Touch Screen, Stylus or Both

Touch Screen, Stylus or Both by Peter Cassidy
AirPlay Fourth Quarter 2011

Touch screen is invading our lives and the cockpit. It’s the new standard on tablet computers. It's also the primary interface for Garmin’s new GTN series of Nav/Coms and for Garmin's new aera 796 portable GPS. Is touch screen really the answer in the cockpit? What about the alternative, a stylus? Why not have both? The answer to these questions is not as simple as one might expect. In my experience, it all depends.

I’ve been flying with a tablet PC since 2005. I started with an M1400 Motion Computing tablet which had a stylus as a user interface, no touch screen. In 2010 I got an iPad for charts and in 2011 replaced my Motion tablet with an HP Slate 500. The iPad is touch screen only while the HP Slate has both touch screen and stylus.  Here’s how they worked for me from a user interface perspective.

Mounted or Handheld
Whether your tablet is fixed mounted or handheld is an important consideration. The tablet PCs I’m using are really too big to be fixed in place. I made a yoke mount for my Motion but movement of the 4 pound mass was a problem. Another reason for not mounting today’s tablets is screen glare. The screens most vendors use have a shiny surface that’s like a mirror. It’s not a problem indoors as there is enough display brightness to overcome the glare. Brightness in portable devices is primarily limited by battery capacity. The gold standard in a sunlit cockpit (e.g. Garmin G1000 or Aspen panel) is 1000 nits or more. Tablet displays put out significantly less, around 300 nits. Setting the display to maximum brightness is usually necessary but it really drains the internal battery. So tablets are handicapped when it comes to a sunlit cockpit. Moving your head around or shading the display with your hand or a chart is very awkward. My recommendation is to avoid fix mounting your tablet and find a convenient place to park it when not in use. Mine sits on my lap when not in use. As for running the screen at full brightness, you either suffer the shorter battery life or have it connected to aircraft power. My Motion tablet had limited battery at best so was always connected to an external power source. My HP Slate will run several hours on battery, but I keep it connected to external power anyway. I find it’s not necessary to use external power with my iPad. Several times I’ve flown 7 hours in a day and the iPad battery was only down to about 85 percent.

Apple Got Touch Screen Right
The stylus interface on my Motion tablet was a pleasant experience including actions that required a right-click operation. The only tedious part was inputting my flight plan route into WxWorx so it would overlay it on the NexRad data. The virtual keyboard was small and a long routing takes quite a bit of hunt and peck. But the process was reliable and got the job done. A key concern with any stylus is losing it, especially in flight. I always carried a spare, but never had the problem. I only recall dropping it twice on the floor and in each case it was easily retrieved. The Motion tablet provided a convenient storage slot for the stylus in the tablet case.

Apple’s touch screen implementation on the iPad is very good and is the only way to use enroute and sectional charts. Since all iPad applications are designed for touch screen use, the menus work well even for keyboard input. Note the stylus devices you can buy for the iPad are only a substitute for your finger and, in my experience, not particularly useful.

Where touch screen gets to be a problem is when you inadvertently touch the screen activating some random function. Mostly this is just an annoyance, but if you’re doing an approach and lose your approach plate, it’s serious. ForeFlight solved the approach plate problem by letting you lock the screen. This problem makes the argument for fix mounting your tablet and why Garmin’s new touch screen nav/com will be ok. The solution that works well with my iPad is, except during an approach, to always put it in standby mode before I set it on my lap. Startup is virtually instant and it helps save battery since I’m running the display at full brightness.

My HP Slate 500 uses both stylus and touch screen and this setup is not the best of both worlds. In fact, it’s a challenge. The Slate, like my Motion tablet, is Windows based and running applications that are not designed for touch screen. The touch screen implementation works well enough when the menus are large and the operation does not require a shift-click action. Touch screen tends complicate using the stylus as they sometimes interfere with each other. You can’t do without the stylus and touch screen works well enough that I resist disabling the capability. I also wish the Slate had a place in the tablet to park the stylus like the Motion does.

Unlike the iPad, I can’t put the Slate in standby mode inflight. My primary application on the Slate, WxWorx, must be kept running at all times to download the satellite weather data stream. The net result is I have to be very careful that I don’t inadvertently touch the screen while it’s lying on my lap. The Slate is small enough that I could mount it on my yoke, but display brightness is a problem in that location. The Slate display is as bright as my Motion tablet but not as bright as the iPad.

In my opinion, the Slate is a less than ideal tablet for the cockpit.  I’m expecting in-flight NexRad will soon be available on the iPad in which case the Slate will stay in my flight bag and serve and my “laptop” when I travel being smaller and lighter than the laptop I would otherwise carry.

It All Depends
Tablet PCs can be a genuine asset in the cockpit. They have enabled me to eliminate all paper charts. Remember the cockpit is a unique environment, so it’s important to spend serious time figuring out how your tablet will be used. As noted earlier, my tablets sit on my lap when not in use. However, I’ve flown aircraft where this would not be possible due to the lack of space between my lap and the yoke. It almost became a problem for me when I started using an Oregon Aero seat cushion. The 9” display on the iPad is great, but I can see where a smaller 7” device would be more manageable. While touch screen is by far the dominant input medium, there are stylus based solutions available like the HP Slate and Motion line of tablet PCs. I bought the Slate specifically because it was Windows based and would run my WxWorx application. Also, as good as the iPad is, it’s not a PC. Don’t plan on getting rid of your laptop for a while yet.