Engine Ignition Selection - SmartCockpit · 2012. 6. 27. · •All engine manufacturers provide...

Engine Ignition Selection

Operational Liaison Meeting – Fly-By-Wire aircraft 2004

Customer Services

Engine Ignition Selection © A

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Contents

• Description

• AUTOMATIC Ignition Selection

• MANUAL Ignition Selection

• Igniter INHIBITION: CFM & RR

• Effective Igniter Use

• Review of Operational Recommendations

• Conclusion


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Description

• Engine Igniters 4Provide the spark, in the engine combustion section,

to start burning the atomized fuel mist:

–Once the fuel ignites, the combustion process continues until fuel flow is discontinued during the engine shutdown. (Spark is not needed to continue ignition, contrary to piston engine).

–Used, during the “Engine Start” sequence:• On ground and in flight

4Can work in continuous mode:–To produce several sparks within each second.–Used to preserve engine combustion,

in particular situations or flight phases.


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Description …

• Two independent igniter systems per engine:4One is normally-supplied by the AC NORM BUS4The other is supplied by the AC ESS BUS

• For engine start, the FADEC selects:4Ground Autostart : One igniter 4Ground Manual Start : Two igniters4In-flight Start : Two igniters

• Operating modes:

4MANUAL– Igniters are selected by the crew

4AUTOMATIC– Igniters are automatically selected by the FADEC.


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Description …

• The igniter system is composed of:

4IGNITER BOXES– Transform

low-voltage ACinto high-voltageDC current

4WIRING– Connect the

igniter boxesto the igniterplugs

4IGNITER PLUGS– Spark

generation inthe burner


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Contents …

• Description






• Conclusion


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AUTOMATIC Ignition Selection

• The FADEC provides automatic continuous ignition selection in certain circumstances:4Depending on the detection of abnormal situations:

– Flameout– Stall – Heavy rain/hail ingestion

4Depending on the flight phase:– Takeoff– Approach

4Depending on pilot inputs:– Engine anti-ice selection

• The conditions activating automatic ignition depend on:– Engine Type– FADEC Standard


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AUTOMATIC Ignition Selection …

X

X

X

XX

X

XX

X

X

X

X

X

FLAMEOUT

X

X

X

NoNo

X

NoNo

X

No

(1)

X

No

NAI ON

X

No

No

NoNo

No

NoNo

No

No

(2)

X

No

APPIDLE

X

No

No

NoNo

No

NoNo

No

No

No

X

No

TAKEOFF

X

X

X

XX

X

XX

X

X

X

X

X

MLCYCLED

X

X

X

X

No

No

NoNo

No

NoNo

No

No

STALLSURGE

X

X

No

No

No

No

NoNo

No

NoNo

No

No

SEVERE HAIL/RAIN

PREV.

PREV.

PREV.

C3GC3J

PREV.

ALL

SCN8

All

E1N

5BK5BL

ALL

FADEC

CFM 56-5C

CFM 56-5B

CFM 56-5A

RR all Trent

PW

IAE

GE 80


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AUTOMATIC Ignition Selection …

• All engine manufacturers provide flameout protection.

• This function activates the igniters, when the FADEC detects a flameout:4The flameout detection logic consists of:

– Monitoring the N2 speed, and the speed trend • By CFM, GE

– Monitoring the N2 speed• By IAE and PW

– Monitoring the combustor pressure, and the rate of change of the HP shaft speed

• By RR

• All engine manufacturers provideprotection against inadvertentlysetting the master lever OFF then ON.


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Contents …

• Description






• Conclusion


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MANUAL Ignition Selection

• The crew can manually select continuous ignition...

4Depending on the flight phase…– Takeoff, climb, approach

4In adverse weather conditions …– Rain, hail, turbulence

4Depending on the engine type.


