This document transmits Revision 1 of Non-Modification Service Bulletin

TAY-72-A1775.

Document History

Non-Modification Service Bulletin Revision Status

Initial Issue Sep.11/12

Non-Modification Service Bulletin Revision 1

Remove Incorporate Reason for change

Pages 1 to 8 of the

Non-Modification

Service Bulletin.

To include minor

wording corrections in

the Reason.

Printed in Great Britain

Sep.12/12

TAY SERIES PROPULSION SYSTEM SERVICE BULLETIN

ALERT TAY−72−A1775

Transmittal - Page 1 of 1

ALERT

1. Planning Information

A. Effectivity

(1) Fokker 70.

Tay 620-15/20 Engines.

For Engine Serial Numbers 17054, 17085, 17088, 17107 and 17166.

Modules M01100AA and M01100AB (LP Compressor Module).

B. Reason

There has been a reported instance of a multiple fan blade off on a Tay

R The operator of the engine has two aircraft operated with 620-15/20 engine.

Tay 620-15/20 engines. The operating instructions define limitations to

prevent stresses caused by fan flutter that could otherwise cause crack

initiation in the root of the Low Pressure (LP) compressor (fan) blades. To

minimise the potential for further occurrences in the event that the operating

instructions have not been previously fully adhered to, this Non-Modification

Service Bulletin provides an instruction for inspecting the LP compressor

(fan) blades.

Revision 1 of this Service Bulletin has been issued to include minor wording

corrections in the Reason.

R

R

C. Description

This Non-Modification Service Bulletin introduces an ultrasonic inspection to

determine if the fan blades are cracked as a result of increased stresses

resulting from a previous fan flutter event.

D. Compliance

ALERT

This Non-Modification Service Bulletin must be accomplished on all engines

before next flight and be repeated 1250 +/- 250 flight hours.

E. Approval

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

Design Organisation Approval No. EASA.21J.065.

ENGINE - LOW PRESSURE (LP) COMPRESSOR ROTOR BLADES - ULTRASONIC INSPECTION OF THE LP

COMPRESSOR (FAN) BLADE ROOTS - NON-MODIFICATION SERVICE BULLETIN

Printed in Great Britain

TAY−72−A1775

Page 1 of 8

Sep.11/12

Sep.12/12 Revision 1
F. Manpower

Estimated Man-hours:

(1) In Service

4 hours.

(2) At Overhaul/Shop Visit

Not applicable.

G. Material Price and Availability

Not applicable.

H. Tooling Price and Availability

New tools are not required.

I. Industry Support Information

None.

J. Weight and Balance

(1) Weight Change

None.

(2) Moment Arm

No effect.

(3) Datum

ES2540 (PPS100).

K. Electrical Load Data

The aircraft electrical load is not affected by this Non-Modification Service

Bulletin.

L. Software Accomplishment Summary

Not applicable.

Printed in Great Britain

TAY−72−A1775

Page 2 of 8

Sep.11/12

Sep.12/12 Revision 1
M. References

(1) Aircraft Maintenance Manual, Chapters 72-00-31 and 72-31-12.

N. Other Publications Affected

None.

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Sep.11/12

Sep.12/12 Revision 1
2. Material Information

A. Parts to be replaced

None.

B. Expendable Parts

None.

C. Instruction/Disposition Codes

None.

Printed in Great Britain

TAY−72−A1775

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Sep.11/12

Sep.12/12 Revision 1
3. Accomplishment Instruction

A. General

NOTE: In order to reduce the potential for multiple-engine in-flight

shutdown, power loss, or other anomaly due to maintenance error,

Rolls-Royce Deutschland recommends that Operators avoid performing

maintenance on multiple engines installed on the same aircraft at the

same time. If it is not possible to avoid maintenance on more than one

engine at the same time, Rolls-Royce Deutschland recommends that

additional controls are applied in order to ensure that maintenance

tasks have been completed as defined.

WARNING: YOU MUST BE CAREFUL WHEN YOU WORK ON THE ENGINE COMPONENTS AFTER THE

ENGINE IS STOPPED. THE ENGINE COMPONENTS CAN STAY HOT FOR ALMOST ONE

HOUR.

WARNING: YOU MUST NOT TOUCH HOT PARTS WITHOUT APPLICABLE GLOVES. HOT PARTS CAN

CAUSE AN INJURY. IF YOU GET AN INJURY PUT IT IN COLD WATER FOR 10

MINUTES AND GET MEDICAL AID.

