The document outlines the introduction to avionics, emphasizing its necessity for civil and military aircraft, and detailing avionic architecture and subsystems. It describes the components and functions within an aircraft, including the fuselage, wings, tail, and engine types, while also highlighting the importance of avionics systems in navigation, communication, and aircraft control. Additionally, it presents the role of avionic systems in military aircraft and space systems, highlighting their contributions to safety, efficiency, and performance.

1. AE8751 - AVIONICS
Dr. K. Kannan, M.E., M.E., Ph.D.,
Professor & Head,
Department of Mechatronics Engineering
UNIT I
INTRODUCTION TO AVIONICS (9)

2. OBJECTIVES
• To introduce the basic of avionics and its need
for civil and military aircrafts
• To impart knowledge about the avionic
architecture and various avionics data buses
• To gain more knowledge on various avionics
subsystems

3. UNIT I
INTRODUCTION TO AVIONICS (9)
• Need for avionics in civil and military aircraft
and space systems – integrated avionics and
weapon systems – typical avionics subsystems,
design, technologies – Introduction to digital
computer and memories.
• CO1:To explain the basics of avionics and its
need for civil and military aircrafts.

4. Aircraft

5. Fuselage
The plane’s body, or fuselage, holds the aircraft
together, with pilots sitting at the front of the
fuselage, passengers and cargo in the back.

6. This is similar to a car’s dashboard, providing the
pilot with information about the flight, the engine
and the circumstances of the aircraft. Depending
on the aviation electronics (avionics) installed in
an aircraft this may be on an interactive screen or
using the typical ‘6 Pack’ for key pieces of
information.
• Altimeter, Airspeed Indicator, Vertical Speed
Indicator, Attitude Indicator, Heading Indicator,
Turn Coordinator.
Cockpit
Instrument Panel

7. Cockpit

8. Pilot seats
In the cockpit are two seats, one for the pilot and the
other for the co-pilot.
Rudder pedals
Rudder pedals control yaw in flight and are used for
steering on the ground during a taxi.
Overhead panel
The overhead panel contains aircraft systems, such as
air conditioning, electrical, fuel and hydraulics.
Side consoles
Side consoles are for communication instruments and
documentation, depending on the aircraft.
Cockpit

9. Wings
An aircraft’s wings are critical to flight through
the production of lift, but they have many parts
of the wing to control this lift amount and
direction.

10. Aircraft Rotations

11. Wings
Ailerons
Ailerons are located on the trailing edge of the wing to
control the roll of a plane. When a pilot turns to the left in
the cockpit, the left aileron goes up, reducing lift on that
side, and the right aileron goes down, increasing lift
causing that side to rise. This causes the plane to roll to
the left and begin a turn.
Flaps
Flaps, like ailerons, are located on the trailing edge of the
wing. Unlike ailerons, the flaps move symmetrically on
each side and create more lift and drag. Flaps are
typically used during takeoff and landing, when aircraft
speeds are lower, to create additional lift and reduce stall
speeds.

12. Winglet
On an airliner, the tip of the wing is bent up. This is known
as a winglet. Winglets were created to reduce induced
drag.
Slats
Slats are similar to flaps, only located at the front of the
wing (a leading-edge device) and change a wing’s shape
temporarily to increase lift.
Spoilers
Spoilers are used to help the aircraft descend and reduces the
lift component of an airfoil. This allows the plane to
descend and lose altitude without gaining airspeed.
Wings

13. Tail (Empennage)
An aircraft’s tail is mainly used for stability, as
well as creating lift in combination with the
wings.

14. Tail (Empennage)
Horizontal Stabilizer and Elevator
The horizontal stabilizer keeps the airplane’s nose from
moving up and down (pitch). The hinged part on the
horizontal stabilizer is the elevator. When the pilot pulls
back on the yoke, the elevators go up, causing more force to
push down on the tail, lifting up the nose of the aircraft.
Raising the nose changes the angle of attack on the wings,
increasing lift.
Vertical Stabilizer and Rudder
The vertical stabilizer allows the airplane to weathervane into
the relative wind. This helps prevent the side-to-side motion
of the aircraft’s nose (yaw). The rudder on the trailing edge
of the vertical stabilizer is controlled by using the left and
right pedals. When the left pedal is pushed, the rudder
deflects to the left, pushing the tail right and the nose to yaw
left. Using the rudder in combination with the ailerons
causes the aircraft to turn.

