Thursday 12 September 2019

Flying the G1000 - a Six-Pack Pilot's Initiation

Getting Started

My plane is not flying at the moment, for reasons I won't go into. Instead I have a good deal with a local flying club, allowing me to fly any of their aircraft subject to a checkout. They have several recent fixed-gear Cessna 182s, which make a reasonable substitute for my retractable, turbo 1980 TR182.

Most of them are new enough to have a Garmin G1000 panel instead of the traditional six-pack of mechanically driven "steam gauges" like my own plane. They do also have some older steam-gauge 182s, and I've flown quite a bit in one of them, but it seemed a good opportunity to learn some new technology.

I started by looking at the manual, readily available online. It runs to over 500 pages, making it pretty much impossible just to sit and read from end to end. It struck me how similar it is to the familiar old Garmin GNS530, which I fitted to my plane when I bought it 17 years ago. I have over 1000 hours of flying with it now, so I hoped the transition to the G1000 would be straightforward. It also includes a very sophisticated autopilot, the GFC700, which has all the features you'd find in an airliner (well, except Cat III autoland) - vertical navigation, coupled approaches and so on.

G1000 in a Diamond DA40, on the way back to Palo Alto
A G1000 installation has two screens. The one in front of the pilot is called the Primary Flight Display (PFD) and replaces a normal six-pack of mechanical instruments. The one to the right is called the Multi Function Display (MFD) and contains all sorts of other things, including the moving map, flight plan and engine instruments. They are both covered in knobs and buttons, about 40 of them, which mostly do the same thing on each panel - but not always.

Flying the Simulator

Fortunately the club also has a G1000 flight simulator, made by Precision Flight Controls. It has a panel like a G1000-equipped 172, plus an X-plane based simulator with an instructor station that lets you set up weather conditions, create failures, position the aircraft and various other things. I quickly got myself set up on this, with the help of a friendly instructor.

The first challenge was flying the simulator. It seems hyper-sensitive, unlike a real 182 which is extremely stable. It took me an hour or so to be able to "fly" it smoothly and achieve decent approaches, with the G1000 serving just as a simple glass panel replicating the traditional attitude indicator and HSI. It's very hard to land, and although that's not really necessary for learning the G1000 it does seem like something you should be able to do. Every landing is "good" in the sense that you can always walk away from it, and even use the simulator again, but at first several of them turned into simulated crashes requiring a reset at the instructor station. Once I could get the plane stopped on the runway I decided that was good enough. It's hard to get any real feeling for how high you are above the runway, something which comes surprisingly easily when flying a real aircraft. On my one and only flight in a wartime B-25 bomber I landed it smoothly even though the sight-picture is very different from anything else I've flown.

My first couple of sessions with the simulator brought several moments of severe frustration of the "How the ***** do you do that?" variety. A big advantage of an old fashioned panel, where each instrument stands by itself, is that you have a pretty good idea which buttons to try pressing even if you're not sure. For example, my panel has a GTX-345 transponder which includes a bunch of timers. Even if you have no idea how to get to the flight timer, there aren't too many things to try. With the G1000, the function could be anywhere in dozens of nested menus and soft-buttons. The flight timer is a case in point. It's there, but buried in one of the 'aux' pages - and certainly not accessed through the 'timer' soft-button, which would be much too easy.

Another example is the minimum fuel setting. It's nice to be able to set this, so you can get a warning if you reach it. In a 182 I never plan to land with less than 20 gallons. That's pretty conservative, enough for 90 minutes of flying, but with tanks that hold 88 usable gallons it's easy to do, and reduces the chances of becoming the subject of a feature article in the NTSB Reporter. There's a whole sub-menu for dealing with fuel management, allowing you to enter the actual amount of fuel in the tanks, and so it's obviously on that page. Wrong. It's under a sub-sub-menu of the Map setup page. There is some kind of logic to that, because all it does is to show a ring on the map where you will reach fuel minimums. But it certainly isn't intuitive.

Operating the simulator by myself was interesting. You could just position yourself at the start of the runway, then take off and fly just like the real thing. But it would waste a lot of time climbing and getting to the start of the approach. One nice thing about the sim is that you can position the airplane anywhere you want, for example just outside the initial approach fix. But this takes some acrobatics. If you just take a stationary airplane and position it at altitude, it instantly enters a power-off dive. That's recoverable but not really necessary.

