Dual GNS430 + KAP140 question

[BackPacker]

I'm regularly flying a fully airways-equipped DA-40, with dual GNS430, KAP140 autopilot, Mode S, ADF, the works. I'm only a PPL without IMC/IR, but I want to use this equipment to the fullest (I pay for it anyway) on my VFR flights. Got a couple of questions related to a flight I'm planning which will be a VOR-to-VOR flight crossing the Channel (COA-KOK-DVR-DET-OCK to be exact).

1. Having painstakenly inputted my flight plan (8 or so waypoints in total) in nav1, is there an easy way to copy it to nav2? The Garmin GNS430 simulator doesn't seem to have such a menu option but that sim only simulates one, not two GNS430s, so it might be hidden somewhere.
2. If I have my full plan in the GNS430, put the OBS in "GPS" mode and turn on the autopilot (in NAV mode), will the autopilot actually fly the whole route for me along all VORs or is there anything extra I need to do to achieve that? Any reason NOT to recommend this?
3. If I don't want to rely on the GPS function but actually fly VOR to VOR, with the OBS in "NAV" mode, what is the proper procedure to intercept the next radial upon arriving at a VOR? Obviously I can hand-fly the aircraft over the VOR while setting up the frequency and OBS for the next radial, or I can let the AP fly based on the heading bug. But how do the "pros" use an autopilot when going from one leg, over a VOR, to the next? And how do you properly do this if you hand-fly the aircraft?

Obviously I want to find this out now rather than in the air. Up there, I prefer to keep my eyes outside the cockpit. Particularly when crossing a popular waypoint such as a VOR.

[IO540]

I have a different GPS (KLN94) and a different autopilot (KFC225) so these are mainly general comments:

You can copy a flight plan from one GNS430 to another using a feature called "crossfill" but this requires that the two units have the same version of the Jeppesen database.

With an autopilot, one normally tracks a GPS (programmed with a route on which the waypoints are VORs or NDBs, if you wish) rather than a VOR, because the GPS track is much more accurate and does not suffer from loss of VOR reception which always happens when overhead or beyond a certain distance. At typical UK GA levels, many VORs are nor usable beyond say 20-30nm.

One then tunes in a VOR as a backup to the GPS, and keeps an eye on it.
Autopilot behaviour is avionics and installation specific but in general, for the Bendix-King autopilots, the simplest way to intercept and track is:

1) Fly the autopilot in the HDG mode (tracking the heading bug). The HSI course pointer is set to the track value.

2) Ensure that the HSI bar is at least 3 divisions deflected - this is normally a 3nm off-track error but the HSI sensitivity can be adjusted (when tracking a GPS) to 5nm, 1nm or 0.3nm full-scale and the last two obviously reduce the required minimum off-track error. However, the 0.3nm FS sensitivity is often difficult to use enroute due to stability problems and is reserved for GPS approaches where there is a smooth transition from 1nm to 0.3nm FS during the approach.

3) Fly a reasonable intercept to the track - not 90 degrees!

4) Press NAV - the AP should display "NAV ARM"

5) When the aircraft reaches the track, the AP should turn onto it nice and sharp, and track it through wind changes etc. Tracking of a GPS track is fairly precise; probably within a few tens of yards.

The NAV mode is good for flying long legs, or for the very minimum cockpit workload. However, the simple HDG mode (and aligning the aircraft track with the desired track; the magenta line) is perfectly OK and requires much less understanding of the equipment. These autopilots are pretty stupid; the NAV mode can do weird and unwanted things if you engage it with the HSI deflection below 3 divisions, causing ATC to wonder what you are up to, so if I am under an intensive ATC environment I usually fly in the plain HDG mode - it's no hardship to twiddle the heading bug every once in a while.

The NAV mode will track a VOR but it's a bit woolly because the track error increases with the distance, and you lose it when overhead anyway.

You can find the GNS430 pilot manual and a PC sim on the Garmin website, and the KAP140 manual should be on the Honeywell / Bendin-King website. I have the KAP140 installation manual (not available to the public) if you need it.

You need to find an instructor who knows this aircraft down to the last detail. I never found one who knew any of this stuff (when I was in your position a few years ago) and gradually worked it out. IMHO you need to fully understand everything in the panel.

I don't know if you have altitude capture but you need to remember that you can be at 3000ft, put 5000ft into the altitude preselect, and descend at -500fpm all the way into the ground, and no warning will ever be emitted by anything. In a similar way, you can descend at -1000fpm towards some level, with a corresponding low power setting (to keep the speed reasonable), and when the level is reached the aircraft will stall because the power setting was too low for level flight. That's why a proper understanding of these things is required.

