Rnp and Ils, Vor approaches

[9.G]

galaxy flyer, true or not true depends entirely on OPS specs of the operator and state approval e.g. AIP. FAA does allow the nav aid to be u/s EU OPS doesn't, as simple as that.

[Denti]

@changer, the 737NG and 787 can do it all using the APProach mode, older 737 still have to use LNAV/VNAV, and of course if you are equipped to fly other than ILS precision approaches, for example GLS (standard for the last 5 years on our 737s) or MLS, there is no LOC/GS to connect to in the first place. It's called IAN and provides a FMC generated localiser and glide slope alike presentation for NPA approaches.

galaxy flyer, true or not true depends entirely on OPS specs of the operator and state approval e.g. AIP. FAA does allow the nav aid to be u/s EU OPS doesn't, as simple as that.

True, however EU OPS does not require that it is displayed and monitored. Might be a special approval since we used that allready back when JAR-OPS was current and it is now grandfathered in, but i seriously doubt that.

[9.G]

Denti, let's keep it simple as usual. Whatever is written on the plate shall determine the type of approach one will fly, hope we all agree so far.
Unless you fly a GPS (DME/DME if approved) raw data monitoring is required due to following:

1.8 APPROACH OPERATIONS UTILIZING BARO-VNAV EQUIPMENT

1.8.1 Baro-VNAV equipment can be applied to two different approach and landing operations:

a.
Approach and landing operations with the vertical guidance. In this case, the use of a VNAV system such as baro-VNAV is required. When baro-VNAV is used, the lateral navigation guidance is based on the RNP APCH and RNP AR APCH navigation specifications.

b.
Non-precision approach and landing operations. In this case, the use of a baro-VNAV system is not required but auxiliary to facilitate the CDFA technique as described in 1.7.2. This means that advisory VNAV guidance is being overlaid on a non-precision approach. The lateral navigation guidance is predicated on the navigation system designated on the chart.

Furthermore Airbus FM says following:

Approach Procedure with GPS PRIMARY

Before starting the approach, check that GPS PRIMARY is available on both MCDU.
If GPS PRIMARY LOST indication appears on ND during the approach, discontinue the approach unless :
‐ GPS is not required and navigation accuracy is confirmed against the radio navaid raw data, or
‐ For RNAV approach not requiring GPS, HIGH accuracy is displayed on MCDU with the appropriate RNP value.
‐ If GPS PRIMARY is lost on only one FMGC, the approach can be continued using AP/FD associated to the other FMGC.

Once again all depends on which approach you're shooting.

[9.G]

the reference made earlier to the US specs was referring to the GPS approaches as well

GPS Approach Procedures

As the production of stand-alone GPS approaches has progressed, many of the original overlay approaches have been replaced with stand-alone procedures specifically designed for use by GPS systems. The title of the remaining GPS overlay procedures has been revised on the approach chart to “or GPS” (e.g., “VOR or GPS RWY 24,” “GPS RWY 24,” or “RNAV (GPS) RWY 24”). During these GPS approaches, underlying ground-based NAVAIDs are not required to be operational and associated aircraft avionics need not be installed, operational, turned on or monitored (monitoring of the underlying approach is suggested when equipment is available and functional). Existing overlay approaches may be requested using the GPS title, such as “GPS RWY 24” for the VOR or GPS RWY 24.

NOTE: Any required alternate airport must have an approved instrument approach procedure other than GPS that is anticipated to be operational and available at the estimated time of arrival and which the aircraft is equipped to fly.

Once again it's the title in the right corner determining the primary means of navigation. OR GPS means can be flown as GPS stand alone approach

[Denti]

And apparently it depends on aircraft type. I posted above the relevant excerpt from a EU-OPS approved 737 FCOM which states quite clearly "raw data monitoring is not required".

Of course the approach is predicated on the relevant nav aid, but that doesn't necessarily mean you have to check it if there are other means of compliance which assure you stay within the limits of the relevant approach.

In terms of RNP monitoring boeing makes it very easy, it directly displays your ANP and RNP as navigation performance scales on the PFD and on the legs page on the CDU. No need to care about GPS or RAIM, as long as your ANP is within limits everything is fine.

[aristoclis]

Galaxy Flyer,

Phase III. Phase III began April 28, 1994, when the first instrument approach procedures were published to include “or GPS” in the title of the published approach procedure. Neither the aircraft traditional avionics nor the underlying ground station navaid(s) need be installed, operational, or monitored to fly the nonprecision approaches at the destination airport. For GPS systems that do not use RAIM for integrity, the ground-based navaid(s) and the airborne avionics that provide the equivalent integrity must be installed and operating during the approach. For any required alternate airport, the traditional ground-based and airborne navigational equipment that defines the instrument approach procedure and route to the alternate must be installed and operational.

