Jsbsim Tutorial Apr 2026

Alex adds landing gear:

<propulsion> <engine file="Rotax912"> <location> 0 0 0 </location> </engine> <propeller file="fixed_pitch"> <ixx> 0.2 </ixx> <diameter> 1.6 </diameter> <num_blades> 2 </num_blades> </propeller> </propulsion> He writes a taxi script: throttle 0.3, release brakes, wait 10 seconds, full rudder right.

Maya smiles. “You don’t fly it. You build the laws of physics for it. JSBSim is a library—a simulation engine. It takes an XML model and outputs time‑step states: position, orientation, velocities. You visualize separately.” jsbsim tutorial

jsbsim --script=scripts/x1_test.xml The script: set prop/engine[0]/running 1 , set fcs/throttle-cmd-norm 0.7 , run 30 .

The first section: <?xml version="1.0"?> followed by <fdm_config> . You build the laws of physics for it

“But how do I even fly it?” Alex asks.

She also runs a stability analysis using JSBSim’s --output=stability flag, which generates eigenvalues. “Look – your dutch roll mode is barely damped. Increase vertical tail area in <metrics> .” You visualize separately

Maya hands Alex wind tunnel data: CL(alpha, camber) , CD(alpha) , Cm(alpha) .

At 5 PM, Maya hands him a FlightGear configuration file that references x1.xml . “Now go see your aircraft fly for real.”

Alex opens the drive. Inside: x1_fdm.xml , a blank JSBSim configuration file. No UI. Just XML.

import jsbsim fdm = jsbsim.FGFDMExec() fdm.load_model('x1') fdm['propulsion/engine[0]/running'] = 1 fdm['fcs/throttle-cmd-norm'] = 1.0 for t in range(1000): fdm.Run() if t == 200: fdm['fcs/elevator-cmd-norm'] = -0.3 # pitch up print(fdm['position/h-sl-ft'], fdm['attitude/theta-deg'])