This document transmits Revision 9 to Service Bulletin RB211-72-AB482

Document History

Service Bulletin Revision Status Supplement Revision Status

Initial Issue Jul.21/95

Revision 1 Sep.29/95

Revision 2 Mar.11/96

Revision 3 Sep.27/96

Revision 4 Apr.18/97

Revision 5 May 23/97

Revision 6 May 24/97

Revision 7 Sep.7/99

Revision 8 Nov.15/01

Bulletin Revision 9

Remove Incorporate Reason for change

All pages of the

Service Bulletin

Pages 1 to 12 of the

Service Bulletin

To reduce inspection

intervals of RB211-524B-02,

524B2, 524B3 and 524B4

engines that have not been

repaired to FRS5367/B.

Printed in Great Britain

Jul.28/03

RB211-524 SERIES PROPULSION SYSTEMS ALERT NON-MODIFICATION SERVICE BULLETIN

RB.211−72−AB482

Transmittal - Page 1 of 2

Signed Date

ALERT

ALERT
LIST OF EFFECTIVE PAGES

The effective pages to this Service Bulletin following incorporation of Revision

9 are as follows:

Page Revision Number Revision Date

Bulletin

R 1 9 Jul.28/03

R 2 9 Jul.28/03

R 3 9 Jul.28/03

R 4 9 Jul.28/03

R 5 9 Jul.28/03

R 6 9 Jul.28/03

R 7 9 Jul.28/03

R 8 9 Jul.28/03

R 9 9 Jul.28/03

R 10 9 Jul.28/03

R 11 9 Jul.28/03

R 12 9 Jul.28/03

Printed in Great Britain

RB.211−72−AB482

Transmittal - Page 2
1. Planning Information

A. Effectivity

(1) Boeing 747-400 Aircraft

All RB211-524G and 524H engines not incorporating SB RB211-72-9764

(2) Boeing 747 Aircraft

All RB211-524B2, 524C2 and 524D4 engines incorporating SB RB211-72-7221 or

SB RB211-72-7998 but not incorporating SB RB211-72-9670 or SB

RB211-72-9764 combustion liners

(3) Lockheed L-1011 Aircraft

All RB211-524B-02, 524B3 and 524B4 engines incorporating SB RB211-72-7221

or SB RB211-72-7998 but not incorporating SB RB211-72-9670 or SB

RB211-72-9764 combustion liners

B. Reason

With the introduction of combustion liners featuring hairpin head location in

RB211-524 engines, there has been a significant reduction in combustion liner

related engine removals. However, in higher rated 524G/H engine marks, head

section break-up has been apparent at lives in excess of 2000 cycles since new

or 1000 cycles since repair. Whilst the majority of these events have been

identified through routine condition monitoring, in line with the airline

scheduled maintenance programme, a small number have resulted in secondary

effects leading to combustion breakout and firewarning.

Non-Modification Service Bulletin 72-9768 (see 1.F. References) was issued in

August 1993 recommending a periodic inspection of the head section to minimise

the exposure to combustion breakout. This was subsequently revised in April

1994 to inspect for abnormal liner distress as a guide to developing head

section break-up.

Since then an RB211-524 engine experienced head section break-up which resulted

in combustion breakout at engine top dead centre and although the degree of

core engine distress was similar to previous incidents, greater than

anticipated secondary distress of the power plant was experienced. As a

consequence of further work we are now in a position to define enhanced

inspection techniques by direct borescope of the head section. In addition it

is necessary to reduce the inspection threshold and revise the acceptance

criteria.

ENGINE - COMBUSTION SECTION - INSPECTION OF FRONT COMBUSTION LINER HEAD SECTION AND

METERPANEL ASSEMBLY FOR POTENTIAL FAILURE - ALERT NON MODIFICATION SERVICE BULLETIN -

MOD.72-AB482

Printed in Great Britain

RB.211−72−AB482

Page 1 of 12

Jul.21/95

Jul.28/03
In November 1994 an RB211-524G engine experienced combustion flame breakout as

a result of meterpanel circumferential failure leading to a local traverse

shift. Following this failure Non-Modification Service Bulletin 72-B114 (see

1.F. References) was issued to recommend a borescope inspection of the

combustion liner to check for heatshield displacement and fuel spray nozzle

disengagement. Since that date a further two cracked meterpanels have been

detected by borescope inspection and both involved combustion liners where the

meterpanel had not been replaced at previous rework. Since meterpanel

displacement could result in similar powerplant secondary distress were it to

occur near to the top of the engine, it is also necessary to instruct borescope

inspection at specific lives.

