Carrying out trimming operations on aircraft composite components

URN: SEMAER226
Business Sectors (Suites): Aeronautical Engineering Suite 2
Developed by: Enginuity
Approved on: 2017

Overview

This standard identifies the competences you need to trim aircraft composite mouldings using hand and power tools, in accordance with approved procedures. You will be required to follow the appropriate instructions, drawings, specifications and documentation to trim the various composite mouldings, using the correct trimming techniques.

You will be expected to select and use the correct tools and equipment for the trimming activity. You will trim a range of composite mouldings, incorporating a variety of features, by using cutting, sanding, drilling and polishing techniques and processes. Mouldings to be trimmed will include a range of resin and fibre materials.

Your responsibilities will require you to comply with organisational policy and procedures for the composite trimming activities undertaken, and to report any problems with the trimming activities, equipment or materials that you cannot personally resolve, or are outside your permitted authority, to the relevant people. You will need to ensure that all tools, equipment and materials used in the trimming are correctly accounted for on completion of the activities, and you must complete all necessary job/task documentation accurately and legibly.

You will be expected to work either with a high level of supervision or as a member of a team, and you will take personal responsibility for your own actions and for the quality and accuracy of the work that you carry out. Where team working is involved, you must demonstrate a significant personal contribution during the team activities in order to satisfy the requirements of this standard, and you must demonstrate competence in all the areas required by the standard.

Your underpinning knowledge will be sufficient to provide a sound basis for your work, and will provide an informed approach to applying the appropriate composite trimming techniques and procedures. You will understand the trimming procedures and techniques used, and will know about the tools and techniques, in adequate depth to provide sound basis for carrying out the activities to the required specification.

You will understand the safety precautions required when carrying out the composite trimming activities, and when using the associated tools and equipment. You will be required to demonstrate safe working practices throughout. You will also understand your responsibilities for safety, and the importance of taking the necessary safeguards to protect yourself and others in the workplace.


Performance criteria

You must be able to:

  1. work safely at all times, complying with health and safety legislation, regulations, directives and other relevant guidelines
  2. follow relevant specifications for the component to be produced
  3. obtain the appropriate tools and equipment for the trimming operations and check they are in a safe and usable condition
  4. trim the materials using appropriate methods and techniques (including techniques such as marking out, sanding and polishing)
  5. check that all the required trimming operations have been completed to the required specification
  6. complete relevant paperwork and pass on to appropriate people
  7. deal promptly and effectively with problems within your control and report those that cannot be solved

Knowledge and Understanding

You need to know and understand:

  1. the health and safety precautions to be taken and procedures used when working with composite materials, consumables, tools and equipment in the specific work area
  2. the hazards associated with trimming composite materials, and with the consumables, tools and equipment used, and how to minimise these hazards in the work area
  3. protective equipment that is needed for personal protection (PPE) and, where required, the protection of others
  4. the application of COSHH regulations in relation to the storage, use and disposal of composite materials and consumables
  5. the specific workshop environmental conditions that must be observed when trimming aircraft composite mouldings (including itemssuch as temperature, humidity, styrene levels to threshold limits, fume/dust extraction systems and equipment)
  6. how to use and extract information from engineering drawings and related specifications (to include symbols and conventions to appropriate BS or ISO standards), in relation to work undertaken
  7. how to interpret drawings, imperial and metric systems of measurement, workpiece reference points and system of tolerancing
  8. how to prepare for the trimming activities, and how to mark out the mouldings for the material to be removed
  9. the quality procedures used in the workplace to ensure production control (in relation to currency, issue, meeting specification)
  10. the conventions and terminology used for trimming activities (including items such as scribe lines, sanding grades, types of cutting tools, speeds)
  11. the visual identification of cured composite materials
  12. how to identify defects in composite mouldings
  13. the methods used in the trimming of composite mouldings
  14. the different types of manual and power tools used in composite trimming operations
  15. the different types of cutting tools and abrasives used in trimming composite materials, and their application
  16. the procedure for the safe disposal of waste materials
  17. the care and safe handling of composite mouldings throughout the trimming cycle
  18. the recording documentation to be completed for the trimming activities undertaken and, where appropriate, the importance of marking and identifying specific pieces of work in relation to the documentation
  19. the extent of your own authority, and whom you should report to if you have problems that you cannot resolve

