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18th Apr 2015, 19:51
Good afternoon,

How do I know if I'm authorized to fly an RNAV procedure (STAR,IAP)
on an A320 when RF Is REQUIRED?

Thank you

18th Apr 2015, 20:20
As far as I know for a RNAV approach a RF leg after the FAF would make it a RNP AR approach. You would need to be certified as well as your aircraft + company (AR = authorization required). Not sure about RF legs prior to the FAF.

Kathmandu is the best example I could find http://s201.photobucket.com/user/aterpster/media/VNKTRNAVRNP02_zps78126b9e.jpg.html

19th Apr 2015, 02:20
I used to fly the kathmandu RNP AR and thats when i learned about RF legs, but at this new operator I'm finding STARs with an RF REQUIRED note, leading to an RNAV GNSS IAP, but no one seems to know if we can legaly fly it.

19th Apr 2015, 03:26
What is the nav accuracy required for the procedure. A sure sign that authorization may be required is values of less than 0.3nm

19th Apr 2015, 18:25
1. I think yes. Assuming this is just PRNAV/RNAV 1 standard STAR, approved in your OPS spec. RF leg is no different to an DME arc if navigated with onboard NAV. I believe your aircraft is fully capable of doing this, though some other's RNAV boxes may not - hence the note. :ok:

2. No, since your training (reason to ask) and operational oversight (colleagues unaware) had obviously been insufficient. :E

no offence intended.

22nd Apr 2015, 16:08
by the lack of replies its seems im not alone.

22nd Apr 2015, 21:03
That info should be on your aircraft Operations Specifications (OpSpecs); I also check it on the "Coded ICAO Flight Plan" part of our Operational Flight Plan; on the "PBN" section, it should say next to a bunch of other stuff, "T1", that means the aircraft is approved for "RNP AR APCH with RF (authorization required)". There are several codes for what kind of PBN operations the aircraft is approved, and that's a quick way to know.

Hope that helps.

22nd Apr 2015, 22:24
Here you have it all


23rd Apr 2015, 02:39
If you are talking about flying RF Legs associated with terminal procedures e.g. STAR/SID or even RNAV(GNSS) approach, then these documents have the answers:

Aircraft approval is published in the Airplane Flight Manual in LIM-22 under "AIRWORTHINESS STANDARDS COMPLIANCE" paragraph.

Individual aircraft capability can be confirmed in FCOM/DSC-22 in the "FLIGHT PLANNING - LATERAL FUNCTIONS section.

RF Leg Training is addressed in FCTM/SI-110 (ICAO recommends “training” for RF Legs).

All of the above was only addressed by Airbus last year due to guidance from ICAO and FAA only recently published.

Many airlines do not publish their AFM for Flight Crew to see, so this needs to be addressed somehow e.g. on a placard or checklist.

RF Leg associated with RNP AR approach is subject to different approvals.

25th Apr 2015, 23:23
thanks gentlemen I'll have a read.

16th Oct 2015, 17:06
RNAV procedures relay on FMS databases. These databases are coded with path-terminators according to the Arinc 424 standard. There are 23 of them like, CF Course to Fix, IF Initial Fix,CF Course to Fix or RF Constant Radius Arc Leg.
Not all of these path terminators are required to construct a RNAV procedure,that is, a PBN specification, and not all of these PBN specifications require the same path-terminators.RNP AR APCH and Advanced RNP are the only specifications where RF is compulsory but the rest of them like RNAV 1 or RNP 1 (used for SIDs and STARS) normally don't use it.
RF permits to fly an arc very accurately, normally based on a database fix, opposite to the "traditional arcs" where the plane just flies from one fix to the next one, not following always the same track.
The RF leg is designed to be used for terminal procedures.

24th Mar 2023, 14:51
RF capability is found in Aircraft Config Summary in the QRH of A320 family.

24th Mar 2023, 21:05
RF capability is found in Aircraft Config Summary in the QRH of A320 family.
Ours have RNP AR capability but no mention of RF.

24th Mar 2023, 21:18
Just checked one of ours, RF leg capability is mentioned as part of the FMS2 Release 1A entry.

28th Mar 2023, 00:25
Just checked one of ours, RF leg capability is mentioned as part of the FMS2 Release 1A entry.
You are quite right, it’s there on ours as well.