15. Engine
The engine(s) or power plant creates thrust needed
for the plane to fly. There are two types of aircraft
engines, reciprocating and turbine.
In reciprocating engines, compressed air is mixed
with fuel and ignited by an electric spark. The
exhaust gases leaves through the back of the
engine through the manifold. The engine spins the
propeller which then creates thrust to move the
plane forward.
With a turbine engine, the action of compressing air,
mixing with fuel, ignition and exhaust are similar
but occur inline. In this case the power is
generated by the air being exhausted from the
engine.

16. Engine

17. Propeller
An aircraft’s propeller(s) are airfoils installed
vertically to create thrust to drive the plane
forward. Attached to the engine, they spin
quickly, creating lift from the pressure
difference they create, only instead of this lift
causing the plane to move upwards, it drives
the plane forward creating thrust. This thrust
and forward motion in turn causes air to pass
over the wings, creating the vertical lift.

18. Propeller

19. Landing Gear
Landing gear is located under the belly of the
plane consisting of a wheel and strut to soften
impact with the ground and may be retractable
into the fuselage. Tricycle type wheels are
common for general aviation with one wheel at
the front and two behind or the reverse for tail
wheels with two wheels at the front of the
plane and one under the tail.

20. Landing Gear

21. Aircraft

22. Various Civilian Aircrafts
1. Boeing - 727, 737, 747, 757, 767 - Boeing
Seatle, USA
2. A300, A310, A318 to A321, A330, A340 -
Airbus, German
3. DC-3,DC-10 - Douglas – California
4. Falcon 50, 900, 2000 - Dassault Aviations,
France

23. Various Civilian Aircrafts

24. Avionic companies
• Honeywell, USA-Supplier of Avionic systems
• Bendix & King, USA- MFD, GPS
• Baker Electronics, USA -PILOT audio systems
• Rockwell Collins, USA- Aerospace & Defense
communication
• Thales, France - Aerospace & Defense
communication
• Garmin, USA-GPS systems
• Sagem, France -Avionic Recorders and Pilot
components

25. Various Flight Phases

26. Definitions
Course - The angle aircraft makes with a fixed
reference, true North-0° being North, true
North-90° being East
Heading- The direction of the aircraft's nose
pointing ; North- 0*, East – 90*, South -180*
and West -270* degrees
Track - The actual path followed by the aircraft
from A to B in a given scheme.

27. Military Aircrafts
Any type of aircraft adapted for military use is called as
Military Aircrafts.
Fighter aircraft, aircraft designed primarily to secure
control of essential airspace by destroying enemy
aircraft in combat. The opposition may consist of
fighters of equal capability or of bombers carrying
protective armament. For such purposes fighters must
be capable of the highest possible performance in
order to be able to out fly and out maneuver opposing
fighters. Above all, they must be armed with
specialized weapons capable of hitting and destroying
enemy aircraft.

28. Military Aircrafts - Fighter

29. Bomber, are designed to drop bombs on surface targets.
Military Aircrafts - Bomber

30. Helicopter is an aircraft with one or more power-driven
horizontal propellers of rotors that enable it to take
off and land vertically, to move in any direction, or to
remain stationary in the air.
Military Aircrafts - Helicopter

31. Unmanned aerial vehicle (UAV) that is guided
autonomously or by remote control or both and that
carries sensors, target designators, offensive
ordnance, or electronic transmitters designed to
interfere with or destroy enemy targets.
Military Aircrafts - UAV

32. Aeronautics
Aeronautics is the science or art involved with
the study, design and manufacturing of
air flight capable machines, and the techniques
of operating aircraft and rockets within
atmosphere. The overall aeronautics system is
classified into 4 important sub systems. They
are
Air Frame System, Vehicle System,
Mission System and Avionics System

33. Aeronautical Sub Systems
The sub systems of aeronautics are,
– Air frame system which is a complex and
integrated set of structural components that
supports the mass of systems and passengers, and
carries loads and stresses throughout the structure.
– Vehicle System is also known as aircraft system or
General Systems or Utility System. Many of these
systems are common to both civil and military
aircraft. They are a mixture of systems with very
different characteristics.

34. Aeronautical Sub Systems
The sub systems of aeronautics are,
- The mission systems which gain information
about the outside world from active and
passive sensors and process this information to
form intelligence. It is used in military
aircrafts.
- The avionic systems which are common to
both civil and military aircraft. The majority of
the systems collect, process, transfer and
respond to data.

