Maintaining fuselage, nacelles and pylons on aircraft

URN: SEMAE3327
Business Sectors (Suites): Aeronautical Engineering Suite 3
Developed by: Enginuity
Approved on: 2021

Overview

This standard identifies the competences you need to carry out maintenance activities on aircraft fuselage, nacelles and pylons, in accordance with the approved aircraft maintenance manual, structural repair manual, approved change documentation (service bulletin) and airworthiness requirements. It covers both fixed wing and rotary winged aircraft, and includes structural units and associated components which make up the compartments for equipment, passengers, crew and cargo/baggage, and structural units and associated components which provide a means of mounting and housing the power plant or rotor assembly. The maintenance activities will include the removal, fitting and, where appropriate, testing of a range of fuselage components. 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 or fitted. The fuselage maintenance activities will include removing the required components, fitting approved replacements, and making repairs to primary and secondary airframe structures, as appropriate to the aircraft type.

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 the aircraft fuselage, nacelles and pylons. You will understand the removal, refitting and repair methods and procedures, and their application, along with the fuselage maintenance requirements. You will know 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 fuselage, nacelles and pylons are maintained to the required standard.

You will understand the safety precautions required when working on the aircraft fuselage, nacelles and pylons, and when using the associated tools and equipment. 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:

  1. This standard is designed to cover the practical experience requirements of the Airline Transport Association (ATA) Chapter 53 Fuselage and Chapter 54 Nacelles/Pylons.
  2. To display competence in this standard, it is necessary to both remove and fit fuselage and nacelles/pylon components. You must remove fuselage and/or nacelles/pylon components; however, you may fit replacement components 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:

  1. work safely at all times, complying with health and safety and other relevant regulations, directives and guidelines
  2. follow the relevant maintenance schedules to carry out the required work
  3. carry out the maintenance activities within the limits of your personal authority
  4. carry out the maintenance activities, and replace components in the specified sequence and in an agreed timescale
  5. report any instances where the maintenance activities cannot be fully met or where there are identified defects outside the planned schedule
  6. complete relevant documentation in accordance with organisational requirements
  7. dispose of waste materials in accordance with safe working practices and approved procedures
  8. 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:

  1. the specific safety practices and procedures that you need to observe when carrying out maintenance activities on the aircraft fuselage and nacelles/pylons (including any specific legislation, regulations/codes of practice for the activities, equipment or materials)
  2. the importance of maintenance on aircraft fuselage systems, and impact upon (Extended Range Twin-Engine Operations Procedures) ETOPS systems, legislation and local procedures
  3. the hazards associated with repairing airframes, removing and fitting aircraft fuselage components, and with the tools and equipment used, and how to minimise them and reduce any risk
  4. 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
  5. the protective equipment that you need to use for both personal protection (PPE) and protection of the aircraft

  6. what constitutes a hazardous voltage and how to recognise victims of electric shock

  7. how to reduce the risks of a phase to earth shock (such as insulated tools, rubber matting and isolating transformers)

  8. 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

  9. how to extract and use information from aircraft manuals, log books, flight logs, and other documents needed in the maintenance process
  10. how to carry out currency/issue checks on the specifications you are working with
  11. preparations to be undertaken on the fuselage or nacelles/pylons, prior to repair
  12. the repair methods and procedures to be used, and the importance of adhering to these procedures
  13. the various mechanical fasteners that are used to hold the equipment in place, and their methods of removal and replacement (such as threaded fasteners, open and blind rivets, special securing devices)
  14. the application of sealants and adhesives within the repair activities, and the precautions that must be taken when working with them
  15. the various types of electrical connector that are used, methods of unlocking, orientation indicators and locating and locking-in of the connections
  16. the importance of using the specified fasteners for the particular repair, and why you must not substitute others 
  17. why securing devices need to be locked and labelled, and the different methods that are used to remove and install them
  18. the torque loading requirements on the fasteners, and what to do if these loadings are exceeded or not achieved
  19. the need to take care when removing fuselage components so as not to cause damage to the equipment or surrounding structure
  20. the need to check that replaced components have the correct part/identification markings and accompanying release documentation
  21. the need to position, align, adjust and secure correctly the replaced equipment in the aircraft, without damage to the components or surrounding structure
  22. methods of lifting, handling and supporting the components during the maintenance activities
  23. why electrical bonding is critical, and why it must be both mechanically and electrically secure
  24. how to carry out routine checks of the fuselage (such as checking for corrosion, stress/fatigue cracks, torque on critical fastenings)
  25. how to conduct any necessary checks to ensure the accuracy and quality of the repair
  26. recognising defects (such as skin blemishes, poor skin lines, ineffective fasteners, foreign object damage)
  27. 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
  28. the problems that can occur with the maintenance/repair operations, and how these can be overcome
  29. 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
  30. the procedure for the safe disposal of waste materials and scrap components
  31. the extent of your own authority and to whom you should report if you have problems that you cannot resolve

