By Michael Gillmour 

Discussing avionics with pilots is like talking about which religion they belong to. There are a number of camps that most pilots fall into starting with ‘glass versus analogue’ and finishing with one brand versus another. When I reflect upon my recent aviation journey I find that there is a lot more to the selection of avionics than first meets the eye.

Flying for me started with movies like ‘The Battle of Britain’ where Spitfires soared across the sky chasing down German bombers at the height of the Blitz. What really entranced me about the movie were the shots from the cockpit where the instruments were clearly in view. For example, a spinning altimeter told the pilot that it was a time for a quick exit.

In the 80s I graduated from ‘The Battle of Britain' to the infamous Tom Cruise classic ‘Top Gun’. I was once again thrust into the exciting world of aviation while watching Viper and Maverick battle it out for supremacy. Goose’s exit courtesy of a flat spin and avionics going crazy was a particular highlight.
So what do these two movies have in common? Dials, lots of dials. There’s nothing quite like seeing the face of a passenger climbing aboard as they survey the mass of dials, buttons, levers and knobs before them.

Let’s face it, if you ever want impress a friend, family member or dare I say member of the opposite sex, do your pre-flight briefing like this. “No drinking, touching controls etc”, followed by, “and yes I actually know what all of these instruments do.” I can bet that you’ll get a nervous laugh followed by comments that can be summarised as, “I’m glad that you do!”

Fundamentally, what instruments do is create a separation between us and our passengers. The more instruments the better, after all, we’ve all spent a lot of time trying to understand the things so we need to get some level of satisfaction from our indoctrination into the ‘pilot priesthood’.

I remember climbing aboard an old Warrior for my first ever flight and staring at the multitude of instruments in front of me. It was all incredibly daunting. At the holding point I had an almost irresistible desire to quote from Star Wars by saying, “Red Five standing by”. I’m sure that the tower would have responded by saying, “Cut the chatter Red Five”.

So I’m told to look at an instrument called the ASI and, when it reaches about 65 knots, rotate. With complete confusion on my face I said, “Look at what and you want me to do what, when?” I think that I must have had a very sympathetic instructor as he responded by saying, “the ASI is the top left instrument with the red, white and green colours around a circle. When the needle displays 65 slowly pull back on the controls and we will get airborne.”

Thank goodness that he didn’t tell me anything about VNE and the red area as I think my brain would have exploded with everything that it was taking in. I just gathered that red was bad and 65 was a magic good number. So we raced down the runway (everything happens fast the first time) with my eyes simultaneously glued to both the runway and the ASI (I’m learning the lingo by now). At 65 I pulled gently back and we were airborne. There’s just nothing like that first time feeling!

Feeling pretty happy with myself for what I thought was a great take-off lasted for about as long as it took the instructor to point out to me another dial marked Altimeter. I’m not stupid so I can guess what that means (thank goodness that he didn’t tell me about setting the QNH earlier on) and at 500 feet we banked and kept on climbing out to the south-east. Luckily I knew where south-east was!

Levelling off at 2500 feet was a little bit of a challenge as the concept of a VSI was thrown in for good measure. “What the heck is a VSI?” I politely asked. You’re always polite to the instructor when you realise that the only way that you’ll survive your first flight is through their good graces. “The VSI is the Vertical Speed Indicator and when you are level it should read zero,” was the patient reply. I imagine that we’ve all done it. Chasing the VSI is almost like a game the first time you fly.

I sometimes wonder whether instructors have a perverse sense of humour watching a rookie chase the VSI up and down for a while prior to telling them about holding attitudes etc.

Next came the DG. I jumped in quickly when I heard yet another acronym and was quickly told that the DG is the Directional Gyro or in other words, “where you are going”. I’m glad that I wasn’t told at this stage about caging, aligning the DG with the magnet compass etc.

So by this time, I’d forgotten about the ASI and concentrated on the DG, VSI and Altimeter and it wasn’t long before all of them got out of kilter and the instructor gently set the controls right again. Flying lopsided isn’t a really pleasant experience so the Artificial Horizon (AH) and Turn and Balance were brought into play and I felt my brain expand in another order of magnitude. I momentarily realised that the level of expansion would be in direct proportion to the headache later that night.

It wasn’t long before I was scanning the instruments in a methodical pattern, one after the other, making sure that they were where they were supposed to be. It was helped greatly by the introduction of the ‘trim wheel’ – thank goodness! The one problem was that my head was staring at instruments and I completely forgot about the fact that I may be about to fly into the side of a mountain. Looking outside of the cockpit is always a good thing: there’s no point looking at the Altimeter to tell you that you are steady at 3000 feet if you plough into the side of a 4000 foot mountain.

