Module 5: Digital Techniques and
Electronic Instrument Systems
5.1 Electronic Instrument Systems

Course Overview
 08 – 11/4: 5.1, 5.2
 15 – 18/4: 5.3, 5.4
 22 – 25/4: 5.5, 5.6
 13 – 16/5: 5.7, 5.8
 20 – 23/5: 5.9, 5.10
 27 – 30/5: 5.11, 5.12
 03 – 06/6: 5.13, 5.14
 10 – 13/6: 5.15
 17 – 20/6: Review
 24 – 27/6: Review
 01 – 04/7: Review
 08 – 09/7: Review and Final Test
 10/7: Exams

Aircraft Principal Axes
 An aircraft in flight is free to rotate in three dimensions:
 roll, rotation about an axis running from nose to tail.
 pitch, nose up or down about an axis running from wing to wing.
 yaw, nose left or right about an axis running up and down.

Flight Control Surfaces
 An Aircraft Rolling:
 Ailerons are used in pairs to control the aircraft in
roll, or movement around the aircraft's longitudinal
axis, which normally results in a change in heading.

Flight Control Surfaces
 An aircraft pitching:
 An elevator is mounted on the
trailing edge of the horizontal
stabilizer on each side of the
fin in the tail. They move up
and down together.
 When the pilot pulls the
stick backward, the
elevators go up. Raised
elevators push down on the
tail and cause the nose to
pitch up
 Pushing the stick forward
causes the elevators to go
down and the tail goes up.

Flight Control Surfaces
 An aircraft yaws:  The rudder is
attached to the
vertical stabilizer
and allows the pilot
to control the yaw.
 If the rudder is turned
left, the plain turns
left along the yaw
axis.
 If the rudder is turns
right, the plane turns
right along the yaw
axis.

Other flight control surfaces
 Flaps:
 Used to increase the descend and uplift
angle.
 Decrease the safe speed at which the
aircraft can fly.
 Spoilers:
 Lower the descend speed.
 Assist the rolling.
 Trim tap:
 Used to hold the aircraft in a certain
altitude. The pilot does not have to keep
constant control to the elevator

Cessna Cockpit

The Six Primary Flight Instruments
 Airspeed is measured
in Knots (1 nautical
mile / hour).
 1 Knot = 1.852 Km/h
Airspeed Indicator (ASI)

The Six Primary Flight Instruments
 Shows the
orientation of the
aircraft relatively to
the earth’s horizon.
 Also called “Artificial
Horizon”.
Attitude Indicator (AI)

The Six Primary Flight Instruments
 Displays altitude.
 Altitude is measured in
feet.
 1 foot = 0.3m
Altimeter (ALT)

The Six Primary Flight Instruments
 Information about
the heading.
 Older names:
 Directional
Gyro, Direction
Indicator etc.
Heading Indicator (HI)
 Airspeed indicator, attitude indicator, Altimeter and
heading indicator form the “classic – T” configuration.

The Six Primary Flight Instruments
 Indicates the rate of
turn of the aircraft.
 Shows turns in roll
and yaw axis.
Turn Coordinator (T/C)

The Six Primary Flight Instruments
 Displays ascend and
descend rate in feet /
min.
 Typical maximum
values in non-
pressurized aircrafts:
 ascend: 700 fpm
 descend: 500 fpm
Vertical Speed Indicator (VSI)

Other Instruments
Flaps
VOR
Indicators
Automatic Direction
Finder (ADF)
Engine
Indicators
Communi-
cation and
Navigation
Radios
Autopilot
Throttle
Elevator
Trim
Automatic
Direction
Finder (ADF)
Distance
Measuring
Equipment
(DME)

Types of Navigation
 ADF Navigation (Automatic Direction Finder)
 VOR Navigation (VHF omnidirectional range)
 GPS Navigation (Global Positioning System)

ADF Navigation
 Non-directional Beacons (NDB): Radio transmitters used as
navigation aids.
 Each NDB transmits a signal of a specific frequency.
NDBs
417.0 KHZ
386.0 KHZ
307.0KHZ
431.0KHZ

ADF Navigation
 The NDB frequency to
which we navigate is placed
in the Automatic Direction
Finder.
 The direction to the NDB is
indicated in the ADF
indicator.
 ADF navigation is the oldest
way of navigation.
 There are very few NDBs
today.
 Is affected by atmospheric
conditions, rough terrain,
electrical storms, etc.

VOR Navigation
 VOR: Very High Frequency omnidirectional
range.
 Each VOR beacon transmits a signal of a
specific frequency.
VOR
SAT: 109.6 MHz
ATV: 117.2 MHz
DDM: 114.6 MHz
PLH: 108.8 MHz

VOR Navigation
 I place the VOR
frequency on a
NAV (NAV1 or
NAV2).
 I select from the
Audio Control
Panel the correct
NAV.
 VOR indicator
shows the
direction to the
VOR beacon.
Communication
Radio 1 (COM 1)
Communication
Radio 2 (COM 2)
Navigation Radio
1 (NAV 1)
Navigation Radio
2 (NAV 2)
Distance
Measuring
Equipment (DME)
VOR Indicator 1
VOR Indicator 2
Audio Control Panel

VOR Navigation Direction to VOR
Beacon
The VOR
frequency
Distance to VOR
Beacon
Selector Beacon Direction (The
VOR beacon is behind
the airplane  FROM
indication).

