearing of the linear transducer was subject

to binding and the control range was limited. With this Alert Service Bulletin an inspection

and, if necessary, the replacement of the linear transducer bearing and the modification of

the rod (21, Figure 1) and the floor shall be accomplished.

D. Description

Inspect bearing of the linear transducer and the lower side of the floor. If there is binding

and/or chafing on the floor, replace bearing.

Modify rod and floor.
ALERT SERVICE BULLETIN

EC135

EC135-67A-012

PAGE 2 of 14 REVISION 01, 2006-10-18

2006-09-04

E. Compliance

(1) Accomplish inspection and, if necessary, replacement of the bearing as well as

modification of floor i.a.w. Section 3.A. up to and including Section 3.G. of this Alert

Service Bulletin by 31.10.2006 at the latest.

(2) Modification of rod i.a.w. Section 3.H. of this Alert Service Bulletin must be

accomplished with the next periodical inspection (800 fh) at the latest.

(3) In future, the inspection of the bearing must be repeated with every periodical

inspection (800 fh).

(4) Spare parts affected must be modified i.a.w. this Alert Service Bulletin before they are

installed in the helicopter at the latest.

F. Approval

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

DOA No. EASA.21J.034.

G. Manpower

– Approx. 10 man–hours for modification of rod and floor.

– Approx. 13 man–hours for modification of rod and floor as well as for replacement of

bearing.

H. Weight and Balance

Not applicable.

I. Electrical Load Data

Not applicable.

J. Software Accomplishment Summary

Not applicable.

K. References

AMM EC135.

L. Other Publications affected

The changes to AMM EC135, MSM EC135, AMM EC135/635 T1 (CPDS) and to

MSM EC135/635 T1 (CPDS) wich are required as a result of this Alert Service Bulletin will

be incorporated with one of the next revisions.

M. Interchangeability of Parts

Not applicable.
ALERT SERVICE BULLETIN

EC135

EC135-67A-012

PAGE 3 of 14

2006-09-04

REVISION 01, 2006-10-18

2. Material Information

A. Material – Price and Availability

Information on cost and availability of required kit EC135-67A-012-2.C will be provided by

ECD, Dept. Spares Order Administration on request.

B. Support Information

Not applicable.

C. Material Necessary for Each Helicopter

Retrofit kit EC135-67A-012-2.C.

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

1 LN9367GE6N2 Bearing LN9367GE6N2 1 A, C

2 EN236714018 Cotter pin EN236714018 1 A

3 LN90250615L Washer − 1 A

4 LN9415018 Cotter pin LN9415018 2 A

5 ABS0635407 Teflon strip (0.150 m) − 1 E

6 − Corrosion preventive paste

(CM 518)

− a.n.* B

7 − Adhesive

(CM 671)

− a.n.* B

8 − Chemical conversion material

(CM 316)

− a.n.* B

9 − Acetone

(CM 203)

− a.n.* B

10 − Lacquer

(CM 4012)

− a.n.* B

11 − Hardener

(CM 4013)

− a.n.* B

12 − Adhesive

(CM 671)

− a.n.* B, D

*a.n. = as needed

Disposition:

A = The material kit contains no standard parts (DIN, ISO, EN etc.).

If this item is needed, a separate order has to be placed for it.

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 = Only needed, if bearing is replaced.
ALERT SERVICE BULLETIN

EC135

EC135-67A-012

PAGE 4 of 14 REVISION 01, 2006-10-18

2006-09-04

D = Only needed, if floor is repaired.

E = New, included in kit.

D. Material Necessary for Each Spare

See Section 2.C.

E. Reidentified Parts

After modification of the rod i.a.w. section 3.H. of this Alert Service Bulletin the part number

of the rod changes from L671M5040205 to L671M5040215 and the part number of the lever

changes from L671M5040101 to L671M5040102.

Accomplish reidentification i.a.w. Section 3.H.(2)(c) of this Alert Service Bulletin.

F. Special Tooling

Not applicable.

3. Accomplishment Instructions

A. Preliminary work steps:

(1) Remove forward access cover i.a.w. AMM, 52-40-00, 4-3.

