GE ADTS542F User Manual page 66

3-32
Typical Aircraft Instrument Performance Checks
The required aircraft specific procedures will be detailed in the AMM but the following generic test
is provided purely as an example of how the ADTS facilities might be best utilised.
The ADTS produces controlled altitudes based on the standard sea level pressure (zero feet
reference) that is defined in the ICAO international standard atmosphere model. In order to
correctly check the aircraft instruments for accuracy against the ADTS, it is vital that the altimeter
baroscale datum adjustment is set to the same 1013.25 mbar (29.92 inHg).
Systematically enter the required aims for the Ps and Pt channel from each row of the test table
below. Aims may be entered either in aeronautical units or absolute/differential pressure units
according to the requirements of the AMM. For each of the six test row conditions, allow the ADTS
to approach and stabilise the aims until the ADTS Touch shows each measurement in green
record the difference between the ADTS and the Aircraft instrument under test.
Altitude
Test Point
(feet)
1 0
2 5,000
3 15,000
4 *29,000
5 35,000
6 *41,000
7 GROUND
*= RVSM boundaries
By using the ADTS Touch controls it is possible to present the Ps and Pt channel data for each of
the 6 test condition rows in all of the formats shown in the table. By using the settings menu to
change either the chosen pressure or aeronautical unit it is very simple to convert the displayed
aims and measurement values to the desired format. Such changes can be done without turning
off control, so the terminal can effectively also be used as a pressure converter/calculator when
designing your aircraft test procedures.
The aircraft status screen can be used to give you a very quick overview of whether the aircraft is
climbing, descending or at stable altitude. If you make a mistake with your data entry, use the
green "hand" symbol to stop ramping and HOLD stable the current pressure, while you consider
and correct the intended test point aim. Pressing the now orange "hand" again will release the
hold when you are ready. The "Hand" returns to green as ramping to the corrected aim begins
again. If the ADTS Touch loses radio link or the cable accidentally becomes severed, the ADTS will
automatically enter the HOLD state after 10 seconds. If communications has not been re-
established after 10 minutes, then the ADTS will automatically begin a descent to ground
pressures.
ADTS542F/552F/553F/554F User Manual
Ps Pressure Airspeed
(mbar Abs.) (Knots)
1013.25 90.0
843.07 130.0
571.82 250.0
314.85 310.0
238.42 280.0
178.74 270.0
AMBIENT 0.0
Pt Pressure
Qc Diff.
(mbar Abs.)
Press. (mbar)
1026.44 13.19
870.73 27.66
676.80 104.98
479.37 164.52
371.30 132.88
301.91 123.18
AMBIENT 0.00
Mach
0.136
0.215
0.497
0.799
0.821
0.899
0.000
K0553 Revision C