A Brief Report On Use Of Computerized Tomography for Wreckage and Wire Examination Robert L. Swaim Systems Engineering National Resource Specialist

Test parts first, potentially obscuring evidence that disassembly might find? OR Disassemble parts first, potentially losing the integrity of the phenomenon that created the problem? Eternal Question In Accident Investigation: ??

X-ray is Two-Dimensional Circuit breaker X-ray shows: 1.Outline of plastic case. 2.Internal mechanism. (Note misaligned contacts) 3.Differences in density for various materials, such as plastic versus steel.

Computerized Tomography Process ( KEV)

Considerations Resolution dependant on distance between collimators & other factors. Requires parts to fit in radiation enclosure and between colimators. Aberdeen12” X 48” DearbornTruck transmission sized High energy (150KEV to 400+ KEV). Limited number of test facilities. Time and energy consuming. Requires post-processing software. Costs more than x-ray.

BENEFITS Computerized Tomography is Three Dimensional Model of the inner and outer surfaces of fine art statuette depicts: 3-D capabilities, Rendering & shadow, Level of detail obtainable

BENEFITS CT Can Differentiate Between Densities Egyptian Statuette: Wooden Head Gold Inlay (Note wide variation in densities) Transducer: Plastic Case Copper Windings Ferrite Elements

BENEFITS CT Can Be Used To Examine & Rotate Parts External features of burned actuator

BENEFITS CT Can Be Used To Examine & Rotate Parts Internal features of burned actuator

Details May Be Enhanced Note: Gear Relationships, Condition of Teeth, Detail of Safety Wire

Capability to Section or Internally Examine Parts Sectioned Valve: Perpendicular View of Sectioned Valve: Cross- Section of Valve: Visually Examine Through Valve Passages:

Capability For Internal Examination Orientation of View: View Inside Bore:

Connectors Show Electrical Investigation Potential

Sample Bent Connector Pin Thousands of sections need to be post-processed

Need to determine ability of software to compensate for density variations Higher Density Copper Shadows & Obscures A Cut In The Lower Density Rubber Grommet. (Note Shadows)

Due To Density Differences, Shielded Wire Braiding is Visible, But Plastic Insulation is Barely Detected: Limitation Currently Encountered Working on Software Compensation

Sectioned Wire Bundle Evaluating Software Compensation Power Required to Penetrate Copper Loses Insulation Detail Bundle May Be Sectioned to Follow Wires, But…

Summary: Computerized Tomography is a highly effective tool for numerous purposes. The process is generally nondestructive, therefore, little risk in attempting to use CT. The limitations must be recognized. The fixed equipment make this ineffective for on-aircraft use. The power required to penetrate higher densities may obscure lower density materials. We are currently evaluating software resolution that has been very effective for larger parts.