FAA Advisory Circular 43.13-1B
Acceptable Methods, Techniques, and Practices
Aircraft Inspection and Repair
AC 43.13-1B | 5. Nondestructive Inspection (NDI) | 4. Magnetic Particle Inspection | 5-42. Applications
AC 43.13-1B
9/8/98
c. Operators must understand nonrele-
vant error indications and recognize them
during examination. Proper analysis of indi-
cations in these regions will require consider-
able skill and experience, and supplemental
methods may be required before a final
evaluation can be made. Special techniques
for examination of these areas are given in
subsequent paragraphs.
areas of large components can be adequately
checked with the use of small, inexpensive
permanent magnets or electromagnetic yokes.
In procuring magnetizing equipment, the
maximum rated output should be greater than
the required examination amperage. Actual
current flow through a complex part may be
reduced as much as 20 percent by the resis-
tance load of the rated output.
5-42. APPLICATIONS. Use magnetic par-
ticle inspection on any well-cleaned surface
that is accessible for close visual examination.
Typical parts deserving magnetic particle ex-
amination are: steel fasteners and pins; critical
structural elements; linkages; landing gear
components; splice and attach fittings; and
actuating mechanisms.
a. During field repair operations, disas-
sembly is often not necessary, except when the
parts have critical areas or delicate installed
components. However, for overhaul opera-
tions, a more thorough and critical examina-
tion may be obtained with stationary equip-
ment in a shop environment with completely
disassembled, and thoroughly cleaned and
stripped parts.
b. Magnetic rubber examination mate-
rial is useful for in-field service examinations
of fastener holes in areas where the accessibil-
ity is limited or restricted, where particle sus-
pensions may cause unwanted contamination,
when a permanent record is desired, and when
the examination area cannot be observed visu-
ally.
5-43. ELECTRICAL MAGNETIZING
EQUIPMENT. Stationary equipment in the
range of 100 to 6000 amperes is normal for use
within the aerospace industry for overhaul op-
erations. Mobile equipment with similar am-
perage outputs is available for field examina-
tion of heavy structures, such as landing gear
cylinders and axles. Small parts and local
5-44. MATERIALS USED IN MAG-
NETIC PARTICLE INSPECTION. The
particles used in magnetic particle inspection
are finely divided ferro-magnetic materials that
have been treated with color or fluorescent
dyes to improve visibility against the various
surface backgrounds of the parts under inspec-
tion. Magnetic particles, particle-suspension
vehicles, and cleaners are required for con-
ducting magnetic particle inspection. Re-
quirements for magnetic particle inspec-
tion materials, other than cleaners, are con-
tained in the aerospace industry standard,
ASTM-E1444, Inspection, Magnetic Particle
(as revised). A certification statement which
will certify that the material meets applicable
specification requirements will generally be
received when a magnetic particle inspection
material is purchased. Magnetic particle in-
spection materials for use on a specific part or
component will generally be specified by the
aircraft or component manufacturer or the
FAA in documents such as; maintenance or
overhaul manuals, AD’s, SSID’s, or manufac-
turer’s SB’s. However, if the magnetic parti-
cle inspection materials are not specified for
the specific part or component to be inspected,
it is recommended that personnel use materials
meeting the aircraft or component manufactur-
ers’ specifications or materials meeting the re-
quirements of ASTM-E1444. Other FAA en-
gineering-approved materials may also be
used. Table 5-2 provides a partial listing of
commonly accepted standards and specifica-
tions for magnetic particle inspection.
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