VOR Navigation
 How to find the correct
direction the VOR
beacon?
 Turn the selector until the
needle is centered and the
indication shows a “TO”
indication.
 Write down the Heading.
 To fly to the VOR beacon,
we must fly at 248 degrees.
 So, we place the heading to
the heading indicator.
“TO” indication
“TO” indication and needle is
centered.
Heading: 248o.

VOR Navigation
 I fly at 248 degrees, trying to keep the needle of VOR 1 centered.
 If the needle, while I fly is placed left, then I should turn left, until it is
centered again. .
 If needle, while I fly is placed right, then I should turn right, until it is centered
again.
 The needle shows to which direction the pilot should fly, to reach the beacon.
I placed the
heading
indicated by
VOR 1 to the
Heading
Indicator.

GPS Navigation
 Route is
loaded in the
GPS.
 We just follow
the route.
 The route
Current
Heading
Target
Heading
Distance
to next
waypoint
Time
until next
waypoint
Current
airspeed

GPS Navigation
 Usually pilots do not rely explicitly in GPS for
navigation.
 They use a combination of FMC (flight management
computer), VOR and GPS to follow the planed route.
 However, GPS is likely to replace VOR navigation in the
near future.

The AutopilotAutopilot will follow
NAV or GPS flight
plan?
The autopilot
Engage /
disengage
the
autopilot
Reach
on
maintain
the
heading
displaye
d by the
HI.
Follow
the
navigati
on plan
of the
selected
NAV or
GPS.
Reach or
maintain
the
altitude
as
indicated
in the
autopilot.
The target
altitude.
The maximum
vertical speed to
reach the target
altitude. .

Types of approaches
 Visual approach.
 GPS approach (Global Positioning System).
 ILS approach (Instrument Landing System).

The Approach
 Before approaching the
airport the pilot is informed
by the ATC about the runway
he will land.
 Then, he makes the
approach flight path.
 For example:
 We are approaching KJFK
(New York International
Airport) and we are instructed
to land to Runaway 31L.
 Runway 31L means the left
runway that is placed in 310o.
 There are usually more than
one ways to approach the
runaway.
 We select the one (with the
help of the ATC) that better
fits our inbound direction.

The Approach
 Each different approach to 18R
has a specific name, depending
from the direction the pilot
approaches the airport.
 There are many ways
to approach the
runaway.
 We select the one
(with the help of the
ATC) that fits us best.

The Landing
 4 lights on the
runway
indicate if the
plane follows
the glidepath.Altitude
The glidepath. The optimal
descending route for landing.

The Landing
 Before landing:
 Landing gears are
extended.
 Flaps are fully extended.
 Throttle is off.
 The aircraft moves parallel
to the runway, until the rear
landing gears touch the
runway and finally the front.

Visual Approach
 We just follow ATC (Air Traffic Control) instructions to
approach the airport.
 The pilot must always have clear sight of the airport.
 Can be only made in clear weather.

ILS Approach
 ILS: Instrument Landing System.
 Each runway that provides ILS
has a specific ILS frequency.
 The pilot, while approaching the
airport places the ILS frequency
in the NAV.
 Localizer
indicates the
correct position
to land to the
runway.
 Glideslope
indicates the
correct altitude.

ILS Approach
 VOR indicator works
now as an ILS indicator.
 The vertical needle
shows the localizer
position and the
horizontal the
glideslope position.
 Both needles must
always be vertical in
order to move on the
glidepath.
Am I left or
right of the
runway?
Is my
altitude
correct?

Airbus A320 cockpit layout
 4 types of instruments: PFD, ND, E/WD, SD.

EIS = EFIS + ECAM
E.I.S.
E.F.I.S.
ECAM
 EIS: Electronic Instrument System.
 EFIS: Electronic Flight Instrument System (Glass Cockpit).
 ECAM: Electronic Centralized Aircraft Monitor.
 4 types of instruments: PFD, ND, E/WD, SD.

EFIS: PFD & ND
 PFD: Primary Flight Display
 All information to fly the aircraft
 Attitude Indicator
 Airspeed indicator
 Altitude indicator
 Vertical speed
 Compass
 ND: Navigation System Display
 All information to navigate the aircraft:
 Several Different Modes:
 Heading Indicator
 VOR
 ILS
 TCAS (Traffic Collision Avoidance System)

EFIS: Failure Warnings
 EFIS Failure flag are shown with a flashing
red flags.
 Warnings
on PFD

ECAM: SD & E/WD
 E/WD: Engine/Warning
Display
 Engine indicators, fuel
quantity, flaps and slats
position
 Warning and caution
messages
 SD: System Display

ECAM
 ECAM: Electronic Centralized Aircraft Monitoring:
 A system that monitors aircraft functions and relays them to the
pilots.
 Produces messages detailing failures and in certain cases, lists
procedures to undertake to correct the problem.
 It is managed by a central maintenance computer, which is
provided with data from several systems and sensors.
ECAM Indications Aural Visual
Level 3 warning overspeed, fire, stall Repetitive
chime
Red light flashing /
Level 2 warning system failure, but not
direct consequence on
flight safety
Single
chime
Amber light
Level 1 warning failure leading to
system degradation
none Amber light
Information None Green light