Scope/range


Scope Performance

  1. Carry out all of the following during the composite trimming activities:

    1. ensure that you have the correct documentation for the composite trimming operations (including items such as drawings, job instructions, aircraft standards)
    2. adhere to procedures or systems in place for risk assessment, COSHH, personal protective equipment and other relevant safety regulations
    3. use the correct tools and equipment for the activity, and ensure that they are in a safe and usable condition
    4. apply safe and appropriate working practices and procedures at all times
    5. dispose of waste items and materials in a safe and environmentally acceptable manner, in line with company procedures
    6. return all tools and equipment to the correct location on completion of the activities
    7. leave the work area in a safe condition and free from foreign object debris
  2. Carry out all of the following when preparing for the trimming activity:

    1. check that the moulding is correct and complete
    2. check for any defects in the moulding
    3. identify and protect the moulding in the work area
  3. Mark out mouldings, using four of the following methods:

    1. scriber                                   
    2. moulded scribe lines       
    3. trimming templates
    4. height gauge                          
    5. centre punch
    6. other specific method
  4. Trim mouldings, using one the following methods:

    1. cutting wheels/discs                      
    2. routers
    3. saws                                            
    4. trim jigs
  5. Sand mouldings, using two of the following methods:

    1. rubbing blocks                  
    2. pencil grinders                
    3. belt sanders
    4. diamond files                    
    5. disc sanders
  6. Use a hand drill or pedestal drill to drill mouldings, using two of the following:

    1. drill jigs                            
    2. counterbore tools            
    3. drill bits
    4. hole saws                         
    5. countersink tools
  7. Polish mouldings, using three of the following methods:

    1. wet sanding                            
    2. polishing compound        
    3. orbital sander
    4. cutting compound                   
    5. rubbing block                  
    6. polisher
  8. Trim mouldings, using appropriate techniques for both of the following:

    1. resins (including items such as polyester, vinyl ester, epoxy, phenolic, bismaleimide, cyanate ester, acrylic)
    2. fibres (including items such as polyethylene, glass, aramid, carbon, hybrid)
  9. Trim mouldings that require, or incorporate, five of the following features:

    1. straight edges                             
    2. nett edges                                    
    3. further lay-up stages
    4. curved edges                              
    5. joggle details                               
    6. inserts to be drilled
    7. flat surfaces                                
    8. removal of join lines                     
    9. inserts to be tapped
    10. polished surfaces                        
    11. holes                                         
    12. solid cores
    13. shaped surfaces                          
    14. multiple hole sizes                       
    15. honeycomb cores
    16. radius corners                             
    17. countersinks                              
    18. edge filling
    19. returns                                        
    20. counterbores
  10. Ensure that trimmed mouldings comply with one of the following quality and accuracy standards:

    1. Civil Aviation Authority (CAA)                                    
    2. Ministry of Defence (MoD)                                        
    3. customer standards and requirements
    4. Federal Aviation Authority (FAA)                                
    5. company standards and procedures
  11. Complete the relevant paperwork, to include one from the following, and pass it to the appropriate people:

    1. production documentation                                         
    2. build records
    3. quality control documentation                                    
    4. other specific records

Scope Knowledge


Values


Behaviours

​​Additional Information

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

2

Indicative Review Date

2020

Validity

Current

Status

Original

Originating Organisation

Semta

Original URN

SEMAER2-26

Relevant Occupations

Engineering, Engineering and Manufacturing Technologies, Engineering Professionals, Science and Engineering Technicians

SOC Code

5234

Keywords

Aeronautical; Engineering; aircraft composite mouldings; drawings; specifications and documentation