I've seen some published but have never been asked to fly one.
Some offer just a single path from the end of the enroute segment to the IAF, so it looks just like a normal RNAV STAR, albeit made very complicated. Some of them (LOWW is one) fill the whole plate...
Some of the transitions (can't find one right now but have seen them) offer say 5 alternative routes from the enroute terminating waypoint to the IAP IAF. Presumably the intention in those is to enable ATC to assign you the one they want at short notice, to achieve a specific total track distance i.e. a time delay, so they get both a procedural approach and traffic spacing at the same time, without having to vector you.
All the ones I have seen are at radar airports anyway, so are they actually operated?
To reduce communication and workload. They are coming more into vogue in the US. We have RNAV ODP (Obstacle Departure Procedures) starting to show up, particularly in mountainous areas where ground based Navaids are sparce. For us to fly the RNAV SID, STAR, or ODP (they have RNAV in the title), the aircraft has to have a GPS capable to fly RNP 1. Most of the older GPS units don't qualify (example the KLN94), but the GNS430/530 and the WAAS versions do. Here in the US, there is a directive to only use a feeder route if it adds a significant operational advantage for joining the approach. This tends to limit the number of variations or transitions.
Yes, but they are just a SID/STARs using RNAV. I flew an RNAV departure out of EDDK last week. No different from a "normal" SID other than using waypoints instead of headings, VORs and radials ie much easier to use.
In the US, RNAV SIDS and STARS require the GPS have RNP 1 capability to maintain containment that matches the obstacle protection. Is that not true in the Europe?
Yes, it is true. But I mean assuming you have equipment capable, I don't see them as a big deal.
AIUI - you need an IFR GPS installation which is approved for RNAV SIDs/STARs.
This requires, firstly, an LoA from the manufacturer. For some unknown reason, Honeywell
never did the letter, and
while they include the individual RNAV SID/STAR waypoints in the box, they did not include the RNAV procedures in the database
One pilot I was in contact with some years ago managed to get stuff from a Honeywell insider which (partly) showed how the database is encoded, and it was claimed the reason was they could not fit them in...
It might be a big deal if a KLN94 or similar vintage GPS was being used to fly the procedure. Here in the US, we have to use a ICAO flightplan and include the supporting equipment codes in order to be assigned a RNAV SID, STAR, or ODP. Our coding is different than the rest of the world, we have to specifiy G and Z in field 10 and NAV/RNVA1D1E2 in field 18 to be assigned one. I assume in Europe one would need to include G and R in field 10 and PBN/D2 in field 18 (maybe O2 would also work).
Here in Europe, I am not aware of ATC ever being even aware of the equipment capability declared in the flight plan. So they are not basing any decisions on it.
A year or two ago I made some enquiries in a forum frequented by ATCOs and the only non-US instance of where ATC cared about the declared equipment was in Australia.
Similarly, the ATC or Eurocontrol system doesn't check if what you declare is correct or legal. Obviously they have no way to verify 8.33 (Y). But they also have no way to check your RNAV or PRNAV capability. RNAV is not verifiable anyway (they can't see your GPS AFMS) but PRNAV in theory could be, because the airframe-specific LOAs could be in some worldwide aircraft reg database - but there is no indication they check. I know for a fact that many people fly with PBN/D2 (or whatever the "full gold plated PRNAV" declaration is) and it is never queried.
Eurocontrol (the IFR flight plan processing agency) currently rejects flight plans if
Notwithstanding that a KLN94 is not legal for RNAV SIDs/STARs, why would a KLN94 not be accurate enough to control the plane laterally? It updates the lateral deviation analog output (going straight to the autopilot) continuously, even though it squirts out the NMEA data packet only every 1 sec or so (something which various people have declared is too slow for a roll steering converter).
And it is 100% legal for flying RNAV GPS approaches, which contain 90 degree fly-by turns, and the turn performance (about 80% down the page here) is excellent. This is the reason I think the non-support of RNAV is just Honeywell's stupidity and ignorance, more than a decade ago when they started washing their hands of the GA avionics business.
Peter,
The KLN94 doesn't support the leg type CF - Course to Fix. Although you can get the same effect by using the OBS mode, this is not permitted as it can't be loaded from the database. Because of this, the KLN94 is not approved for VOR substitution or for RNAV SID, STAR, ODP. Most of the GPS units of this vintage do not support the CF leg type and are also excluded. In the US, CF is not required to fly T or Q RNAV routes which are RNP 2 (same as airways) and don't use the CF leg. Also CF is not required to substitute for ADF or DME. Details can be found in AC 90-100A and in the associated spreadsheet that lists compliance by manufacturer and GPS model. Later models include this data in the AFMS, for example the Garmin GTN series.
NCYankee,
I still can't get my head around this, because a GPS approach is not RNP2. It is RNP0.3 (0.3nm full-scale on the HSI) after the FAF. If it was RNP2, most people would never find the runway.
One would also not fly a RNAV SID/STAR using the OBS mode. With the KLN94, one has the actual waypoints in the database. The legality (or lack of) hangs on the pilot not being allowed to use these waypoints in a flight plan and fly the RNAV procedure that way. For example, taking this SID, the waypoints ZH554, ZH558, etc are in the KLN94 database. Why did Honeywell include them?
My point is that somebody watching the plane on radar would never tell the difference between somebody doing that with a KLN94, and somebody doing that with "approved" kit.
