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Comment by vwcx | Hacker News Reader

I'd love to see similar testing conducted on "consumer" avionics boxes used in general aviation. Garmin has moved many of their units from fully-tactile buttons and knobs to touchscreens. This puts the onus on the pilot to fully master the system before entering a situation where you can't simply swipe/scroll your way to success. But using a touch screen in turbulence is nearly impossible; Garmin engineered a physical lip edge around the unit to hang onto to assist the pilot in stabilizing their finger.

There's a reason professional cockpits still largely eschew touchscreens when 250+ lives are at stake in the back.

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Same general trend on marine MFDs (basically the equivalent thing for boats). Models with knobs and buttons are the "premium" version, the default is typically just a giant touchscreen, which is not always great when you have wet hands.

The flat screens look good, and work great in calm situations, but in heavy seas and/or rain, they can be challenging at times. In my case the manufacturer (Raymarine) offers a wired remote control, so I have a knobs-n-buttons controller that is easy to reach and offers more direct control when needed.

It is for this reason that I have almost no Garmin avionics. I use Avidyne IFD GPS navigators which can do almost everything without using the touch screen. Even then I find the knobs are too easily turned to use very accurately in turbulence. To use them or the physical buttons in turbulence it is necessary to brace part of your hand or some fingers on the bezel, which is fine.

You can't use a touchscreen either when the cockpit fills with smoke.

Critical checklist items for a smoke filled cockpit have zero to do with avionics. And those items are practiced so much that any pilot should be able to handle smoke in cockpit with their eyes literally closed.

One could argue that the EGT and other secondary engine items could be hidden on secondary tabs on something like a G3X. Unless they own their own aircraft, I don't think most GA pilots can do much with their eyes closed.

Military pilots like the F-35 except for the touchscreen.

Which should kind of be a sign that for any important high-stakes task you should be using physical switches.

I predict in 10 years car manufacturers will bring back physical controls for some things (if not all).

One advantage physical controls have is that I can operate them sightless once I learn the layout. Most touchscreens I've seen in cars don't really have that feature because of the design of the system behind it (whole screens shift so returning to navigation isn't often simple, for example).

They should always be available on trucks. How can I turn on the heater with work gloves?

> I predict in 10 years car manufacturers will bring back physical controls for some things (if not all).

Maybe. If new cars are all self driving, I could see manufacturers keeping with touchscreens. It's safer to stay distracted longer if you're not in direct control of the vehicle.

Touchscreens are fine for performing car-related settings and tweaks.

Eventually if we get to actual full-self-driving they might go that route. That's way more than 10 years out though, I think. You're talking about a point where cars are able to not have a driver at all before that becomes a reasonable option IMO. That said, even elevators have buttons.

Exactly. Why can't we invent better manual controls that don't wear out as quickly, rather than switching entirely to something as problematic as a screen?

Or just design the manual controls to be easily replaceable.

Not hard to make an insertable switch component that snaps into a slot, and which can be removed and replaced in 10 seconds using a simple tool (or maybe no tool at all).

There is one practical argument that can be made against mechanical switches and buttons, and that is they will eventually fail from long-term use.

I've heard from friends in the aviation industry that pilots take extra care to put as little stress on switches and buttons as possible during normal use to prolong their service live.

The uninitiated might think why bother when a switch or button is dirt cheap, like several cents per unit cheap. And they would be right, the best kind of right. But when a switch/button does inevitably fail and needs to be replaced, the cost can easily come out to at least several hundred bucks between the labor, reinspections, and recertifications among other red tape that help ensure safety.

So if (if!) touchscreen interfaces are more durable and last longer, that is one fair argument in favor of them over mechanical switches and buttons.

> There is one practical argument that can be made against mechanical switches and buttons, and that is they will eventually fail from long-term use.

Before a touch interface fails from long-term use? I highly doubt it. Plus, a switch is a very easy component to replace. Touch screens can be but aren't always.

I think service life arguments are just poor effort. We well understand the appropriate average service life of a variety of switches. We don't understand the same for touchscreens, especially modern ones, as they haven't been around as long.

> Plus, a switch is a very easy component to replace.

From experience, in aviation nothing is simple or cheap to replace. Cheaper than replacing the entire Garmin unit though, yes.

> From experience, in aviation nothing is simple or cheap to replace.

Of course it is relative but I would still assume a switch in aviation is easier to replace than a touchscreen.

Also the touchscreen is more of a single point of failure. If the touchscreen fails, a whole range of systems and functions are affected. If on the other hand a single switch fails, only one function/system will be affected.

In my twenty years of driving I have had a single manual control fail in a vehicle and it cost less than $50 to get it fixed. I can’t imagine fixing anything on these modern cars being less than several hundred.

Do keep in mind I was talking about replacing failed switches in the context of commercial airliners. As far as ordinary cars are concerned, I agree those would be dirt cheap and easy affairs.

My experience after flying 737, MD80, A320, A330 and A340 is that nobody takes special care with cockpit buttons. They are work tools and treated as such.

The main ones (autopilot and flight controls), rarely fail if at all. The only ones failing from time to time are small switches for radio channel volume or cockpit light adjustments and system buttons at the overhead panel that are easy to replace by maintenance.

Touchscreens are not a good option for main controls due to poor visibility(dirt from fingers and sun reflections), hidden submenus, turbulence making hard to press the correct button…

The A350 and 787 are using trackball controlls for submenus and the onboard computers, not a touchscreen.

I must add that one place where we are using touchscreens is in the fly documentation. Most airlines use somekind of tablet, ipad or surface with apps for performance calculation, navigation charts, pdf manuals, etc… they are working mostly ok now a days and I’dont think you can substitute the touch screen with buttons for that without loosing a lot of functions.

The only people taking special care are the ones that pay for the maintenance.

>using a touch screen in turbulence is nearly impossible

This is one of the biggest reasons I dislike touch screens in cars, yeah. Tons of roads are more than turbulent enough to make it hard to hit buttons. Not having a physical edge / clicking / etc to tell you where you are and when you've done a thing means you have to use your eyes, which means disabling what is by far your biggest safety tool while driving.

I'd personally agree with this, but at the same time, I think aircraft like the F-35 have moved to touch displays instead of 4th gen MFDs (but works with gloves?), and didn't some of the SpaceX stuff have touchscreens. There must be some logic driving it in the defence/space industry...

> but works with gloves?

I bet Lockheed Martin sells a $50K glove that works with the F-35 touchscreens.

It's not that bad, however. In a car you need to be constantly aware of the road ahead of you. On a plane, you are not required to have your hands on the controls while on autopilot and you can pay attention to the screens, as well as operate them - there won't be any wildlife crossing ahead of you, not any red lights forcing you to brake.

And if the plane sees a threat it will warn you well before your human senses can so you can pay full attention to it (and the helmet-mounted displays). I assume the F-35 also has stick-mounted controls to operate in the helmet display.

Touchscreens are potentially very useful in a fighter (maps, general SA, designation etc), but not for everything and not in every situation. But just because you get a touchscreen doesn't mean you have to forfeit frame buttons with onscreen labels, HOTAS etc.

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