Maintaining stabilisers on aircraft
Overview
This standard identifies the competences you need to carry out maintenance activities on aircraft stabilisers, in accordance with the approved aircraft maintenance manual, structural repair manual, approved change documentation (service bulletin) and airworthiness requirements. The maintenance activities will include the removal, fitting and testing of a range of aircraft stabiliser components, and making repairs to primary and secondary airframe/stabiliser structures, as appropriate to the aircraft type.
You will be required to select the correct tools and equipment to use, based on the operations to be performed and the components to be removed, fitted and tested. The aircraft stabiliser components will include items such as horizontal stabiliser/stabilator or canard/fore planes, vertical stabiliser, elevator/elevon, rudder/ruddevator, and associated components. You will remove the required stabiliser components and fit approved replacements, as appropriate. You will then need to test and adjust the completed system to meet the aircraft maintenance manual, change documentation (service bulletin) and airworthiness requirements.
Your responsibilities will require you to comply with the specific practices and procedures identified in the aircraft manual, structural repair manual, change/service bulletin documentation and airworthiness requirements for the maintenance activities undertaken, and to report any problems with these requirements that you cannot personally resolve, or that are outside your permitted authority, to the relevant people. You must ensure that all tools, equipment and materials used are correctly accounted for on completion of the activities, and that all necessary job/task documentation is completed thoroughly, accurately and legibly. You will be expected to work with a minimum of supervision, taking personal responsibility for your own actions and for the quality and accuracy of the work that you carry out.
Your underpinning knowledge will provide a good understanding of your work, and will provide an informed approach to applying the appropriate maintenance techniques and procedures to aircraft stabilisers. You will understand the removal, fitting and testing methods and procedures, and their application, along with the aircraft stabiliser maintenance requirements. You will know how the aircraft stabiliser functions, the common problems that can occur, the purpose of the individual components and associated defects, in adequate depth to provide a sound basis for carrying out the maintenance activities, correcting faults and for ensuring that the equipment is maintained to the required standard.
You will understand the safety precautions required when working on aircraft stabiliser systems, especially those for isolating the equipment, lifting and handling stabiliser components. You will be required to demonstrate safe working practices throughout, and will understand your responsibility for taking the necessary safeguards to protect yourself and others in the workplace.
Notes:
- This standard is designed to cover the practical experience requirements of the Airline Transport Association (ATA) Chapter 55 Stabilisers.
- To display competence in this standard, it is necessary to both remove and fit aircraft stabiliser components. You must remove components; however, you may fit a replacement component where the original was previously removed by another person. You should also be aware of how to leave a system in a safe condition if maintenance tasks cannot be completed. This covers both the physical systems and the job documentation.
Performance criteria
You must be able to:
- work safely at all times, complying with health and safety and other relevant regulations, directives and guidelines
follow the relevant maintenance schedules to carry out the required work
carry out the maintenance activities within the limits of your personal authority
- carry out the maintenance activities, and replace components in the specified sequence and in an agreed timescale
- report any instances where the maintenance activities cannot be fully met or where there are identified defects outside the planned schedule
- complete relevant documentation in accordance with organisational requirements
- dispose of waste materials in accordance with safe working practices and approved procedures
- leave the aircraft and in a safe and appropriate condition, free from foreign object debris on completion of the activities
Knowledge and Understanding
You need to know and understand:
- the specific safety practices and procedures that you need to observe when working on aircraft stabilisers (including any specific legislation, regulations/codes of practice for the activities, equipment or materials)
- the importance of maintenance on, and impact upon (Extended Range Twin-Engine Operations Procedures) ETOPS systems, legislation and local procedures
- hazards associated with removing, fitting and testing aircraft stabiliser components, and with the tools and equipment used, and how to minimise them and reduce any risk
- the requirements and importance of understanding and applying human factors as defined by the regulatory requirements and the potential impact if these are not adhered to
