+ float phidot; // roll rate (radians/sec)
+ float thetadot; // pitch rate (radians/sec)
+ float psidot; // yaw rate (radians/sec)
+ float vcas; // calibrated airspeed
+ float climb_rate; // feet per second
+ float v_north; // north velocity in local/body frame, fps
+ float v_east; // east velocity in local/body frame, fps
+ float v_down; // down/vertical velocity in local/body frame, fps
+ float v_body_u; // ECEF velocity in body frame
+ float v_body_v; // ECEF velocity in body frame
+ float v_body_w; // ECEF velocity in body frame
+
+ // Accelerations
+ float A_X_pilot; // X accel in body frame ft/sec^2
+ float A_Y_pilot; // Y accel in body frame ft/sec^2
+ float A_Z_pilot; // Z accel in body frame ft/sec^2
+
+ // Stall
+ float stall_warning; // 0.0 - 1.0 indicating the amount of stall
+ float slip_deg; // slip ball deflection
+
+ // Pressure
+
+ // Engine status
+ uint32_t num_engines; // Number of valid engines
+ uint32_t eng_state[FG_MAX_ENGINES];// Engine state (off, cranking, running)
+ float rpm[FG_MAX_ENGINES]; // Engine RPM rev/min
+ float fuel_flow[FG_MAX_ENGINES]; // Fuel flow gallons/hr
+ float fuel_px[FG_MAX_ENGINES]; // Fuel pressure psi
+ float egt[FG_MAX_ENGINES]; // Exhuast gas temp deg F
+ float cht[FG_MAX_ENGINES]; // Cylinder head temp deg F
+ float mp_osi[FG_MAX_ENGINES]; // Manifold pressure
+ float tit[FG_MAX_ENGINES]; // Turbine Inlet Temperature
+ float oil_temp[FG_MAX_ENGINES]; // Oil temp deg F
+ float oil_px[FG_MAX_ENGINES]; // Oil pressure psi
+
+ // Consumables
+ uint32_t num_tanks; // Max number of fuel tanks
+ float fuel_quantity[FG_MAX_TANKS];
+
+ // Gear status
+ uint32_t num_wheels;
+ uint32_t wow[FG_MAX_WHEELS];
+ float gear_pos[FG_MAX_WHEELS];
+ float gear_steer[FG_MAX_WHEELS];
+ float gear_compression[FG_MAX_WHEELS];
+
+ // Environment
+ uint32_t cur_time; // current unix time
+ // FIXME: make this uint64_t before 2038
+ int32_t warp; // offset in seconds to unix time
+ float visibility; // visibility in meters (for env. effects)