Composite Repair Services

helicopters

Applying NDT on composite repair “from a customer’s perspective”

Composite Repair Services

Content

Content:

• Company introduction SPECTO Aerospace• Need for NDT (preventive versus corrective maintenance)• Which type of NDT would you use?• Challenges• Considerations

Composite Repair Services

Fixed wing

Airport Lelystad - Amsterdam, The Netherlands

Woensdrecht Air base,The Netherlands

Helicopters

Company Introduction

SPECTO Woensdrecht

• MRO of rotor blades and helicopter structures

• EASA and FAA Part 145, MAR 145, AS9110

SPECTO Lelystad

• MRO of radomes, nacelles and flight controls for fixed wing

• EASA, FAA and CAA Part 145, AS9100

Composite Repair Services

Woensdrecht Air base,The Netherlands

Helicopters

Company Introduction

EASA / FAA / MAR Part 145 Maintenance organisation approvals:

Compliance to EU regulation standards for civil aviation

Privilege to release aircraft or components to service based on scope

Our license to work

NDT is subcontracted but performed within SPECTO’s Quality System

SPECTO Woensdrecht

• MRO of rotor blades and helicopter structures

• EASA and FAA Part 145, MAR 145, AS9110

Composite Repair Services

Need for NDT

Where does a composites repair station use NDT for?

As part of PREVENTIVE maintenance

• General condition check (absence of defects)

• Usually whole component/large area• Except for latest generation of

airplanes, no high-tech methods prescribed/defined in manual

• Not too much detail desired • Focus on low cost

Characteristics:

As part of CORRECTIVE maintenance or suspected damage

• Only area that is suspected/damaged• Relative small area, different locations• Usually more sophisticated methods

required• (Some) freedom in technique to be used

(depending on OEM/approved data)• Detailed inspection, exact location and

extend of damage• Focus on quality (not primary on costs)

Characteristics:

Composite Repair Services

Need for NDT

Where does a composites repair station use NDT for?

As part of PREVENTIVE maintenance As part of CORRECTIVE maintenance or suspected damage

Composite Repair Services

Need for NDT

Where does a composites repair station use NDT for?

As part of PREVENTIVE maintenance

• Logging/recording/imaging to compare inspection results with previous/future inspections

• Repeatable, same results for different inspectors

Acceptability of costs:Part of initial component inspection price

Desired functionality:

As part of CORRECTIVE maintenance or suspected damage

• Clear and unambiguous inspection results • Able to inspect different geometry (curved,

in dimples) and materials/build up• Reporting of results supported with

data/pictures

Acceptability of costs:Part of repair price

Desired functionality:

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Rotor blade leading edge suspected delamination:

Which type of NDT

Which type of NDT would you use?

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Rotor blade leading edge pinhole:

Which type of NDT

Which type of NDT would you use?

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Pitch housing damage:

Which type of NDT

Which type of NDT would you use?

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Rotor blade trailing edge suspected delamination:

Which type of NDT

Which type of NDT would you use?

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Challenges

In the ideal world…

• The OEM defined inspection method and parameters for NDT inspection…• The maintenance manual, repair manual or SRM provides detailed information about the

materials and build-up… • Resins and fibres used in the components including individual properties are published by the

OEM…• Exact build-up of the structure with corresponding dimensions are published by the OEM…• Test specimens of undistorted segments and defects are available…

It is no surprise that we do not live in an ideal world

but we need an answer to be able to determine if the component can be repaired

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Challenges

Challenges in composite repair NDT• Many different fibres and resins used• Often in combination with metals• Frequent use of sandwich build up• Can only be reached from one side

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Considerations

Considerations

• Different techniques are available, but which will work best for the requested inspection?

=> Testing might be necessary • Where are you looking for?

=> Do you see the difference between production irregularities and defects?

• Accuracy?=> More accurate is not always better. More questions can be raised than answered

• Conditions?=> Some techniques require special conditions

• Costs?=> The aim is to get a result that is good enough to be able to make a statement

Composite Repair Services

Considerations

It is all about communication

Ask the right questions upfront:• Ensure that the goal of the NDT inspection is clear• Which kind of inspection do you suggest • The repair specialist has knowledge about the component to be inspected, but

has limited NDT knowledge. It is important to “speak the same language”• Required OEM info might not be available. Requesting additional info at the

OEM takes time

Manage expectations: • How certain are you that the chosen NDT technique provides the desired

result?• What are the options if insufficient results are booked?• Who is taking the financial risk (time & material versus fixed inspection price)

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Questions

Questions?