T.O. 33B-1-1
1-14
SECTION IV
PROCESS CONTROL OF ALL NDI METHODS
1.4
PROCESS CONTROL.
1.4.1
Reason For Process Control.
Process control is an essential ingredient in achieving irrefutable results in NDI inspections, regardless of method. A
well-regimented NDI process control program will not allow conditions to develop that render inspection methods a
source of misinformation. This misinformation may take two forms. The first arises when NDI has determined that a
part is defective when indeed it is not (false call). This is a waste of resources and an unnecessary reduction in mission
capability. The second form is the most dangerous, that is, determining a part is serviceable when in fact it is defective
(a miss). Both forms of misinformation can be minimized through the implementation of effective process control.
1.4.2
Scope Of Process Control.
All aspects of these categories are interrelated. They have to be tuned to each other to achieve valid inspection results.
If any one of these requirements is altered, the final outcome of the inspection will change, regardless of the inspector's
proficiency.
a. Process control is a general term used to encompass the actions and documentation, required by
established directives and logic, that are necessary for a nondestructive inspection (NDI) method to be
effective in detecting conditions of interest (e.g., cracks, foreign objects, corrosion, alignment of parts
and thickness of parts).
b. The general areas that fall within the scope of process control are as follows:
(1)
Inspector training and the demonstrated practical skills of inspectors.
(2)
Inspection environment; for example, temperature, specific type and levels of light, safety and
human engineering.
(3)
Material control; for examples, the serviceability of ultrasonic transducers, eddy current probes,
penetrant materials, X-ray film and chemicals, and magnetic particle suspensions.
(4)
Equipment control; for example its operational and performance capability and PMEL/user
calibration.
(5)
Adequate, specific inspection instructions; for example, -36, -26, and -9 technical orders.
(6) Adherence to the inspection requirements dictated by specific NDI procedures and commonly
accepted basic NDI practices.
1.4.3
Scope Of Documentation Requirements.
a. The documentation requirements and process control are completed to verify conformance to
established requisites in the areas described in paragraph 1.4.2. The requirements prescribed within
this technical order apply to all Major Air Force Commands, Air National Guard and Air Force Reserve
that use Nondestructive Inspection Laboratories per AFI 21-105. These requirements also apply to
Army, Army National Guard (ARNG), and Army Reserve (USAR) units.
b. Separate documentation SHALL be maintained for each NDI method, equipment and material with
established process control requirements. Process control requirements SHALL NOT be documented on
the same form used for equipment maintenance. This documentation SHALL reflect, as a minimum,
each element of process control with respect to required time intervals between checks, date of
