Saturday, April 28, 2007

G1000 - Get rid of the six-pack

Apart from plastic body (still no news about the gelcoat problem...) and plastic engine, the bigger change recently is certainly the plastic instruments - a.k.a glass cockpits.

This change has been made in steps, from years now, but the revolution is now complete.

One of the first step was probably electronic HSI like sandel tubes, which presented HSI on a small CRT tube, with additional route information. In parallel, GPS coupled with databases like the famous GNS 430 / 530 familly did bring moving maps in our cockpits.

An other step was the introduction of "low cost" inertial devices, allowing to replace the good old mechanical gyros, providing electronical attitude information.

Mix all of that together, and you obtain a G1000. I won't say a lot here on concurent product like Avidyne Entegra as I have no flying experience with them. However one must note one advantage of the G1000 over its competitors: it is the only one to integrate GPS and COM/NAV boxes. With Avidyne, it is still necessary to have separate GNSs.

So, when you fly a glass cockpit plane, the classical six instruments are all represented symbolically on the screen in front of you. And by represented, I don't mean "replicated as the mechanical". Typically, speed and and altitude indicators are in form of sliding tapes, not with round dials and needles.

My progression during the conversion to G1000 was in steps:

1) Get used to the HUGE attitude indicator that fills the whole screen
2) Find where information is
3) Sort out where the knobs are
4) Fly the bugs, not the figures

All of them will be detailled later, but here are a few words on each.

1) The vertical displacement corresponding to a given pitch change is much larger than on a classical horizon. This can be disturbing, when you're used to move your horizon by a few millimeters, to move it by centimeters to establish climb attitude.

2) Any IFR pilot is used to the T layout. This no longer exists with G1000, and even if the reading of the Primary Flight Display (PFD) is logical and easy, some training is needed.

3) In an electromechanical cockpit, each knob is situated in the corresponding instrument, i.e. baro setting on the altimeter, HDG bug and CRS selector on the HSI. As information is on the screen of the G1000, the knobs are all grouped on the side. Finding the proper knob can not be based on the instrument location, and there is noting worse than turning the baro setting instead of the CRS selector (based on my own experience...)

4) Even when flying with classical instrument, what we look at is the position of the needle, in the geometrical sense, not the actual values. Typically, when maintaining an altitude in cruise, one just manage to keep the needle vertical. This seems obvious, or even silly, but when flying with a G1000, there is no such thing, but a vertical tape with a bug you can set. The equivalent of keeping the needle vertical is to keep the bug aligned. Trying to interpret the figures displayed beside the tape is just not possible, and will lead to serious delay in the scanning.

As mentionned eariler, I will develop all of these topics, but the first conclusion is that conversion to G1000, even for VFR only, requires both theoretical and practical training. This is not an easy transition.