This statement in bold is true as long as you have the "or GPS" on the plate.

AIM 1-32 paragraph 3 (2004)
The GPS Approach overlay Program is an authorization for pilots to use GPS avionics under IFR for flying designated nonprecision instrument approach procedures, except LOC, LDA and simplified directional facility (SDF) procedures. These procedures are now identified by the name of the procedure and “or GPS” (eg., VOR/DME or GPS RWY 15). Other previous types of overlays have either been converted to this format or replaced with stand-alone procedures. Only approaches contained in the current onboard navigation database are authorized. The navigation database may contain information about nonoverlay approach procedures that is intended to be used to enhance position orientation, generally by providing a map, while flying these approaches using conventional NAVAIDS. This approach information should not be confused with GPS overlay approach (see the receiver operating manual, AFM, or AFM supplement for details on how to identify these approaches in the navigation database.

Glad to here if something has changed in the US since then.

I am sure your airplanes are capable of doing many many things, but this is not the issue here.

Again I would be very glad to know which eu countries permit to fly a conventional VOR/DME approach when the radionavaid is unserviceable...

[9.G]

excerpt from 777 FCTM:

Raw Data Monitoring Requirements
During localizer-based approaches; LOC, LOC-BC, LDA, SDF, and IGS, applicable raw data must be monitored throughout the approach.
During non-localizer based approaches where the FMC is used for course or path tracking (VOR, TACAN, NDB, RNAV, GPS etc.), monitoring raw data is recommended, if available. Although continuous monitoring of raw data during approaches is not required, ground based navigation aid(s) should be checked for correct navigation no later than final approach.

Airbus:

VOR, VOR/DME, NDB or NDB/DME approach procedures may be performed, in NAV, or NAV and FINAL APP mode, provided AP or FD is used, and : GPS PRIMARY is available.
In this case, the reference navaid may be unserviceable, or the airborne radio equipment may be inoperative, or not installed, provided operational approval is obtained.

Without GPS PRIMARY :
The reference navaid and the corresponding airborne equipment is serviceable, tuned, and monitored during the approach, or the radio navaid coverage supports the RNP value, specified for the approach procedure, and an operational approval is obtained.

For GPS approach, GPS PRIMARY must be available.

Once again, I strongly suggest to check your part A for the operator's approval as a manufacturer recommendation doesn't imply operational approval.

Aristoclis, no matter EU OPS or AIM unless you fly a GPS approach or one of those OR GPS approaches monitoring of a raw data is required as it constitutes primary navigation means.

[FE Hoppy]

@aterpster

it was your quote:

1. RNAV IAPs that are not RNP AR APRCH, are nonetheless performance based, as implied in the ICAO title you state

that I'm not convinced by.

In the ICAO title I stated there are no approaches named "RNAV". All approaches are RNP.

That's not to say that RNP isn't a type of "area navigation" specification which uses performance as the basis for procedural design.

Semantics I know, but as a simpleton I need as much clarity as I can get. I certainly didn’t mean to cause offence.

[ImbracableCrunk]

the 737NG and 787 can do it all using the APProach mode, older 737 still have to use LNAV/VNAV, and of course if you are equipped to fly other than ILS precision approaches, for example GLS (standard for the last 5 years on our 737s) or MLS, there is no LOC/GS to connect to in the first place. It's called IAN and provides a FMC generated localiser and glide slope alike presentation for NPA approaches.

Whoa. You do LNAV approaches with APP mode in the 737NG?

From my current FCOM:

The approach mode arms AFDS to capture and track localizer and glideslope and can be engaged for dual or single autopilot operation.

One VHF NAV receiver must be tuned to an ILS frequency before approach mode can be engaged. With one VHF NAV receiver tuned, onside AFDS is enabled for guidance and operation.

Do you have a reference?

[engfireleft]

engfireleft


Quote:
If you are flying an NDB or VOR approach then you must have the radio tuned and displayed as your primary reference.
As I said, that is NOT true. One, with FAA approval, can do so with the proper equipment. There is no requirement on a Global or Challenger (ProLine 4 or 21) to tune, display or monitor the underlaying navaid. Obviously, you must have and use a current database, have the crew training, and have the correct annunciations. There is no RNP associated with the underlying approach, so no need for a specified RNP. We just need to have APPR annunciation, indicating proper RAIM calculations and, at least, 1 nm scaling.