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

(3) If installed, remove equipment plate i.a.w. AMM, 25-70-00, 4-2.

B. Inspection of bearing and floor:

CAUTION IF THE LINEAR TRANSDUCER (11, FIGURE 1) IS DETACHED, AVOID

MOVING IT FURTHER THAN ITS NORMAL CONTROL RANGE.

OTHERWISE, THE LINEAR TRANSDUCERS WILL BE DAMAGED.

(1) Remove cotter pin (10, Figure 1), nut (9), washers (8) and bushing (7). Detach linear

transducer (11) with washer (6) downwards.

(2) Check bearing (1, Figure 2) for freedom of movement. If binding, rough or not smooth

turning is detected during turning or tilting of bearing (1), the bearing (1) must be

replaced. Replacement i.a.w. Section 3.C. of this Alert Service Bulletin.

(3) If new signs of chafing i.a.w. Figure 4 are detected on the lower side of the

floor (1, Figure 4), the bearing (4, Figure 3) must be replaced. Replacement of bearing

i.a.w. Section 3.C. of this Alert Service Bulletin.

(4) If the lower side of the floor (1, Figure 4) is damaged in the area of the assembly opening

(with open honeycomb part and/or layer), the bearing (4, Figure 3) must be replaced

and the floor must be repaired.

Replacement of bearing i.a.w. Section 3.C. and repair of floor (1) i.a.w. Section 3.D of

this Alert Service Bulletin.
ALERT SERVICE BULLETIN

EC135

EC135-67A-012

PAGE 5 of 14

2006-09-04

REVISION 01, 2006-10-18

(5) If there is no binding on the bearing (1, Figure 2) and the floor (1, Figure 4) has no new

signs of chafing i.a.w. Figure 4 and is not damaged in the area of the assembly opening,

proceed i.a.w. Section 3.E. of this Alert Service Bulletin.

C. Replacement of bearing (4, Figure 3):

(1) Remove lockwire from nuts (1, Figure 3).

(2) Remove nuts (1, Figure 3) and detach plate (2) from linear transducer (3). Protect linear

transducers (3) from damage with suitable measures.

(3) Replacement of bearing (4, Figure 3) i.a.w. AMM, 20-00-00, 2-14.

NOTE Nuts (1, Figure 3) will finally be tightened and secured only when the linear

transducers (3) are adjusted.

(4) Put linear transducers (3, Figure 3) through plate (2). Loosely screw nuts (1) onto linear

transducers, so that linear transducers (3) do not slip out of the plate (2).

(5) Adjust linear transducers i.a.w. AMM, 76-10-00, 5-3.

(6) Actuate tail rotor pedals and check tail rotor controls for free and smooth movement.

By doing so, especially check transducer linkage rod (19, Figure 1) and rod (21) for

freedom of movement.

(7) After completion of work, accomplish inspection for foreign matter and objects.

(8) If the floor (1, Figure 4) has no new signs of chafing, proceed i.a.w. Section 3.F of this

Alert Service Bulletin.

D. Repair of floor (1, Figure 4):

NOTE If honeycomb part/layer is damaged within an area of more than 2 cm by

6 cm, contact ECD customer support.

(1) If necessary, carefully remove protruding burr from the area around the edge of the

assembly opening using a file. Remove chips.

(2) Fill up floor honeycomb part (1, Figure 4) with adhesive (CM 671).

E. Affixing of teflon strip (2, Bild 6):

CAUTION WHEN PROCESSING THE ADHESIVE COMPLY WITH THE

MANUFACTURER‘S INSTRUCTIONS.

(1) Using abrasive paper, roughen bonding surface on the lower side of the floor (1, Figure

6), clean with acetone (CM 203) and leave to air.

(2) Using abrasive paper, roughen brown side of teflon strip (2, Figure 6), clean with

acetone (CM 203) and leave to air.
ALERT SERVICE BULLETIN

EC135

EC135-67A-012

PAGE 6 of 14 REVISION 01, 2006-10-18

2006-09-04

(3) Affix teflon strip (2, Figure 6) i.a.w. figure 6 to the lower side of the floor (1) in parallel

to the floor edge. By doing so, evenly apply adhesive to the brown side of the teflon strip

(2) and to the floor (1). Using a suitable aid, press teflon strip (2) onto the floor (1).

