EFFECTIVITY
ALL CFM56 ENGINES
CFMI PROPRIETARY INFORMATION
CFM56-ALL
TRAINING MANUAL
REQUIREMENTS
BORESCOPE INSPECTION
Page 64
Sep 03
EQUIPMENT CHECKS
(ALL) :
The resolution target.
The resolution target is divided into group and element
numbers, which gradually diminish in size towards the
center of the display.
Group 0 is the largest display and group 7 is the smallest.
All 7 groups have 6 elements in each.
Group 0, element 1, is located at the lower right of the
target and its 6 lines (horizontal and vertical) should be
clearly visible to the eye.
Group 1 is located in the top right side of the target and is
smaller than group 0.
In the center of the display, group 2 is located on the left
side of the target and group 3 is located on the right side.
Each group continues to diminish in size down to group 7.
Rigid probes.
For rigid probes with a 1:1 magnification at 2in., the
6 individual lines (3 vertical and 3 horizontal) of group 3,
element 4, should be distinguishable.
For rigid probes with a magnification of 1:1 at 7in., the
6 individual lines of group 5, element 2, should be
distinguishable.
Flexible probes.
For flexible probes with 90° direction of view, the
6 individual lines of group 1, element 4, should be
distinguishable.
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