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Contents …

• Description






• Conclusion


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Igniter INHIBITION: CFM & RR

• Even if manually-selected, the igniters may be inhibited by the FADEC:4CFM 56 5B/C (FADEC 5BK, 5BL, C3G, C3J)

– If burner pressure (PS3) is higher than 225 psi

4RR Trent 500, Trent 700– If burner pressure (PS3) is higher than 300 psi

• CFM tests have shown that, with the exception of brand new igniters, they will not produce spark:

– For high burner pressure (PS3)

4During takeoff, PS3 will usually be above this value.

To prevent abusive use of the igniters,and premature wear…


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Igniter INHIBITION: CFM & RR …

• This change does not affect the flameout logic,which automatically pulses the igniters, if:

4A flameout is detected, regardless of the PS3


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Igniter INHIBITION Review

NoPREV

NoPREV

NoPREVCFM 56-5C

If P>225psiIf P>225psi

C3GC3J

NoPREV

ALL

SCN8

All

E1N

5BK5BL

ALL

FADEC

If P>225psiIf P>225psi

CFM 56-5B

NoCFM 56-5A

If P>300psiRR all Trent

No

PW

NoIAE

No

GE 80

HIGH BURNER PRESSURE

ENGINE


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Contents …

• Description






• Conclusion


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Effective Igniter Use

• Igniter life is limited …4In-service experience has revealed cases of abusive igniter use.

4To reduce unnecessary maintenance costs, and ensure theigniter is operational when needed, igniters should only be usedas recommended.

• Engine and aircraft manufacturers strive to enhanceigniter life:4By developing FADEC logics that automatically detect the

conditions for which igniters should be used:– Flameout

4In order to ease the crew’s workload.

4In order to reduce the possibility of crew error:– If forgotten in adverse conditions: SAFETY impact– If abusive use: IGNITER LIFE, COST, and SAFETY impact


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Contents …

• Description






• Conclusion


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Review of Operational Recommendations

• The FCOM currently recommends selecting the igniters during takeoff, after takeoff, approach, andduring go-around, in the following cases:

4Heavy rain4Standing water4Severe turbulence

• However, it is no longer recommended toselect the igniters, if turbulent conditions occurduring cruise, since …

4The flameout logic is efficient.4This phase is less critical than the others.


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Review of Operational Recommendations …

• Airbus recommendations are more restrictive thanthose of some engine manufacturers:4RR does not require the crew to manually select igniters.4Latest CFM standards inhibit the igniters, if PS3> 225 psi

– Selecting the igniters before takeoff is ineffective4Fleet harmonization was considered in Airbus’ approach

• Airbus is currently considering the possibility of revising the SOP to be consistent with engine manufacturer recommendations.

• Other considerations, recommended bythe engine manufacturer, such as startingthe APU in heavy rain, will also be added tothe Adverse Weather section of the FCOM 3.


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Conclusion

• Operational recommendations, concerning the use of igniters, differ from one engine manufacturer to another…

• The latest engine manufacturer design tendency is to limit the use of the igniters, when not necessary …

• Igniter use should be used judiciously, to save igniter life andpreserve them for use, when needed.

• Adhere to Airbus recommendations….

• The flameout logic provides additional engine relight protection.


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This document and all information contained herein is the sole property of AIRBUS S.A.S. No intellectual property rights are granted by the delivery of this document or the disclosure of its content. This document shall not be reproduced or disclosed to a third party without the express written consent of AIRBUS S.A.S. This document and its content shall not be used for any purpose other than that for which it is supplied.

The statements made herein do not constitute an offer. They are based on the mentioned assumptions and are expressed in good faith. Where the supporting grounds for these statements are not shown, AIRBUS S.A.S. will be pleased to explain the basis thereof.

AN EADS JOINT COMPANYWITH BAE SYSTEMS

Engine Ignition Selection - SmartCockpit · 2012. 6. 27. · •All engine manufacturers provide...

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Transcript of Engine Ignition Selection - SmartCockpit · 2012. 6. 27. · •All engine manufacturers provide...