README.txt
The Century III autopilot model is the joint effort of Torsten Dreyer (3D model)
and Dave Perry (Aircraft/Generic/century3.nas, and Systems/CENTURYIII.xml).
The model and cascaded PID controller design attempt to recreate the performance
and pilot interface described in
CENTURY(R) FLIGHT SYSTEMS, INC.
CENTURY III
AUTOPILOT FLIGHT SYSTEM
PILOT'S OPERATIONG HANDBOOK
NOVEMBER 1998, 68S25
This manual is available free as a pdf download from www.centuryflight.com.
Piper Aircraft used this autopilot relabled as the Altimatic IIIc from the mid
1960's through the mid 1980's. The Century III is used by the pa24-250 and the Altimatic IIIc is used by the SenecaII in FlightGear.
From a pilot's point of view, there is one significant difference between the Century III and the Altimatic IIIc. The Altimatic IIIc couples to the HSI needle so the heading bug has no affect in modes other than HDG. With the Century III, the D.G. heading bug must be aligned with the NAV1 Omni Bearing Selector for the coupled modes Nav, and OMNI to function properly, and to the localizer bearing for LOC NORM mode to work properly. For proper functioning in LOC REV mode, the heading bug should be set to the back course bearing (180 deg from the LOC bearing).
Both use the nasal file
Aircraft/Generic/century3.nas
and the following xml files:
Aircraft/Instruments-3d/Century-III/AutopilotMode.xml,
Aircraft/Instruments-3d/Century-III/AutopilotModePanel.xml, and
Aircraft/Instruments-3d/Century-III/AltimaticIIIcPanel.xml.
Because the 3d models differ, the Century III requires a model entry for
Aircraft/Instruments-3d/Century-III/CenturyIII.xml
and the Altimatic IIIc requires a model entry for
Aircraft/Instruments-3d/Century-III/AltimaticIIIc.xml
as well as the additional nasal link to the hsi
hsiBugError.nas.
See the SenecaII/Nasal/hsiBugError.nas for an example.
Additionally, the autopilot config files are different because of this heading bug difference. See the /Systems/CENTURYIII.xml files for the pa24-250 and the SenecaII for examples of both.