Carefully remove surplus adhesive and allow the bonding to cure i.a.w. the

manufacturer‘s instructions.

(4) Identification of floor:

(a) Using acetone (CM 203), remove grease and dirt from the surface to be marked

in the immediate vicinity of the teflon strip (2, Figure 6) on the lower side of the floor

(1) and leave to air.

(b) Using a permanent marker, identify accomplishment of this Alert Service Bulletin

by marking the Alert Service Bulletin number to the immediate vicinity of the teflon

strip (2, Figure 6).

(c) Protect marking by means of lacquer (CM 4012, CM 4013).

F. Final work steps:

(1) Slide washer (6, Figure 1) and linear transducer (11) onto rod. Attach linear transducer

with bushing (7), washer (8) and nut (9). Tighten nut (9) only until attachment hardware

is free from play. Secure nut (9) with cotter pin (10).

(2) After completion of work, accomplish inspection for foreign matter and objects.

(3) If removed, install equipment plate i.a.w. AMM, 25-70-00, 4-2.

(4) Install middle cover i.a.w. AMM, 52-40-00, 4-4.

(5) Install forward access cover i.a.w. AMM, 52-40-00, 4-3.

G. Confirm accomplishment of Section 3.A up to and including Section 3.F of this Alert Service

Bulletin by an entry in the historical record of the helicopter.

H. Modification of rod (21, Figure 1).

NOTE Accomplish modification of rod by the next periodical inspection at the

latest.

(1) Removal of rod:

(a) Remove cover cap (1, Figure 1) from floor (3) and align rod (21) so that screw (22)

can be removed through the assembly opening in the floor (3). Store cover cap (1)

for reuse.

CAUTION IF THE TRANSDUCER LINKAGE ROD (19) IS DETACHED, AVOID

MOVING ROD (21) FURTHER THAN ITS NORMAL CONTROL

RANGE. OTHERWISE, THE LINEAR TRANSDUCERS LVDT

COLLECTIVE (11) WILL BECOME DAMAGED.
ALERT SERVICE BULLETIN

EC135

EC135-67A-012

PAGE 7 of 14

2006-09-04

REVISION 01, 2006-10-18

(b) Remove cotter pin (16, Figure 1), nut (15), washers (17, 20) and screw (22).

Disconnect transducer linkage rod (19) from rod (21). Protect transducer linkage

rod (19) from damage with suitable measures.

(c) Remove cotter pin (10, Figure 1), nut (9), washers (6, 8) and bushing (7). Pull rod

(5) out of plate (12).

(d) Remove cotter pin (14, Figure 1), nut (13), washer (4) and screw (2). Remove

rod (21) from floor (3).

(2) Modification and reidentification of rod (1, Figure 5):

CAUTION DURING LOWERING, ENSURE NOT TO LOWER SCREW HEAD

MORE THAN 0.2 MM THAN THE SURFACE OF THE

ROD (1, FIGURE 5) IS.

(a) Using a 100 degree countersink, lower borehole of rod (1, Figure 5) until screw

head of screw (2) is flush with the surface of the rod (1).

(b) Re–establish surface protection using chemical conversion material (CM 316) and

leave to dry i.a.w. the manufacturer‘s instructions.

(c) Reidentification of rod and lever:

1 Using a black permanent marker, cross out old part number L671M5040205

of rod (1, Figure 5) and old part number L671M5040101 of lever but

leave them still legible.

2 Using a black permanent marker, write new part number L671M5040215 of

rod (1, Figure 5) and new part number L671M5040102 of lever to the

immediate vicinity of the old part numbers and protect by means of

lacquer (CM 4012, CM 4013).

(3) Installation of rod (21, Figure 1):

(a) Position rod (5, Figure 1) together with washers (6, 8), bushing (7) and nut (9) in

plate (12). Tighten nut (15) only to such an degree that attachment hardware is free

from play. Secure nut (9) with cotter pin (10).

