We got a visit from Mercedes (because we are their general dealer) and they gave us a list of things we have to change… from the latest version of the star on the roof (€ 10.000) to tools, new colors in the showroom … and you better comply with those rules if you want to stay their dealer.
We hate it sometimes, but we also see the advantage. Of our 34 mechanics one part is always on training at Mercedes, which is VERY expensive, but necessary.
- Why do i get a Localizer indication on the PFD now and TERM (not ENR) when all i do is a normal “Direct” to my VFR home field? Is that WAAS specific? I guess it has to do with the WAAS precision, which obviously uses the same indicator as the localizer, but I have never seen that
Not sure about the localiser but the TERM is just describing the scaling of the CDI. I think +-1nm from memory.
- Maybe it was there before, but i have never seen it. When I away from the course (i switched to HDG to scud run home in 188 ft MSL…) … the CDI of the HSI turns yellow now? Is that a warning? WAAS specific?
Does it mean you are on magenta needles (GPS mode on the CDI) but in a non-GPS A/P mode? Something like that would be my guess.
It makes no difference in a DFC90/Avidyne Cirrus if you fly a GPS track in GPSS or NAV. 100 % the same and all more experienced pilots know that – because this way you do not have to change modes when you go from GPS enroute to a LOC or ILS approach which makes it easier.
For a long time i have not believed this. Until i found out that the DFC100 A/P, which is practically the same A/P but for the R9 version, does not HAVE a GPSS key. I then asked Avidyne. Answer: we ONLY put the GPSS key becasue the DFC90 is a retrofit for the S-TEC 55 and the pilots are “used to it”.
Then I asked an engieer who does seminars about DFC90 and Avidyne Avionics. His answer: “Forget the GPSS key, fly everything in NAV mode” of the A/P … and that’s what beeing taught on all COPA seminars now.
That means your office rent must be very cheap
It is 
It makes no difference in a DFC90/Avidyne Cirrus if you fly a GPS track in GPSS or NAV. 100 % the same and all more experienced pilots know that – because this way you do not have to change modes when you go from GPS enroute to a LOC or ILS approach which makes it easier.
This is going to sound like somebody in the Royal Institute of Navigation moaning about how GPS has made everybody stupid, but tracking a LOC is very different from tracking a GPS. For a start, the limits of coverage are different. You could set up a GPS track from Tehran to Kabul and intercept it from Shoreham, but not knowing the LOC reception limits is dangerous. How does the system handle false LOC signals? Does it switch from GPS to LOC at some specific intercept bearing at which the LOC signal “should” be in spec? You have to know which signal is being tracked at any time.
Maybe this explains why there are so many reports of these systems not intercepting a LOC if left to do it automatically. OTOH I suspect many pilots really don’t know how the box works…
Forget the GPSS key, fly everything in NAV mode
Without a detailed explanation that is just rubbish. Maybe they think the audience will never learn the knobs so they come up with these statements?
In traditional GA systems terminology, “NAV” is tracking a VOR or LOC, and GPSS is available only when tracking a GPS track. Hence the “old” (> 10 years ago) planes have a “GPS/NAV” switch, to select the HSI (and thus the autopilot) source. The two could certainly be merged; there is no reason why one could not have (predictive and air data compensated) roll steering when changing from a GPS track to the LOC, but obviously only GPS is capable of having multiple legs between which roll steering will be relevant.
fly everything in NAV mode” of the A/P
I find that disturbing also. Why “of the A/P”? The A/P should be merely following PFD indications. If the pilot doesn’t know the sources of those, he has no hope of knowing that the A/P is going to do next.
Peter, maybe you should inform yourself about the topic before you say it’s rubbish?
As I said, the DFC100 is the same autopilot but has no GPSS key. Avidyne, COPA specialists, and two electronics engineer who are very active in COPA – they all confirm that it makes no difference if you use NAV or GPSS. It will intecept any course and at any angle just as fine in NAv, and so on.
Why in NAV mode? There’s a NAV key on the A/P and a GPSS key. That’s why. And you can fly a GPS fligtplan, GPSS approacsh, everything, in NAV mode of the A/P.
Jason,
I’ll test it this afternoon and make some pictures. I know you had a Avidyne/DFC90 PA-46, so you should know.
@ Achim
that’s actually what I hop. That the shop can do that inofficially. I have no interst in goung after the seller (i already forgot him) and I am willing to come up for it if it can be done without Garmin. But if not_ He’ll take GPS back, or both. Now that I have WAAS antennas I could simply slide in two IFD440s :-) or simply buy other GNS430Ws
Why in NAV mode? There’s a NAV key on the A/P and a GPSS key. That’s why. And you can fly a GPS fligtplan, GPSS approacsh, everything, in NAV mode of the A/P.
Do they explain why there is a GPSS key, if they say it should not be used.
By “rubbish” I meant a rubbish statement.
It’s certainly true that if you have an integrated GPS+NAV box, that could be outputting ARINC429 turn commands for all navigation sources. But then why have a “GPSS” button because that is normally used in the same way.
you have to know which signal is being tracked at any time.
You know that by sleecting the NAV SOURCE on the PFD: GPS 1, GPS 2, VLOC 1, VLOC 2 ….
As i said. I asked one of the guys who actually DEVELOPED the DFC90. As ubelievable as it sounds he told e that they only put the GPSS key on the DFC90 becasue “pilots are used to it” and pointed out that the DFC100 doesn’t have that key, although it’s really the saem A/P
