// llSitTarget parameters:
vector avPosition = ; // position of avatar in plane, relative to parent
rotation avRotation = ; // rotation of avatar, relative to parent
 
// Thrust variables:
// thrust = fwd * thrust_multiplier
// Edit the maxThrottle and thrustMultiplier to determine max speed.
integer fwd; // this changes when pilot uses throttle controls
integer maxThrottle = 10; // Number of "clicks" in throttle control. Arbitrary, really.
integer thrustMultiplier = 3; // Amount thrust increases per click.
 
// Lift and speed
float cruiseSpeed = 25.0; // speed at which plane achieves full lift
float lift;
float liftMax = 0.977; // Maximum allowable lift
float speed;
 
float timerFreq = 0.5;
 
integer fwdLast; 
integer sit;
key owner;
 
default
{
     
    state_entry() 
    { 
        llSitTarget(avPosition, avRotation); // Position and rotation of pilot's avatar.
         
        llSetCameraEyeOffset(); // Position of camera, relative to parent. 
        llSetCameraAtOffset();   // Point to look at, relative to parent.
         
 
        llSetSitText("Fly"); // Text that appears in pie menu when you sit
 
        llCollisionSound("", 0.0); // Remove the annoying thump sound from collisions  
  
        //SET VEHICLE PARAMETERS -- See www.secondlife.com/badgeo for an explanation
        llSetVehicleType(VEHICLE_TYPE_AIRPLANE);
              
        // uniform angular friction 
        llSetVehicleFloatParam( VEHICLE_ANGULAR_FRICTION_TIMESCALE, 2 );
         
        // linear motor
        llSetVehicleVectorParam( VEHICLE_LINEAR_FRICTION_TIMESCALE,  );
        llSetVehicleVectorParam( VEHICLE_LINEAR_MOTOR_DIRECTION,  );
        llSetVehicleFloatParam( VEHICLE_LINEAR_MOTOR_TIMESCALE, 2 );
        llSetVehicleFloatParam( VEHICLE_LINEAR_MOTOR_DECAY_TIMESCALE, 120 );
         
        // agular motor
        llSetVehicleVectorParam( VEHICLE_ANGULAR_MOTOR_DIRECTION,  );
        llSetVehicleFloatParam( VEHICLE_ANGULAR_MOTOR_TIMESCALE, 0 ); 
        llSetVehicleFloatParam( VEHICLE_ANGULAR_MOTOR_DECAY_TIMESCALE, 0.4);
         
        // hover 
        llSetVehicleFloatParam( VEHICLE_HOVER_HEIGHT, 0 );
        llSetVehicleFloatParam( VEHICLE_HOVER_EFFICIENCY, 0 ); 
        llSetVehicleFloatParam( VEHICLE_HOVER_TIMESCALE, 10 );
        llSetVehicleFloatParam( VEHICLE_BUOYANCY, .977 );
         
        // no linear deflection 
        llSetVehicleFloatParam( VEHICLE_LINEAR_DEFLECTION_EFFICIENCY, 0.2 );
        llSetVehicleFloatParam( VEHICLE_LINEAR_DEFLECTION_TIMESCALE, 0.5 ); 
         
        // no angular deflection 
        llSetVehicleFloatParam( VEHICLE_ANGULAR_DEFLECTION_EFFICIENCY, 1);
        llSetVehicleFloatParam( VEHICLE_ANGULAR_DEFLECTION_TIMESCALE, 0.6);
             
        // no vertical attractor 
        llSetVehicleFloatParam( VEHICLE_VERTICAL_ATTRACTION_EFFICIENCY, 0.8 );
        llSetVehicleFloatParam( VEHICLE_VERTICAL_ATTRACTION_TIMESCALE, 2 );
         
        /// banking
        llSetVehicleFloatParam( VEHICLE_BANKING_EFFICIENCY, 1);
        llSetVehicleFloatParam( VEHICLE_BANKING_MIX, .85);
        llSetVehicleFloatParam( VEHICLE_BANKING_TIMESCALE, 0.01);
         
         
        // default rotation of local frame
        llSetVehicleRotationParam( VEHICLE_REFERENCE_FRAME, );
         
        // remove these flags 
        llRemoveVehicleFlags( VEHICLE_FLAG_NO_DEFLECTION_UP 
                              | VEHICLE_FLAG_HOVER_WATER_ONLY 
                              | VEHICLE_FLAG_HOVER_TERRAIN_ONLY 
                              | VEHICLE_FLAG_HOVER_GLOBAL_HEIGHT 
                              | VEHICLE_FLAG_HOVER_UP_ONLY 
                              | VEHICLE_FLAG_LIMIT_MOTOR_UP );
 