- the protective equipment that you need to use for both personal protection (PPE) and protection of the aircraft
- the importance of aircraft husbandry and of ensuring that, throughout the maintenance activity, the aircraft and work area are maintained free from foreign objects, and the implications of FOD to the safety of the aircraft
- how to extract and use information from aircraft maintenance manuals, log books, flight logs, and other documents needed in the maintenance process
- how to carry out currency/issue checks on the specifications you are working with
- terminology used in aircraft stabiliser systems, and the use of system diagrams and associated symbols
- the principles of operation of the aircraft stabiliser being worked on, and the function of the various units/components
- preparations to be undertaken on the aircraft stabilisers, prior to repair
- the repair methods and procedures to be used, and the importance of adhering to these procedures
- the application of sealants and adhesives within the repair activities, and the precautions that must be taken when working with them
- how to conduct any necessary checks to ensure the accuracy and quality of the repair
- how to recognise defects (such as skin blemishes, poor skin lines, ineffective fasteners, foreign object damage)
the techniques used to remove components from aircraft stabilisers without damage to the components or surrounding structure (such as release of pressures/force, proof marking, extraction of components, and the need to protect the system integrity by fitting blanking plugs and ensuring exposed components are correctly covered/protected)
the various mechanical fasteners to be removed and replaced, and their methods of removal and replacement (such as threaded fasteners, special securing devices)
- the various types of electrical connector that are used, methods of unlocking, orientation indicators and locating and locking-in of the connections
- methods of lifting, handling and supporting the components/equipment during the removal and fitting activities
- methods of checking that components are fit for purpose, and how to identify defects and wear characteristics
- the need to replace items such as seals and gaskets
- the need to label and store correctly components that require repair or overhaul, and to check that replacement components have the correct part/identification markings and accompanying release documentation
- how to replace and reconnect components into the system (such as ensuring correct orientation, position and alignment; tightening securing devices to the required torque; replacing locking and securing devices; eliminating stress on pipework/connections; ensuring that pipework and cables are correctly supported at suitable intervals; carrying out visual checks of all components)
- how to make adjustments to components/assemblies to ensure they function correctly (such as setting working clearance, setting travel)
- why electrical bonding is critical, and why it must be both mechanically and electrically secure
- the purpose of symmetry and rigging checks; how they are carried out; how to locate the rigging points and faces; and the use of incidence boards
- how to carry out routine checks and servicing of the aircraft stabilisers
- the need to check that cabin/cockpit switches, selectors and circuit breakers are in the correct position before removing stabiliser components
- the types of test to be carried out on the aircraft stabiliser and the test equipment to be used
- the methods and procedures to be used to carry out the various tests
- the importance of carrying out the tests in the specified sequence, checking all readings and movements at each stage
- how to record the results of each individual test and the documentation that must be used
- how to analyse the test results, and how to make valid decisions about the acceptability of the stabiliser system
- the procedures to be followed if the equipment or system fails to meet the test specification
- why tool/equipment control is critical and what to do if a tool or piece of equipment is unaccounted for on completion of the activities
the problems that can occur with the aircraft stabiliser maintenance operations and how these can be overcome
the recording documentation to be completed for the activities undertaken and, where appropriate, the importance of marking and identifying specific pieces of work in relation to the documentation
- the procedure for the safe disposal of waste materials and scrap components
- the extent of your own authority, and to whom you should report if you have problems that you cannot resolve
Scope/range
Scope Performance
Carry out all of the following during the maintenance of the aircraft stabilisers:
- ensure that appropriate authorisation to work on the aircraft is obtained, and observe all relevant isolation and safety procedures
- obtain and use the correct documentation (such as job instructions, technical instructions, aircraft manuals and maintenance documentation)
- obtain the correct tools and equipment for the activity, and check that they are in a safe, tested and usable condition and within current calibration dates
- adhere to procedures or systems in place for risk assessment, COSHH, personal protective equipment and other relevant safety regulations and procedures to realise a safe system of work
