i) The purpose of an Electronic Flight Instrument System (EFIS) in an aircraft. 3 marks
The purpose of having the Electronic Flight Instrument System (EFIS) is to change inputs from the aircraft sensors, long-range navigation (LRN) and short-range navigation (SRN) systems into video signals to be shown on the electronic display units. EFIS systems consists of a Primary Flight Display(PFD) which is an Electronic Attitude Direction Indicator (EADI) and Electronic Horizontal Situation Indicator (EHSI) which is a Navigation Display.
ii) Show and label clearly the block diagram of an EFIS. 5 marks
Block diagram of EFIS:
iii) Show the location and placement of the EFIS display units, control panel, warning and caution lights of a commercial aircraft in the cockpit.
The block diagram shows pilot and copilot display systems are identical and functions is identical as well.
Electronic Attitude Direction Indicator(EADI)
· It is a newer type of a primary flight display instrument (PFD), it reduces the workload of the pilot when the pilot is in manual flight. It also facilitates flight.
· It monitors with the use of autopilot information required is display on a single instrument.
· It provides additional information such as heading, altitude and airspeed.
· It also virtually provides information display on the aircraft’s basic flight parameters such as: altitude, attitude, airspeed, heading, rate of climb. Other than basic parameter it provides: auto-throttle and auto pilot engagement status, engagement status flight director modes and approach status.
Electronics horizontal situation indicator (EHSI)
· It is the navigation display that provides directional information into two different navigational aids and the heading of the aircraft.
· It is used to display pertinent portion of the compass rose. Annunciation of active mode and selected features will appear with information such as distance, and arrival time to next waypoint, airport designator speed and more.
· Some of systems can depicts traffic when integrated with TCAS system.
· Other than that, by using management computer and a display computer, it can display information in PLAN, MAP, VOR, ILS modes.
PLAN mode- shows a fixed map of the input flight plan and includes all selected navigational aids for each flight segment and the destination airport.
MAP mode- Shows aircraft against a detailed moving map background. Active and inactive navigational aids are shown and airport and waypoints.
VOR mode- shows focus on a selected VOR, or other navigational station being used, during flight segment.
ILS mode- shows aircraft in relation to the ILS approach aids and selected runway with varying degrees of details.
· Known as the control panel it allows each pilot to control formatting on their respective EHSI and EADI and to select the source of navigation, attitude, and heading information.
· provide analog discrete and digital signal interfaces with the aircraft systems display units and the display controller and they perform symbol generation system monitoring, power control and the main control functions of EFIS
· For the center symbol generator, it acts as a backup for the pilot and copilot symbol generator.
iv) Show the location and placement of the EFIS display units, control panel, warning and caution lights of a commercial aircraft in the cockpit.
v) Show and discuss the data displayed on the primary flight information (PFD) and navigation information (ND) display unit.
Primary flight information display:
Based on the diagram, the primary flight information consists of:
1. attitude Indicator
2. Airspeed Indicator
3. Altitude Indicator
4. vertical speed Indicator
5. heading Display
-Is in the middle of the display
– Display information of the aircraft pitch and roll characteristics and orientation of the aircraft with respect to earth horizon.
-On the left of the display
-It provides an exact readout of current airspeed in knots.
-Displayed airspeed scale is approximately 110knots, the scale is graduated in 10 knot increments and numbered each 20 knots.
-On the right of the display
-It provides a digital readout of the altitude above the sea level.
– Displayed scale is approximately 800 feet, ton scale will give a higher number, the scale is graduated in 100-foot increment and numbered each 200-foot increment.
Vertical speed Indicator
-On the extreme right of the display beside the Altitude.
-It is used to display the climb/dive rate.
-It is used to determine how fast the plane is descending or climbing
-Scale is plus or minus 4000 feet per 16 minutes.
-At the bottom of the display
-Display the magnetic heading value and also the actual path over the ground of aircraft
-70 scale degree in view
– Scale is shown in 5 degree increments numbered with two digit numbers each 10 degrees.
Navigation information display unit:
· Navigation information display unit shows information about your lateral situation..
It has a total of 5 modes (shown in the image above):
· Instrument Landing System (ILS)
· VHF Omnidirectional Range (VOR)
· Navigation (NAV)
Instrument Landing System (ILS)
· ILS is to display the ILS frequency course and identifiers.
· It is use for approach and landing.
VHF Omnidirectional Range (VOR)
· It is used to display VOR frequency, selected course, and identifier.
· It gives a raw data style display (expanded in this case) for FMC data
· It is like navigation mode however Arc representation is limited to forward 90 degrees sector.
· Is used at the planning stage, to check the route when it is entered the FMC. A visual error check of the route can be easily performed and any discontinuities, duplications removed.
· It can be use inflight to inspect later part of the route.