This NMSB combines the intent of NMSB 72-9768 and NMSB 72-B114 for RB211-524G/H

engines and includes the revised borescope technique and frequency. The

relevant Maintenance Manuals will be revised to reflect the new acceptance

criteria. Consequently NMSB 72-B114 is to be cancelled and NMSB 72-9768 revised

to delete reference to RB211-524G and 524H engine marks.

Since the original issue of this NMSB, considerable data has been gathered with

regard to the level of strut cracking subsequently experienced on previously

Nicrobraze repaired head sections. This shows that the level of subsequent

strut cracking is much reduced and that the requirement for initial and repeat

inspections can be relaxed.

In January 1996 another RB211-524G engine experienced meterpanel failure and

combustion flame breakout, even though it had been inspected in accordance with

this NMSB only a short time previously. As a result it is apparent that the

existing method of inspection, utilising the routine borescope access ports,

cannot be relied upon to prevent further failures. Consequently it is necessary

to specify a revised method of inspection giving direct access to the

meterpanel.

In March 1997 another RB211-524H engine experienced hot gas escape as a result

of meterpanel failure. This engine had achieved 1278 cycles since new. It is

therefore necessary to reduce the inspection threshold for meterpanels not

previously repaired.

In March 1997 an RB211-524D4 engine experienced combustion flame breakout as a

result of combustion liner meterpanel failure. The affected engine was one of a

small number (17) to feature a combustion liner to the same basic standard (SB

RB211-72-7998) as that fitted to all RB211-524G/H engines. Although Operators

have been inspecting these engines to NMSB 72-B114, this did not detect the

latest incident. Revision 5 of this NMSB therefore included RB211-524D4 engines

within its effectivity.

A small number of RB211-524B4 engines also incorporate the same basic standard

of combustion liner (SB RB211-72-7998) as that fitted to RB211-524G/H engines.

Although no significant meterpanel cracking has been seen in this engine mark,

significant head break-up has been experienced on a number of occasions, albeit

at higher cyclic lives. This NMSB therefore also includes RB211-524B4 engines

within its effectivity.

Printed in Great Britain

RB.211−72−AB482

Page 2

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Jul.28/03
The SB RB211-72-7221 standard of combustion liner head section has an identical

construction to the SB RB211-72-7998 combustor and service experience has

revealed it to suffer from head section break-up in an identical manner. While

NMSB RB211-72-9768 instructs inspection for secondary damage this has not

succeeded in identifying head break-up in all cases. Revision 6 of this NMSB

therefore included RB211-524B-02, 524B4, 524C2 and 524D4 engines incorporating

SB RB211-72-7221 within its effectivity for head break-up only. Revision 7

further included RB211-524B2 and 524B3 engines incorporating SB RB211-72-7221

within its effectivity for head break-up only. There is no requirement to

inspect meter panels for combustors to pre SB RB211-72-7998 standard.

Revision 8 of this NMSB was issued to clarify at what interval the head section

should be inspected following repair to FRS5367. The original issue of this

NMSB was written with the intent that the nicrobraze repair, FRS5367, be

applied to all 18 head section struts. Rolls-Royce have been made aware that

sometimes the repair is only applied to those struts that are found to be

cracked. FRS5367 has therefore been re-issued to include the instructions to

mark the combustion liner head section after repair with either FRS5367/A or

FRS5367/B. FRS5367/A indicates that not all of the struts have had the

Nicrobraze repair. FRS5367/B indicates that the nicrobraze has been applied to

all head section struts. Section 1. C. (1) of NMSB RB211-72-B482 has been

amended accordingly.

