Formation Stations
- vertical
 - longtitudinal
 - lateral
 
The bearing line is the imaginary line from the lead aircraft along which following aircraft formate. For echelon, the bearing line is 45o from the centre of the lead aircraft's cockpit. For right echelon, the bearing line is to the right; for left echelon, to the left. For line astern and line abreast, the bearing line is 180o and 90o respectively.
The bearing line helps establish position in the lateral and longtitudal planes, but doesn't establish the correct distance from the lead aircraft.
