ASB EC135-62A-029

Revision 7, 2012-10-22 PAGE 1 of 11

Effective for version(s): T1, T2, T2+, P1, P2, P2+

635 T1, 635 T2+, 635 P2+

ALERT SERVICE BULLETIN

SUBJECT: MAIN ROTOR SYSTEM -- Main Rotor Hub-Shaft

Visual inspection of the upper and lower hub-shaft flange for cracks

Revision number Issue date

Revision 0 2012-03-08

Revision 1 2012-05-16

Revision 2 2012-05-17

Revision 3 2012-08-09

Revision 4 2012-08-23

Revision 5 2012-09-10

Revision 6 2012-10-02

Revision 7 2012-10-22

Summary:

During a PERIODICAL INSPECTION a crack was detected on the lower hub-shaft flange of a main

rotor hub-shaft. Since Revision 0 of this Alert Service Bulletin 3 further cracks had been detected, while

carrying out the preflight check.

Reason for the Revision:

Revision 7 increases the compliance time for the visual inspection of the hub-shaft flanges according

to Part 2 from 40 fh to 50 fh, based on the results from the full scale component testing. In addition,

the note regarding the preflight check was revised. However, the measures remain the same. Please

replace Revision 6 of Alert Service Bulletin EC135-62A-029 with Revision 7.

Compliance:

Compliance with this Alert Service Bulletin is prescribed. See Section 1.E.

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PAGE 2 of 11 Revision 7, 2012-10-22

1. PLANNING INFORMATION

1.A. EFFECTIVITY

1.A.1. Helicopters/installed equipment

(a) EC135/EC635, all models.

(b) Main rotor hub-shaft: all versions

1.A.2. Non--installed equipment

Not applicable.

1.B. ASSOCIATED REQUIREMENTS

Not applicable.

1.C. REASON

During a PERIODICAL INSPECTION a crack was detected on the lower hub-shaft flange of a

main rotor hub-shaft. Since Revision 0 of this Alert Service Bulletin 3 further cracks had been

detected, while carrying out the preflight check.

-- Revision 0 required a one--time visual inspection.

-- Revision 1 and 2 introduced:

→ Part 1: a dedicated preflight check

→ Part 2: a repetitive visual inspection

→ Part 3: a visual inspection with removal of components, nut and washer.

-- Revision 3 of this Alert Service Bulletin is based on experience gained and the supporting

results from the full scale component test:

→ Part 1: The preflight check is incorporated in the Flight Manual. Additional supporting

material for the accomplishment of the preflight check, as per the FLM, has been

included to this ASB.

→ Part 3: is no longer required and was removed

-- Revision 4 introduced:

→ Part 2: The visual inspection interval is increased from 10 fh to 15 fh.

→ Inspection requirements for main rotor hub-shafts with SB EC135-62-030 and/or SB

EC135-62-032 incorporated are detailed.

-- Revision 5 introduced:

→ Part 2: The visual inspection interval is increased from 15 fh to 25 fh.

-- Revision 6 introduced:

→ Part 2: The visual inspection interval is increased from 25 fh to 40 fh.

-- Revision 7 introduced:

→ Part 2: The visual inspection interval is increased from 40 fh to 50 fh.

1.D. DESCRIPTION

If necessary, remove the rotor hub cap and, if necessary, the transmission fairings. Visual

inspection of the upper and lower hub-shaft flange. If removed, install rotor hub cap and

transmission fairings.

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Revision 7, 2012-10-22 PAGE 3 of 11

1.E. COMPLIANCE

1.E.1. Compliance at the works

Helicopters/installed equipment

EFFECTIVITY -- Main rotor hub-shafts with more than 400 fh TSN or

-- Main rotor hub-shafts with more than 400 fh TSR* i.a.w. SB EC135-62-030

or

-- Main rotor hub-shafts with more than 400 fh TSR* i.a.w. SB EC135-62-032.

*Time Since Rework (last accomplished STEP).

See Section 1.E.2.

Non--installed equipment

Not applicable.

