It’s not dubious but common practice. Normal and safe. It only means that there’s a GPS procedure for the track of the radio based non-precision approach. An airline captain who “doesn’t like” that has no idea about today’s navigation.
Flyer59 wrote:
It only means that there’s a GPS procedure for the track of the radio based non-precision approach
OK, but what does that mean? Is it a real GPS procedure, or just a “faked” NDB procedure using GPS? I’m just trying to understand what he reacted to.
It simply means that you set up the approach as usual on the ADF / VOR / DME, and also load the procedure on the GPS.
The track is displayed on the GPS display, and you can cross check your instruments with the GPS track.
If you fly an traditional approach and the instruments deviate from what the GPS shows, the instruments are leading.
This is what I was teached on day one of my IR training.
The above is different from a GPS approach (RNAV / LPV / you name it) where the GPS is the primary source for navigation.
lenthamen wrote:
If you fly an traditional approach and the instruments deviate from what the GPS shows, the instruments are leading.
I’d say the opposite. If GPS and ADF disagree, I surely with the GPS. Having an ADF and tuning it is just an anachronism to keep the regulator happy but actually following the ADF needle would be a clear sign of brain injury…
achimha wrote:
If GPS and ADF disagree, I surely with the GPS.
I would say: If GPS and ADF (or any two navaids working in parallel for the sake of redundancy) disagree, then I discontinue the approach and sort out my problem before commencing another one. What other reason could there be for getting data from a different source? Just wisecracking, sorry…
LeSving wrote:
So you are saying you are right, and a 20k hour senior pilot with 10 different ratings are wrong?
That’s exactly what he is saying. And he is right. A 20k pilot has a lot of flight experience, but that doesn’t mean they know everything.
achimha wrote:
If GPS and ADF disagree, I surely with the GPS
he didn´t say what he is doing, he said what his training said ;-).
what_next wrote:
I would say: If GPS and ADF (or any two navaids working in parallel for the sake of redundancy) disagree, then I discontinue the approach and sort out my problem before commencing another one. What other reason could there be for getting data from a different source?I agree!
A lot of confusion arises from differences in terminology, and lack of knowledge of GPS GA avionics.
Airliners fly using an FMS (flight management system), and it is general practice to fly NDB approaches using the FMS while monitoring the primary aid. Their FMS are multi-sensor, and in the past were primarily driven by an inertial navigation system, with the position being updated using DME/DME navigation. More recently, position updates are also made using GPS.
What many airline pilots don’t realise is that even the humble GNS430 has many of the functions of an FMS, albeit a single-sensor one.
Airborne_Again wrote:
A 20k pilot has a lot of flight experience, but that doesn’t mean they know everything.
Well, frankly? After that many years of PFC twice a year, 20k flight hours short or medium haul… He should.
If he has a point, he should make it in a nice way, and with arguments to back up his claims. Otherwise he should shut up.
Credentials are like a pretty girl. Her looks make you want to know her, but if she speaks nonsense, the magic is soon gone. 
