Cessna 510 Mustang Structural Repair Manual page 29

NOTE:
(a) Determine the degree of corrosion damage as to classification described above. Use dial depth gage if
damaged area is accessible. Before measurements are made, visually determine if corrosion is in an area
which has previously been reworked.
1 If the corrosion damage is located in an area that has been previously ground out, measure the damage to
include the material which has been previously removed. A straight edge and 4-10X magnifying glass may
be used to help to find out if an area has been previously reworked. Look for irregularities or grinding
marks. Place the straight edge, at various angles, across the area to be examined and observe for
irregularities, low spots and/or depressions (refer to Figure 1).
2 If irregularities, low spots or depressions are found and a visual determination cannot verify previous
rework, closer examination of the suspected surface area should be made. Use a 4-10X magnifier to
compare the surface finish of the suspected area with the surface finish of the surrounding area .
3 If checks show that the area has been previously reworked, examine the depth of the previous rework with
a depth gage (mechanical material grind-out) to determine if further metal removal will exceed grind-out
limits.
(3) Measure corrosion damage with a standard depth gage.
(a) Before starting the corrosion damage evaluation using a dial indicator, find out if the corroded area has been
previously reworked.
(b) If this determination cannot be made by unaided examination, refer to the procedure described in the paragraph
on determining degree of corrosion damage. In performing the examination and measurement, be sure to
consider any curvature, convex or concave, of the surface being checked.
(c) Procedure used with dial depth gage.
1 The following procedure outlines the method for taking measurements with a dial depth gage.
2 Remove loose corrosion particles and paint, if present.
NOTE:
3 Determine the measurement reading with the depth gage (refer to Figure 2).
4 Several depth readings must be taken in this manner.
5 Select the deepest reading as the depth of the corrosion damage.
6 Where there are several damaged areas in the same skin panel or component part, sketch a diagram of
the depth and location of each damaged area. Forward a copy of the sketch to Cessna Aircraft Company,
Customer Support Citation Marketing Division, Wichita KS 67277.
Copyright © Textron Aviation Inc.
Retain printed data for historical reference only. For future maintenance, use only current data.
On thin sheet material, waviness in the material may result in an untrue depth reading. Several
readings may be necessary to determine the depth of the corrosion damage.
The base of the depth gage must be flat against the bare metal of the undamaged
surface on each side of the corrosion. When taking measurements on concave or
convex surfaces, place the base perpendicular to the radius of the surface.
FOR TRAINING PURPOSES ONLY
ISSUE 02 , JAN 2018
Model 510 Structural Repair Manual (Rev 2)
51-10-01-0 (Original Issue)
Print Date: Wed Mar 21 05:09:56 CDT 2018
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