2 x TSO145/6 GPS require an alternate?

[Lumps]

For CHTR does two independent TSO 145/6 GPS units in an aircraft cover it as two independent and separate airborne aids, meaning if you were flying to an airport with an RNAV approach only, are you required to nominate an alternate?

AIP ENR 1.1 58.3.1: two independent and separate radio navigation systems, each of which is capable of using the aid

Does this exclude GNSS? Further down it seems to define a radio navigation aid as a VOR or NDB exclusively, is this really true in this day and age? What is GNSS if not radio navigation? I've tried digging around in CAOs but can't find anything illuminating.

58.3 Radio Navigation Aids
58.3.1 A flight which is planned to be conducted under the IFR on the last
route segment to its destination must provide for a suitable alter- nate aerodrome, unless:
a. for Regular Public Transport and Charter operations:
(1) the destination is served by a radio navigation aid for which an instrument approach procedure has been pre- scribed and the aircraft is fitted with two independent and separate radio navigation systems, each of which is capable of using the aid; or
(2) the destination is served by two radio navigation aids for which independent and separate instrument approach procedures have been prescribed and the aircraft is fitted with independent and separate radio navigation systems capable of using these aids;
b. for Aerial Work and Private operations:
the destination is served by a radio navigation aid for which an instrument approach procedure has been prescribed and the aircraft is fitted with the radio navigation system capable of using the aid.

------------

58.3.3 A flight permitted to operate under the VFR at night (see ENR 1.2, Section 1.1) must provide an alternate aerodrome within one (1) hour flight time of the destination unless:
a. the destination is served by a radio navigation aid (NDB/VOR)
and the aircraft is fitted with the appropriate radio navigation system capable of using the aid, or

[Wally Mk2]

There's a CASA CAAP 179A-1 that outlines everything you need to know about GPS/GNSS inc Alt req's.
Reading the Reg's alone could be misinterpreted because as far as I understand the GPS is a satellite based nav system & not ground based as would be for NDB/VOR. But basically the TSO'd units as mentioned are suitable for use to an Alt if req'd.

Anyway read away 'till ya hearts content:ok:

Wmk2

[scavenger]

Does this exclude GNSS?

No. AIP GEN 1.5, para 8.5.5.3 page 16 specifically says GPS counts for alternate requirements in ENR 58.3. (I couldn't copy the text sorry)

The table in 8.5.5.4 page 18 says the same thing in notes 3 and 4 in the middle column.

Must have TSO 145a, 146a or 196 unit (2 for CHTR and RPT) and the airservices prediction of RAIM to avoid a navaid alternate.

Warning on airservices RAIM prediction page says you should use the unit in flight to check RAIM as well, despite the attitude of many I fly with.

[Lumps]

Thanks, that seems to be that then. Except for the AIP I find the rest of Australian aviation publications (CAAP, CASR, CAO etc) particularly hard to find what your looking for on the web. Keep ending up on CommLaw site which is a weird mismatch that makes my head spin. Is it just me?

[Capn Bloggs]

AIP GEN 1.5, para 8.5.5.3 page 16 specifically says GPS counts for alternate requirements in ENR 58.3. (I couldn't copy the text sorry)

The table in 8.5.5.4 page 18 says the same thing in notes 3 and 4 in the middle column.
At the risk of slight thread drift, the two references are contradictory, because the first includes TSO 129 gear, but the second permits only 145/146 gear to remove the need for an alternate.

Ironically, both pages were revised on the same day. :confused:

Keep ending up on CommLaw site which is a weird mismatch that makes my head spin. Is it just me?
No. Administratively neat for some office-worker, but very difficult to keep up with for us at the front end.

[scavenger]

At the risk of slight thread drift, the two references are contradictory, because the first includes TSO 129 gear, but the second permits only 145/146 gear to remove the need for an alternate.

Not really because 129 gear can remove the alternate requirement for NVFR, which ENR 53.8 refers to as well as IFR alternate requirements.

[601]

CAO

The CAOs are to old and senile to know what GNSS is.

[Agent86]

As Wally said, the CAAP lays it out (legislation by advisory information)

See Page 49 of the pdf here (http://www.casa.gov.au/wcmswr/_assets/main/download/caaps/ops/179a_1.pdf) for a logic diagram.

[Capn Bloggs]

So, do we all agree that this statement is not correct (my bolding) in relation to ENR 58.3.1 and 2 (ie excluding Night VFR):

GEN 1.5 8.5.5.3
RNAV(GNSS) non precision approach (or RNP APCH) capability using a TSO C129a, C145a, C146a or C196 receiver and the valid prediction of approach availability from the Airservices Australia RAIM prediction service may be used to satisfy the requirements set out in ENR 1.1 para 58.3

[Lumps]

So, do we all agree that this statement is not correct (my bolding) in relation to ENR 58.3.1 and 2 (ie excluding Night VFR):

Yes!

Thanks for everyone that answered btw, this post has come in very handy over 1 year later.