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FAST / NUMBER 2318

CONCLUSION

Airbus Industrie is able to demonstrate that its aircraft families share large commonality in aircraft spares, enabling opera-tors to reduce their operating costs. This has been achieved through aircraft design with maintenance in mind. Further, thefly-by-wire technology has lent itself to improving commonality by integrating the Automated Flight System Computersinto a reduced number of LRUs, which share high commonality and reliability within the family groups. So, when it comesto aircraft spare parts, Airbus Industrie is glad to be called common, reliable and punctual. v

However with eleven years of techno-logical improvements the Auto Flightsystem MTBUR has increased quitedramatically from the non-FBW aircraftto the latest technology FBW aircraft,the A320 and A340.

The savings for a recommendedspares investment in dollar terms as aresult of the integration of AFS func-tions are considerable. The investmentrequired for the AFS equipment for tenA340 or A320 being roughly half ofthat required for ten non FBW type air-

craft. The advances made in componentintegration offsets the increase in priceof the individual LRUs (Figure 10).

The cost effectiveness of the integra-tion of the AFS can be measured by di-viding the recommended spares invest-ment figures by the AFS reliability i.e.Cost/AFS MTBUR. The results can beseen in the Figure 11.

The AFS fitted to the A320 is fourtimes, and the A340 seven times, morecost effective than the pre-FBW aircraftand as fleet size increases this effect be-comes more pronounced.

PUNCTUALITY

The turnaround time for rotable and re-pairable spares is a combination of thetransit time and the repair processingtime.

The transit time

The transit time is dependent on the

two following factors:q The administrative efficiency of anairline in realising that a spare has beenremoved, shipping the spare part outand then, when the spare part returns,placing it back on the shelf.q The speed and efficiency of the

freight forwarder and Customs authori-ties in importing/exporting and trans-porting the spare part will have an im-pact on the transit time. AirbusIndustrie has been working closely withseveral major forwarders and logistics

service suppliers to develop an off-the-shelf transit management programme.This will offer customers a choice offorwarder service with defined perfor-mance levels and terms.

The repair processing time

Airbus Industrie has taken the initiativewith its proprietary parts repair turn-around time.

Airbus Industrie now guarantees amaximum of 15 calendar days repairtime for its proprietary parts. This isbacked up by a forward exchange at noadditional cost should the repair timeexceed this guarantee. The operator inthis case is then only invoiced for therepair charges and not the exchangefee. This significantly reduces the levelof inventory which needs to be stored

to cover those just-in-case situationsand moves away from the currentindustry standard of guaranteeing av-erage repair times.

Figure 11

AFSCOST EFFECTIVENESS

COMPARISON

100

190

Relative MTBUR value

LRU MTBUR

AFS MTBUR

400

350

300

250

200

150

10050

0FAC FMGC FMGECFCC FAC TCC FMCNon FBW a/c A320 A340

364

Index value

Non FBW a/c

(10 aircraft fleet)

A320

A340

120

100

80

60

40

20

0

RelativeSpares investment/ AFS MTBUR

19

COMBINING ENVIRONMENT

PROTECTION AND

WINDSHIELD RAIN PROTECTION

ON AIRBUS AIRCRAFT

Windshield rain protection providesthe flight crew with a clear vision through

the aircraft windshield when rain is

encountered. The Rainboe rainrepellent fluid, originally used on Airbus

aircraft in addition to the basic windshield

wiper system, has been phased out aspart of the worldwide effort to protect the

Ozone layer. Airbus Industrie has been

actively working on alternative solutions

and is now in a position to provide theoperators with a choice of environmentally

friendly rain repellent fluid or windshield

hydrophobic coating. This combines

maximum windshield rain protection with

safe guards for the environment.