In August 2002 an RB211-524B4 engine suffered a combustion case burnthrough as

a result of combustor head break-up. The combustor head had been inspected in

accordance with this NMSB only 228 cycles prior to the event. Revision 9 of

this NMSB is therefore issued to reduce the inspection interval of

RB211-524B-02, 524B2, 524B3 and 524B4 engines that have not been repaired in

accordance with FRS5367/B, from 400 cycles to 200 cycles, in line with all

other engine marks.

C. Compliance

ALERT

This (Non-Modification) Service Bulletin is declared Mandatory by the United

Kingdom Civil Aviation Authority (CAA) and is subject to the incorporation

requirements of a UK Civil Aviation Authority Airworthiness Directive (AD).

(1) Head section

(a) Not previously repaired

(i) RB211-524C2, 524D4, 524G and 524H engines:

Printed in Great Britain

RB.211−72−AB482

Page 3

Jul.21/95

Jul.28/03
Inspect in accordance with 3. Accomplishment Instructions

(A) at between 1400 and 1600 cycles since new and repeat at

intervals not exceeding 200 cycles subject to 1. E.

Acceptance Limits. For combustion liners in excess of 1600

cycles since new, which have not been previously inspected

to NMSB RB211-72-B482, inspect within 100 cycles.

(ii) RB211-524B-02, 524B2, 524B3 and 524B4 engines:

Inspect in accordance with 3. Accomplishment Instructions

(A) at between 3000 and 3200 cycles since new and repeat at

intervals not exceeding 200 cycles subject to 1. E.

Acceptance Limits. For combustion liners in excess of 3200

cycles since new, which have not been previously inspected

to NMSB RB211-72-B482, inspect within 200 cycles.

(b) Repaired in accordance with FRS5367/B when the head section was last

repaired.

(i) RB211-524C2, 524D4, 524G and 524H engines:

Inspect in accordance with 3. Accomplishment Instructions

(A) at between 1800 and 2200 cycles since FRS5367/B was

carried out and repeat at intervals not exceeding 400

cycles subject to 1. E. Acceptance Limits. For those head

sections which exceed 2200 cycles since FRS5367/B, and have

not been previously inspected to NMSB RB211-72-B482,

inspect within 200 cycles.

(ii) RB211-524B-02, 524B2, 524B3 and 524B4 engines:

Inspect in accordance with 3. Accomplishment Instructions

(A) at between 3000 and 3200 cycles since FRS5367/B was

carried out and repeat at intervals not exceeding 400

cycles subject to 1. E. Acceptance Limits. For those head

sections which exceed 3200 cycles since FRS5367/B, and have

not been previously inspectd to NMSB RB211-72-B482, inspect

within 200 cycles.

(c) Repaired by means other than FRS5367/B when the head section was last

repaired.

(i) RB211-524C2, 524D4, 524G and 524H engines:

Printed in Great Britain

RB.211−72−AB482

Page 4

Jul.21/95

Jul.28/03
Inspect in accordance with 3. Accomplishment Instructions

(A) at between 500 and 700 cycles since last head section

repair and repeat at intervals not exceeding 200 cycles

subject to 1. E. Acceptance Limits. For combustion liners

in excess of 700 cycles since repair, which have not been

previously inspected to NMSB RB211-B482, inspect within 100

cycles.

(ii) RB211-524B-02, 524B2, 524B3 and 524B4 engines:

Inspect in accordance with 3. Accomplishment instructions

(A) at between 2000 and 2200 cycles since last head section

repair and repeat at intervals not exceeding 200 cycles

subject to 1. E. Acceptance limits. For head sections in

excess of 2200 cycles since repair, which have not been

previously inspected to NMSB RB211-72-B482 inspect within

200 cycles.

NOTE: For an installed Front Combustion Liner that is

subject to NMSB RB211-72-B482: If the operator can

confirm with the relevant Overhaul Base or Repair

Vendor that the Nicrobraze repair FRS5367, has been

applied to all 18 struts, then this is equivalent to

FRS5367/B.

NOTE: Head sections repaired by replacement of all 18 struts

in accordance with FRS6548 are considered as

equivalent to fitting a new head section for

inspection purposes.

