Alternate aerodrome navaids

[Navajo King]

Been away from flying for a while so just have a couple of quick questions...

I'm flying a day IFR charter to an aerodrome which only has an NDB. My aircraft is only fitted with one ADF, therefore I need to nominate an alternate. Am i correct in saying that the alternate can not be another aerodrome with a single NDB (and no other aids)?

What about if the original destination has a GPS NPA and my aircraft is fitted with a TSO129 GPS, plus pilot qualified for the approach? Do I still need to nominate an alternate due to having only one ADF?

Any references for the above answers would be appreciated too.

Thanks
NK.

[Awnick]

just off the top of my head, i would think the alternate aerodrome would need to have 2 NDBs on the ground as you must be able to carry out an instrument approach if one of the ground stations were to fail.

and GPS cannot be considered in flight planning unless it is certified to TSO-145 (a) or 146 (a) so an alternate would be required because you only have 1 aid (the ADF) and IFR charter requires 2 either in the a/c or on the ground

Hope that helps.

[Awnick]

but was it correct twaddle ...

[ForkTailedDrKiller]

I'm flying a day IFR charter to an aerodrome which only has an NDB. My aircraft is only fitted with one ADF, therefore I need to nominate an alternate.

"a flight may be planned under the IFR by day to a destination aerodrome which is not served by a radio navigation aid without the requirement to provide for a suitable alternate aerodrome, provided that:

a. not more than SCT cloud is forecast below the final route segment LSALT plus 500 ft and forecast visibility at the destination aerodrome is not less than 8 km; and

b. the aircraft can be navigated to the destination aerodrome in accordance with General Flight Procedures, paragraph 5.1"

If the flight is to an aerodrome that only has an NDB, then that aerodrome is going to be in non-CTA ( I can't think of any aerodrome in CTA that only has an NDB), so

by my Jepp

"CHTR/AWK 5700kg or less MTOW in non-CTA - 1 system required - ADF or VOR or GNSS-C145/6a"

if your destination aerodrome was in CTA

"CHTR/AWK 5700kg or less MTOW in CTA - 2 systems required - ADF or VOR or DME or GPS (ie min TSO C129)"

What about if the original destination has a GPS NPA and my aircraft is fitted with a TSO129 GPS, plus pilot qualified for the approach? Do I still need to nominate an alternate due to having only one ADF?

Nope - see Jepp General Flight Procedures 5.11 Radio Navigation Systems

Dr

[RUMBEAR]

Awnick,

The Dr forgot to answer your last question. Yes complete and incorrect twaddle. I cant think of any airports in Australia that are equipped with dual NDB ground stations. I think you are referring to the alternate requirement that says two ADF fitted in the aircraft capable of using a single NDB ground station. Also last time I flew in Aus (which was a couple of years ago) we flight planned and used a TSO-C129 certified GPS for primary means enroute navigation and RNAV GNSS approaches. Unless things have changed (in last 2 years) GPS equipment cannot be used to safisfy any alternate criteria though.

So to answer the original question, alternate is required unless the weather is better than quoted by the Dr.

[jumpuFOKKERjump]

I can't think of any aerodrome in CTA that only has an NDB

...besides Moorabbin, Jandakot, Bankstown, Parafield...

Back to PA31_King's first question, AIP ENR 1-1 73.1.2:
When a flight is required to provide for an alternate aerodrome, any aerodrome may be so nominated for that flight provided:
a. it is suitable as a destination for that flight; and
b. is not an aerodrome for which that flight would require to provide for an alternate aerodrome.

You only need the alternate if you will be IFR on the last leg, as the good Dr. says, (ENR 1-1 73.3). The aerodrome with only an NDB can't be an alternate, UNLESS you can get there without proceeding IFR on the last leg.

[aviation_enthus]

In simple terms...

Flying charter under IFR you need to be able to suffer the loss of one airborne aid and still be able to carry out an approach.

Unless...

The weather is:
Cloud: no more than SCT below 500ft above route LSALT
Vis: not less than 8km

Otherwise you need an aid!

Simple rule:
Two in the air - one on the ground
One of each in the air - One of each on the ground

[Peter Fanelli]

I can't think of any aerodrome in CTA that only has an NDB

...besides Moorabbin, Jandakot, Bankstown, Parafield...

Parafield and Jandakot also both have VOR approaches available based on Adelaide and Perth located aids.

[insertnamehere]

may help to think about it from the point of view that the alternate itself cannot require an alternate.

There is one exception, and thats regarding the PAL and a responsible person, but that's another story!