2. Making a Measurement
Measurements are made in two steps. First the aircraft setup is verified. If the verification is successful
the actual measurement can be made and the data acquired.
To make a measurement, position the cursor over the desired Test State and press the DO key. A flight
condition message will be displayed. If no errors occur, the Test State progress window will be displayed
with an asterisk (*) as the first character in the highlighted window, see figure 1. If the verification of setup
data fails, an error message will be displayed. Press the DO key again to proceed with the measurement.
3. Aborting a Measurement
A measurement can be aborted at any time by pressing the QUIT key. Measurement data will not be
stored if the measurement operation is aborted.
4. Repeating a Measurement
Measurements may be repeated as long as the flight condition is maintained. To repeat a measurement,
place the cursor over the desired Test State and press the DO key. Data previously measured and
stored will be overwritten by the new measured data
5. Completing a Measurement
Successful acquisition of the measurement data results in a screen that reads:
This display is used to indicate to the pilot to proceed to the next flight condition. No key presses are
required. The CADU will automatically progress to the next screen.
If the measurement was successful a "done" will appear to the right of Test State, see figure 1. If channel
errors occurred for some, but not all, of the channels measured, "partial" will appear to the right of Test
State. If no data was acquired due to channel errors, "failed" will appear to the right of Test State.
To exit the measurement mode, press the QUIT key. The action screen will be displayed with the
following choices, see figure 1:
(a) Continue. Select this option to continue with the measurement mode by pressing DO over the
Continue selection. Any Test States that have not yet been measured for the flight will appear (below
a similar message) in the bottom right hand corner of the screen.
(b) Save and Exit. Select this option to save flight data taken and exit the measurement mode. At this
point, an End Of Flight Menu will appear with the following options:
(1) Diagnostics. Place the cursor over this option and press the DO key to perform diagnostics on
the flight just measured.
(2) Main Menu. Place the cursor over this option and press the DO key to return to the Main Menu.
(c) Abandon Flight. Place cursor over this option and press the DO key. Follow any further instructions
that appear. This will remove all measured data, for this flight, from the database.
6. General Capabilities
The AVA performs five basic types of measurements. The results of these measurements are available
for use in diagnostics or data displays. The five basic types are:
(a) Asynchronous Sampled Power Averaged (ASPA) vibration spectrum with zoom
(b) Synchronous Sampled Power Averaged vibration spectrum (SSPA) with zoom (signature ratio)
(c) Synchronous Sampled Time Averaged spectrum (SSTA/SSTAR) (harmonic spectrum)
(d) Average Blade Track
(e) Average Blade Lag
Processing Data . . .
*** PILOT TRANSITION ***
Next Test State : (selected Test State)
STAND-BY . . . While data is loading