35. MISSION SYSTEMS
The military aircraft requires a range of sensors and
computing to enable the crew to prosecute
designated missions. The following are the major
systems of a mission system:
•Attack or surveillance radar to provide
information on hostile and friendly targets.
•Electro-optical sensors to provide a passive
surveillance of targets.
•Electronic support measures (ESM) to provide
emitter information, range and bearing of hostile
transmitters

36. • Magnetic anomaly detector (MAD) to confirm the
presence of large metallic objects under the sea surface.
Military MAD equipment is used to search for minerals
by detecting their disturbance of the normal earth-field.
• Acoustic sensors to provide a means of detecting and
tracking the passage of under water objects.
• Mission computing to collate the sensor information
and to provide a fused data picture to the cockpit or
mission crew stations.
• Defensive aids to provide a means of detecting missile
attack and deploying countermeasures
MISSION SYSTEMS

37. AVIONIC SYSTEMS
Avionics is Aviation Electronics
They are the electronic systems used
on aircraft, artificial satellites, and spacecraft.
Avionic systems include communications,
navigation, the display and management of
multiple systems, and the hundreds of systems
that are fitted to aircraft to perform individual
functions.

38. Onboard Avionics:
Flight Control Avionics, Cockpit avionics,
Communication and Navigation avionics,
Cabin Avionics and Auxiliary & power
systems
Ground Avionics:
Air traffic Management Electronics (ATC),
the equipment at the ground to control and
monitor the air vehicle
AVIONIC SYSTEMS

39. AVIONIC SYSTEMS

40. Core Avionics Systems

41. AVIONIC SYSTEMS
The common avionic systems both for civil and
military aircrafts are
• Displays provide the crew with information and
warnings with which to operate the aircraft. It
provides the visual interface between the pilot and
the aircraft systems.
Types
• HUD - Head Up Displays
• HMD - Helmet Mounted Displays
• HDD – Head Down Displays

42. Displays

43. Communication System
It provides the two way communication between the Air
Traffic Control (ground bases) & the aircraft or
between aircrafts. Communications also connect the
flight deck to the passengers. A Radio Transmitter and
Receiver was the first avionics system installed in an
aircraft. The different types of frequencies used for
several ranges are given below.
- Long Range Communication, High Frequency (2 –
30 MHz)
- Medium Range Communication, Very High
Frequency (30 – 100 MHz)
- Military Aircraft, Ultra High Frequency (250 – 400
MHz)
- Satellite Communications

44. • Weather radar to provide information on
weather conditions ahead of the aircraft.
• Secondary Surveillance Radar to provide
information on the aircraft identification and
height to air traffic is a radar system used in air
traffic control (ATC), that detects and
measures the position of aircraft
• Ground proximity warning system
(GPWS)/Terrain avoidance warning
system(TAWS) to reduce the risk of aircraft
flying into the ground or into high ground
Communication System

45. Air Traffic Control

46. Data Entry and Control System
• It is essential for the crew to interact with the avionic
system.
• Examples are
– Keyboards
– Touch Panels
– Direct voice Input,
– Voice warning systems and so on.

47. Data Entry and Control System
• Distance measuring equipment (DME) is a
transponder-based radio navigation technology
that measures slant range distance by timing
the propagation delay of VHF or UHF radio
signals.
• Air data measurement to provide information
to other systems on altitude, air speed, outside
air temperature and Mach number.
• Accident data recorder to continuously record
specified aircraft parameters for use in analysis
of serious incidents.

48. Data Entry and Control System
• Instrument Landing Systems or Microwave Landing
System is used for approach guidance to the airfield.
• Cockpit voice recorder to continuously record
specified aircrew speech for use in analysis of serious
incidents.
• Internal lighting to provide a balanced lighting
solution on the flight deck for all panels and displays.

49. Flight Control System
• It uses the electronic system in two areas.
(i) Auto Stabilization
– Pitch Auto Stabilizer System
– Yaw Auto Stabilizer System
– Roll Auto Stabilizer System
(ii) FBW Flight Control Systems
It provides continuous automatic stabilization
of the aircraft by computer control of the
control surfaces from appropriate motion
sensors.

50. Aircraft State Sensor Systems
• For control and navigation of the aircraft the air data
quantities are essential. Air Data Quantities are,
– Altitude
– Calibrated Airspeed Vertical speed
– True Airspeed
– Mach Number
– Airstream Incidence Angle.
• The air data computing system computes these quantities
from the outputs of sensors which measure the static and
total pressure and the outside air temperature.

