Both TruTrak and Trio have STCs for the Cessna 177RG, so which to chose ?
Operation of the TruTrak looks complicated, or at least not totally obvious. Several Arrow owners (which for some obscure reason is not included on the GFC500 STC) on a PA28 forum I frequent go Trio for this reason.
Download the operation manuals and see for youself.
Arne wrote:
Download the operation manuals and see for youself.
Ouch! Poor user interface design. Also, it doesn’t have a heading mode!?
No HDG mode is really strange – that is about the single most used mode in IFR flight.
I wonder if anyone knows the answer to post #20 – the approval basis?
Peter wrote:
No HDG mode is really strange – that is about the single most used mode in IFR flight.
It has a TRK mode instead. I really don’t see the point of a TRK mode when you also have a GNSS mode — which is has.
Traditional IFR is done using
I have never come across a feature which flies a track. It doesn’t appear to have any use. I wonder if this product was designed by someone who flies IFR (rather than by someone who flies VFR with a GPS)?
Peter wrote:
I have never come across a feature which flies a track. It doesn’t appear to have any use. I wonder if this product was designed by someone who flies IFR (rather than by someone who flies VFR with a GPS)?
A non-intercepting track-only autopilot is not unusual. The Century 1 and S-Tec 20/30/40/50 all operate in this way. You have to fly the aircraft onto the desired track (deviation bar centred) and point the aircraft typically within +/- 15 degrees of the desired track and then engage Nav mode (works equally for VOR/ILS or GPS). The autopilot will then keep the deviation bar centred and aircraft on track. They’re not perfect in this mode – some struggle with cross-wind correction and turbulance, but do reasonably well. Adding a GPSS roll-steering converter and flying GPS in that mode is far better.
wigglyamp wrote:
A non-intercepting track-only autopilot is not unusual. The Century 1 and S-Tec 20/30/40/50 all operate in this way. You have to fly the aircraft onto the desired track (deviation bar centred) and point the aircraft typically within +/- 15 degrees of the desired track and then engage Nav mode (works equally for VOR/ILS or GPS). The autopilot will then keep the deviation bar centred and aircraft on track.What you describe is an A/P that follows a track in the sense of a line over the ground defined by a VOR/ILS or GPS waypoint(s). That’s not what the TruTrak TRK mode does. It works like a HDG mode, but instead of keeping the nose pointed in a particular direction, it keeps the aircraft moving in a particular direction relative to the ground.
Airbus started to have a TRK mode with the A320. You are able to change from HDG-V/S to TRK/FPA (Flight Path Angle). This mode was faciliated to ease NPAs, but I am not aware of any other manufacturer implementing it.
That sounds like the OBS mode which every IFR GPS has. You set up a waypoint and a radial which passes through it and you can intercept and fly that track.
The majority of IR holders don’t use that mode because they don’t know what it does 
It is great for flying navaid approaches e.g. NDB approaches, or DIY approaches. It is also great for flying an ILS, as a reference for where you can expect to see the LOC.
Except in this case you don’t need to load a waypoint…