With 2,000 hours in these types, I understand what navigation sources are being used or not. It is a matter of regulatory approval. Here is the relevant part of AC 90-94


Quote:
Phase III. Phase III began April 28, 1994, when the first instrument approach procedures were published to include “or GPS” in the title of the published approach procedure. Neither the aircraft traditional avionics nor the underlying ground station navaid(s) need be installed, operational, or monitored to fly the nonprecision approaches at the destination airport. For GPS systems that do not use RAIM for integrity, the ground-based navaid(s) and the airborne avionics that provide the equivalent integrity must be installed and operating during the approach. For any required alternate airport, the traditional ground-based and airborne navigational equipment that defines the instrument approach procedure and route to the alternate must be installed and operational.
It is OBE, but does apply for systems approved under it.


GF

If you don't have the VOR tuned you are not flying a VOR approach. If you don't have the ILS tuned you are not flying an ILS approach. If you are flying an approach using the FMS as primary guidance you are flying an RNAV approach. Your quote from the AC even says so (read the bolded sentence, if you did it back then you are flying a GPS approach, not VOR). If for instance the title of the approach was "VOR RWY 25" you could not do the approach if the VOR was not functioning. Why not? Because it didn't say "or GPS" in the title.

But even that is out of date because they are not called GPS approaches anymore although some plates may still have that in the title. According to the ICAO PBN manual they aren't even called RNAV approaches anymore, but almost all of the plates still say RNAV (in Canada overlays have (GNSS) in the title). It takes a while for naming nomenclature to make its way through the system.

Another thing I'm detecting here is too much reliance on aircraft FCOM's and FCTM's to tell the crew what they can and cannot do. If the aircraft says it will do something that doesn't mean you can from a regulatory standpoint, and vice versa. If the aircraft FMS displays a specific RNP during certain phases of flight, that doesn't mean that's the RNP that is actually required. You will notice that virtually all aircraft have the ability to input different RNP values by the crew.

One example of what I mean is GPS equipped Airbus. The RNP will automatically decrement down to 0.3 nm, but only if the approach selected from the database is titled "GPS". It won't if the approach is titled "RNAV" even though you still need 0.3. So the pilot has to select it manually.

PBN is a rapidly evolving discipline and it is impossible for a single country to keep everything up to date which is why you still have "GPS" approaches around even though they aren't officially called that anymore. When you bring different countries into the mix it is a hundred times worse than herding cats.

[Denti]

Do you have a reference?

Of course:

Airplanes with IAN are capable of using the MCP APP switch to execute instrument approaches based on flight path guidance from the navigation radios, the FMC, or a combination of both. All IAN approaches provide the functions, indications and alerting features similar to an ILS approach. Although non-ILS approaches using LNAV and VNAV can still be performed, IAN is normally used in place of LNAV and VNAV because of improved approach displays, alerts and standardized procedures.

IAN approach types:
• RNAV
• GPS
• VOR approach
• NDB approach
• LOC, LOC-BC, LDA or similar approaches.

Note: IAN annunciations are not displayed on the standby ADI or ISFD.

For LOC based approaches the localizer has to be tuned, however if the localizer is identical to an ILS you have to select G/S off on the INIT REF page or when selecting the approach. For all other approaches you have to make sure not to tune any ILS/LOC frequency, but there is no required nav aid setting (company recommends to tune the relevant nav aid, but again, it is not required).

IAN is limited to single channel autopilot usage and CAT I minima (there will be an auto-callout "AUTOPILOT" at 100ft AGL to remind the pilots to disconnect the AP), however the APProach mode works for GLS as well which is capable of autoland and automatic rollout to CAT IIIb minima (although only certified for CAT I currently) both for both engines and CAT IIIa with automatic rollout for OEI same as ILS, but different to ILS curved approaches and approaches with different descent angles during different parts of the approaches are possible.

[9.G]

to finalize the subject here is the reference from FLIGHT PROCEDURES (DOC 8168) - GENERAL PRINCIPLES Extracted from ICAO Document 8168, Volume I - Fifth Edition — Flight Procedures, PROCEDURES FOR AIR NAVIGATION SERVICES — AIRCRAFT OPERATIONS, herein known as PANS-OPS.

USE OF FLIGHT MANAGEMENT SYSTEM (FMS)/AREA NAVIGATION (RNAV) EQUIPMENT Where FMS/RNAV equipment is available, it may be used to fly conventional procedures provided:
a. the procedure is monitored using the basic display normally associated with that procedure; and
b. the tolerances for flight using raw data on the basic display are complied with.

The conclusive answer is obvious.

[Topper80]

so make me clear:

VOR, VOR/DME, NDB or NDB/DME approach procedures may be performed with the FMS stored procedures, but the reference navaid must be serviceable and the airborne radio equipment must be operative and monitored... And ANP at the same time...

[FlightDetent]

No?. 9.g provides the full verse. You may adopt LNAV or so for conventional APCHs, as long as you monitor raw data navaid and stay within its limits.

No regulatory ANP value. Not needed.