Dual control
This is an add-on for FlightGear that adds basic support for shared control of an aircraft over the FlightGear multiplayer network. The main part is a set of generic Nasal modules and modified instrument files that form the core of the networked shared control functionality.
Note: The Open Scene Graph based FlightGear/CVS (developer's version) is needed to use this add-on. The aircraft will load in FlightGear 1.0.0 too but the copilot cannot see or touch anything in the cockpit.
Feel free to drop me an e-mail (see bottom of page for the address) if you find some of this software useful or have other comments, suggestions or questions.
Aircraft
The tar.gz archive for each aircraft should be extracted in $FG_ROOT/Aircraft/. You can find archives for all aircraft below in the hangar.
Currently there is only one aircraft with dual control support.
c172p Skyhawk with dual control (c172p-pilot and c172p-copilot)
This aircraft is based on David Megginson's c172p single control c172p.
The aircraft enables a pilot and copilot to jointly fly the aircraft over the FlightGear multiplayer network. Pilot and copilot currently have shared control over primary flight controls, throttle, mixture, elevator trim, flaps, brakes, cockpit switches, part of the radio stack and some instrument settings. The copilot has a subset of the full instrumentation, including airspeed, altimeter, VSI, HSI, turn coordinator, engine RPM and the radio stack. NavComm 1 and the first VOR indicator is best controlled by the pilot, while NavComm 2 and the corresponding VOR indicator is faster for the copilot.
Usage instruction
The system consists of two "aircraft":
The pilot uses a special variant of the c172p, c172p-pilot. The pilot need to specify the callsign of the copilot (other copilots will be ignored).
Pilot usage example:
fgfs --aircraft=c172p-pilot --prop:/sim/remote/pilot-callsign="someone"
The copilot uses a special "aircraft", c172p-copilot, which piggybacks on the designated pilot and captures the local control inputs. A current limitation is that only the cockpit view (ctrl-v) is jitter free. There is also a noticeable delay between control inputs and effect, since they are passed via the the multiplayer protocol. The severity of this delay depend on round trip time and some other factors - the delay seems significantly longer than the round trip time itself which is due to buffering in the MP protocol receiver. That said, I have flown successfully as copilot in a setup with 100-120ms round trip time between both pilot and server and copilot and server (total delay >500ms). Landing is a bit exciting in that case, however.
Copilot usage example:
fgfs --aircraft=c172p-copilot --prop:/sim/remote/pilot-callsign="anybody"
Note: The copilot will want to reset the view (ctrl-v) to avoid jitter as external views are jitter prone (this will be fixed later).
Status: Beta, perfectly flyable but some functions are not yet shared between the pilot and co-pilot.