RF Legs in Europe

jwoolard wrote:

Is this remotely relevant to us in Europe?

The airbase that is very close to my homebase has an RF leg approach. I guess I could use it for cloud break if my navigator supported it. Sometimes, their ILS is unusable because the army parks trucks in front of the glideslope antennas…

jwoolard wrote:

Is this remotely relevant to us in Europe?

In theory yes, as there are approaches using RF legs in Europe. (Here is one.) In practise, I guess not, since all (?) of these approaches are “authorisation required”.

We have a few approaches in the US that are published with RF legs and are not authorization required. There is one RNAV at KCRQ and an ILS in Alaska that use an RF leg for the initial leg or feeder route. More RNAV STARs and maybe some RNAV SIDs use them as well.

Would this not allow DME arc approaches to be coded as overlays? Could be useful.

The approach at Benbecula has a DME arc that is coded by Jeppeson. I have flown it on the autopilot

I am sorry but… what do you call an RF leg exactly ?

RF = Radius to Fix. It’s the RNAV/GPS equivalent of a DME arc, where you continuously turn (slowly) and maintain the same distance from a known point.

If you consider that smaller, slower GA aircraft turn much more quickly that a fast moving jet airliner (even when both doing Rate One turns), the radius of those turns would be much greater for the jet. By specifying a known fixed radial, all traffic can be routed along a known path. This is considered helpful in future airspace routings and is expected to become more common in STARs and SIDs (standard instrument arrivals and departure routes) in the future.