Navaid outtage & SID

[LLLK]

Oh yes, and P-RNAV = RNAV 1 (except for the bit about VOR/DME) not RNP 1 or RNP 0.5

[Permafrost_ATPL]

A lot of answers that are not appropriate to the question :-)

Checkboard has given the answer in official wording. Here is a simple version:

- once you are navigating towards the failed SID Navaid (remember, the original question is about SID, not approach), you must be above MSA UNLESS IT'S A P-RNAV SID (I am assuming here we are talking about minimum B-RNAV equipped aircraft).

Simples.

So it all depends where that failed NAVAID is in the SID. On a side note, you are allowed to START a turn towards the failed Navaid below MSA (e.g. when passing 2000', turn towards ABC). You just need to be above it once your FMGS starts tracking towards it (using GPS/IRS). Again, all of this does not apply in the case of P-RNAV.

P

[RMC]

Our ops manual that we can fly an RNAV STAR below MSA up to the Final Approach Waypoint (FAWP).

My understanding of this is that an FAWP should appear on RNAV STAR plates...but the handful of places we fly into with RNAV STARs don't depict a FAWP only an IAF?

Can anyone direct me to a chart with a FAWP and verify if this restriction is similar for other airlines with both BRNAV and PRNAV approval?

[Speedwinner]

If I have a SID which is RNAV/GPS. Can i fly it without GPS wenn there are waypoints like NEGRA which are undefined. So i mean with raw data nav not pointable?

Or do I just have to check wether my RNP and actual RNP are good?

Thanks

[reynoldsno1]

My understanding of this is that an FAWP should appear on RNAV STAR plates

The FAWP is part of the instrument approach, not the STAR - the STAR ends at the IAF. There is no ICAO charting requirment to have the FAWP on the STAR chart, and I have never ever heard of thus before - I assume it is a company 'thing'?

If it is an Ops Manual requirement, then it sounds as though you need company customised charts.

[LLLK]

The term FAWP was used to define the extent of the P-RNAV approval. You have approval to fly RNAV 1 (P-RNAV) up to but not past the FAWP. (These days the term FAWP has been replaced by the term FAF.)

There is no requirement for the STAR to end anywhere near the FAF. However, there are some States that publish STARs or Approach Transitions which end at the IF or FAF.

See EDDF Transition to Final Approach

As for RNAV/GPS SIDs - you can only fly them if you have GPS as a navigation sensor and are approved for Basic RNP 1 or RNAV 1 (P-RNAV)

[Denti]

As for pure GPS SIDs i would agree, however for P-RNAV SIDs or RNAV/GPS SIDs only the applicable RNAV ANP is required, not a GPS if you can achieve the ANP without it. We had all our 737 classics without GPS certified to P-RNAV and could fly everything down to RNP 0,5 legally with them, except for pure GPS-Procedures.

[LLLK]

We had all our 737 classics without GPS certified to P-RNAV and could fly everything down to RNP 0,5 legally with them, except for pure GPS-Procedures.

If the SID is charted as RNAV(GNSS) then the ANSP has not assessed the DME/DME coverage and has only protected the procedure for GNSS (GPS). I would call that a pure GPS procedure. If the ANSP has done a DME/DME assessment then the chart title should just be RNAV - no '/GPS' - and then the RNP<0.5 would apply.

[FE Hoppy]

I would recommend that almost everyone on this thread needs to do a Performance Based Nav course and read the ICAO PBN doc. The terms P-RNAV and B-RNAV and many others used in this thread have no relevance in China where they have adopted and are implementing PBN precisely as prescribed by ICAO.

If you want to fly RNAV1 or RNAV2 procedures you need to ask for them. If you ask for a radio nav based procedure in China that's exactly what you are expected to fly and if the navaid is out then you can't.

Not everywhere is surveyed to WGS84 yet which is why you cannot use an RNAV system to fly non RNAV procedures and when flying RNAV1 then you must only use GPS, DME/DME or DME/DME/IRS position solutions. VOR/DME updating is not allowed.

[alosaurus]

FE Hoppy... I also need to do a performance based nav course. Please can you advise how the WGS84 survey (which I have seen mentioned but don't really know what it is) will protect you (once fully completed) when flying an RNAV system with non RNAV procedures.

In the meantime will work on the management to get me on a course!

Thanks in advance

[FE Hoppy]

alosaurus,

In the simplest terms WGS84 is a grid system used by GPS based on the position of true north in 1984. Your GPS position is with reference to this grid.
Now imagine taking your chart and drawing the lat and long lines a little offset to the north and west. Your gps tells you you are N10W10. on your chart using the original grid there is a navaid at this position but because the GPS grid and the charts grid are not the same when you tune the navaid you find it is displace from your position by the difference between the two grids.
Any navaid based procedure will have you at the appropriate position because it's based on the grid used to define the navaids position and your position is referenced to the navaid.
If you try and use an RNAV system that is using GPS as it's position solution on a procedure based on a different grid and ground based navaids, you may well find yourself offset from where you should be. And this may put you somewhere unsafe.
Some aircrafts AFMs specify that GPS position updating is prohibited in areas which are not WGS84.
So you shouldn't fly a radio based procedure using only GPS based RNAV without using the navaid raw data to confirm your position unless (as is the case in many places) the local regulations allow.