(b) Apply corrosion preventive paste (CM 518) onto screw (2, Bild 1). Position rod (21)

on floor (3) and attach to floor (3) by means of screw (2), washer (4) and nut (13).

Torque–tighten nut (13) to 1–1.5 Nm and secure with cotter pin (14).

(c) Apply corrosion preventive paste (CM 518) onto screw (22, Figure 1) and align

rod (21) so that screw (22) can be put through the assembly opening in the

floor (3).

(d) Attach transducer linkage rod (19, Figure 1) to rod (21) with screw (22),

washers (17, 20), additional washer (18) and nut (15). Tighten nut (15) only to such

an degree that attachment hardware is free from play. Secure nut (15) with cotter

pin (16).
ALERT SERVICE BULLETIN

EC135

EC135-67A-012

PAGE 8 of 14 REVISION 01, 2006-10-18

2006-09-04

(e) Close assembly opening in the floor (3, Figure 1) with cover cap (1). By doing so,

insert cover cap (1) from the upper side of the floor.

(f) Actuate tail rotor pedals and check tail rotor controls for free and smooth

movement. By doing so, especially check transducer linkage rod (19, Figure 1) and

rod (21) for freedom of movement.

(4) Confirm accomplishment of Section 3.H. of this Alert Service Bulletin by an entry in the

historical record of the helicopter.

4. Appendix

Not applicable.
ALERT SERVICE BULLETIN

EC135

EC135-67A-012

PAGE 9 of 14

2006-09-04

REVISION 01, 2006-10-18

Removal/Installation of Rod

Figure 1

1 Cover cap

2 Screw

3 Floor

4 Washer

5 Rod

6 Washer

7 Bushing

8 Washer

9 Nut

10 Cotter pin

11 Linear Transducers

12 Plate

13 Nut

14 Cotter pin

15 Nut

16 Cotter pin

17 Washer

18 Washer LN9025-0615L

19 Transducer linkage rod

20 Washer

21 Rod

22 Screw

1

2

3

4

5

6

7

8

9

10 11

12

11

13

14

16

17

19

20

21

22

After modification.

1–1.5 Nm

Assembly opening.

15

18
ALERT SERVICE BULLETIN

EC135

EC135-67A-012

PAGE 10 of 14 REVISION 01, 2006-10-18

2006-09-04

Inspection of Bearing

Figure 2

1 Bearing

2 Linear Transducers

1

2

2

Inspect bearing for binding, rough or not smooth turning by turning and tilting

bearing.
ALERT SERVICE BULLETIN

EC135

EC135-67A-012

PAGE 11 of 14

2006-09-04

REVISION 01, 2006-10-18

Replacement of Bearing

Figure 3

1 Nut

2 Plate

3 Linear Transducers

4 Bearing LN9367GE6N2

1

1

3

2

3

4
ALERT SERVICE BULLETIN

EC135

EC135-67A-012

PAGE 12 of 14 REVISION 01, 2006-10-18

2006-09-04

Lower Side of Floor

Figure 4

1 Floor

2 Rod

3 Transducer linkage rod

Possible chafing.

1

2

3

Assembly opening.

View on lower side of floor.

FLIGHT DIRECTION
ALERT SERVICE BULLETIN

EC135

EC135-67A-012

PAGE 13 of 14

2006-09-04

REVISION 01, 2006-10-18

Modification of Rod

Figure 5

1 Rod

2 Screw

3 Rod

1

2

2

Using a 100 degree countersink, lower borehole of rod (1) until screw head

of screw (2) is flush with the surface of the rod (1).

Chemical conversion material (CM 316).

Part number of lever (lower side of part).

Part number of rod (1).

1

3

Lever consists of rod (1) and rod (3).

L671M50401XX
ALERT SERVICE BULLETIN

EC135

EC135-67A-012

PAGE 14 of 14 REVISION 01, 2006-10-18

2006-09-04

Modification of Floor

Figure 6

1 Floor

2 Teflon strip

Lower side of floor

1

2

Assembly opening

Affixed with adhesive (CM 671).

All dimensions in mm.

Identify with the number of the Alert Service Bulletin.

ASB EC135-67A-012

FLIGHT DIRECTION