In the end the routine I developed was to take off normally and set the autopilot to climb on a fixed heading. The next step is to leap over to the instructor station and position the aircraft at the altitude and location where you want it. But this disconnects the autopilot, so now you have to leap back to the pilot station and re-engage it, being careful to set up the same altitude as the one the sim thinks it's at. After a while it becomes routine, but there are lots of ways to mess it up. For example, before setting position, it's a good idea to think about terrain. Once I didn't, and leaping into the pilot seat was disconcerted to see the scenery a lot closer than it should be, shortly before ploughing into the trees. I had set the position of the airplane in the hills, without first setting the altitude to something that would put me above them.

Another good thing about the sim is that you can set the weather conditions. As an instrument pilot you practice under the "hood" - actually a pair of glasses adapted so you can only see down to the panel. That does a reasonable job of seeing nothing at all, as when you are in a cloud, but there is no way to simulate very poor visibility. An ILS or LPV approach can typically be flown with less than one mile, and without a sim it's pretty much impossible to know what that feels like unless you get lucky (or maybe unlucky) with the weather. Old-fashioned non-precision approaches are particularly hard. I tried the VOR 13 into Salinas, with minimums of 500 feet and one mile. You reach MDA and see... nothing at all, ploughing on through the murk, until just before the MAP you can faintly make out some runway lights. It's a great exercise but I wouldn't be very happy to do it for real. An ILS - or LPV to a similarly equipped runway - seems a lot easier, even to lower minimums. I flew the RNAV 25 to Livermore, with minimums of 200 and a half. As you reach decision height the approach lights are right there, allowing a further descent to 100 feet - no peering through the murk hoping to see something.

Time to Go Flying

After several hours on the simulator and numerous approaches, it was time to go fly for real. We flew three approaches, entirely using the autopilot down to minimums. The G1000 was a pleasure to use, and certainly a lot less stressful than hand flying. It does all seem a bit like a video game though.

With that flight over, I was signed off to go fly by myself. We took the same airplane down to San Luis Obispo for a fish taco lunch at Cayucos and an apple-buying excursion at Gopher Glen, surely the finest apple farm in the country. It was a perfect VFR day with very modest winds aloft, an excellent opportunity to give the G1000 a workout with the reassurance that if ever things started to get tricky, it would be easy to take over and hand fly. The goal, from a flying point of view, was to get comfortable with the G1000, so I let the autopilot do all the flying. Well, almost all - of course I had to do the takeoffs and landings. That led to the uncomfortable discovery that the wheels on the fixed-gear 182 are an inch or two lower than on my retractable. It's not much, but it's the difference between a perfectly smooth landing and one that raises my wife's eyebrows.

Vertical Navigation (VNAV)

One thing I really wanted to try was the autopilot's VNAV (vertical navigation) feature. The idea is simple enough. Instead of telling it the climb or descent rate you want (VS mode) or the airspeed (FLC mode), you just tell it where you want to be at a certain altitude, and it figures the rest out for itself. If you are flying an instrument approach or standard arrival (STAR), the altitudes are built in and are displayed on the flight plan page beside each waypoint. For VFR flight, you can create a waypoint on the final leg to the airport, and create a "track offset" a given distance before, and set an altitude for that. For example, on my way to Palo Alto I set a waypoint 5 miles before the field with an altitude of 1500 feet. The G1000 figures out where it needs to start the descent to meet that, for a specified (but not normally changed) descent profile, e.g. 500 ft/min. As long as you press the right buttons at the right time, it will fly the descent all by itself, leaving you only to monitor the throttles.

Sounds good, except that the documentation for how to use the feature is terrifying. It runs for several pages in the manual, mainly telling you all the things that will make it refuse to do what you want and other things that can go wrong. For example, the altitude associated with a waypoint can be shown in four different ways: in blue or in white, and in a large or a small font. They all mean different things and woe betide you if you can't remember which means what. But after reading it a couple of times and trying it in the sim, I realised that normal operation is pretty simple.

