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HYDRAULIC SYSTEMS
A training coursefor repairinghydraulicproblems on all Airbusaircraft types
Your aircraft is scheduled to departin two minutes and you are comfor-tably seated. Suddenly, a voice isheard in the cabin: ‘ladies andgentlemen, this is the captain, we have a technical problem andmaintenance is checking it. We willinform you as soon as possible ofthe result’.Even if you don’t see them, outsidethe aircraft maintenance techniciansare already busy. The aircraft has a hydraulic leak and they have to quickly answer crucial ques-
tions such as ‘is the leak within the Aircraft Maintenance Manual(AMM) limits?’ or ‘is there a de-activation to perform?’ and manyothers. Then they have to make agood decision, because the longerthe aircraft is delayed, the morepassengers will be inconveniencedand the more expensive and pro-blematic will be the consequences.Their decision making depends onseveral factors, such as: Severity ofthe problem, maintenance staffskill and experience and a numberof others.
To help and improve the perfor-mance, knowledge, skill and deci-sion making of maintenance tech-nicians on hydraulic system pro-blems, Airbus has developed a spe-cific two days training course,applicable for all Airbus aircrafttypes. This article explains the cou-rse content and its advantages.
HYDRAULIC SYSTEMS FA
ST43
2
Franck GERMAINDeputy Senior Programme DirectorA300/A310 Family Programme Airbus Customer Services
Franck GAYAircraft Maintenance Instructor
Maintenance Training OperationsAirbus Customer Services
Hydraulic problems can be a source of scheduledisruptions for operators. This article is in two parts with the first partdescribing an Airbus training course for repai-ring hydraulic problems on all Airbus aircrafttypes and the second part explaining the impro-vements and maintenance recommendationsspecifically developed for hydraulic systems onA300/A310 Family aircraft.
Hydraulic systems
FAST
43
3
Part 1
Stéphane ADERHydraulic System Senior EngineerAirbus Customer Services
HYDRAULIC SYSTEMS
A training coursefor repairinghydraulicproblems on all Airbusaircraft types
Your aircraft is scheduled to departin two minutes and you are comfor-tably seated. Suddenly, a voice isheard in the cabin: ‘ladies andgentlemen, this is the captain, we have a technical problem andmaintenance is checking it. We willinform you as soon as possible ofthe result’.Even if you don’t see them, outsidethe aircraft maintenance techniciansare already busy. The aircraft has a hydraulic leak and they have to quickly answer crucial ques-
tions such as ‘is the leak within the Aircraft Maintenance Manual(AMM) limits?’ or ‘is there a de-activation to perform?’ and manyothers. Then they have to make agood decision, because the longerthe aircraft is delayed, the morepassengers will be inconveniencedand the more expensive and pro-blematic will be the consequences.Their decision making depends onseveral factors, such as: Severity ofthe problem, maintenance staffskill and experience and a numberof others.
To help and improve the perfor-mance, knowledge, skill and deci-sion making of maintenance tech-nicians on hydraulic system pro-blems, Airbus has developed a spe-cific two days training course,applicable for all Airbus aircrafttypes. This article explains the cou-rse content and its advantages.
HYDRAULIC SYSTEMS
FAST
43
2
Franck GERMAINDeputy Senior Programme DirectorA300/A310 Family Programme Airbus Customer Services
Franck GAYAircraft Maintenance Instructor
Maintenance Training OperationsAirbus Customer Services
Hydraulic problems can be a source of scheduledisruptions for operators. This article is in two parts with the first partdescribing an Airbus training course for repai-ring hydraulic problems on all Airbus aircrafttypes and the second part explaining the impro-vements and maintenance recommendationsspecifically developed for hydraulic systems onA300/A310 Family aircraft.
Hydraulic systems
FAST
43
3
Part 1
Stéphane ADERHydraulic System Senior EngineerAirbus Customer Services
Hydraulic problems can be a source of aircraft delays and cancellations and can cause significant operationaldisruption for operators and theirpassengers. The Hydraulic Practices,Repairs And Precautions Course offersoperators the opportunity to familiarize or refresh their staff with such problemsand fixes and to minimize the disruptionsto their operations that can be caused by them.This course, applicable for all Airbusaircraft families, provides answers when working on hydraulic systems and clarifies, explains and demystifies
what is needed to fix hydraulic systems.Some courses have been run already withpositive feedback, such as the followingexamples from operator participants: ‘Course was really good, was informativefor today’s activities’, ‘It’s interesting and knowledgeable and it gives me the correct information or procedures’,‘Was very clear and presentation was excellent, could clear all doubts when ever raised during the course’, ‘We hope that in the future there will bemore frequency of training informationsuch as this, to further broaden our knowledge.’
