RNP-1 v Rnav-1

[A360]

Hi all,


On the A320, Rnav-1 SID/STAR can be done w/o having GPS. but what about RNP-1 STAR/SID? Is a GPS a requirement for such SID/STAR? I could not find an answer in the ICAO PBN manual


Thanks

[Dan Winterland]

It depends on your authority's clearance, and you should require FMGC1A or FMGC2 with the latest MMR standard. As the difference between RNAV and RNP is that RNAV is radar monitored and RNP is self monitoring, you need to be in GPS Primary. So Yes.

However, you shouldn't be doing RNP without authorisation - they are AR (Authorisation required) procedures and you should at least have them explained in your Ops Manual.

[md-100]

RNAV systems use navigation signals from various ground and space-based NAVAIDs. Then they are able to define any location on the map in terms of latitude and longitude and display it as a waypoint. The airborne RNAV computer determines the present airplane position and calculates bearing and distance to or from any waypoint.

While conventional routes are paths between ground NAVAIDs, RNAV routes use waypoints. In this way, RNAV overcomes a major limitation of conventional navigation techniques, which require ground NAVAIDs overflying.

Required Navigation Performance (RNP) is the latest advancement in terms of RNAV systems. It defines the navigation performance required to operate in a particular airspace or on a designated route. RNP-approved systems provide the same onboard capability to conduct traditional RNAV operations. However, RNP systems enable on-board navigation performance monitoring and alerting.

According to the ICAO PBN concept, the RNAV 1 and RNAV 2 navigation specifications were primarily developed for operations in radar environments. RNAV1 is a harmonization between the European Precision RNAV (P-RNAV) and the U.S. Type B RNAV definition, while RNAV 2 corresponds to the previous U.S. Type A RNAV definition.

The RNAV 1 specification is similar to the European P-RNAV specification. However, although RNAV 1 requires the same navigation accuracy as P-RNAV (±1 NM, Table 02), P-RNAV does not satisfy all the requirements of RNAV 1.

For example, in Europe, P-RNAV permits the use of VOR/DME as the only input for position determination in limited circumstances. For more information on the differences between RNAV 1 and P-RNAV, refer to ICAO Doc 9613, Volume II, Part B, Chapter 3, section 3.3.2.4.

The RNP 1 specification was originally published as Basic-RNP 1 to distinguish from a specification named Advanced-RNP 1, which was initially planned. But Advanced-RNP 1 evolved into Advanced-RNP and the prefix “Basic“ was no longer necessary. For this reason, ICAO adopted the term RNP 1 instead of Basic-RNP 1. Existing approvals granted under the original nomenclature remain valid.

RNP 1 allows the development of routes to connect Enroute and terminal airspaces with no or limited ATS surveillance and with low to medium density traffic.

The RNP 1 specification relies on GNSS. Some RNAV systems based on DME/DME are also able to achieve the RNP 1 accuracy. However, RNP 1 is primarily intended for environments where the DME infrastructure is not able to support DME/DME area navigation with the required performance.

[divinehover]

This is a cut n paste from the PBN Manual Ch 'Implementing RNP1'

Note: For RNP procedures, the RNP system may only use DME updating when authorized by the State. The manufacturer should identify any operating constraints (e.g., manual inhibit of DME) in order for a given aircraft to comply with this requirement.

So yes you can fly RNP 1 without GPS, if authorised.

[ACMS]

Request radar vectors.......:}

[Microburst2002]

PBN was made so that you could meet the criteria no matter what devices you use, but the truth is that for the most important specifications there is mandatory equipment required: the GPS.

They have been playing with the Future Air Navigation Systems and the RNP, lately the PBN, for years and years, and the future is here and it is still a quite incoherent mess.

[hawk37]

I realize this is an old thread, however I was interesting in looking at an rnp 1 or rnp2 arrival or departure in the US or Europe?

Much talk here in this thread about RNP1, but I can't seem to find any actual plates.

Or is rnp1 or 2 terminal procedures still too new?

I'm talking rnp here, not rnav

Nobody flying them?

Hawk

[reynoldsno1]

Queenstown, NZ has RNP1 STARs & SIDs

[hawk37]

thanks Reynoldsno1, I do see the Queenstown New Zealand departures requiring RNP1, for example the

RNAV( RNP )ANPOV ONE ALFA DEPARTURE

Interesting that the chart says "Navigation requirement: RNP 1" at the top in large letters, yet in the text description further down in smaller writing says

"Requires RNP 0.30 or lower to METUX"

Metux is the 7th waypoint in the departure, so despite the "RNP 1" requirement, it actually .3 or less!!

Hawk.

[Judd]

Question. You are conducting an NDB approach of which the final approach track coincides with an ILS final approach. The purpose of the trip which is in a simulator, is to demonstrate competency during an IPC on an NDB approach. The NDB approach is in the FMC data place. The aircraft is not equipped with GPS.

One school of thought is that LNAV is legal to be used with vertical guidance using published chart DME v height for the descent path. An eye is kept on the NDB RMI tracking to ensure the tracking is within lateral limits of plus or minus five degrees tolerance.


The aircraft is equipped with two VHF Navigation sets that may be used for DME read-outs from a VOR on the airport. There is a DME hold facility. One DME can be placed in AUTO mode allowing position updates while the second DME is used for the published profile descent.

LNAV is then used for the main tracking aid. From observation this is reasonably accurate thus ensuring the ADF readings are within published tolerances. The Regulator's Manual states over-lay approaches are not permitted for the purposes of an IPC.


The questions arises as to the integrity of a flight test that requires the pilot to demonstrate competence at flying an NDB approach within stated tolerance by using NDB bearings. Does use of LNAV for final approach tracking necessarily prove his competence at flying an NDB approach - or - should the approach be solely flown using ADF needles and DME with LNAV switched off?