IFR procedures, terms & rule of thumb

IFR interceptions terms img

If:	Heading to choose:
10° ≥ AoD	3 x AoD on the required course (tracking phase)
10° < AoD ≤ 60°	30° attack on actual bearing
60° < AoD < 90°	90° attack on the required course
90° ≤ AoD	opposite heading to the required course up to 2 min after passed abeam position, then 90° attack on the required course
OUTBOUND	AoD / 3 on the required course (minimum 45°, maximum 90°)
AoD = Angle of Difference

DME arc img

interception from the outside	80° turn
interception from the inside	110° turn
required lead before turn	KTAS / 200 (in NM)
turn 20°	when the bearing points 10° before the abeam position
0.1 NM too far	turn 20° towards the station
till 0.2 NM too close	maintain heading
more than 0.2 NM too close	turn 10° away from the station