Figure 10

AFS MTBURCOMPARED TO INDIVIDUAL LRU MTBUR

by Franois PovedaEngineer Fire, Ice and Rain Protection

Customer Services EngineeringAirbus Industrie

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21

S S

RAIN RPLNT WIPER

OFF

SLOW

FAST

Figure 3

RAIN REPELLENT SYSTEM SCHEMATIC

Fromhot airmanifold

Test check valve

Purge check valves

Solenoid valves

RAINBOE RAIN REPELLENT FLUID DEACTIVATIONA300 A300-600 A310 A319/A320/A321 A330 A340

MOD 11480 11480 11480 25419 44482 44482SB A 30 0- 30 -0 04 4 A 30 0- 30 -6 02 3 A 31 0- 30 -2 02 9 A 32 0- 30 -1 03 2 A 33 0- 30 -3 01 5 A 34 0- 30 -4 02 0

(1) (1) (1) (1) (1) (1)

CFC FREE (LBFS) RAIN REPELLENT FLUID INSTALLATION

A300 A300-600 A310 A319/A320/A321 A330 A340

MOD 11974 11974 11974 26963 45897 45897SB A 30 0- 30 -0 04 6 A 30 0- 30 -6 02 5 A 31 0- 30 -2 03 2 A 32 0- 30 -1 03 7 A 33 0- 30 -3 01 9 A 34 0- 30 -4 02 2

(2) (2) (2) (3) (3) (3)

PPG SURFACE SEAL COATING INSTALLATION

AIRBUS Service Information Letter 30-024 - Issued in July 1997

(1) SB issued in January 1996 (2) SB will be issued by end of 1998 (3) SB issued in July 1998

Applicable Service Bulletins and Modifications references

FAST / NUMBER 2320

Figure 1

WINDSHIELD WIPER SYSTEM

Figure 2

WINDSHIELD RAIN PROTECTION COCKPIT CONTROLS

Wiper blade

Wiper arm

Motor converter

SLOW

WIPER

OFF

FAST

RAIN RPLNTRAIN RPLNT WIPER

OFF

SLOW

FAST

- WINDSHIELD WIPERS -

THE BASIC RAIN

PROTECTION SYSTEM

The basic windshield rain protectionsystem on Airbus aircraft consists oftwo electrically operated windshieldwipers, one on the Captains side andone on the First Officers side(Figure 1). The wipers can be operatedindependently and at low or high speed,depending on the level of the precipita-

tion (Figure 2). An optional intermittentfunction is also available.All Airbus aircraft are certified for

operation without further windshieldrain protection system.

- RAIN REPELLENT -

AN ADDITIONAL FORM

OF RAIN PROTECTION

All Airbus aircraft are also equippedwith a so-called rain repellent system.This system allows spraying of a fluidonto the windshield outer surface whenheavy rain is encountered (see Figure 3on the following page).

The fluid can be sprayed indepen-dently on the Captains side and on theFirst Officers side. It temporarily mod-ifies the surface tension on the wind-

shield and, combined with the effect ofthe air flow caused by aircraft move-ment, prevents water droplets from ad-hering to the windshield outer surface.

- RAINBOE -

RAIN REPELLENT FLUID

PHASE OUT

The Rainboe rain repellent fluid origi-nally used on Airbus aircraft and on allother jetliners equipped with a similarsystem contains CFC 113. This sub-stance is a type of freon (Chloro-fluorocarbon). It is officially listed asan Ozone depleting substance by theMontreal Protocol which bans its pro-

duction, import and export since 1stJanuary 1996.Since this date and in order to comply

with the international agreements forthe protection of the Ozone layer(Vienna Convention and MontrealProtocol), the Rainboe fluid bottle isno longer installed on delivered aircraft.Airbus Industrie has nevertheless takenthe option to leave the rain repellentsystem installed on the aircraft (electri-cally deactivated) whilst actively work-ing with chemical manufacturers on thedevelopment of a new rain repellentfluid free of CFC.

