Friday, July 21, 2006

You've got ...TERRAIN

The new glass panels that are quickly becoming commonplace in GA aircraft provide a wealth of information. Topography, traffic, weather. All in beautiful color. But the designers weren't content just to stimulate your retina. They also use sounds and voices to communicate with you. In fact, the only senses these systems don't seem to yet take advantage of are smell, taste, and touch.

I think most pilots can learn to selectively ignore the dazzling array of colors, when necessary. Sound is another issue. Some Cessna aircraft have autopilots and traffic information systems that beep or talk to you. The beeps and talking are quite loud. Pilots are constantly using their hearing and if these gadgets make noise at the wrong time, the results can be downright dangerous.

My first experience with these noisy bastards was the TrafficWatch system in the Cirrus. When transponder-equipped aircraft get too close, the system begins loudly barking "Traffic! Traffic!" Often, this is a great help. Other times, it's just a pain. All it takes to get the TrafficWatch blaring like you are about to die is a pilot in aircraft holding short of the runway turning on their transponder while you are on short final. Of course, you're not about to die. And there is no way to turn it off. You can momentarily stop the racket by diverting your attention to press a button. Perhaps there's a circuit breaker you can pull.

The Cessna G1000's provide a TIS traffic alerting system that, with the proper button pushes, you can turn off if you so desire. While TrafficWatch is a self-contained system that should detect any aircraft that has its transponder turned on, TIS depends on traffic information being uploaded from a properly-equipped ATC radar facility through a Mode-S transponder. Not all areas support TIS and rumor has it that the FAA has plans to phase out TIS. If this comes to pass, this will not be a boon for all the TIS-equipped aircraft out there.

One of the odd things about TIS seems to occur when you practice stalls (it's probaby the very slow airspeed) or when you transition from a non-TIS service area to an area that provides TIS. In both cases, the sytem get confused and you suddenly see a target right at you altitude, right where you are, and you hear "TRAFFIC! TRAFFIC!" Then just as suddenly, the TIS figures out that target is you and shuts up. Oh, and when you transition to an area where TIS is not supported, a voice loudly announces "Traffic unavailable". But traffic alert systems are just one of the noisy beasts in the new cockpits.

Cessna G1000-equipped aircraft with autopilots will either beep or talk to you at various times. When the autopilots disconnects or is disconnected, you will hear a loud, 2-second beep. In the Cirrus, you get a long, annoying sequence of beeps lasting several seconds that are loud enough to blot out any important sound. In a Cessna 182 I fly, disconnecting the autopilot causes a Keanu Reeves-like voice to say "Otto Piiilot!"


When you are within 1000' of a selected altitude or you deviate from a selected altitude, you'll hear another beep or Keanu saying "Altituuude"


If this happens when ATC is trying to tell you or ask you something, you'll probably have to ask them to "say again." Then there's the perfect noise storm - when the autopilot and the traffic alert system simultaneously vie for you attention. ATC is usually annoyed by having to repeat themselves, but they probably have no idea of the cacophony of sound occuring in some cockpits.

Today, I met a new noise-maker: A newly installed terrain awareness/warning system in a Cirrus SR22. On an instructional flight to one of my old freight dog haunts, we decided to do some touch and goes. There is rising terrain to the south of the westerly facing runway and as soon as we turned onto the base leg, a polite female voice announced "terrain." This was said in a very low-key way, like "Darling, I know you're the best pilot in the world, but you've turned toward rising terrain." Of course, we had every intention of turning away from the hillside and toward the runway at the appropriate moment, but Darling had no way of knowing this. Halfway through the base leg, about to turn final, Darling said "Terrain! Pull up!" with a "Honey, you're starting to scare me" sort of intonation. I thought when we turned final that Darling would relax, but she was wound up really tightly. "Terrain! Pull UP! Pull UP!" she insisted as we approached the runway. The pilot I was instructing was flying and he remained remarkably calm.

I was now resolved to find a way to turn Darling off, but try as I might, I couldn't find a way to disable the voice. I did find a menu item called "Disable Terrain" on the #2 Garmin 430, but selecting it had no effect. I plan to research this further. If anyone knows how to turn off the terrain voice, I'm all ears, as it were. And if you think I'm sexist, let me add that there is a male voice in a Bendix/King-equipped aircraft I fly that barks "Traffic! Traffic!" with such intense intonation that the first time I heard it, I nearly jumped out of my skin.

There is technology available to sort out this mess. My LightSpeed Mach1 headset has an auxiliary audio input for music, like an MP3 player. If listening to an MP3 player while flying sounds dumb, then the Mach1 is smart. When it senses someone talking over the intercom or ATC trying to say something to you, it automatically reduces the volume of the auxiliary audio by about 70%. It is remarkably effective and it happens so quickly, it seems like the unit has ESP. Why can't Garmin, King, BF Goodrich, and the others find a way to do the same with all the voices, beeps, and alarms? Seems to me that only the audio panel/intercom would need to be modified.

I used to fly to get a peaceful feeling. Now, sometimes the only time I feel peaceful is on the drive home.


Chad said...

With essentially the same equipment installed in all of the G1000 birds, I'm surprised at the wide variety of noises they make depending on the model. For instance, the Diamond DA40 has the loud beep for autopilot disconnect while the Cessna 182 has both the beep and "autopiiilot."

I'd imagine (or, at least, I'd like to believe) they try to find a balance between drowning you with ambiguous beeps and scaring you to death with voices from beyond.

What I find strange is these preferences seem to be set in stone. It seems like there should be some setting somewhere that allows me to specify that I don't want a voice from the autopilot, but I want a voice for terrain and traffic and the volume of each.

I too have suffered from "annunciator fright." TIS always seems to false alert on your aircraft after a significant lull in chatter from ATC, in cruise flight, when you least expect it. The subsequent, unexpected, and loud "TRAFFIC" announcement then causes you leap against your seat-belt.

Ron said...

I'm assuming that the TAWS installation in the SR22 you were flying was retrofitted and not something that came from Duluth that way?

I say this because the TAWS-equipped SR22s that I'm familiar with have a button just to the left of the PFD marked "Terrain Inhibit" (or something to that effect). You press the button, it lights up, and terrain advisories are history.

The annunciation that always scares the crap out of me is the "FIVE HUNDRED!!" call from the terrain system.

It usually happens on base, or if you're shooting an instrument approach, it's close enough to minimums that it can be quite startling. It seems to be louder than the other annunciations. Or maybe it's just me.