Scope/range


Scope Performance

  1. Carry out all of the following during the maintenance of the aircraft fuselage, nacelles and pylons:

    1. ensure that appropriate authorisation to work on the aircraft is obtained, and observe all relevant isolation and safety procedures
    2. obtain and use the correct documentation (such as job instructions, technical instructions, aircraft manuals and maintenance documentation)
    3. 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
    4. 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
    5. ensure that the relevant safety devices and mechanical/physical locks are in place (where appropriate)
    6. use approved removal, fitting and repair techniques and procedures at all times
    7. return tools and equipment to the correct storage location on completion of the activities
    8. ensure that work carried out is correctly documented and recorded
    9. ensure that any outstanding tests are correctly documented
  2. Carry out maintenance/repairs on three of the following areas of the aircraft fuselage:

    1. fuselage sections    
    2. fin    
    3. pressure dome  
    4. engine nacelle
    5. skins        
    6. nose       
    7. scuppers      
    8. pylons
    9. floor beams      
    10. tail         
    11. hatches    
    12. box sections
    13. floor                   
    14. tail cone     
    15. bulkheads     
    16. avionics cabinets
    17. stringers     
    18. cockpit/cabin   
    19. mission consoles
    20. drains
  3. Undertake three of the following structural repair activities:

    1. insertion repair                 
    2. overlay patch repair
    3. primary structure repair            
    4. composite repair
    5. secondary structure repair         
    6. blend repair
    7. tertiary structure repair                
    8. reworking of aluminium structures and limitations forming
    9. damage assessment and evaluation    
    10. NDT inspection requirements (post damage removal)
  4. Use six of the following during the structural repair activities:

    1. marking out airframe materials         
    2. profiling                       
    3. securing and locking components
    4. making holes in airframe materials    
    5. countersinking          
    6. using adhesives and sealants
    7. cutting/shaping airframe materials      
    8. deburring                    
    9. anti-corrosive treatment
    10. bending and forming materials    
    11. riveting                      
    12. blending out permissible damage to structural components
    13. drilling the extremities of cracks
  5. Carry out fifteen of the following maintenance activities:

    1. removing access panels and covers to expose components/fastenings to be removed
    2. preparing the fuselage for the maintenance/repair activities (such as isolating, depressurising/draining systems that need disconnecting)
    3. disconnecting electrical connections                      
    4. ensuring the correct specification of replacement material
    5. removal of bonding              
    6. removing securing devices and mechanical fasteners 
    7. refitting components in the correct position, orientation and alignment
    8. disconnecting/removing hoses and pipes                             
    9. supporting components to be removed                  
    10. positioning and aligning replaced equipment
    11. dismantling equipment to an appropriate level      
    12. setting and adjusting replaced components
    13. covering (protecting) exposed components, wires, pipework or vents    
    14. making mechanical connections
    15. making electrical connections
    16. checking components for serviceability  
    17. carrying out bonding
    18. fitting securing devices and mechanical fasteners   
    19. torque loading as required
    20. replacing damaged/defective components
    21. ensuring that replacement equipment is of the correct type (have the correct part numbers)
    22. labelling (and storing in the correct location) components that requires repair or overhaul
    23. applying bolt locking methods (such as split pins, wire locking, lock nuts)
    24. carrying out area inspections prior to task close down
  6. Check aircraft fuselage components, to include carrying out three of the following:

    1. checking structural components for signs of corrosion
    2. checking components for fatigue cracks
    3. checking for lightning strike damage
    4. checking critical fastenings for security
    5. checking hoses and looms for security and chafing
    6. checking surface protection (such as paint finish, polish)
    7. checking for de-bonding of aircraft structure
    8. checking for oil canning
    9. checking dents, scratches/scoring on skin/structure against manufacturers tolerances
    10. checking aircraft structure for distortion (such as panting and quilting)
    11. checking components for wear (mechanical or otherwise) or damage
    12. checking for non-approved repairs
    13. carrying out symmetry and rigging checks
    14. other specific checks
  7. Complete the relevant paperwork, to include one from the following and pass it to the appropriate people:

    1. job cards/work sheets
    2. computer records
    3. aircraft technical log
    4. aircraft cabin log
    5. aircraft log book
  8. Carry out maintenance/repairs on aircraft fuselage components in compliance with one of the following:

    1. Civil Aviation Authority (CAA)/European Aviation Safety Agency (EASA)
    2. Extended Range Twin-Engine Operations Procedures (ETOPS) (where appropriate)
    3. Ministry of Defence (MoD)
    4. Military Aviation Authority (MAA)
    5. Aerospace Quality Management Standards (AS)
    6. Federal Aviation Authority (FAA)
    7. aircraft maintenance manual/structural repair manual/approved change documentation (service bulletin)
    8. 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

Skills


Glossary


Links To Other NOS


External Links


Version Number

3

Indicative Review Date

2024

Validity

Current

Status

Original

Originating Organisation

Enginuity

Original URN

SEMAE3327

Relevant Occupations

Engineer, Engineering, Engineering and Manufacturing Technologies, Engineering Technicians

SOC Code

5234

Keywords

engineering; aeronautical; maintenance activities; aircraft fuselage; nacelles and pylons; compartments; equipment; passengers; crew and cargo/baggage; structural units