TM 1-6625-724-13&P
0003 00
0003 00-1
TECHNICAL PRINCIPLES OF OPERATION
AVIATION VIBRATION ANALYZER
Figures
Figure 1. AVA Overall Menu Structure ............................................................................................................................2
PRINCIPLES OF OPERATION
The AVA system maintains a database of measured data, diagnostic outputs, and aircraft history. The system will
generate printed reports from this database to support historical review and trending of data. All or part of the
database may be deleted, transferred to an external computer, or restored from a computer. Transfer is
accomplished by means of an RS-232 link using KERMIT protocol, or a solid-state memory unit the size of a credit
card. Diagnostic programs and replacement software modules are transferable by the same means.
The primary mission of the AVA is to collect helicopter blade track height, blade lead/lag, vertical/lateral vibration
measurements, shaft vibration, and to calculate the recommended maintenance correction to the rotor system that will
result in reduced vibration levels. This system may also be used for engine vibration analysis.
The actual measurements are carried out automatically and simultaneously by a single operator keystroke. The AVA
executes configured, internally stored software programs limited to the established aircraft maintenance procedures
that reduce vibration levels. User interface is needed for entry of aircraft identification, single key commands for data
collection, results display, and computed maintenance corrections.
Each of the AVA functions provides an overview style of direction to the operator in the form of a main diagram. The
diagram contains all of the elements and options that the operator can invoke along with a general description of what
to do in making the desired selections.
Figure 1 shows the four main functions performed by the AVA and the basic elements associated within each
function.
