TM 1-6625-724-13&P
0011 00
0011 00-1
SYSTEM DIAGNOSTICS
AVIATION VIBRATION ANALYZER
Figures
Figure 1. Diagnostic Menu Hierarchy ............................................................................................................................... 2
Figure 2. Edit Adjustables Screen .................................................................................................................................... 4
DIAGNOSTICS
The Diagnostics function executes the diagnostics routine on the selected Flight Plan's data. The diagnostics routine
will typically calculate the required mass balance, pitch rod and tab adjustments necessary to reduce system vibration
and track to acceptable levels.
The Diagnostic operation is started by pressing the F3 key from the Main Menu, see figure 1. The aircraft setup script
must have been previously configured with diagnostic coefficients and weighting factors for the diagnostics to
function. (Weighting factors can be described as a set of “priorities” for the diagnostics to consider. Certain vibration
or track data points can be weighted to have more priority than others in the diagnostics.) The diagnostic operation is
executed on data from the currently selected flight ID. These corrections are the optimum set of adjustments that
shall be made to reduce the vibration levels to the lowest possible level (all indicated corrections must be made). If a
reduced or modified set of adjustments is required or desired, the diagnostic editing functions (Edit Adjustables or Edit
Defaults) must be used.
a.
Viewing the Corrections
Upon pressing the F3 key at the Main Menu, the first screen will be a comparison of the vibration and/or track split
measurements as compared against the limits defined by the script file. If multiple pages exist, the LEFT and
RIGHT arrow keys can be used to scroll through the displays. Pressing the UP and DOWN arrow keys will toggle
from the default of displaying only “above limits” values to displaying all values as compared to their defined limits.
Pressing QUIT or DO will instruct the system to exit out of the limits page and continue with the diagnostics
routine.
NOTE
If “All Measurements are Within Specified Limits” is
displayed, pressing QUIT will return the system to the
Main Menu, while pressing DO will instruct the system to
continue with the processing and diagnosis of the
remaining vibration and track values.
The second screen (optional, dependent on script file configuration) is a display of the system’s current record of
absolute adjustment values. In the case of a new aircraft being measured for the first time with this system, all
values will be zero. In all other cases, the display shows a cumulative record of the adjustments already
performed. This display is interactive and provides the operator the ability to enter any information already known
about the rotor configuration for the system to consider while calculating corrections. Pressing DO will continue
the diagnostics calculation with any manual changes entered. Pressing QUIT will continue without the changes
being saved.
The Diagnostics operation will display a corrections screen indicating the desired corrections. To scroll through
the corrections list, use the LEFT and RIGHT arrow keys on the CADU keypad. To print the entire screen, press
the PRINT key. Pressing the DO key will advance to the Diagnostics Menu screen.
b.
Viewing the Predicted Response
The Predicted Response, assuming the corrections indicated in the corrections screen are fully implemented, is
displayed on the Predicted Response screen. This screen can be viewed by selecting the view prediction options
from the Diagnostics Menu. The Predicted Response screen shows a table of predicted responses for the
various vibration and track measurements at each test condition. For instance, data was collected at a test
condition called FPG100, the predicted amplitude and phase of the vibration and the predicted track in mm are
displayed. If additional Test States were performed there, predicted vibration and track levels would also be
displayed. The predicted response is useful for a couple of reasons. It allows a user to use the diagnostic editor
to eliminate a particular adjustment or families of adjustments and view the predicted response. This makes it
possible to select a limited set of adjustments that still meet a user's vibration criteria that potentially can save
work and time. The second useful aspect is to monitor the effectiveness of the diagnostic solution. The predicted
