TM 1-1520-253-23
INTRODUCTION
1. INTRODUCTION.
a. This manual contains instructions for accomplishing Nondestructive Inspection (NDI) of the CH/MH-47
helicopters at the AVUM and AVIM levels. The procedures described in this manual are intended to provide instructions
for the NDI of locations where service defects would prevent items from performing their designated functions, and of
components for serviceability. These procedures were developed through review of CH/MH-47 Technical Manual
inspection requirements. The goal is to upgrade these requirements wherever possible using NDI methodology to
improve inspection quality, decrease inspection time, and increase systems operational readiness. Other factors
involved were maintenance engineering analysis, experience, and comparison with similar installations. Procedures
shall be reviewed and changes and additions made during the service life of the equipment by continually evaluating the
following: performance of the equipment, results of scheduled inspections, and thorough study of failure data. Local
conditions, such as special utilization or climatic environment, may dictate more detailed inspections. Commanders and
their maintenance officers are expected to exercise their prerogative to increase the frequency and scope of any
inspection as required.
b. This manual may pertain to part, or all types and series, of a model, and may, therefore, contain requirements
applicable to specific equipment that is not installed on an individual model.
When this situation is encountered, those requirements that are not applicable should be disregarded.
c. This manual does not contain inspection level or frequency, acceptance and rejection limitations, or instructions
for correcting defective conditions. Inspection levels and frequency are provided in the inspection requirements
manuals. Detailed acceptance and rejection criteria and instructions for correcting defective conditions are provided in
appropriate maintenance manuals and are, therefore, not contained in this manual. Decisions regarding the
serviceability of components properly belong with maintenance technicians trained, skilled, and experienced in their
particular specialty, such as airframe, hydraulic, or propulsion. Also, it would duplicate existing information and make the
task of incorporating the numerous changes to inspection frequency and repair instructions impractical.
d. The inspection requirements are stated in such a manner as to address the following: (1) What part or area is to
be inspected? (2) What conditions are to be sought? (3) What NDI method is to be used? (4) How is the method to be
performed? In scope, the inspection procedures are designed to direct attention of maintenance personnel to
components and areas where service defects can occur. The procedures also provide detailed instructions on the
application of NDI in an effort to ensure the serviceability of these areas.
e. Nondestructive inspection methods require application by trained, experienced, and proficient technicians. This
manual provides detailed procedures for the application of nondestructive methods to inspect specific areas or locations.
However, it must be emphasized that the reliability of the inspection depends upon the proper evaluation of the results
obtained from the inspection equipment.
