Aircraft Composite Inspection

The emphasis of the course is on developing the background knowledge necessary to inspect and sign off aircraft composite repairs and to ensure that they have been carried out in accordance with published manufacturers' structural repair manuals. The course contains some practical demonstrations to highlight areas of potential problems

The importance of quality assurance is stressed throughout, recognising good and bad practices within the repair procedure.

The course aims to:

• to familiarise the delegate with the materials and techniques used to repair aircraft composite structures.
• to provide the delegate with the knowledge to satisfy the appropriate health and safety requirements.
• to equip the delegate with the knowledge to inspect aircraft composite repairs as they are carried out and to be able to sign them off as being completed according to the methods recommended and accepted by the aircraft manufacturers.
• to familiarise the delegate with the proper storage and handling of composite materials and to recommend effective methods of record keeping.
• to allow the delegate to recognise bad practices.
• to provide the knowledge required to interpret standard structural repair manuals and to relate them to a given repair situation.
• to satisfy all the relevant quality assurance requirements.

The course covers:

Delegates will be introduced to the characteristics of the materials used in repair. This will equip them with the knowledge to ensure that the procedures carried out during a repair are appropriate to the materials being used. The health and safety procedures and requirements for each material will be stressed throughout.

Repair configuration types and their bond integrity will be outlined. Delegates will be shown the signs and effect of bonding deficiencies associated with a variety of repair processes.

The difference between wet and prepreg repairs and the SRM rules of proximity by aircraft type will be discussed and illustrated. Delegates will find out how to decide which system is appropriate to a given repair situation and the impact the choice can have on final finish. Delegates will be asked to assess the required proximity of repairs and the impact of incorrect spacing.

Levels of repair will be discussed: cosmetic, temporary, interim and permanent. The various aircraft manufacturers' attitudes to each type of repair will be dealt with. Advice on how to decide which level of repair to use will be given.

This section will involve extensive use of SRMs.

Delegates will be taken through the methods of removing damage and paint surfaces using mechanical and chemical methods and the issues associated with both. The impact of mesh substrates and monolithic substrates will be discussed.

Methods of assessing damage impact prior to and after repair will be considered with reference to the relevant SRM’s and the impact this has on subsequent paint finishing. Delegates will be shown the common types of damage encountered in composite components, followed by a discussion of the best repair strategy to adopt for each damage type.

After a brief introduction to the vacuum bagging methods, Delegates will be shown the signs of incorrect vacuum bagging and the effect on repair quality and integrity this has. This will be discussed in association with the common faults associated with hot bonder failure/deviation from SRM requirement.

Demonstration of bond failure will be shown and the level of damage that can be caused by inappropriate repair techniques and procedures and the impact this has on inspection and repair integrity prior to paint preparation and after painting. Acceptable and unacceptable defects alongside allowable repair site sanding in preparation for painting will be identified.

Inspection intervals and requirements for different repair types and accepted inspection techniques by aircraft type will be illustrated, Delegates will be given an exercise to identify the appropriate techniques/types using SRMs.

Restrictions on repair methods will be discussed in relation to the above. An overview of the NDT techniques for composite repairs will be given with demonstration of simple methods available.

Demonstration will be used to illustrate good and bad repair and the characteristics associated with both.

Delegates will be asked to define how they would address specific surface imperfections prior to painting and the techniques they would use to address the imperfections.

Good and poor paint surface finishes and their implications on fuel economy and longevity will be reviewed and discussed.

SRMs will be used throughout with a view to understanding how to extract the large amount of information that is necessary for each repair

Delegates will be shown common mistakes in repairs, so that they can judge the best way to inspect a repair for integrity.

After recommendations relating to the importance of reporting and record keeping for repair life cycle management the delegates will be asked to identify procedures and actions required for the reporting of SRM repair non-compliance. The responsibilities of releasing the aircraft back into service will be reviewed.

Delegates will be presented with a case study to use SRMs to identify factors relevant to inspection and correct procedures prior to and following painting.

The course will be summarised, and delegates will be given a chance to evaluate it.