Analogue dials vs digital screens?

ad-panelI’m asked a lot about the pro’s and con’s of digital flat screen ‘glass’ cockpits for the Foxbat and Vixxen aircraft. The quality and reliability of LSA/recreational digital instruments has improved immensely over the last 5 years and, although they are not inexpensive, they actually represent reasonable value for money – particularly when compared with their GA-certified counterparts.

Personally, I am a great one for old ‘steam’ gauges – easy to see in all lights, relatively simple and usually reliable. Although I must agree that reliability of the current crop of ‘glass’ cockpits is not an issue. And digital screens do have some big benefits – visual and audible warnings if/when any set parameter is exceeded; an almost infinite number of ways to customise the look of the information; a high degree of modularity – meaning you can add bits like a fuel computer or an autopilot at a relatively reasonable cost at a later time; and, last but not least, most digital panels have a datalogger which enables you to review flight and engine information from previous flights. This can be particularly useful – as we have found – when analysing ‘incidents’ and ‘accidents’ which the aircraft may have experienced.

However, a particular question has been raised a couple of times recently, by pilots/buyers with quite different aviation backgrounds – one, a very experienced airline pilot, the other a novice student pilot. The question was: ‘Do digital screens tend to focus the pilot inside the aircraft?’ And, I suppose by implication, that if they do, this is a bad thing, where sport and recreational flying is so much about what’s going on outside the aeroplane – ‘see and be seen’ and all that.

The point made by the airline pilot was that what’s going on outside a commercial jetliner is almost (but not always!) irrelevant. The screens provide all the data you could possibly need to negotiate the aircraft from wheels up on departure from airport A to wheels down at airport B. If such a pilot decides to buy an LSA with a digital panel they will, so it goes, be more likely to be looking at the screen a much higher proportion of the time than looking outside.

The point being made by the ab initio pilot was that while you’re learning, you can become transfixed by the figures on the screen. Let’s take digital speed readouts – eg a pilot manual approach speed of 57 knots  is something you have to concentrate on much more than a wavering analogue needle, which points somewhere (on average) between 55 and 60 knots. So you try to stick to the magic digital 57 knots to the exclusion of some outward attention.

It’s all a far cry from the days when a slip ball was the most prominent instrument in the aircraft, and the only compulsory gauges were a compass, an airspeed indicator and an altimeter. With maybe engine rpm and oil pressure if you were lucky!

So having heard these points of view from pilots from very different perspectives – what’s your view? Do digital screens tend to focus the pilot inside the aircraft, to the detriment of good external observation?

3 thoughts on “Analogue dials vs digital screens?

  1. Interesting question Peter. My own preference is steam gauges, plus panel mounted iPad. I also chose a GPS digital track and Artificial Horizon. I believe this gives me the best of both worlds. I found the AH/track useful recently when flying directly into the setting sun with no useful horizon in the haze and glare.

    Other than the aspects you mention, I believe the personal choice depends on how each individual perceives and uses information. My own brain struggles to absorb digital readout of speed and altitude. In hand flying we are generally more interested in trends than in absolute values anyway and in approximate rather than exact numbers. There is an old saying that goes “I would rather be approximately right than precisely wrong”. Perhaps this expresses the “big picture” awareness we want to cultivate ?


  2. From Warren Butler, A32 owner in New Zealand:
    I have always been a ‘stick and rudder’ pilot with eyes outside while flying. So much so that during one portion of my training, 30 years ago, my instructor decided to blank off the instruments for the entire lesson, just to prove that by having a good look outside, you really don’t need to rely so much on your instruments as what you would have thought. A few years ago I flew with a friend in his new Cirrus SR22 with a Garmin 1000 fitout and I must confess, I was totally blown away with the glass cockpit idea. During our 1 hour flight, he was so keen on showing me (during the flight) all the capabilities of the glass panel that we had a near-miss with a glider and tow-plane combination which was so easily prevented had we both been looking out as much as we should have. I recently bought a Dynon D2 pocket panel at Oshkosh and even with this tiny screen, I was pretty fixated and amazed by it just being there, so bright and so clear, constantly streaming out it’s high definition information. I shudder to think of my position had I opted for a full glass cockpit, but maybe that’s just me. I have an old iPad and recently downloaded the AvPlan EFB app with the annual paid subscription of around NZ80. I fitted it to the yolk stem of my Vixxen A32 so the iPad sits vertically between the horns with a Ram mount and this works really well for me. The reason that I am not fixated by this new screen is twofold: I have to look down by at least 40 degrees of tilt to see the iPad screen properly (bi-focal sunglasses are awesome!) and secondly, since I would often be referring to a paper chart en route anyway, the iPad takes the place of that. For non-cross country flying where constant reference to a chart or screen is not needed, I simply unclip the Ram mount and there I have my ‘steam gauge panel.’

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