Aircraft performance monitoring - caac.gov.cn€¦ · Compares the IFP model to actual aircraft...

Aircraft performance monitoring

April 2013

Presented bySteve BARKER / Senior Performance Engineer

Regional Seminar

Aircraft performance monitoring

© AIRBUS China LTD. All rights reserved. Confidential and proprietary document.

Contents

April 2013Aircraft performance monitoring

What is aircraft performance monitoring?1

Performance monitoring principle2

Causes of deterioration3

Implications4

Performance recovery5

APM results6

Conclusion7


Contents



Page 3



Implications4


APM results6

Conclusion7


• Definition

• Procedure of determination of the actual performance level of each airplane of the fleet versus the manufacturer’s book level through analysis of data gathered in operations

• Book level• established by the aircraft manufacturer as a result of theoretical

analysis and test flights• Flight Crew Operating Manual• IFP, FLIP or APM software

(part of the Performance Engineers’ Package)




• Definition

• Baseline level • established at the entry into service of an individual aircraft during

the acceptance flight or delivery flight• can be above or below the book level

• Trends• performance levels are measured over time so that trends are

identified• the baseline level is the starting point for the trend monitoring




• Aim• To adjust the performance factor of

• the computerised flight plan• the FMS predictions

• To monitor the aircraft condition periodically in order to analyze the trend of a given tail number or of a whole fleet

• To identify any degraded aircraft within the fleet and take the necessary corrective actions:• Maintenance actions• Operational recommendations

• Regulatory requirement from authorities for ETOPS and reduced reserves operations




Contents



Page 7



Implications4


APM results6

Conclusion7


• Three commonly used methods

• The fuel used method

• The fuel on board method

• The specific range method




• The fuel used method

• measurement of the fuel burnt by the aircraft in level flight (stabilized cruise) over a significantly long time leg

• comparison to the fuel prediction of the Flight Crew Operating Manual (FCOM, Volume 2, Flight Planning sections) or the High Speed Performance calculation program developed by Airbus Industrie (the IFP program).

• Compares the IFP model to the actual aircraft in cruise

Advantage:

Smoothes variations in recorded parameters over the recording period

Disadvantage:

Tedious manual recording of data in flight




• The fuel burn off method

• comparison of the aircraft performance over a complete flight with the one forecasted by the computerized flight planning

• the actual aircraft performance is corrected depending on the differences between the actual flight profile and the predicted one.

• Compares the IFP model to actual aircraft over a all phases of a flight

Advantage:

Easy to implement

Disadvantage:

Accumulation of errors due to differences between CFP and the actual flight




• The specific range method• The data observed in flight represents punctual (instantaneous)

airframe/engine performance capability. • The data is recorded during stable cruise flight legs and is used

to determine:• the actual specific range,• the delta specific range in percentage relative to the book

level (predicted specific range),• the delta EPR/N1 required to maintain the flight conditions,• the delta fuel flow resulting from this delta EPR/N1,• the delta fuel flow required to maintain this delta EPR/N1.

• Compares the IFP model to actual aircraft




Aircraft Model

Real Aircraft

CruisePoint

GWCGEPRBleedsMachTATFuel Flow...

Theoretical N1 or EPR

Theoretical Fuel Flow

Calculated Fuel Flow

Actual Fuel Flow

A/C

Airframe*

Actual N1 or EPR

* Only if engine thrust to N1/EPR relationship same as model

Engine Model

Real Engine

Engine Model

Engine*




Calculated Fuel Flow A/C

DSR: Delta Specific Range

Aircraft Model

Real Aircraft

CruisePoint

GWCGEPRBleedsMachTATFuel Flow...

Theoretical N1 or EPR

Actual N1 or EPR

Engine Model

Real Engine

Engine Model

Theoretical Fuel Flow

Actual Fuel Flow

DSR

DSR: Delta Specific RangeDFFA, DFFB: Delta Fuel Flow A, B

Airframe*DFFA

Engine*DFFB




Contents



Page 14



Implications4


APM results6

Conclusion7


• Engines

80%Fan blade Leading Edge erosion

Blended blades (FOD)

Fan rubstrip wear

Fan & Compressor dirt

High time engine core deterioration

System settings

Nacelle air leakage




• Airframe

20%Aerodynamic surface misrigging

Seals missing or damaged

Doors not flush or leaking

Rough or deformed surfaces

Chipped paint

Dirty aircraft

Airbus experience is that this is no more than 1 to 1.5% DSR for an aircraft in bad condition




• Examples of aerodynamic degradationExternal Patches


Peeling Paint

Misrigged Slat

Misrigged SpoilerMismatched Doors

Rough or Damaged Panels

Repaired Lightning Damage



Contents



Page 18



Implications4


APM results6

Conclusion7


• Flight planning• If the Computerised Flight Plan is based on new aircraft performance,

deteriorated aircraft will burn more trip fuel than planned. Planned reserve fuel will also be optimistic.