Conclusion
CONTACT DETAILS
Franck GAYAircraft Maintenance InstructorMaintenance Training OperationsAirbus Customer ServicesTel: +33 (0) 5 62119720Fax +33 (0) 5 [email protected]
THE HYDRAULIC PRACTICES,REPAIRS AND PRECAUTIONS COURSE
The course is designed for allAirbus aircraft families and can bedelivered at a customer’s site, oranywhere else. The target popu-lation is maintenance certifyingstaff (European Aviation SafetyAgency B1, B2, A, C categories,Federal Aviation Agency A&P orequivalent) and non certifying staffdirectly dealing with the aircraft.The course is divided into twoparts. The first day is theory withthe second day being practical andon aircraft, including a repair ses-sion with kits.
DAY ONE - THEORY
Servicing recommendations is thefirst topic. Whether it is done at theoperator main base or elsewhere,improper servicing can be a contri-buting factor for delays (overservicing, quantity level variation,reservoir or accumulator confi-guration not set…etc).Therefore, it is essential to know orreview the ‘MUST DO and MUSTNOT DO’ during servicing.
Another maintenance duty is ins-pection. This is to ensure hy-draulic systems; components andlines are in good condition. This isvery important for prevention ofhydraulic leaks. They can be certi-fied airworthy according to theAMM, which provides criteria,limits and tolerances. What andwhere to check, is part of thecourse. Additionally, the coursehelps to find the damage tolerancesfor dispatch. Leak prevention incase of line damage is studied. Inaddition, videos review the basicsof seal, line and hose installation.A significant amount of air trappedin hydraulic fluid can generatesubstantial issues. Therefore, it isessential to know how to tackle thispossible case, so the procedures tobe used are part of the course. When a leak or a problem is disco-vered, what we quickly want toknow, are the steps to dispatch the
aircraft airworthy or/and thingsthat can reduce a delay durationsuch as usage of a Fly Away Kit orwhen to call AIRTAC (AirbusTechnical AOG Centre). The last part of day one explainsavailable hydraulic line repairmethods. Today, for Airbus, the su-ppliers for on wing repairs arePermaswage and Rynglok and bothof these technologies are studied.Throughout the day participantsare not passive, questions are askedand answers have to be found in the AMM. Also trainees areguided and coached by the ins-tructor using AirN@v (Airbus elec-tronic technical data tool). Thepurpose is to help them identify howand where to find necessary data fortheir everyday life.
DAY TWO - PRACTICAL
This is split in two: on aircraft andwith repair kits. On aircraft, parti-cipants with the instructor see all theareas where there are points ofinterest in safety, dispatch, servi-cing, inspection, de-activation, testor installation.
For example: Applicable to allAirbus aircraft types with lowerdeck cargo doors, includingfreighters with the main deck cargohydraulic actuated door. Duringmaintenance checks cargo doorsare left open for long periods. Dueto safety concerns, before the firstclosing of the door it is required tobleed the door actuators, as if thisis not done the doors could slamshut due to air ingress. Therefore,this task is emphasized and thetype of tool and how to perform thebleeding is reviewed.
Another example is on the A320Family: to ensure safety on somemaintenance tasks it is a goodpractice to isolate systems. On thePower Transfer Unit (PTU) there isan isolation coupling and duringthe course it is reviewed why,where and how to disconnect thiscoupling.
4
FAST
43HYDRAULIC SYSTEMS
These are just two examples, butmany more are covered.
If an operator has more than oneaircraft type, everything is done onthe first type then only thedifferences are covered for theother types.
Using the repair kits is the last part of the course, Permaswage andRynglok repair kits are used andeach participant must cut, clean,deburr and swage under theinstructor’s coaching/supervision.After the repair is made ins-pections are carried out.
5
FAST
43
5
HYDRAULIC SYSTEMS
Hydraulic problems can be a source of aircraft delays and cancellations and can cause significant operationaldisruption for operators and theirpassengers. The Hydraulic Practices,Repairs And Precautions Course offersoperators the opportunity to familiarize or refresh their staff with such problemsand fixes and to minimize the disruptionsto their operations that can be caused by them.This course, applicable for all Airbusaircraft families, provides answers when working on hydraulic systems and clarifies, explains and demystifies
what is needed to fix hydraulic systems.Some courses have been run already withpositive feedback, such as the followingexamples from operator participants: ‘Course was really good, was informativefor today’s activities’, ‘It’s interesting and knowledgeable and it gives me the correct information or procedures’,‘Was very clear and presentation was excellent, could clear all doubts when ever raised during the course’, ‘We hope that in the future there will bemore frequency of training informationsuch as this, to further broaden our knowledge.’
