Thursday, March 13, 2008

G1000 Wishlist

Having spent several hundreds of hours providing instruction in G1000-equipped aircraft, I've identified some enhancements that could really improve the unit's usability. Some of the features (or were they bugs?) that I've mentioned in earlier posts have actually been addressed by Garmin in software upgrades. I'm not taking credit for inspiring these fixes, but maybe Garmin is listening? With that in mind ...

Disappearing Flight Plan Screen
In a recent software upgrade, Garmin fixed the G1000 behavior of jumping to the end of the flight plan any time you entered cursor mode on the Primary Flight Display (PFD) with the flight plan inset window. It's soooo nice to have it fixed. Now they need to fix the problem of the disappearing flight plan window.

Here's the setup. ATC tells you "When able, proceed direct Linden," so you press the FPL button and scroll with the big knob to select LIN.

Next, you press DIRECT.

Press ENT two times to confirm and you're in business. Unfortunately, the very act of proceeding direct to a waypoint makes the inset flight plan window disappear.

You can press FPL again, but why should you have to?

Hidden Baro Minima
In new G1000 units, you can set the minimum descent altitude or decision height for your approach. When you reach that altitude, you'll hear an aural annunciation "Minimums, Minimums!" (sic). This is a very cool feature, but guess where you access this feature? Press the TMR/REF (timer/reference) softkey and you'll see this inset window.

The TMR/REF window is quite the catch-all because this is where you can change the V-Speeds that are bugged on the speed tape, access a count-up timer, and set the minimum descent altitude. Forget for a moment that changing the bugged V-speed in most light GA aircraft is stupid. How is a pilot supposed to know that he or she can set their minimum descent altitude with this softkey? You need to memorize and remember it's location. If your minimum descent altitude is several thousand feet (like at South Lake Tahoe), you're going to have to twirl that little knob quite a bit to dial in the desired altitude. Actually, the altitude setting is probably optimized for the most frequently occurring altitudes and isn't so bad. Some of the other G1000 altitude inputs make you select one digit at a time, starting with tens of thousands of feet.

Inset Window Amnesia
A related behavior with all the PFD inset windows is that the G1000 does not remember what you were last doing. Press the FPL button to display your flight plan. Then press the TMR/REF softkey to set your Baro Minima. Press the TMR/REF softkey again to dismiss that inset window and ... voila! Instead of displaying the flight plan inset window, there's no inset window displayed at all. The same thing happens if you press NRST, PROC, MENU or any button that displays an inset window. Being able to preserve the last window (or windows) should be child's play for programmers who understand linked lists and the basic concept of LIFO.

XPDR Code, Where Art Thou?
A frequent occurrence when calling ATC to get into the system is being told "Standby for a transponder code." So you press XPDR softkey, the CODE softkey, and wait, ready to punch in the four-digit code.

The problem is that after a few seconds, the G1000 assumes you're done and helpfully dumps you out of the transponder code mode. Gee, thanks ...

Reversionary Mode
As an instructor, I use the reversionary mode a fair amount to simulate the failure of one of the displays for training - the equivalent of partial panel in a steam gauge aircraft. To do this, you press the RED button at the bottom of the audio panel to make both screens display the same basic data - Attitude, Speed, Altitude, engine gauges, and so on. Then press the MENU key and the fun begins.

Using the big knob, you select the brightness setting for the display you wish to make dark and change it from AUTO to MANUAL. Then you select the percentage brightness field and twist the small knob to lower that value to 0%. You must twist, and twist, and twist, and twist, because one complete revolution of the small knob reduces the brightness only about 5%. I'm certain that one day that knob will come off in my hand or just quit working altogether.

One solution would be to have three basic settings: AUTO, MANUAL, OFF. Without some improvement in this interface, Garmin will eventually get sued by some enterprising instructor claiming the G1000 caused repetitive strain injury to their wrist!

Nav Source Change
This is a biggie. The G1000 will automatically (and silently) change navigation source for the HSI (and consequently the autopilot) from GPS to Nav 1 when a ILS approach is loaded. This behavior is generally a good thing, but with the Cessna 172's KAP 140 autopilot in NAV mode, it can be treacherous.

