VOR Radial Intercept

[Boeing 777-300ER]

Would greatly appreciate any feedback on the following basic scenario which quite frankly has left me thinking.

During a sim excersise a trainee pilot was tracking inbound to a VOR on the 180 radial (heading 360). I asked him to intercept the 140 radial outbound. A few miles before reaching the VOR he turned right to intercept the instructed radial. Since the turn was tight the radial was overshot but he recovered well. I have been thought in the past that given given the intercept we should first fly over the VOR, do a kind of procedure turn (or enter the hold if one is published) and than proceed on the said radial.

My question is whether there a prescribed procedure on the correct way of doing such an intercept?

[Intruder]

From where he is, the shortest turn to the prescribed course.

The immediate right turn is correct. Depending on DME and turn radius, adjust rollout heading to intercept the 140 radial.

Unless the clearance is via the VOR and then outbound, your "procedure turn" idea is incorrect.

[helopat]

I'd say it also depends on how far out from the VOR you are when you tell him to do the intercept. Further out (greater than 5 NM) you'd want him to turn right and take up, say, a thirty degree intercept heading...closer in, as already discussed, it'd be a turn directly onto the outbound unless there were some other specifics involved.

HP

[Slashmashpotato]

On that same note, I have encountered numerous debates on the VOR radial intercepts for outbound to inbound radial intercepts. One school of thought believes that the intercept procedure for outbound to inbound is to 'turn the wrong way round', i.e. turning in a longer distance, whereas the other school believes that the way is the same as per all other intercepts, i.e. turning in the shortest and most direct way.

Does anyone know of any website or literature on this issue which I can further look into?


Slash

[Rainboe]

I think he did well! Obviously had a good solid 'picture' of what he wanted to achieve and set about it and almost achieved a perfect outcome. EXCEPT, if he was joining an approach sequence, you should not try and track outbound in the approach if the turn required is more than 30 degrees.

He deserves a dog biscuit!

[Cx292]

According our Basic Navigation book:

If the VOR has DME you can turn before overfly the VOR and as rule of thumb you can use this simply calculation:

Your flight level divided 100 + your ground speed divided 100 this is how many NM you have to turn before.

i.e = F250 GS 300 kts = 5,5 NM before you can turn right with Int HDG = to radial difference divided by 3 max 30° int HDG, in this case 180 - 140 = 40 ; 40 divided by 3 more or less 13° int HDG = 140 -13 = 127° (I would take 130°)

Nice sky, hope this helps

[Alteburger]

To illustrate this issue, try looking at an ELTAR 1E arrival for Brescia (LIPO). Involves a 155 degree turn to follow the STAR to the IAF which is only 4 miles from the NDB. Try doing that at the Cat D initial approach limiting speed as per PANS-OPS....