Ok Teroc I will try to keep it simple. If you can get hold of any approach plate with DME arc that will help you understand this, here we go:
1) Tune and identify the VOR/DME to be used.
2) Determine position and distance from the facility using all available equipment.
3) Check (minimum every 10-15 mins) and set your Direction Indicator with Mag Compass.
4) Track inbound or outbound on the specified radial.
5) Check the DME readout frequently while tracking to the arc.
6) When within 0.5 mile of the desired arc, commence a standard rate turn in the direction of the arc rotaion (clockwise or anti-clockwise).
7) Turn 90 degree from the radial specified in step 4.
8) Center the needle on the #2 VOR with a "FROM" indiacation. Advance the OBS 10 degrees in the desired direction.
9) Monitor the DME readout to hold the desired distance. If the readout increases turn into the arc by approx 10 degrees. If the readout decreases turn away from the arc.
10)While established on the arc, change the aircraft heading 10 degrees towards the inside of the arc each time #2 VOR needle centers.
11) Continue to reset the #2 VOR 10 degree each time the needle centre while changing the aircraft heading 10 degree as that radial is crossed.
12) Before crossing the lead-in radial(LR) for the approach, tune and identify the #1 VOR to the approproate frequency and adjust the CDI to the inbound approach course. If the approach does not have a lead-in radial, use a 3-5 degree lead radial.
13) Upon reaching the lead-in radial, turn to a 45 degree course intercept heading. COmplete the course intercept as the #1 navigation CDI begins to centre.
phhhheeewwwwwwww I hope Teroc all this make sense. The DME arc's are designed for specific approach and it could be and usually is different for different approach.
[This message has been edited by DesiPilot (edited 22 April 2000).]