Wind Data
The FMC uses wind data to improve performance calculation accuracy.
PEGASUS FMC
The FMC applies the first entered wind to all waypoints in the flight plan. Wind data includes altitude and direction/speed.
NON PEGASUS FMC
The wind entered on the PERF INIT page applies to all the cruise waypoints in the flight plan.
Wind data entered at another waypoint changes the wind only for the waypoints down track from that waypoint either to the end of the track, or to the next entered wind. Therefore, enter winds for waypoints closest to the airplane first, then enter winds for waypoints further down track.
PEGASUS FMC
For example: at FL 350, 100'/085 is entered at waypoint OED. All waypoints in the route have the OED wind data. Then, additional wind data entered at OAK changes the wind data at OAK and through the end of the route.
Entered winds are mixed with sensed winds for performance calculations. The FMC uses entered winds for predictions far ahead of the airplane and sensed winds close to the airplane. The FMC mixes these winds for predictions in between. Sensed winds are displayed on the HSI and on progress page 2.
