Flight Training Instruction - Cnatra - U.S. Navy
Flight Training Instruction - Cnatra - U.S. Navy
Flight Training Instruction - Cnatra - U.S. Navy
Create successful ePaper yourself
Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.
T-6B PRIMARY INSTRUMENT NAVIGATION CHAPTER SIX<br />
Common Errors.<br />
1. Not providing adequate lead for turns, thus overshooting the arc.<br />
2. Turning in the wrong direction to get back on the arc. Remember the head of the needle<br />
points at the station.<br />
606. ARC / RADIAL INTERCEPTS<br />
General. To determine the lead turn required in order to align the aircraft on a course off of an<br />
arc.<br />
Description. On some approaches, missed approaches and departure procedures, you will be<br />
required to fly an arc and then intercept a radial (inbound or outbound) from that arc. In this<br />
situation, you have to decide when to start your turn off the arc to intercept the radial.<br />
Procedure. In the following example, consider an aircraft on the 12 DME arc flying at 180<br />
KIAS, turning onto a course inbound.<br />
Determining Lead Radial<br />
1. Determine the number of radials per mile. Recall from the 60–to–1 rule, that 60 divided by<br />
DME equals the number of radials in one mile.<br />
In this example: 60/12 = 5 radials per mile on the 12 DME arc.<br />
2. Determine the turn radius of the aircraft (for 90° of turn). This is 0.5% of the groundspeed.<br />
In this example: 0.5% of 180 = 0.9 NM.<br />
3. Multiply the turn radius by the number of radials per mile.<br />
0.9 NM * (5 radials /NM) = 4.5 radials<br />
4. In this case, start the turn 4.5 radials prior to the intended course.<br />
It should also be noted that this is a no wind calculation. In the aircraft, you will need to take<br />
winds into account.<br />
607. INTERSECTIONS<br />
General. An intersection is a point defined by any combination of courses, radials, or bearings<br />
of two or more NAVAIDS.<br />
Description. With DME available, an intersection may be identified as a radial and distance<br />
from a station. The station used to navigate on the airway is called the primary station. If a<br />
ENROUTE PROCEDURES 6-9