Service Bulletins for all aircraft typeswere issued in January 1996 in order toallow Rainboe fluid bottle removaland system deactivation on aircraft inservice (refer to Table below for the

applicable Service Bulletins andModifications references).

Rain repellent fluid can assembly

Gauge assembly

Rain repellent blowoutreservoir

Spray nozzles

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WINDSHIELD

HYDROPHOBIC COATINGS

- AN ALTERNATIVE -

For those operators wishing to leave therain repellent system deactivated,Airbus Industrie has also formally ap-proved the use of the PPG IndustriesSurface Seal windshield hydrophobiccoating on all Airbus aircraft types

The coating, which can be used with-out restriction on all types of wind-shields available on Airbus aircraft,

consists of a treatment applied on thewindshield outer surface in a liquidform. It dries out to provide rain repel-lent characteristics similar to those ofthe fluid.

The coating does not contain CFCand is therefore not subjected to the re-quirements of the Montreal protocol.

The treatment has a limited service

life and needs to be reapplied on a regu-lar basis.

Airbus Service Information Letter30-024, issued in July 1997, providesprocurement and material informationrelated to the coating, as well as recom-mendations for application and servic-ing. The content of this SIL is being in-corporated in the Aircraft MaintenanceManual, Maintenance Planning docu-ment, Consumable Materials List andTool and Equipment Manual in accor-dance with the normal revision plan-

ning set for each document and aircrafttype.

Airbus Industrie is closely monitor-ing the development of other wind-shield hydrophobic coatings, which willalso be incorporated in the SIL and inthe aircraft documentation if their per-formance is found to be satisfactory onAirbus aircraft.

NEW RAIN REPELLENT

FLUID FREE OF CFC

A new rain repellent fluid has been suc-cessfully developed. The product com-plies with all the existing regulationsfor the protection of the environment.Laboratory testing has confirmed itscompliance with the existing toxicityrequirements and its compatibility withthe surrounding materials on Airbusaircraft (windshield, structure, paint).

The excellent rain repellent charac-teristics of the fluid and its endurancehave been demonstrated by extensive

bench testing and flight testing(Figure 4). The fluid bottle can be in-stalled on the aircraft with only minormodification of the existing rain repel-lent system.

Airbus Industrie is now preparing theintroduction of the new fluid in produc-tion. Service Bulletins allow reactiva-tion of the rain repellent system and in-stallation of the fluid bottle on aircraftin service (Figure 5).

The rain repellent fluid bottle is sup-plied by Le Bozec Filtration and

Systems (LBFS). Refer to the Table onthe preceding page for the applicableService Bulletins and Mod references.

FAST / NUMBER 23 23FAST / NUMBER 2322

Figure 5

CFC-FREE RAIN REPELLENT FLUID

BOTTLE REPLACEMENT

Figure 4

CFC-FREE RAIN REPELLENT FLUID - ENDURANCE TESTING

HEAVY RAIN

No rain repellent

Rain repellent fluid applied

After 15 seconds

After 2 minutes

Before After

After 10 minutes

EFFECT OF RAIN REPELLENT OR HYDROPHOBIC COATING ON WATER DROPLET/WINDSHIELD CONTACT ANGLE

BEFORE APPLICATION AFTER APPLICATION

CONCLUSION

The commitments of Airbus Industrie on the subject of windshield rain protection were twofold:q To comply with the requirements of the Montreal Protocol on Ozone depleting substances.q To provide Airbus operators with an alternative form of windshield rain protection, in addition to the basic wiper system.

These commitments are today achieved with the removal of the Rainboe fluid from the Airbus aircraft and with theavailability of two alternative forms of windshield rain protection for use on all Airbus aircraft types:q A new rain repellent fluid,q A windshield hydrophobic coating.

The needs of Airbus operators regarding windshield rain protection vary a lot, depending on local weather conditions,habits, operational and maintenance procedures.

Airbus Industrie strongly believes that the choice of fluid or coating now available provides the best response to these dif-ferent needs. v

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