(1) Obey all the WARNINGS and CAUTIONS in the procedures that are referred

to.

(2) Consumable Materials

(a) Refer to the related Manual tasks given in this instruction.

(3) Tools and Equipment

(a) Refer to the related Manual tasks given in this instruction.

B. Get access to the Low Pressure (LP) compressor (fan) blades.

C. Remove the complete set of LP compressor (fan) blades from the engine (Refer

to the Aircraft Maintenance Manual, Chapter 72-31-12, TASK 72-31-12-000-814).

Printed in Great Britain

TAY−72−A1775

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Sep.11/12

Sep.12/12 Revision 1
D. Examine the LP compressor (fan) blades

(1) Examine the LP compressor (fan) blades for general condition (Refer to

the Aircraft Maintenance Manual, Chapter 72-31-12, TASK

72-31-12-220-816).

(2) Do an ultrasonic inspection on the LP compressor (fan) blades (Refer to

the Aircraft Maintenance Manual, Chapter 72-31-12, TASK 72-31-12-270-816)

NOTE: Rolls-Royce Deutschland Ltd & Co KG, Service Engineering, must be

informed of the results of the inspection.

(a) If there is a LP compressor (fan) blade that shows signs of cracks,

the complete set of LP compressor (fan) blades including the LP

compressor (fan) disk must be rejected and returned to Rolls-Royce

Deutschland Ltd & Co KG. continue with step E.

(b) If the LP compressor rotor blades show no signs of cracks, the

complete LP compressor (fan) blade set can be re-installed on the

engine. Continue with step F.

E. Replace the LP compressor (fan) disk from the engine

(1) Remove the LP compressor (fan) disk from the engine (Refer to the

Aircraft Maintenance Manual, Chapter 72-00-31, TASK 72-00-31-000-814).

(2) Install a replacement LP compressor (fan) disk on the engine (Refer to

the Aircraft Maintenance Manual, Chapter 72-00-31, TASK

72-00-31-400-814).

F. Install a complete set of replacement LP compressor (fan) blades on the engine

(Refer to the Aircraft Maintenance Manual, Chapter 72-31-12, TASK

72-31-12-400-824).

G. Complete the Accomplishment Form on pages 7 and 8 and send it to Rolls-Royce

Deutschland, Service Engineering.

H. A record of accomplishment is required. Rolls-Royce Deutschland suggests to

put an entry into the engine log book.

Printed in Great Britain

TAY−72−A1775

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Sep.11/12

Sep.12/12 Revision 1
Accomplishment Form

(Sheet 1 of 2)

Printed in Great Britain

TAY−72−A1775

Page 7 of 8

Sep.11/12

Sep.12/12 Revision 1
Accomplishment Form

(Sheet 2 of 2)

Printed in Great Britain

TAY−72−A1775

Page 8 of 8

Sep.11/12

Sep.12/12 Revision 1
 

 SERVICE BULLETIN FEEDBACK FORM

Sep.12/12

Revision 1

© Rolls-Royce Deutschland Ltd & Co KG

TAY-72-A1775

Page 1 of 1

Printed in Great Britain

Please use this form to give feedback on the quality of this Service Bulletin. The input you provide will be used to 

analyse areas of improvement and to take action to further improvement on the quality of our Service Bulletins.

We thank you for the time you spent in completing this form.

Please rate on a scale of 1 to 5, with 5 being the highest score:

- General quality rating of this Service Bulletin  1  2  3  4  5

- Quality rating of the Accomplishment Instructions  1  2  3  4  5

- Quality rating of the Illustration  1  2  3  4  5

- Is this Service Bulletin easy to understand ?  Yes  No 

If you have had difficulties to perform this Service Bulletin please quote below the area(s) and give a short 

description of the issue:

Operator: Overhaul Site:

Name/Title: Date:

Please send the completed Service Bulletin Feedback Form to Rolls-Royce Deutschland, Service Bulletin Group.

Email: mailto:RRD.SERVICE.BULLETINS@ROLLS-ROYCE.COM 

Planning Information

Section:

Material Information

Section:

Accomplishment Instruction

Section:

  1.A.  1.I.  2.A.  General

  1.B.  1.J.  2.B.  Get Access

  1.C.  1.K.  2.C.  Removal/Installation

  1.D.  1.L.  2.D.  Inspection

  1.E.  1.M.  2.E.  Test

  1.F.  1.N.  2.F.  Close the Access

  1.G.  1.O.  Log Book Entry

  1.H  1.P. 

Explanatory notes: