scopes have a flexible probe, which can be snaked
difference between the man-hours spent rejecting
a perfectly good engine or obtaining more flight
around, behind, and into areas impossible to
hours from that same engine after damage was
reach with the other scope. See figures 9-14 and
9-15.
suspected.
The advantage of the flexible probe is
BoreScope Use
that many areas can now be inspected without
opening the engine. The probe can be worked
Know your equipment. Borescopes are easily
damaged and have different characteristics. For
back through the compressor from the front of
example, optical characteristics of the small
the engine. It can also be inserted through
borescope magnify and distort all areas other than
a fuel nozzle opening, and worked back to the
the turbine blade leading edge. This often results
turbine area to as close as one-quarter of an
inch from the surface being inspected. Being able
in what appears to be an alarming vane condi-
tion. Know and be able to locate all inspection
to assess possible damage at that close range has
areas or ports on your engine. Figure 9-16 shows
a distinct advantage over the rigid type of
an example of inspection ports and areas that you
borescope. A fiber-optic borescope and an
can inspect from that port.
inspector experienced in its use could make the
Figure 9-14.-Rigid borescope.
Figure 9-15.-Fiber-optic (flexible) borescope.
9-18