        // set these flags 
        llSetVehicleFlags( VEHICLE_FLAG_LIMIT_ROLL_ONLY ); 
 
    }
     
    on_rez(integer num) 
    {
        llResetScript();
    } 
     
 
    // DETECT AV SITTING/UNSITTING AND TAKE CONTROLS
    changed(integer change)
    {
       if(change & CHANGED_LINK)
       {
            key agent = llAvatarOnSitTarget();
            
            // Pilot gets off vehicle
            if((agent == NULL_KEY) && (sit))
            {
                llSetStatus(STATUS_PHYSICS, FALSE);
                llSetTimerEvent(0.0);
                llMessageLinked(LINK_SET, 0, "unseated", "");
                llStopSound();
                llReleaseControls();
                sit = FALSE;
            }
             
            // Pilot sits on vehicle
            else if((agent == llGetOwner()) && (!sit))
            {
                llRequestPermissions(agent, PERMISSION_TAKE_CONTROLS | PERMISSION_TRIGGER_ANIMATION);
                llSetTimerEvent(timerFreq);
                llMessageLinked(LINK_SET, 0, "seated", "");
                sit = TRUE;
                llSetStatus(STATUS_PHYSICS, TRUE);
            }
        }
    }
 
 
    //CHECK PERMISSIONS AND TAKE CONTROLS
    run_time_permissions(integer perm) 
    {
        if (perm & (PERMISSION_TAKE_CONTROLS)) 
        {            
        llTakeControls(CONTROL_ML_LBUTTON | CONTROL_LBUTTON | CONTROL_UP | CONTROL_DOWN | CONTROL_FWD | CONTROL_BACK | CONTROL_RIGHT | CONTROL_LEFT | CONTROL_ROT_RIGHT | CONTROL_ROT_LEFT, TRUE, FALSE);
        }
    }
             
             
    //FLIGHT CONTROLS     
    control(key id, integer level, integer edge) 
    {
            if (edge) llMessageLinked(LINK_SET, level, "tc ctrl", "");
            integer throttle_up = CONTROL_UP;
            integer throttle_down = CONTROL_DOWN;
            integer yoke_fwd = CONTROL_FWD;
            integer yoke_back = CONTROL_BACK;
 
            vector angular_motor; 
             
             
            // THROTTLE CONTROL--------------
            if (level & throttle_up) 
            {
                if (fwd  0)
                {
                    fwd -= 1;
                }
            }
             
            if (fwd != fwdLast)
            {
                llSetVehicleVectorParam(VEHICLE_LINEAR_MOTOR_DIRECTION, );
                 
                // calculate percent of max throttle and send to child prims as link message
                float thrustPercent = (((float)fwd/(float)maxThrottle) * 100);
                llMessageLinked(LINK_SET, (integer)thrustPercent, "throttle", "");
                llOwnerSay("Throttle at "+(string)((integer)thrustPercent)+"%");
                 
                fwdLast = fwd;
                llSleep(0.15); // crappy kludge <span class="wp-smiley wp-emoji wp-emoji-tongue" title=":P">:P</span>
            }
 
             
            // PITCH CONTROL ----------------
            if (level &amp; yoke_fwd) 
            {
                angular_motor.y = 3.0;
            }
            else if (level &amp; yoke_back) 
            {
                angular_motor.y = -3.0;
            }
            else
            {
                angular_motor.y = 0;
            }
             
 
            // BANKING CONTROL----------------
 
            if ((level &amp; CONTROL_RIGHT) || (level &amp; CONTROL_ROT_RIGHT)) 
            {
                angular_motor.x = TWO_PI;
            }   
            else if ((level &amp; CONTROL_LEFT) || (level &amp; CONTROL_ROT_LEFT)) 
            {
                angular_motor.x = -TWO_PI;
            }
            else
            {
                angular_motor.x = 0;
            }
 
            llSetVehicleVectorParam(VEHICLE_ANGULAR_MOTOR_DIRECTION, angular_motor);
             
    } 
     
    timer()
    {
        // Calculate speed in knots
        speed = (integer)(llVecMag(llGetVel()) * 1.94384449 + 0.5);
         
        // Provide lift proportionally to speed
        cruiseSpeed = 25.0; // speed at which you achieve full lift
        lift = (speed/cruiseSpeed); //Lift is varied proportionally to the speed
        if (lift &gt; liftMax) lift = liftMax;
        llSetVehicleFloatParam( VEHICLE_BUOYANCY, lift );
    }
 
}