(2) Meterpanel assembly

RB211-524D4, 524G and 524H engines incorporating SB RB211-72-7998 (not

524B4)

(a) Not previously repaired

Inspect in accordance with 3. Accomplishment Instructions (B) at

between 1000 and 1200 cycles since new and repeat at intervals not

exceeding 400 cycles subject to 1. E. Acceptance Limits. For

meterpanels in excess of 1200 cycles since new, and not previously

inspected to NMSB RB211-72-B482, inspection is required within 50

cycles. For those operators who do not use RB211-524H rating at any

time, the inspection threshold may be increased to between 1800 and

2000 cycles.

Printed in Great Britain

RB.211−72−AB482

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(b) Previously repaired

Inspect in accordance with 3. Accomplishment Instructions (B) at

between 500 and 700 cycles since last repair, if meterpanel not

replaced by new, and repeat at intervals not exceeding 400 cycles

subject to 1. E. Acceptance Limits. For meterpanels in excess of 700

cycles since last repair and not previously inspected to NMSB

RB211-72-B482, inspection is required within 50 cycles.

NOTE: For meterpanels previously inspected in accordance with 1.

C.(2) and placed on a 200 or 400 cycle repeat interval, these

must be re-inspected within 100 cycles or the next scheduled

inspection, whichever is the sooner, and assessed against the

latest Aircraft Maintenance Manual Acceptance Limits for Row 3

and 4 cracking. Alternatively, the crack mapping records from

the previous inspection should be reviewed against these limits

and re-inspection instructed accordingly.

D. Approval

The content of this Non-Modification Service Bulletin was approved by a

representative of the United Kingdom Civil Aviation Authority (CAA) on

Jul.18/95, and re-approved on Sep.26/95, Feb.28/96, Sep.16/96, Apr.11/97, May

9/97, Oct.26/98, Jul.26/99, Nov.12/01 and Jul.16/03.

E. Acceptance Limits

Refer to Aircraft Maintenance Manual, 72-00-00, Inspection/Check.

NOTE: Missing or displaced head section or meterpanel material is not

acceptable unless associated with bleed strut support tube release.

F. References

(1) Rolls-Royce RB211 Service Bulletins:

72-7221 Front combustion liner flexible mounting (hairpin section)

and improved cooling

72-7998 Phase 2 low emission front combustion liner with Parker

Hannifin fuel spray nozzles

72-9670 Improved package 1 combustion liner head in C263 material

and local thickened diffuser walls around struts

72-9764 Improved phase 2 combustion liner with strengthened head

section in C263 material

Printed in Great Britain

RB.211−72−AB482

Page 6

Jul.21/95

Jul.28/03
(2) Rolls-Royce RB211 Non-Modification Service Bulletins:

72-9768 Inspection of front combustion liner head section for

possible break-up

72-B114 Inspection of meterpanel assembly for potential failure

(3) Rolls-Royce Repair Schemes:

FRS5367 Nicrobraze repair combustion liner head section cracking

FRS6548 Repair combustion liner head section by fitting new bleed

struts

(4) Aircraft Maintenance Manual:

(a) 72-00-00, Inspection/Check

(b) 73-11-06, Fuel Spray Nozzle, Removal/Installation

2. Material Information

None.

Printed in Great Britain

RB.211−72−AB482

Page 7

Jul.21/95

Jul.28/03
3. Accomplishment Instructions

A. Inspect for head section break-up at fuel spray nozzle positions 2, 3, 16 and

17 in accordance with Aircraft Maintenance Manual, 72-00-00. Make an inspection

of the Diffuser Case Bleed Struts, Front Section Outer Liner and Inner Liner.

The following alternative procedure may be used subject to Operator

preference:

(1) Remove one of the two rearmost fuel spray nozzle retaining bolts (typical

IPC Ref. 73-11-05, 01-012) in accordance with Aircraft Maintenance Manual,

73-11-06, Fuel Spray Nozzle, Removal/Installation from a FSN position.

(2) Using a 4mm. (0.157in.) flexible borescope, or suitable alternative

inserted through the bolt hole and corresponding clearance hole in outer

diffuser case (Fig 1), inspect bleed struts in region between outer

diffuser case and front section outer liner. Bleed struts either side of

fuel spray nozzle can be inspected. With flexible borescope further

inserted, using the HP compressor OGV's as a visual reference, it can be

manipulated to give a view of the bleed struts between front section inner

and outer liners.