Conclusion
CONTACT DETAILS
Franck GAYAircraft Maintenance InstructorMaintenance Training OperationsAirbus Customer ServicesTel: +33 (0) 5 62119720Fax +33 (0) 5 [email protected]
THE HYDRAULIC PRACTICES,REPAIRS AND PRECAUTIONS COURSE
The course is designed for allAirbus aircraft families and can bedelivered at a customer’s site, oranywhere else. The target popu-lation is maintenance certifyingstaff (European Aviation SafetyAgency B1, B2, A, C categories,Federal Aviation Agency A&P orequivalent) and non certifying staffdirectly dealing with the aircraft.The course is divided into twoparts. The first day is theory withthe second day being practical andon aircraft, including a repair ses-sion with kits.
DAY ONE - THEORY
Servicing recommendations is thefirst topic. Whether it is done at theoperator main base or elsewhere,improper servicing can be a contri-buting factor for delays (overservicing, quantity level variation,reservoir or accumulator confi-guration not set…etc).Therefore, it is essential to know orreview the ‘MUST DO and MUSTNOT DO’ during servicing.
Another maintenance duty is ins-pection. This is to ensure hy-draulic systems; components andlines are in good condition. This isvery important for prevention ofhydraulic leaks. They can be certi-fied airworthy according to theAMM, which provides criteria,limits and tolerances. What andwhere to check, is part of thecourse. Additionally, the coursehelps to find the damage tolerancesfor dispatch. Leak prevention incase of line damage is studied. Inaddition, videos review the basicsof seal, line and hose installation.A significant amount of air trappedin hydraulic fluid can generatesubstantial issues. Therefore, it isessential to know how to tackle thispossible case, so the procedures tobe used are part of the course. When a leak or a problem is disco-vered, what we quickly want toknow, are the steps to dispatch the
aircraft airworthy or/and thingsthat can reduce a delay durationsuch as usage of a Fly Away Kit orwhen to call AIRTAC (AirbusTechnical AOG Centre). The last part of day one explainsavailable hydraulic line repairmethods. Today, for Airbus, the su-ppliers for on wing repairs arePermaswage and Rynglok and bothof these technologies are studied.Throughout the day participantsare not passive, questions are askedand answers have to be found in the AMM. Also trainees areguided and coached by the ins-tructor using AirN@v (Airbus elec-tronic technical data tool). Thepurpose is to help them identify howand where to find necessary data fortheir everyday life.
DAY TWO - PRACTICAL
This is split in two: on aircraft andwith repair kits. On aircraft, parti-cipants with the instructor see all theareas where there are points ofinterest in safety, dispatch, servi-cing, inspection, de-activation, testor installation.
For example: Applicable to allAirbus aircraft types with lowerdeck cargo doors, includingfreighters with the main deck cargohydraulic actuated door. Duringmaintenance checks cargo doorsare left open for long periods. Dueto safety concerns, before the firstclosing of the door it is required tobleed the door actuators, as if thisis not done the doors could slamshut due to air ingress. Therefore,this task is emphasized and thetype of tool and how to perform thebleeding is reviewed.
Another example is on the A320Family: to ensure safety on somemaintenance tasks it is a goodpractice to isolate systems. On thePower Transfer Unit (PTU) there isan isolation coupling and duringthe course it is reviewed why,where and how to disconnect thiscoupling.
4
FAST
43
HYDRAULIC SYSTEMS
These are just two examples, butmany more are covered.
If an operator has more than oneaircraft type, everything is done onthe first type then only thedifferences are covered for theother types.
Using the repair kits is the last part of the course, Permaswage andRynglok repair kits are used andeach participant must cut, clean,deburr and swage under theinstructor’s coaching/supervision.After the repair is made ins-pections are carried out.
5
FAST
43
5
HYDRAULIC SYSTEMS
7
FAST
43
7
HYDRAULIC SYSTEMS HYDRAULIC SYSTEMS FA
ST43
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Hydraulic system leaks are recognised as a significant driver for unscheduledmaintenance actions on A300/A310 Family aircraft, so during the A300/A310 2007 TechnicalSymposium in Toulouse a review of available hardwareimprovements was made and a presentation was given of recommendations for maintenancepractices to prevent leaks. Numerous hardware improvements have been defined by Airbus and are summarized in SIL 29-032.
