Tuesday, September 26, 2006

Garmin G1000 Glass panel

In the early 1980s Microsoft released Flight Simulator. This computer program was intended to make a personal computer's display resemble the instrument panel of an airplane. In the early 21st century, Garmin created the G1000 instrument panel which uses a computer display to present flight information. We've come full circle.

I flew N1464F for the first time last Friday. This 2005 Cessna Skyhawk SP is equipped with the NavIII option that replaces the traditional six-pack of instruments instruments inlcuding airspeed, turn coordinator, altimeter, heading indicator, vertical speed indicator, and attitude indicator with a computer panel. But, it does much more than that. Instead of a heading indicator, there is a horizontal situation indicator that can be linked to the integrated GPS and the two NAV radios. The gyro for this device is a solid state gyro - which means that there really isn't a spinning gyro at all, therefore there's no precession. No more matching the heading to the compass and the inherent inaccuracy of doing so. There are still back ups for the altimeter, attitude indicator and airspeed indicator, but they are mounted low on the panel beneath the autopilot and between the yokes.

Airspeed and altitude are represented by moving tapes with indicators showing the changes. For the altitude, a bug can be set to a target altitude with the setting appearing above the tape on the right side of the display. To the right of the tape is a pointer that represents the VSI. The actual vertical speed is shown inside the pointer in 50 fpm increments, but the pointer also moves up or down depending on the direction of the change. To the immediate left of the altimeter is an indicator for the glideslope for ILS approaches. There's much more space between the high and low of the glideslope and I think this will lead to more precise control of altitude during approaches.

The attitude indicator takes up the majority of the central portion of the screen and it truly resembles something from a video game. The pitch angle scrolls up and down and the bank is shown with notches across the top. This is the easiest part of the transition, in my opinion. There is no specific turn coordinator with the bank angle and ball of the traditional gauge. Instead, coordination is shown by a small bar that moves left or right at the top of the attitude indicator. It is synched with the pointer and replaces the ball. The rate of turn is shown by a magenta line that appears on the compass heading of the HSI. Two notches shows a 2 minute turn.

One of the best things about the panel is the HSI. Three separate indicators can be superimposed on the compass card to show three different navigation devices. During my flight to F45 - North Palm Beach County - I used the primary to show the GPS course, and used the two additional indicators to back up the GPS with VORs and to triangulate my position with VORs that were not on my course. Since there's a GPs involved, the boxes that appeared next to the HSI also showed the distance to the selected position. With this much navigation information, anyone who gets lost in a G1000 aircraft has absolutely no business flying.

Flying an ILS is a little different and requires a different scan. But, without the traditional six pack to scan, and a well-conceived interface, you get the same information with less mental digestion. With the traditional ILS approach, you have a single gauge that shows your position relative to a horizontal course and a vertical path. Keep the two needles centered, and you are perfectly on course. However, the other information you need, such as attitude, heading, airspeed and rate of descent are on different gauges, so you have to break your concentration momentarily to glance at the other gauges. With the G1000, the display is very different. Your horizontal course is displayed on the HSI. At a glance you get both the heading, the course and your relative position to the course from a single indicator. Now glance up and to the right slightly and you've got your altitude, rate of descent, and your glideslope from a single composite indicator. Attitude is right in the center and airspeed to the left of that. You could just keep looking in a circle and everything would be there.

I flew the ILS 32 at Craig in daylight -or at least part of it until the tower said we had to break off due to traffic. I also flew the ILS 31 at St Augustine up to 3 miles also broken off due to traffic. At Palm Beach, I flew the ILS 8R to a full stop. Coming home, I flew the ILS32 Circle to 5 at Craig at 10pm. I never deviated more than half a ball from the VSI and hardly that on the HSI. I believe these instruments will make for a much more precise flying situation.

I've spent all this time talking about the primary flight display...in my next post, I'll talk about the multi-function display.

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