The flight plan panel shows, among many other things, the time to the "top of descent" that has been calculated. As you fly along this gradually goes down, until eventually it gets to one minute. At that point the autopilot status line on the PFD changes. There are two things you have to do, assuming you're currently flying in altitude hold: first press the VNAV button, and then set the desired altitude to something less than the first target. If you're planning to land, it makes sense to set it to minimums for the approach. If you don't reduce the desired altitude, it doesn't descend. But assuming you do, one minute ticks by and then the nose drops, the annunciator changes to say VPTH, and down you go. If there are multiple step-downs (rare these days), it will level off between them but pick up the next one and keep on flying down them until the glideslope activates.

Flying Approaches

There is one more button to press before you land. Once VNAV is active and you have been cleared for the approach, you press the APR button which sets the system up to capture the glideslope. (And don't what I did once, fortunately in the sim, and press the AP button instead - which disables the autopilot. To my pleasant surprise, pressing it again simply re-enabled the autopilot and carried on where it had left off).

If you're used to a traditional HSI or CDI display, finding the glideslope on the G1000 is far from intuitive. Instead of a horizontal bar in the middle of the HSI, it appears as a magenta diamond to the left of the altitude tape. It took me a while to find it at first, though it's simple enough once you know. For a traditional ILS, it is active as soon as the physical glide slope signal is received. For a GPS approach (LNAV or LPV) it's a bit less obvious. It shows up at the first fix outside the FAF. It's the same for the 530W, and I remember a very frustrating moment flying the GPS into Palo Alto, first wondering why it wasn't there, and then wondering why it had suddenly shown up as I flew through the fix in question, ACHOZ.

The G1000 does a very nice job of flying the aircraft all the way down the approach to Decision Height - as long as you press the right buttons at the right time. Compared to hand-flying an ILS or LPV, it's very relaxing! You can set the DH or MDA, but once again it isn't obvious where. It's called "baro mins" (not sure why specifically "baro"), and it's found on... the timer inset, unlike the flight timer. If you do manage to figure out how to set it, a serious-sounding voice calls out "minimums!" at just the right time, so it's pretty useful.

I've had one chance to try the G1000 in actual IMC, luckily, and since it was flying around the Bay Area there was plenty of vectoring, course and altitude changes and everything else that ATC can do to make a flight more interesting. Everything worked perfectly. We flew the ILS into Santa Rosa, in perfect VMC, with the pleasure of watching it keep the runway on the nose down to DH. On the way back we were in actual as we were vectored to the GPS into Palo Alto, including an initial VNAV section. I let it fly all the way down to DH, 460 feet (not currently permitted in IMC due to the Google construction, but we were already in VMC).

Odds and Ends

Since the G1000 knows all of indicated and true airspeed, as well as ground speed and current heading and track, it can figure out what the wind must be doing. It's very nice to see that displayed in a tiny inset on the PFD, giving an instant readout of headwind rather than trying to calculate it by mental arithmetic.

The PFD includes a Flight Director (FD), which is the airplane telling you how it thinks you ought to be flying it. The idea is simple: your current attitude is shown by a pair of yellow lines, which you should try and line up with the magenta lines of the FD. Airline pilots swear by them, and so does my friend who happened to get one in his plane. For myself, I don't really see the point. I'm happy for the plane to fly itself, the yellow and magenta lines always snuggled up together, but if I'm hand flying then I don't really need it. It reminds me of the annoying indicators on stick-shift cars telling you that it thinks you should change gear. At least you can turn the FD off, though it's easy enough to ignore it.

The MFD normally shows a large map, showing you where are relative to the scenery, in much better detail than the 530. It's a nice feature although you can always look out of the window, in VMC anyway. It is good to see where other aircraft are (thanks to ADS-B) relative to the scenery - it is surprisingly hard to see them even when in theory you know where they are. The map also includes terrain warnings - if it's red, don't go there. It's good while you're in the air though a bit dazzling when you're taxiing, since naturally everything is red then. You can turn it off though it's a good idea to remember to turn it back on again, especially at night or in IMC.


I've enjoyed learning and flying the G1000, and I'll miss it when I go back to my own 1980 panel, especially the very capable GFC700 autopilot.

When I started I thought, how different can it be from the good old Garmin 530? In many ways it's very similar, but remembering which buttons to push when is very different and significantly harder because there are just so many of them.

For someone who flies regularly and can stay current with where everything is and which button to push when, it is really an excellent system. I would worry about it though for the typical PPL flying an hour or two per month - it would be just too easy to need some feature and blank completely on how to get to it.