Preventive maintenance is also an important factor to reduce leaks, so a visual inspection guide CD-ROM has been developed and issued by Airbus. Application of the SIL improvements and CD-ROM inspection guide has already led to improved operations for operators and, together with the complementary HydraulicPractices, Repairs And PrecautionsCourse described in Part 1 of this article,can bring increased benefits for operatorsby reducing schedule disruptions due to hydraulic problems.
Conclusion
CONTACT DETAILS
Stéphane ADERHydraulic System Senior EngineerAirbus Customer ServicesTel: +33 (0)5 62 11 97 06Fax: +33 (0)5 61 93 32 [email protected]
checked and the particular areasthey are located in can be summa-rized as follows: Items to be checked are hydraulicseals, flexible hoses and rigidpipes. The particular areas are themain landing gear wheel well, thenose landing gear bay, the enginepylon and nacelle and the wingtrailing edge.Precise and detailed guidelines andprocedures have been defined forthese checks. For all A300/A310Family operators to benefit from thisfleet wide experience a VisualInspection Guide CD-ROM has beendeveloped, which complements theHydraulic Practices, Repairs AndPrecautions Course describedpreviously in this article. Copies ofthis CD-ROM have already beendistributed to all A300/A310 Familyoperators and SIL 00-032 givescontacts for additional copies. Abooklet, the ‘A300, A310, A300-600Hydraulic System MaintenancePractices’ has also been producedand made available to operators.
Preventinghydraulic leaks on A300/A310Family aircraft One outcome of the A300/A310Technical Symposium in Toulousein 2007 was the clear indicationfrom operators that hydraulic leaksrepresent one of the most signi-ficant causes for unscheduledmaintenance on the aircraft. Fromthis came the request for Airbus toassist to improve the situation. Thisarticle explains the steps taken byAirbus to help operators reduceunscheduled maintenance relatedto hydraulic problems.
FLEET STATUS
Leaks from the hydraulic and otherrelated systems (such as flightcontrols, braking systems etc) are amain cause for operational inter-ruptions and unscheduled mainte-nance actions for each of theA300/A310 Family aircraft types.The hydraulic system is regularlyone of the top five identifiedcontributors to unscheduled main-tenance actions.
To understand this phenomenonand define corrective actions,Airbus began some years ago to
closely monitor all reported hy-draulic leak events. This database has been used for the development of varioushardware improvements and alsothe provision of comprehensivemaintenance recommendations forpreventive maintenance. Severaloperators have approached Airbusindividually, recommendationshave been given and the resultshave been clearly positive. Onerecent feedback from Thai Airwaysconcerned a hydraulic leak impro-vement plan developed in 2007,see separate box.
AVAILABLE IMPROVEMENTS
A number of improvements andmodifications have been definedand a complete list is available inService Information Letter 29-032.As experience feedback from in-service is a continual process, thecontents of this SIL are periodi-cally updated and the last revisionwas in October 2007.
GUIDELINES
Analysis of in-service feedbackclearly shows that the rate ofoccurrence of hydraulic leaksincreases as the aircraft ages.Consequently, older aircraft re-quire particular attention and,generally, the main items to be
Part 2
Flexible hoseinspection
Hose to structure clearance1
1 2
3
Hose to pipe clearance2
Chafing marks/braid rupture3
‘Thai Airways have emphasized theoutstanding results achieved thanksto the hydraulic leak preventivemaintenance programme put in place,which has helped to achieve and maintain low cases of hydraulic leaks.’
Mr. Charat ChimpaleeThai Airways Engineering
Documentation SIL 29-032 updated in Oct 2007 with latest improvements
Effectivity:A300A300-600A310
Recentimprovements
0
20
40
60
80
100
120
140
800-849 750-799 700-749 650-699 600-649 550-599 500-549 450-499
Numberof leaks
MSNrange
Number of leaks increasesw ith aircraft age
Maintenance aids
Number of leaks per range of MSN
CD-ROM HydraulicSystem MaintenancePractices
FAST magazine- number 13- number 22
Booklet ‘A300, A310, A300-600 Hydraulic System Maintenance Practices’Available via SIL 00-032
7
FAST
43
7
HYDRAULIC SYSTEMS HYDRAULIC SYSTEMS
FAST
43
6
Hydraulic system leaks are recognised as a significant driver for unscheduledmaintenance actions on A300/A310 Family aircraft, so during the A300/A310 2007 TechnicalSymposium in Toulouse a review of available hardwareimprovements was made and a presentation was given of recommendations for maintenancepractices to prevent leaks. Numerous hardware improvements have been defined by Airbus and are summarized in SIL 29-032.
