Dynon EFIS 10A

Glass Cockpits, EFIS Components

Flight and engine instruments used to be the old school style type round gauges we all (well most of us) learned to fly with. These are familiar to everyone. Latest trend in general aviation is electronic screens in cockpits and aircraft are then usually called 'New Generation' by their manufacturers.

You will find addon EFIS like the Dynon Avionics series to complete integrated systems with 8", 10" and even 15" color LCD screens (daylight visibile!) from Garmin, where even the radio's (COM and NAV) and engine instruments are fully integrated.
These can be coupled to an autopilot and programmed to fly the entire route and instrument approach. You still would have to do the landing yourself.

Installing an EFIS system saves weight and cleans up your panel. It also means that you could go without a vacuum system and remove the hoses, pump and hardware (more weight savings). All of this could mean a single point of failure in the cockpit. But even with the sixpack we normally use to have, would you go flying if your altimeter does not work?

Note that with all these different types of EFIS systems, you as the pilot will need some form of training to become familiar with the multitude of options available in the EFIS software, especially so when flying IFR in IMC conditions.

EFIS Components, II

The EFIS system uses a number of separate components to display all of its possibilities. Some manufacturers sell these sometimes integrated inside the display unit as to reduce the wiring in the aircraft. In case of the magneto meter (flux valve) it might not be a good thing as the engine (large part of metal) can be too close in some aircraft and influence readings.

Air Data Computer and AOA

Air Data Computer

This system uses pitot and static pressure combined with total air temperature to calculate mach number, indicated and true airspeeds, outside air temperatures and vertical speeds to be fed to autopilots, transponders and our EFIS systems.

The angle of attack (AOA) shows the pilot exactly when the aircraft will stall under any condition and he will be able to maintain airspeed precisely if he flies by the AOA. A great help with precision landings flown a couple of knots above stall speed.

GPS

Used to obtain the aircraft location, groundspeed and exact time from satellites orbiting the earth. It eventually supplies information to be used by moving maps and safe taxi diagrams, synthetic vision and the electronic flight bag options.

The GPS receiver is multichannel (12, 20 or even more) and can be built internally in the EFIS but more commonly external on the aircraft. Large aircraft have them on the outside on the top of the aircraft. The receiver needs an unobstructed view of the sky for good performance although the SIRF III chipsets in some receivers are able to pickup satellites indoor.

Fluxgate or Magnetometer

This device senses the earths magnetic field and direction for use in the EFIS even without movement of the aircraft, whereas GPS must move to determine direction and with an accuracy of 10 meters (30 feet) directional indication is not very accurate at slow speeds or standing still.

These devices are also able to detect the magnetic dip (declination) and the vertical and horizontal components of the magnetic field.

Some manufacturers (Dynon Avionics) built the AHRS, Magnetometer and ADC in one box, which makes sense production wise. Just remember to install the AHRS on a stable platfom (away from electrical wiring) and not on a constantly vibrating piece of skin of the aircraft. Such an arrangement would disturb the accelerometers in the AHRS.

Synthetic Vision

Garmin Synthetic Vision

A technology which displays in the PFD the terrain ahead and sometimes around the aircraft in combination with colors indicating terrain higher (red), same level (yellow) and lower (green). Gives a great view and the pilot immidiately knows if the chosen route leads to terrain too high.
Situational awereness is greatly enhanced with synthetic vision and airports can be shown on screen and last but not least HITS, highways in the sky, can be displayed for easy route flying.

Electronic Flight Bag

This is very handy as it keeps the cocpit free of checklists, maps and approach charts. Updating is very simple through a pc or direct internet connection and worldwide charts are available from Jeppesen and other sources.

If you are interested in installing an EFB or a pocket type FMS (on a netbook) system in your aircraft then FAA AC 120-76A is must read. Also do read the next article about EFB's and a paperless office in aircraft by Susan Parson.