If the KAP 140 autopilot senses the NAV source has been changed, it reverts to the wings level, ROL mode. There's no beep, no chime, no aural alert of any kind. The KAP 140 just flashes ROL for several seconds on the autopilot control panel, but that panel is too low and out of the pilot's primary field of view to be of much help. If the pilot doesn't catch what has happened, the autopilot might just fly him or her into oblivion. One fix for this would be for the G1000 to provide an aural warning "Nav source change" or some other helpful phrase.

Of course, aural alerts can be distracting. A pilot I fly with showed me how to enable aural alerts on an older Garmin GNS480 unit. Unbeknownst to me, this unit was set to a female voice and as I was turning final I heard a very sultry voice say "Five hundred." For a second, all I could think was "Tell me more!"


eric said...

A major feature I feel is missing is the ability to add a hold to any waypoint in your flight plan. I had some experience with this functionality in the CRJ sim at university, and it's extremely useful to just drop in a hold when ATC tells you.

It'll FLY holds, why won't it create them?

flyaway said...

the last time "I heard a very sultry voice say Five hundred" she was talking about something completely different.

it is interesting reading your g1000 info though. i've only used steam gauges so far and i'm afraid that if i ever fly with the g1000 i won't want to go back.

Anonymous said...

Excellent post John. One possible reason for putting the "minimums" in the timer menu is perhaps that the G1000 folks thought that you would normally want to start your timer at the FAF or at least go through the 5Ts at the FAF.

A better interface would be to automatically add a timer event and the minimums when you load or activate an approach.

milski said...

One thing I would like to see is a better visual for the altitude tape. As it is now the altitude bug is the only way to have a reasonably easy visual cue that you're not at your altitude, otherwise you're pretty much down to reading the numbers.

Getting the glideslope indicator down to the side of the HSI will be nice also but I can live with how things are currently.

John said...


Glad you liked my post.

I'd recommend setting the baro minima well before the FAF. The last thing I want to be doing on final is diverting my attention with the Garmin's time-consuming big knob, little knob user input scheme.

I have no way of knowing for sure, but I suspect the baro minima feature was added to the TMR/REF window because they couldn't figure out where else to put it.

Timing the approach from the FAF to the MAP isn't really necessary if your GPS is functioning normally: The GPS will give you a far more precise indication of when you have reached the MAP.

Timing is important for ad hoc holds, but to my mind that has nothing to do with V-speed bugs and baro minima. So the whole thing has the feeling of a kludge ...

Grant said...

Are you sure the NAV source doesn't change automatically when you ACTIVATE an ILS approach, vs. just LOADing an ILS approach?

John said...


The Garmin manual say once the approach is activated (you're headed to some fix defined in the approach) and you are within a 1.2 times deflection of the localizer course, within 15 miles of the final approach fix, and have a valid localizer frequency loaded, the G1000 will automatically switch the navigation source from the GPS to nav 1

Grant said...

Ah, I went back and re-read the last part of your post.

I suppose I see your logic, but you should notice the source change when the course goes from a magenta (GPS) pointer to a green (LOC) pointer.

I feel your pain, though. I fly several different Mooney's that have this same symptoms (with a KAP140 installation). Unfortunately, the problem lies within the KAP140. I don't believe there is a discrete output from the autopilot box to the G1000, otherwise it would be easy to annunciate the mode change.


eric said...

Agreed, the KAP 140 is where most of the issues seem to lie. The GFC 700 doesn't seem to have issue with the autoswitching of nav sources, and is an all-around better system.

John said...

Sure the integrated autopilot works better and that's the way it should be.

But there are a bunch of 172s out there with G1000s and KAP 140 autopilots. Since the G1000 seems capable of aural alerts, having it announce "Nav source changed" would give the pilot warning to check their autopilot.

I'll write more about this later, but the G1000 changing nav sources is not always as helpful as it could be.