1.E.2. Compliance in service

Helicopters/installed equipment:

EFFECTIVITY All helicopters

Part 1: Preflight check - Blade attachment area of main rotor mast (upper and

lower)

(a) Inspection requirements have been moved to the FLM, required before every flight.

Additional reference material and details for carrying out the preflight check are detailed

in Section 3.B. Part 1.

NOTE The time between two preflight checks must not exceed 6 fh.One flight may

comprise multiple take--offs and landings. For the content of this AlertService

Bulletin, it is considered that a flight starts when the helicopter takes off, and

ends when the helicopter is on ground with the engines shut off.

EFFECTIVITY -- Main rotor hub-shafts with more than 400 fh TSN or

-- Main rotor hub-shafts with more than 400 fh TSR* i.a.w. SB EC135-62-030

or

-- Main rotor hub-shafts with more than 400 fh TSR* i.a.w. SB EC135-62-032.

*Time Since Rework (last accomplished STEP).

Part 2: Visual inspection of the upper and lower hub--shaft flange:

(a) Accomplish the visual inspection of the upper and lower hub-shaft flange i.a.w. Section 3.B

Part 2 within the next 50 fh after the last inspection Part 2 was carried out i.a.w. Revision 6

of this EASB.

(b) Repeat the visual inspection of the upper and lower hub-shaft flange i.a.w. Section 3.B

Part 2 every 50 fh thereafter.

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PAGE 4 of 11 Revision 7, 2012-10-22

Part 3: Visual inspection of the blade bolt area:

Inspection requirement removed with Revision 3.

Non--installed equipment

EFFECTIVITY -- Main rotor hub-shafts with more than 400 fh TSN or

-- Main rotor hub-shafts with more than 400 fh TSR* i.a.w. SB EC135-62-030

or

-- Main rotor hub-shafts with more than 400 fh TSR* i.a.w. SB EC135-62-032.

*Time Since Rework (last accomplished STEP).

Accomplish the visual inspection of the main rotor hub-shaft i.a.w. Section 3.B Part 2 before the

main rotor hub-shaft is installed on the helicopter.

1.F. APPROVAL

Approval of modifications:

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

DOA No. EASA.21J.034.

1.G. MANPOWER

Qualification Mechanic Electrician Pilot Others

Time approx. 0.5 h -- -- --

1.H. WEIGHT AND BALANCE

Not applicable.

1.I. EFFECT ON ELECTRICAL LOADS

Not applicable.

1.J. SOFTWARE MODIFICATION EMBODIMENT RECORD

Not applicable.

1.K. REFERENCES

AMM EC135 and AMM EC135/635

FLM EC135/635

1.L. DOCUMENTS AFFECTED

Not applicable.

1.M.INTERCHANGEABILITY OR MIXABILITY OF PARTS

Interchangeability:

Not applicable.

Mixability:

Not applicable.

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Revision 7, 2012-10-22 PAGE 5 of 11

2. MATERIAL INFORMATION

2.A. MATERIAL: PRICE -- AVAILABILITY -- PROCUREMENT

Not applicable.

2.B. INFORMATION CONCERNING INDUSTRIAL SUPPORT

Not applicable.

2.C. MATERIAL REQUIRED FOR EACH HELICOPTER/COMPONENT

Not applicable.

2.D. MATERIAL TO BE RETURNED

Not applicable.

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PAGE 6 of 11 Revision 7, 2012-10-22

3. ACCOMPLISHMENT INSTRUCTIONS

3.A. GENERAL INFORMATION

Part 1

(Preflight check)

Before each flight

Part 2

(Visual inspection)

Every 50 fh

Main rotor hub-shaft with less than

400 fh TSN

X not applicable

Main rotor hub-shaft with less than

400 fh TSR

after last accomplisment of

SB EC135- 62- 030

and/or

SB EC135- 62- 032

X not applicable

Main rotor hub-shaft with more

than 400 fh TSN

X X

Main rotor hub-shaft with more

than 400 fh TSR

after last accomplishment of

SB EC135- 62- 030

and/or

SB EC135- 62- 032

X X

Overview

3.B. OPERATIONAL PROCEDURE

Part 1: Preflight check - Blade attachment area of main rotor mast (upper and

lower)

A. The inspection requirements have been moved to the preflight check in the FLM. Refer to

Section 3.D of this Alert Service Bulletin for revision details.