Implications4

• Flight operations• The Flight Management System (FMS) fuel prediction function (FOB

at Destination, Alternate, Extra Time, etc) will initially show values close to CFP, but these values will decrease as the flight continues.

• Crew confidence• If no action is taken at the dispatch level, the aircrew will lose

confidence in the fuel planning and will start adding their own reserves. They will normally overcompensate.



• Perception• Operators with no previous knowledge of aircraft monitoring are often

surprised by the deterioration, and believe that there is a problem with the aircraft.

Implications4

• Operations• Extra fuel due to aircraft deterioration may impact payload, and in the

worst case make some routes not viable for some tail numbers.

• Operating costs• As fuel is a major component of costs, any increase significantly

affects the overall operating costs. In addition, overcompensation of reserves also increases fuel burn and costs.



• Assuming a 5% fuel burn increaseover one year

490 000 kg more fuel

1 400 000 kg more fuel

1 860 000 kg more fuel

Implications4



Contents



Page 22



Implications4


APM results6

Conclusion7


• Major improvements are difficult without engine change

• However



• However• Regular engine core wash reduces deposits helps


• However• Regular engine core wash reduces deposits helps• Keeping an aircraft clean helps


• However• Regular engine core wash reduces deposits helps• Keeping an aircraft clean helps• Aircraft should be well maintained aerodynamically• Engines systems, bleeds, etc. should be kept in trim and functioning

properly


• However• Regular engine core wash reduces deposits helps• Keeping an aircraft clean helps• Aircraft should be well maintained aerodynamically• Engines systems, bleeds, etc. should be kept in trim and functioning

properly

• Remember that trend monitoring of APM results can detectaerodynamic or engine system irregularities



Contents



Page 24



Implications4


APM results6

Conclusion7


• Performance trending:• Allows trending over flight hours, flight cycles:

• For individual tail numbers• For the whole fleet.

• Can be used as a trigger condition for corrective actions.

Performance Monitoring

Evolut ion versus number of flight cycles

-7.00

-6.00

-5.00

-4.00

-3.00

-2.00

-1.00

0.00

1.00

500 1500 2500 3500 4500 5500 6500 7500 8500 9500

Number of T/O from EIS

Spec

ific

Ran

ge D

evia

tion

(%) f

rom

IFP

PERFO RM A N CE I N REV EN U E SERV I C E

EV O LU T I O N SI N CE EI S

-6

-5

-4

-3

-2

-1

00.00 2.00 4.00 6.00 8.00 10.00 12.00 14.00 16.00 18.00

Quarters from EIS

Spec

ific

Ran

ge D

evia

tion

from

IFP

(%)

APM results6



• Changing the fuel factor• Technique 1 - Step Fuel Factors:

• Fuel factor is changed when a difference of more than a given percentage is noticed between the new figure and the last retained one.

APM results6

2.402.50

2.702.80

2.90

2.602.80

3.002.80

1.00

1.50

2.00

2.50

3.00

3.50

Jun 12 Jul 12 Aug 12 Sep 12 Oct 12 Nov 12 Dec 12 Jan 13 Feb 13

Mon

itore

d fu

el fa

ctor

(%)

Actual monitored fuel factor Retained monitored fuel factor



• Changing the fuel factor• Technique 2 - Smoothed Fuel Factors:

• Monitored fuel factors are averaged using a rolling average technique over say three months.

APM results6

2.402.50

2.702.80

2.90

2.602.80

3.002.80

1.00

1.50

2.00

2.50

3.00

3.50

Jun 12 Jul 12 Aug 12 Sep 12 Oct 12 Nov 12 Dec 12 Jan 13 Feb 13

Mon

itore

d fu

el fa

ctor

(%)

Actual monitored fuel factor Retained monitored fuel factor



Contents



Page 28



Implications4


APM results6

Conclusion7


• Routine aircraft performance monitoring identifies trends

• First step towards the identification of a aircraft degradation

• Aid to monitor the shift of the aircraft performance level

• Particular attention to degraded aircraft within the fleet

• Determination of ABSOLUTE aircraft performance level is NOT the goal

Conclusion7



April 2013Noise abatement recommendations

© AIRBUS China LTD. All rights reserved. Confidential and proprietary document. This document and all information contained herein is the sole property of AIRBUS China LTD. No intellectual property rights aregranted 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 China LTD. This document and itscontent 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 China LTD. will be pleased to explain the basis thereof.AIRBUS, its logo, A300, A310, A318, A319, A320, A321, A330, A340, A350, A380, A400M are registered trademarks.

Thank you

Xie xie

谢谢

Aircraft performance monitoring - caac.gov.cn€¦ · Compares the IFP model to actual aircraft...

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