Page 53 - MY STORY

The next job was to find non-destructive methods to

inspect the forging for quality. One of the more difficult
next-steps was to find a machine shop that could turn the
rough forging into a beautiful single piece finished

turbine with thin curved blades carved out of the central
pancake disk with a precision machined shaft. That was a
difficult search – the new high strength titanium alloys

were notoriously difficult to machine to the close
tolerances required of a perfectly balanced high-speed
turbine.

But it got done.

One of the most excruciating, but critical, jobs was to
write the materials and forging procurement specifications,
along with the process control documents defining the

heat treatment, machining, and final inspection
procedures. The final high-speed spin tests to qualify the

material and design were completely successful, and in
the decades of DC-8 flight history the cabin air
compressor system never structurally failed. A historical

heritage all engineers strive for.