Preventive maintenance is also an important factor to reduce leaks, so a visual inspection guide CD-ROM has been developed and issued by Airbus. Application of the SIL improvements and CD-ROM inspection guide has already led to improved operations for operators and, together with the complementary HydraulicPractices, Repairs And PrecautionsCourse described in Part 1 of this article,can bring increased benefits for operatorsby reducing schedule disruptions due to hydraulic problems.
Conclusion
CONTACT DETAILS
Stéphane ADERHydraulic System Senior EngineerAirbus Customer ServicesTel: +33 (0)5 62 11 97 06Fax: +33 (0)5 61 93 32 [email protected]
checked and the particular areasthey are located in can be summa-rized as follows: Items to be checked are hydraulicseals, flexible hoses and rigidpipes. The particular areas are themain landing gear wheel well, thenose landing gear bay, the enginepylon and nacelle and the wingtrailing edge.Precise and detailed guidelines andprocedures have been defined forthese checks. For all A300/A310Family operators to benefit from thisfleet wide experience a VisualInspection Guide CD-ROM has beendeveloped, which complements theHydraulic Practices, Repairs AndPrecautions Course describedpreviously in this article. Copies ofthis CD-ROM have already beendistributed to all A300/A310 Familyoperators and SIL 00-032 givescontacts for additional copies. Abooklet, the ‘A300, A310, A300-600Hydraulic System MaintenancePractices’ has also been producedand made available to operators.
Preventinghydraulic leaks on A300/A310Family aircraft One outcome of the A300/A310Technical Symposium in Toulousein 2007 was the clear indicationfrom operators that hydraulic leaksrepresent one of the most signi-ficant causes for unscheduledmaintenance on the aircraft. Fromthis came the request for Airbus toassist to improve the situation. Thisarticle explains the steps taken byAirbus to help operators reduceunscheduled maintenance relatedto hydraulic problems.
FLEET STATUS
Leaks from the hydraulic and otherrelated systems (such as flightcontrols, braking systems etc) are amain cause for operational inter-ruptions and unscheduled mainte-nance actions for each of theA300/A310 Family aircraft types.The hydraulic system is regularlyone of the top five identifiedcontributors to unscheduled main-tenance actions.
To understand this phenomenonand define corrective actions,Airbus began some years ago to
closely monitor all reported hy-draulic leak events. This database has been used for the development of varioushardware improvements and alsothe provision of comprehensivemaintenance recommendations forpreventive maintenance. Severaloperators have approached Airbusindividually, recommendationshave been given and the resultshave been clearly positive. Onerecent feedback from Thai Airwaysconcerned a hydraulic leak impro-vement plan developed in 2007,see separate box.
AVAILABLE IMPROVEMENTS
A number of improvements andmodifications have been definedand a complete list is available inService Information Letter 29-032.As experience feedback from in-service is a continual process, thecontents of this SIL are periodi-cally updated and the last revisionwas in October 2007.
GUIDELINES
Analysis of in-service feedbackclearly shows that the rate ofoccurrence of hydraulic leaksincreases as the aircraft ages.Consequently, older aircraft re-quire particular attention and,generally, the main items to be
Part 2
Flexible hoseinspection
Hose to structure clearance1
1 2
3
Hose to pipe clearance2
Chafing marks/braid rupture3
‘Thai Airways have emphasized theoutstanding results achieved thanksto the hydraulic leak preventivemaintenance programme put in place,which has helped to achieve and maintain low cases of hydraulic leaks.’
Mr. Charat ChimpaleeThai Airways Engineering
Documentation SIL 29-032 updated in Oct 2007 with latest improvements
Effectivity:A300A300-600A310
Recentimprovements
0
20
40
60
80
100
120
140
800-849 750-799 700-749 650-699 600-649 550-599 500-549 450-499
Numberof leaks
MSNrange
Number of leaks increasesw ith aircraft age
Maintenance aids
Number of leaks per range of MSN
CD-ROM HydraulicSystem MaintenancePractices
FAST magazine- number 13- number 22
Booklet ‘A300, A310, A300-600 Hydraulic System Maintenance Practices’Available via SIL 00-032
