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dhall_polo
11-25-2010, 09:01 PM
I have a regular trutrak d2vsgv a/p. The current manuals mostly just talk about the special afs version of the a/p. Currently my a/p is not wired to the af3500. Assuming no switch and the a/p is only be wired to the gns430w or the af3500, what are the tradeoffs? Please highlight what works versus what features require the special afs a/p head unit.

Thanks

Trevor Conroy
11-29-2010, 09:45 AM
With a standard DFII autopilot, you will get GPSS steering from the GNS-430 and coupled approaches. However, you will not be able to connect it directly to the EFIS to take advantage of it controlling the autopilot. Such features as HDG mode, ALT pre-select and hold, NAV modes (to track a GNS-430/530/480 and/or an SL-30) will not be available. If you already have a DFII, we recommend you consider sending it back to TT to be upgraded to an AF-PILOT. Being able to put it in EFIS mode to completely control it from the EFIS is quite advantageous.

dhall_polo
11-29-2010, 11:18 AM
Replaying this back:
I can connect the D2-VSGV to my 430W today and get GPSV (lat and vert) steering, but the "vert" from the 430W would only apply once I've intercepted ILS or WAAS glideslope on approach. I can do HDG mode on the AP itself. I cannot, however, take advantage of any of the Flight Director features of the AF3500, which includes things like hdg and alt bugs on the AF3500 itself. These features would extend vert guidance capability to all other segments of the flight, with the nice pre-select options. If I have that correct, this make sense.

What I'm curious about is the fact that the AF wiring diagrams have shown hooking up an autopilot selector switch for a while now. What would work without the AF-PILOT?

Trevor Conroy
11-29-2010, 11:54 AM
That is correct. To take advantage of the flight director features you would need an AF Pilot. The switch shown in the drawings is so you could still control the AP from the 430/530/480 if the EFIS were to go offline. It would essentially make it a straight DFII so you could still follow a GPSS course and do an approach, all without the EFIS. We incorporate the switch for redundancy.

amekler
11-29-2010, 06:30 PM
Trevor,
I have the trutrack VSVG and a 3500.(not the AF AP) What is the correct sequence on the EFIS to fly a ILS with the autopilot.(Should the autopilot be in GPSS and GPSV mode?) Specifically on intercepting the glide slope and following it? Also using a 430 in GPS mode the course needle sets itself but in ILS(VLOC) I have to enter the ILS Ccourse with the EFIS.
Alan

dhall_polo
11-30-2010, 08:13 AM
AFAIK, you don't pick GPSS or GPSV. You just pick nav mode (versus HDG mode) on the AP itself. Whether it is GPSS or GPSV is something the AP and 430W work out.

So it goes something like this: You load your flight plan, including procedures when called for, into the 430W.
- While enroute, the AP will follow your flight plan.
- While enroute, you can use the AP's ALT function directly for climb and descent rates.
- When you load an approach into the 430W, the 430W will automatically start sending vertical guidance to the AP when you intercept an ILS or LPV glideslope AND certain conditions are met, such as being on final within a dot of course and intercepting the glideslope from below (as per normal approach).
- If you go missed or get put into holds, you manage all this from the 430W.
- The only role of the AF3500 in this case for the approach is simply to display the needles, vert and lat, so you can watch how good of a pilot the AP is.

The neat stuff for the flight director, as I see it, is the Altitude pre-select that you can leverage when you get IFR clearances to new altitudes enroute, and to manage step downs on approaches, all the way to mins and back up to the MAP. Can't wait to try it out.

amekler
11-30-2010, 10:52 AM
Trevor,
When I first asked TT about doing this they said if I lost EFIS AP would not work and they recommended against it.
I can control heading/nav and alt pre select from the EFIS now.
Alan

Trevor Conroy
11-30-2010, 11:07 AM
Hi Alan, you can indeed control the autopilot directly from the control head should the EFIS go offline. That is the reason we have a toggle switch in our installation manual. It allows you to couple the GNS-430/530 directly to your autopilot as if it was a standard DFII.

amekler
11-30-2010, 12:54 PM
Trevor,
I have the switch to go either EFIS or GNS430. What I am I missing with my current set up?
Alan

Trevor Conroy
11-30-2010, 01:08 PM
Alan, you have a stock DFII, which will not couple with the EFIS for heading, course, or altitude pre-select. Only the AF-Pilot will do that.

gciampa
11-30-2010, 07:10 PM
Hey folks,

I have the AF-3500 (non-S) with the Tru-Trak DFII VSGV, ARINC adapter and did an AP coupled GPS LPV approach a few nights ago.

The procedure was as follows:
GNS-430W: loaded and activated the approach enroute as is normal in the GNS 430W
Enroute: EFIS Lat NAV, Vert ARM
Tru-TraK: GPSS, ALT enroute, descended and leveled off at the IAF using the ALT function of the AP

Then, when on the final approach course, outside the FAF, selected GPSV on the Tru-Trak

Vert ARM went to Vert NAV (although I don't recall if this was prior to enabling GPSV or when I intercepted the final approach course)


I'll do a coupled ILS approach within a few days and observe any differences in an ILS versus LPV;

amekler
12-01-2010, 02:32 AM
I have the same set up as you. I have been using the vert arm but using the EFIS for the ALT and leaving the TT on GPSS and GPSV.
Alan