- ensure that the relevant safety devices and mechanical/physical locks are in place (where appropriate)
- ensure the safe isolation of the control system before commencing work on the equipment
- use approved removal, fitting and testing techniques and procedures at all times
- return tools and equipment to the correct storage location on completion of the activities
- ensure that work carried out is correctly documented and recorded
- ensure that any outstanding tests are correctly documented
Carry out maintenance on two of the following aircraft stabilisers:
- horizontal stabilisers/stabilator/canards/fore planes
- elevator/elevon
- vertical stabiliser
- rudder/yaw/ruddervator
- trim tab
- tailerons
- other specific stabiliser
Undertake three of the following structural repair activities:
- insertion repair
- overlay patch repair
- primary structure repair
- composite repair
- secondary structure repair
- blend repair
- tertiary structure repair
- reworking of aluminium structures and limitations forming
- damage assessment and evaluation
- NDT inspection requirements (post damage removal)
Use six of the following during the structural repair activities:
- marking out airframe materials
- profiling
- securing and locking components
- making holes in airframe materials
- countersinking
- anti-corrosive treatment
- deburring
- using adhesives and sealants
- cutting/shaping airframe materials
- riveting
- bending and forming materials
- drilling the extremities of cracks
- blending out permissible damage to structural components
Remove and fit four different aircraft stabiliser components (at least two must be from group A):
Group A
1. horizontal stabiliser
2. upper rudder
3. inboard elevator
4. vertical stabiliser
5. lower rudder
6. tailerons
7. stabiliser leading edge
8. splice ribs
9. outboard elevator
10. stabiliser tip
11. panel stiffeners
12. stabiliser screw jack
13. stabiliser seals
14. access doors/panels
15. attachment fittings
Group B
16. pivot hinge assembly
17. pivot pin assembly
18. anti-rotation plate
19. bonding jumpers
20. bearing assemblies
21. static wick discharger
22. other specific component
Carry out fifteen of the following maintenance activities:
- removing access panels and covers to expose components to be removed
- carrying out fault diagnosis and system checks
- preparing the system for maintenance (such as isolating, releasing stored pressure)
- disconnecting electrical connections
- replacing items (such as seals, gaskets, sealants)
- removal of bonding
- removing securing devices and mechanical fasteners
- setting and adjusting replaced components (such as freedom of movement, travel)
- supporting equipment to be removed
- dismantling equipment to an appropriate level
- making mechanical connections
- covering (protecting) exposed components, wires, pipework or vents
- making electrical connections
- carrying out bonding
- checking components for serviceability
- torque loading as required
- replacing damaged/defective components
- carrying out functional checks of the system
- refitting components in the correct position, orientation and alignment
- ensuring that replacement components have the correct part numbers
- labelling (and storing in the correct location) components that require repair or overhaul
- applying bolt locking methods (such as split pins, wire locking, lock nuts)
- carrying out area inspections prior to task close down
Carry out three of the following types of test/check on the aircraft stabilisers:
- checking bonding jumpers for tightness, corrosion, melted strands, electrical resistance
- checking ground leads for security and electrical continuity
- checking components for wear (mechanical or otherwise) damage
- check stabiliser skins for dents and scratches against manufacturer's tolerances
- checking structural components for signs of cracking, corrosion or de-bonding
- checking stabilisers for range and freedom of movement
- checking critical fastenings for security
- checking surface protection (such as paint finish, polish)
- carrying out `special-to-type' tests
- carrying out rigging checks
Using two of the following:
11. mechanical measuring equipment
12. ground support equipment
13. `special-to-type' test equipment
14. electrical measuring equipment
15. use of safety locks
Complete the relevant paperwork, to include one from the following and pass it to the appropriate people:
- job cards/work sheets
- aircraft technical log
- aircraft log book
- computer records
- aircraft cabin log
Carry out maintenance on aircraft stabilisers in compliance with one of the following:
- Civil Aviation Authority (CAA)/European Aviation Safety Agency (EASA)
- Extended Range Twin-Engine Operations Procedures (ETOPS) (where appropriate)
- Ministry of Defence (MoD)
- Military Aviation Authority (MAA)
- Aerospace Quality Management Standards (AS)
- Federal Aviation Authority (FAA)
- aircraft maintenance manual/structural repair manual/approved change documentation (service bulletin)
- manufacturers standards and procedures
Scope Knowledge
Values
Behaviours
You will be able to apply the appropriate behaviours required in the workplace to meet the job profile and overall company objectives, such as:
- strong work ethic
- positive attitude
- team player
- dependability
- responsibility
- honesty
- integrity
- motivation
- commitment