[drauk]

Assuming the 430's are wired for it and they have the same database, hit FPL then Menu then select Crossfill and press enter, then enter again. This is assuming that they are not set to automatically crossfill, which is quite common. Personally I prefer not to crossfill automatically, because it allows you to play "what-if" scenarios with the second unit whilst using the first for navigation.

IO540's explanations assumed there is no GPSS (GPS steering) - if there is you can still follow his instructions but you also have some easier and thus better options open to you. Does it have it?

[BackPacker]

Thanks gents. I found the crossfill option in the Garmin sim but expectedly it is greyed out since the sim only simulates one GNS430.

IO540, the AP has altitude capturing but I'm just going to use it to maintain height. Not to intercept an altitude: too much hassle with throttle/trim etc. Might as well hand-fly the climb and descent.

Drauk, what is GPS Steering, if it does not mean "the autopilot will follow the FPL in the GPS"? I assume this DA-40 will have it, since the plane is used to fly coupled ILS approaches as well (not by me!). The only thing not connected to the AP is the rudder, throttle and trim.

Just another question: does anybody know if it's possible to program the Garmin and/or AP so that it will fly a standard 1 or 2 miles right of track? To avoid a head-on with somebody who flies VOR to VOR too by way of GPS and AP, and happens to select the same height? The quadrantical/semi-circular rule only starts at 3000 feet which is no good below the London TMA. I played with the Garmin sim and could not find any such setting.

[S-Works]

No you cant fly an offset. You still have to rely on the big sky theory and proper use of quarrantals and actually look out of the windows rather than staring at all of the gadgets..... After all with the AP on you have bugger all else to do!

GPS steering is a method by which GPS out put data is converted into steering commands that the autopilot can interpet. The GPS will plot an intercept so allow the AP to pre-empt turns.

Classic RNAV requires you to reset the AP over the waypoint after intercepting the track. All of the DA40's I have flown have GPSS steering as standard.

The GPSS steering model tends to be an add on to S-Tec autopilots. I have this function on my S-Tec and GNS430.

[IO540]

GPSS, also called "roll steering" varies in its implementation but basically it takes the data from the GPS (it doesn't work with a VOR) and drives the autopilot directly, faking the pilot twiddling the heading bug, and the turn rate is computed so as to get an accurate intercept onto the new track.

Obviously this is relevant only when you have a multi-leg route programmed in the GPS, or when flying a full GPS approach in the GPS database (not many of the latter in Europe, and none in the UK).

Without GPSS, the AP typically gets its signal from the HSI and will fly whatever the HSI bar deviation says. The AP also uses the HSI course pointer as the initial heading to fly. This means the pilot has the great hardship of having to wake up every 20 mins and rotate the course pointer to the new track - which is why I am not going to spend my money on GPSS....

Whereas with GPSS the HSI course pointer becomes redundant and you don't do any lateral guidance for the entire route... well in theory. In practice, one spends a lot of time flying directed headings, twiddling the heading bug, especially on airways flights... which is the #2 reason I am not getting GPSS ;)

[S-Works]

Ah come on you are just jealous I have a better gadget than you!! I can fly an entire route without twiddling anything accept the wrapper on my sandwiches...... :p ;)

[IO540]

I fly the plane while "in flight catering" passes me freshly peeled oranges, chocolate, juice, Lindors, approach plates, etc - no reason to be jealous of anybody ;)

[drauk]

The GNS 430W or 530W (i.e. the new WAAS models, or upgraded versions of the original) will fly parallel offsets.

Being able to fly an ILS with the AP doesn't indicate that the aircraft has GPSS. This only indicates that the AP can track the CDI, which the majority of them can do.

There are some advantages of GPSS over and above just following a whole GPS flight plan, though of course it's up to the person signing the cheques if it is worth it. GPSS will do a great job of flying an intercept, no matter what the wind might be doing and no matter the difference between your current track and the desired heading. Depending on the GPS unit, GPSS will also enter and fly a hold, or fly a DME-arc; doing these is of course possible without GPSS (or indeed without GPS at all) but it does require quite a bit of heading twiddling if you want to fly them on AP.

[IO540]

I also think that GPSS capabilities vary according to the GPS. I am pretty sure, for example, that installing GPSS with my KLN94 won't make the plane fly holds or DME arcs. One cannot even see these in the approaches database... I think the latest Garmins are a lot better.

A lot of autopilots can fly an ILS, including mine, down to 200ft. As drauk says this is nothing to do with GPSS which is a very rare feature.

I would see the biggest advantage of GPSS the ability to carry out a "smart" intercept of a GPS track, from a current position which is some way (but not too far) off that track. Without GPSS this can get quite messy; the actual track flown may not be bad but the intermediate heading changes can make ATC very worried about what the pilot is smoking... and this makes it tricky to transition from HDG mode to NAV mode while under a radar control service (which is most of the time, under IFR/airways).