NOTE ECD recommends training of the flight crew to ensure that the revised

contents of the FLM are clearly understood. Figure 1--3 have been provided

for reference material in identifying the crack and paragraph B below

provides the details for carrying out the preflight check.

B. Details for carrying out the preflight check/turn around:

(1) Clean the visible area of the upper and lower hub-shaft flanges of the main rotor

hub-shaft.

(2) Check the visible blade attachment area of the main rotor hub-shaft (upper and lower

hub--shafts) for condition and cracks i.a.w. Figure 1. If necessary, use a flashlight.

Figure 3 shows a survey of all detected cracks and the location.

a. If cracks are detected during the preflight check, contact the maintenance staff /

ECD customer support. The rotor hub-shaft must be replaced before the next flight.

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Revision 7, 2012-10-22 PAGE 7 of 11

Part 2: Visual inspection of the upper and lower hub--shaft flange:

A. Preliminary steps:

(1) If necessary, remove rotor hub cap i.a.w. AMM, 62-31-00, 4-1.

(2) If necessary, remove LH and RH transmission fairing i.a.w. AMM, 71-11-00, 4-4.

B. Inspect the upper and lower hub-shaft flanges for cracks:

(1) Clean the visible area of the upper and lower hub-shaft flanges of the main rotor

hub-shaft i.a.w. Figure 2 and inspect for cracks. If necessary, use a flashlight and a

mirror. Paint imperfections are to be inspected with a magnifying glass or a micro

camera.

(2) If cracks are detected during the visual inspection, contact ECD customer support. The

rotor hub-shaft must be replaced before the next flight.

(3) If previously removed, install rotor hub cap i.a.w. AMM, 62-31-00, 4-1.

(4) If previously removed, install LH and RH transmission fairing i.a.w. AMM, 71-11-00, 4-4.

C. Confirm accomplishment of Part 2 i.a.w. Section 3.C.

Part 3: Visual inspection of the blade bolt area:

Inspection procedure removed with Revision 3.

3.C. IDENTIFICATION

Accomplishment of this document:

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

helicopter and in the log card of the main rotor hub-shaft:

Part 2:

”Visual inspection of the upper and lower hub-shaft flanges”

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PAGE 8 of 11 Revision 7, 2012-10-22

3.D. OPERATING AND MAINTENANCE INSTRUCTIONS

Flight manual:

The step added to the preflight check (main rotor area) has been distributed with the following

Temp. Revs of the FLM:

-- EC 135 T2+ Temp. Rev.5

-- EC 135 P2+ Temp. Rev.5

-- EC 635 T2+ Temp. Rev.5

-- EC 635 P2+ Temp. Rev.5

-- EC 135 P2 (CPDS) Temp. Rev.10

-- EC 135 T2 (CPDS) Temp. Rev.12

-- EC 135 T1 (CPDS) Temp. Rev.17

-- EC 635 T1 (CPDS) Temp. Rev.17

-- EC 135 P1 (CPDS) Temp. Rev.13

-- EC 135 T1 (CDS) Temp. Rev.23

-- EC 135 P1 (CDS) Temp. Rev.19

AMM/maintenance manual:

No changes.

4. APPENDIX

Not applicable.

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Revision 7, 2012-10-22 PAGE 9 of 11

Preflight Check / Turn Around -- Upper and Lower Hub--Shaft Flanges

Figure 1

Check the visible area of the upper hub--shaft flange for cracks.

Check the visible area of the lower hub--shaft flange for cracks.

Example for cracks in the lower hub--shaft flange. Crack

Crack

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PAGE 10 of 11 Revision 7, 2012-10-22

Main Rotor Hub--Shaft -- Upper and Lower Hub--Shaft Flanges

Figure 2

Upper hub--shaft flange

Lower hub--shaft flange

Main rotor hub--shaft

Inspect the visible area of the upper and lower hub--shaft flanges.

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Revision 7, 2012-10-22 PAGE 11 of 11

Support to Accomplish the Preflight Check/ Turn Around

Figure 3

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