T-6A INSTRUMENT NAVIGATION
To adjust to/from the arc, use the following:
Displace the bearing pointer 5° from the 90° index for each 1/2 mile deviation to the inside of the
arc and 10° for each 1/2 mile outside the arc.
Example: Figure 4-7 illustrates a typical arcing situation. The aircraft is inbound to the station
at 150 KIAS GS, flying a course of 090° (inbound on the 270° radial). You are instructed to arc
north at 10 NM.
At point "A", the aircraft is at the lead point. Start the turn to intercept the arc now.
At point "B", you have just intercepted the arc. The head of the bearing pointer is on the
90° benchmark and the DME is showing 10.
At point "C", you have drifted inside of the arc possibly due to winds or poor arcing technique.
You need to correct as previously discussed.
At point "D", you have drifted outside the arc. Again, you need to correct as previously
At point "E", you are reestablished on the 10 DME arc.
4-22 INSTRUMENT NAVIGATION