So there I was on my very first flight developing a scan of the same basic instruments that I saw at the cinema in The Battle of Britain and Top Gun. The sheer pleasure of a little knowledge was intoxicating! My dream was becoming a reality. I was on my way to becoming a pilot.

As time flew by, and quite a few Warriors later, I had the opportunity to learn how all of the instruments worked (I also found out about the GPS) and further develop my instrument scanning techniques until finally I was awarded my PPL. Everything was great until I saw a notice advertising new planes for hire!

I admit it, I’m a sucker for new stuff so off I went to find out what a new Archer was like to fly. After hopping into the left hand seat I glanced up to see that my beloved instruments had been replaced by a ‘display’. Sure the cockpit dash was clean as a whistle but a big black rectangle was not nearly as impressive as a mass of dials.

Don’t get me wrong, I work with computers 12 hours each day but the impact of a glass cockpit after eight months of training was a little off-putting. I took a deep breath and, after a few checks, I looked for the key slot to start the engine only to discover that the venerable tried and true ‘turn the key to start the plane and test the magnetos’ had also been replaced by a couple of buttons. Hmmmfff! I think this aircraft is fast getting on my wrong side!

What was great was the fact that they’d left an old analogue ASI to the left of the glass screen so my old 65 knots was happily being displayed by a needle as we rotated off the runway. Thank goodness for that! The instructor and I headed out to the training area and he took me through the many features of the glass cockpit.

He openly related the fact that it took him a few hours to get used to everything but now he absolutely loved the flexibility and useability that the glass cockpit provides. I was dubious about his claims but endeavoured to keep an open mind.

It wasn’t long before the twin screen Avidyne flight management system combined with the dual Garmin 430s and autopilot won me over. Having all of the instruments summarised on one screen while I flicked between the flight plan and engine management on the other was nothing short of brilliant.

Engine management became a breeze with EGT (Exhaust Gas Temperature) information for each cylinder being graphically displayed so that the pilot can use the automated ‘lean assist’ system to lean back the mixture more accurately. Rate of fuel consumption, fuel remaining and time to fuel starvation all help the pilot manage the aircraft more wisely. The RPM, Oil Temp and Oil pressure gauges are clearly displayed as is the electrical positive/negative charge information. This last one is especially important in an electrically powered glass cockpit!

The flight instrumentation is what’s really great. RPM, VSI, DG, AH and Altimeter are all summarised on one clear screen directly in front of the pilot. The turn and balance took a little more getting used to as I tried to keep the two small triangles matched up in turns (I personally like the simplicity of the ball bearing in a trough slide). What I really enjoyed was the autopilot and the ease in which it is integrated into the main flight display for setting the altitude, VSI and heading bugs. It’s an absolute breeze to link either of the Garmin 430s into the autopilot for directional control.

I ended up flying the Archer from Moorabbin to the Gold Coast and back and loved every minute of it. What I enjoyed the most was that it removed a lot of the pilot workload so that I could concentrate on other things such as enjoying the trip. Trust me when I say that as soon as you start up and the screens come to life you will still get the appropriate mouth-gaping response from your passengers.

Despite all of the technology and the incredible ease of using the glass I still find myself staring at the analogue ASI and Altimeter on the left hand as soon as I enter the circuit. There is just something about those older instruments that seem to engender a sense of confidence and familiarity that is missing from my experiences to date in a pure glass cockpit.

I think that the only way that I’ll completely move away from analogue instrumentation is if I cover them up with a sheet of cardboard. I wouldn’t be surprised if, on finals, the cardboard ends up in the back seat!

There is one thing that should never be replaced and that’s good old common sense. Let me give you a quick example. Flying by GPS is easy – just make the picture of the little plane go on the line in the right direction and everything should be OK (assuming you’re watching your LSALT). In a flight earlier this year I had to make a diversion to a point that wasn’t easily accessible in my GPS. I looked down at my map, drew some lines and let dead reckoning do its own special sort of magic.

This brings up an important point. I’ve known pilots that have become so dependent upon their glass that they’ve forgotten how to navigate by hand. I have a rule and that is that the GPS is confirmed by my map and my map is confirmed by the ground. It’s a nice circle that makes me feel that little bit safer.

My recommendation is to enjoy technology but don’t blindly follow it. After all, would Luke Skywalker blindly follow R2D2’s directions? The whole point of Top Gun was that flying still needed the inspirational human input. What would Spitfire aces think of us all if we couldn’t get back to base without a GPS?

So which is better, analogue or glass? I believe it largely boils down to personal preference. For me, I love both and I’ll continue to use the technology available to confirm what the ground tells me is true.