Glass Cockpits, EFIS Description

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.

Electronic Flight Instrument System

An EFIS usually consists of a number of components. They are either installed as separate modules in the aircraft or, as in basic systems, all in one unit. This will have a cost and weight savings aspect. These components are (but not limited to):

We will discuss the most common components as each and every manufacturer has their own set of options in their systems.

EFIS Displays

The most visible part of an EFIS are the LCD screens called primary flight display (PFD) and multifunction display (MFD). Usually experimental aircraft builders install one EFIS and one engine monitoring system with display. Others go so far as to install two EFIS screens, plus a backup GPS with moving map.

For redundancy all data displayed can be seen on either screen. So that the failure of a LCD screen doesn't result in important data not being able to be displayed to the crew.

Primary Flight Display

On this display you will see at a minimum the six conventional basic flying instruments, the layout will differ from one manufacturer to another. Some use round or oval (Trutrak
Trutrak) displays, where others use horizontal or vertical tape or strip displays for airspeed, altitude and heading.

These tape displays can be configured for your aircraft in terms of important speeds like V_NE, V_FE and stall speeds, as you see on a conventional airspeed indicator.

Heading indication is usually along the top of the screen and includes a heading indicator bug to easily set your heading to fly in combination with an autopilot. The attitude indicator sits in the middle with the airspeed to the left and altitude tape to the right. A slip/skid bar is included and even a flight director.

Below the attitude indicator there is a horizontal situation indicator (HSI) displayed. This instrument combines a gyro stabilized heading reference together with navigation information from an ILS/VOR and other radio navigation instrument, either GPS or NDB. When flying instrument approaches this is a must have instrument.

COM NAV

Most PFD screens also are able to display COM NAV controls, outside air temperature, DME information, transponder settings and moving map, even with synthetic vision of the surrounding terrain. The possibilities are really endless.

These modern radio's are equiped with a 8.33 kHz radio as is mandatory above FL 195. You won't find much experimental aircraft up there but if you need too, read this quick reference guide on 8.33 kHz procedures.

Multifunction Display

Used for showing the engine indicating system combined with warnings should one of the parameters go out of the preset range. When the screen is large enough navigation data as a moving map display overlayed with terrain, VFR and IFR waypoints and even weather and radar images can be shown.

These screen have usually multiple pages to configure the system, flight planning options, entering user waypoints, updating navigation databases.

The MFD is also the backup for the PFD in case that one should fail, the information on both screens can also be switched so that the copilot has the PFD and the pilot the MFD.

Cockpit layout

A popular setup is two screens where one (usually the left) functions as PFD and the other as MFD. Aircraft like the Diamond DA-50, Piper Meridian and Quest Kodiak have even a three screen setup: two PFD's and a large screen (15") MFD in the middle. Very cool.