Tuesday, April 01, 2008

Very Demanding

When users have trouble with a technology product, they often blame themselves instead of recognizing the problem is in the design of the product they are using. A popular assumption is "If only I were better trained, more diligent, or smarter then I wouldn't have a problem." Hardware and software designers are notorious for creating hard-to-use systems, though there are some notable exceptions. So extending an earlier post on G1000 enhancements I'd like to see, here is another list of improvements. After all, it's only software, right?

HSI, VOR, and Distance
While it is possible to acquire a G1000 installation with DME (and even an ADF), I've only seen such an installation in the Garmin G1000 simulator. In the G1000 installations I've flown, the only time you'll see a GPS-derived distance to a VOR is when that VOR is your current GPS waypoint or when you have the VOR tuned in and have a bearing pointer enabled for on the PFD. It sure would be nice to have the distance to a VOR automatically displayed somewhere on the PFD when the HSI is set to ... (gasp) ... a VOR instead of the GPS.

Engine Instrumentation
The engine indications on the Multi-Function Display (MFD) include Fuel flow, EGT and CHT. These are displayed as small, horizontal bar graphs that allow you to instantly see if the a gauge is not in the normal, green operating range. To access more detailed information, you must press the ENGINE softkey, then press then the  SYSTEM softkey or the LEAN softkey. While hiding complexity is generally a good user interface policy, I'd like to see a numerical fuel flow display in gallons per hours right next to the bar graph instead of having to go to the SYSTEM page to see it. There's plenty of room to show it and the additional visual clutter would be minimal.

PFD Ground Speed
Not showing ground speed near the TAS on the PFD is mind-numbingly dumb. Sure, ground speed is displayed the top of the MFD, but it's not in the pilot's primary field of view and you lose the display in reversionary mode. Ground speed can be a very important piece of information during an instrument approach, especially when performing a circle to land. While the PFD can display the wind speed and direction, the pilot shouldn't have to perform mental math during an instrument approach.

Bearing Pointers
I wish Garmin wouldn't bury the bearing pointer softkeys under the PFD softkey. By that I mean, always have BRG1 and BRG2 softkeys displayed at the top of the PFD's softkey hierarchy. If I had a dollar for every time I watched a pilot pause while they remembered how to access the bearing pointers ...

When you press the PROC button, there is a menu item called Activate Missed Approach, but it seldom seems to be selectable. In fact, reading the Garmin documentation for Cessna piston airframes (which contains several errors by the way), experimenting with the G1000 simulator and the actual units, it's not at all clear to me how this feature is supposed to work. Some G1000 installations have a TOGA (Takeoff/Go around) button for the autopilot, but Activate Missed Approach should be selectable any time an approach is active and the pilot needs to start the missed approach prior to reaching the missed approach point.

Here's just one example that occurs frequently during practice approaches to Sacramento Executive. The ILS is for runway 2, but runway 20 is almost always in use. While the tower will allow you pilots to fly a practice ILS to runway 2, they will always tell you "at minimums [sic], begin your missed approach, start your left turn prior to the end of the runway." In some cases, they'll tell you to start the missed approach even earlier.

The G1000 sees the MAP as a fly-over waypoint and once you fly over it, the unit will suspend waypoint sequencing and display a SUSP softkey. To start navigating on the missed approach course, you press SUSP (and change the HSI source back to GPS if you were flying a localizer). This means you have one to three button pushes to get the party started. Not ideal, but not too bad for single pilot operations.

If you must execute the missed approach prior to reaching the MAP, there is a lot more button pushing and knob twisting to do: Press FPL, press the small FMS knob, scroll to the appropriate leg in the missed approach procedure, press MENU, Activate Leg will be selected by default, press ENT two times (and change the HSI source back to GPS if you were flying a localizer). That's at least six steps during a critical phase of flight.

A more reasonable design would be to press PROC, scroll to Activate Missed Approach, and press ENT. Three button pushes instead of six or more. Even better would be a dedicated softkey that would appear on the PFD once the aircraft is inside the FAF on an approach.

If I worked for Garmin as a user interface consultant, I wonder how much my few last suggestions would be worth?

It would work something like this: Press the Direct button and a HOLD option would be displayed in the dialog that appears. Select the hold option and you'd see another dialog where you could enter the inbound course, the direction of turns, and an optional leg length. Then the G1000 would display the hold and prompt you on how to enter the hold, just like it does for holds contained in defined procedures.

Alternate Airport
The flight plan feature should implement the concept of an alternate airport. By default, anytime you load an approach or arrival procedure, the last airport in your flight plan is the default target. Currently you can edit or add waypoints to the flight plan after a missed approach. If you then clean up the flight plan by deleting the approach, you'll also delete anything you added after the missed approach. D'oh!

Garmin needs to implement a consistent scheme of indentation in the flight plan that clearly indicates waypoints that are associated with an approach (and will be deleted if the approach is deleted) and those that aren't. And if you enter multiple airports in your flight plan, pressing PROC and using Select Approach should provide you with a list of airports, based on what is in your flight plan, from which to select.

While the improvements I've suggested might not increase sales or impress shareholders, they are the right thing to do: A concept that many U.S. companies have lost sight of. Apparently the DoD recognizes that military personnel need an empathetic user interface to be more effective in stressful situations.


Gian-Paolo said...

Does the G1000 not automatically sequence the missed approach? (Despite having flown it a few times, I spend so much time flying the 480 that I am much more used to its little idiosyncrasies.)

This actually brings up an interesting point: I had an examiner comment that auto-sequencing of the missed was not legal behavior for a GPS. I made some argument compelling enough for the purposes of the conversation, but it seems like almost all GPS navigators won't do this. What's up with that?

John said...


No, the G1000 doesn't automatically sequence the missed approach. One would have to dig into the details of the TSO to which these units are designed to know for sure, but I suspect that the particular TSO requires that compliant units must not auto-sequence.

If this is the case, the TSO is lacking, in my opinion.


Anonymous said...

Re the DoD research you link to - I have been frustrated for many years by the 8-hour bottle-to-throttle rule. In the area of the country where I fly alcohol is as ordinary in our daily lives as coffee. It is such an accustomed part of life that I'm sure many of us would not be safe and effective flyers without it. But we fly in fear of ramp inspections or a troublemaking passenger with a keen sense of smell.

The technology DARPA is working on will surely free us from such concerns.

Cockpit systems that dynamically adapt to the individual pilot's cognitive state and performance would render unnecessary any enforcement of the 8 hour rule and, hopefully, the rule itself.

Your blog is a continual source of new information and ideas. It's a very valuable resource.

Thanks very much,