This raw VOR inside GPS is probably not applicable today at least in UK & EU due to fix substitution and PBN airspace specs
It would be odd that one is now allowed to substitute VOR with GPS (fix substitution in NCO or CAP1926), however, to use GPS you need to have raw VOR capability inside GPS?
I am talking about VOR-VOR en-route navigation (GPS alone can’t be used on FAS segment of VOR approach)
Ibra wrote:
What is the difference between suitable as primary navigation? suitable as alternate mean of navigation? and suitable as substitute mean of navigation?
A substitute means of navigation means that GPS may be used instead of VOR/DME/NDB and the underlying ground facility does not have to be operational and the aircraft does not have to be equipped with the conventional avionics.
An alternate means of navigation means that GPS may be used for navigation, but the underlying ground facility has to be operational and the aircraft has to be equipped with the conventional avionics.
From the US AIM 1−2−3. Use of Suitable Area Navigation (RNAV) Systems on Conventional Procedures and Routes, a. Discussion.:
1. Use of a suitable RNAV system as a Substitute Means of Navigation when a Very−High Frequency (VHF) Omni−directional Range (VOR), Distance Measuring Equipment (DME), Tactical Air Navigation (TACAN), VOR/TACAN (VORTAC), VOR/DME, Non−directional Beacon (NDB), or compass locator facility including locator outer marker and locator middle marker is out−of−service (that is, the navigation aid (NAVAID) information is not available); an aircraft is not equipped with an Automatic Direction Finder (ADF) or DME; or the installed ADF or DME on an aircraft is not operational. For example, if equipped with a suitable RNAV system, a pilot may hold over an out−of−service NDB.
2. Use of a suitable RNAV system as an Alternate Means of Navigation when a VOR, DME, VORTAC, VOR/DME, TACAN, NDB, or compass locator facility including locator outer marker and locator middle marker is operational and the respective aircraft is equipped with operational navigation equipment that is compatible with conventional navaids. For example, if equipped with a suitable RNAV system, a pilot may fly a procedure or route based on operational VOR using that RNAV system without monitoring the VOR.
From the very title of TSO C129a, it is Supplemental Navigation equipment:
TSO-C129a, Airborne Supplemental Navigation Equipment Using the Global Positioning System (GPS)
RTCA DO-208 is the technical specification for TSO-C129 and includes this definition and comment:
Supplemental Air Navigation System – An approved navigation system that can be used in controlled airspace of the National Airspace System in conjunction with a sole means navigation system.
The major difference between a sole means navigation system and a supplemental navigation system is that a sole means navigation system must continue to provide the capability for navigation with a satisfactory degree of accuracy, integrity and availability after a partial system failure without reversion to an alternative sole means system. If a failure is indicated while using a supplemental navigation system, that system can revert to a sole means navigation system. The GPS availability and integrity affect the capability of GPS to meet sole means navigation system requirements. This is particularly true because GPS provides wide area coverage whereas VOR/DME offers distributed system redundancy. As an example, a GPS measurement signal failure (although detected (integrity) reduces or eliminates the GPS navigation capability over a wide area whereas a single VOR/DME failure affects a small area if it has any effect at all.
From the US AIM 1−1−18. Wide Area Augmentation System (WAAS), c. General Requirements:
9. Unlike TSO−C129 avionics, which were certified as a supplement to other means of navigation, WAAS avionics are evaluated without reliance on other navigation systems. As such, installation of WAAS avionics does not require the aircraft to have other equipment appropriate to the route to be flown.
Thanks for the explanations & references !
Ibra wrote:
It would be odd that one is now allowed to substitute VOR with GPS (fix substitution in NCO or CAP1926), however, to use GPS you need to have raw VOR capability inside GPS?
The aircraft has to be equipped with a VOR receiver for IFR use, if the GPS is TSO C129a which is only approved as supplemental navigation, A VOR can be a stand alone or integrated into the same navigator.
I don’t think CAA & EASA went granular on 129 GPS vs 146 GPS? ATS RNAV5 routes can be flown using any IFR GPS without working VOR on ground & aircraft
There are some stuff here and there about radar/dme in controlled airspace, vor required at night, primary vs secondary navigation, backup for failure, checking notams/raim but AFAIK nothing in NCO/ANO laws though?
Having 2×VOR, GPS, DME, ADF while being on radar is nice to have for IFR…non-W G1000 alone is legally enough 
I don’t see how a supplemental system can be used anywhere without a VOR. I seriously doubt if the CAA/EASA are more tolerant than the FAA.
This thread has become totally diffused.
It started with a 1999 POH page saying a GNS430 is not legal for IFR. This is definitely BS. That sort of thing was typical in that era.
Then it moved to both historical and current stuff.
In Europe, most airspace above FL095 is “BRNAV” (or whatever it is now called) and the only means of compliance for flight there is
and for private flying (now called “NCO”) there is today no requirement for a backup. Exceptions exist e.g. that infamous STC for installing two GNS boxes, which EASA would not approve unless a (3rd) COM radio was installed.
It appears that the US still requires a VOR-capable backup, if a pre-WAAS navigator is the only one.
OT posts moved to a previous thread on the general topic.
Peter
I have to agree with you, the POH page was from an age when many in the industry did not understand the regulations, I sat next to two CAA Opps inspectors at an instructors seminar and one of them stood up and stated that GPS was for Supplementary info only , I then stood up and asked him how come I had just flown from Germany in a Four engine turboprop that was using GPS to comply with the BRNAV regulations ?
During the early days of IFR capable GPS units I kept the certification of the King KLN89B I fitted well away from the operations side of the CAA and had no silly restrictions, as things formalised a flight manual supplement was required, as the installation met the requirements for both BRNAV & NP approaches I got a FM supplement for my aircraft ( thanks to a bit of horse trading with wigglyamp ).
A_and_C wrote:
I sat next to two CAA Opps inspectors at an instructors seminar and one of them stood up and stated that GPS was for Supplementary info only ,
TSO C129 was and still is only a supplementary navigation method, which simply means you must have another navigation system not based on GPS installed. It can be used for IFR navigation, but only if the aircraft is equipped with other navigation means. For TSO C145/146 GPS navigators are approved as sole means of IFR navigation and are not a supplementary. Don’t read anymore into it than what supplementary means. It does not mean you can’t navigate IFR using GPS, it simply means you need other stuff installed.