(3) Repeat (2) at other 3 FSN positions by either removing further FSN

retaining bolts or by further insertion of flexible borescope from first

FSN position.

(4) On completion of (2) and (3) remove borescope carefully to avoid damage.

Re-install fuel spray nozzle retaining bolts in accordance with Aircraft

Maintenance Manual, 73-11-06, Fuel Spray Nozzle, Removal/Installation.

(5) In addition to the above, inspect the head section using a 90 degree view

rigid borescope (Fig 1). With this inserted through the normal combustion

section access ports and passing right through the combustion liner into

the annulus between liner inner wall and combustion inner casing, sections

of the head inner liner are visible if they have become displaced towards

the combustion inner casing. Similarly, displaced bleed struts may also be

visible. On withdrawing the borescope, it is also possible to view between

the liner outer wall and combustion inner casing outer barrel. Through

this annulus, cracking and lifting of the front section outer liner rear

of the fuel spray nozzles may be visible.

B. Inspect for meterpanel cracking in the region of Rows 3 and 4 slots (Fig 2) in

accordance with the following procedure:

Record cracks observed within and between Rows 3 and 4. Note Fig 3 provides

a suitable meterpanel section which can be used for mapping cracks. All

inspection findings together with engine serial number and meterpanel

cycles at inspection must be passed to the local Rolls-Royce office.

Printed in Great Britain

RB.211−72−AB482

Page 8

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Jul.28/03
(1) Remove two diametrically opposite fuel spray nozzles in accordance with

Aircraft Maintenance Manual, 73-11-06, Fuel Spray Nozzles,

Removal/Installation. Positions 4 and 14 are suggested.

(2) Insert guide tube HU80283 through FSN port to enable flexible borescope to

be inserted in annulus between combustion liner head section inner wall

and meterpanel inner attachment (Fig 2).

(3) Using suitable flexiscope 8mm. diameter, 1.5 metres minimum length, near

focus, forward facing, 60 degree field of view, mark its outer sheath in

increments of 115mm. (4.5in.) to represent the arc between FSN's.

(4) Insert flexiscope into guide tube and inspect for meterpanel cracking

between first two adjacent FSN positions. Inspect for cracking of small

ligaments between individual circumferential slots in Row 4 (Fig 2). By

manipulating flexiscope also inspect for similar cracking in Row 3 and for

any cracks linking Rows 3 and 4 (Fig 2).

(5) Repeat inspection procedure by further inserting the flexiscope to the

next mark until 9 FSN positions have been covered. By removing the

flexiscope, rotating the guide tube and re-inserting the flexiscope it is

possible to inspect 9 FSN positions either side of the nozzle actually

removed.

(6) Repeat inspection procedure at both removed FSN positions until meterpanel

has been inspected around 360 degrees, i.e. all 18 FSN positions have been

viewed from both directions to ensure adequate Row 3 slot inspection.

(7) On completion of inspection procedure, remove flexiscope and guide tube

and then re-install removed FSN's in accordance with Aircraft Maintenance

Manual, 73-11-06, Fuel Spray Nozzle, Removal/Installation.

NOTE: Alternative methods to the above may be used subject to (i) local

airworthiness authority approval and (ii) achieving a satisfactory

inspection of the Row 3 and 4 slots over the complete circumference

of the meterpanel.

Printed in Great Britain

RB.211−72−AB482

Page 9

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Jul.28/03
Front combustion liner showing typical features and borescope access for the head

section break-up inspection

Fig.1

Printed in Great Britain

RB.211−72−AB482

Page 10

Jul.21/95

Jul.28/03
Front combustion liner head section showing flexible access for meterpanel

inspection and view through flexiscope showing rows 3 and 4 of meterpanel

Fig.2

Printed in Great Britain

RB.211−72−AB482

Page 11

Jul.21/95

Jul.28/03
Typical meterpanel quadrant for mapping cracks

Fig.3

Printed in Great Britain

RB.211−72−AB482

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Jul.28/03