51. Inertial Reference System
The aircraft attitude and the direction in which it
is heading are provided by the inertial sensor
systems
Comprise a set of gyros and accelerometers
which measures the aircraft’s angular and
linear motion.

52. Radio Navigation System
• The Radio Navigation system provides Navigation
Information such as Aircraft’s position, Ground
speed, Track angle. Types are
– Dead Reckoning Systems
– Position Fixing Systems
• DR Navigation systems derive the vehicle’s present
position by estimating the distance travelled from a
known position from knowledge of the speed and
direction of the vehicle.

53. Types of DR Navigation systems
Types of DR Navigation systems are,
i) Inertial Navigation systems
- Most Accurate
ii) Doppler / Heading Reference Systems
- Used in Helicopters
iii) Air Data / Heading Reference Systems
- Low Accuracy when compared to the
above systems

54. Position Fixing Navigation Systems
• In this Position Fixing Systems, Satellite or ground
based transmitter is used to transmit the signal and it
was received by the receiver in the aircraft. According
to the received signals a supporting computer is used
to derive the aircraft’s position. The Prime Position
Fixing System used in aircraft is GPS.

55. Outside World Sensor Systems
These systems comprise both radar and infrared
sensor which enables all weather and night
time operation.
Radar Systems
Fighter Aircrafts Radars
Infrared Systems

56. Radar Systems
• Radar Systems
- Weather Radar detects water droplets, cloud
turbulence and gives warning about storms.
• Fighter Aircrafts Radars
- Multi Mode Radars for ground attack role and
interception role. The Radar must be able to
detect aircraft upto 100 miles away and track
several aircraft simultaneously (12 aircraft’s).
The Radar must have a look down capability to
track low flying aircraft below it.

57. Infrared Systems
It is used to provide a video picture of the thermal
image scene of the outside world by using fixed
Forward Looking Infra Red (FLIR) sensor or a
gimbaled IR imaging sensor.
The thermal image picture at night looks similar to
the visual picture in day time, but highlights heat
sources such as vehicle engines.
FLIR can also be installed in civil aircraft to provide
enhanced vision in addition with HUD.

58. Task Automation Systems
These systems reduce the crew workload and
enable minimum crew operation. They are
– Navigation Management System
– Flight Management System
– Engine Control and Management
– House Keeping Management

59. Navigation Management System
It comprises the operation of all radio navigation
aid systems and the combination of data from
all navigation sources such as GPS and INS
systems, to provide the best estimation of the
aircraft position and ground speed.

60. Flight Management Systems
The FMS tasks are given below.
(i) Flight Planning
(ii) Navigation Management
(iii) Engine control to maintain the planned speed
(iv) Control of Aircraft Flight Path
(v) Minimizing Fuel consumption
(vi) Ensuring the aircraft is at the planned 3D
position at the planned time slot (for Air Traffic
Control).

61. Engine Control and Management
Modern jet engines are having the Full Authority Digital
Engine Control System (FADEC). This controls flow
of fuel. This control system ensures the engine’s
temperature, speed and acceleration in control.
Engine health monitoring system record a wide range of
parameters, so it will give early warning of engine
performance deterioration, excessive wear, fatigue
damage, high vibrations, excessive temperature etc.,

62. House Keeping Management
Automation of the background task which are essential
for the aircraft’s safe and efficient operation. They are
i) Fuel management
ii) Electrical power supply management
iii) Hydraulic power supply management
iv) Cabin / Cockpit pressurization systems
v) Environmental control systems
vi) Warning systems
vii) Maintenance and monitoring systems.

63. NEED FOR AVIONICS
• To enable the flight crew to carry out the aircraft
mission safely and efficiently.
• For civil airliner, the mission is carrying
passengers to their destination.
• For military aircraft, the mission is intercepting a
hostile aircraft, attacking a ground target,
reconnaissance or maritime patrol.

64. NEED FOR AVIONICS
in Civil Aircraft
• For better flight control, performing computations
and increased control over flight control surfaces.
• For navigation, provide information using sensors
like Altitude and Head Reference System (AHRS).
• Provide air data like altitude, atmospheric pressure,
temperature, etc.
• Reduce crew workload.
• Increased safety for crew and passengers.
• Reduction in aircraft weight which can be translated
into increased number of passengers or long range.
• All weather operation
• Reduction in aircraft maintenance cost.

65. NEED FOR AVIONICS
in Military Aircraft
• Avionics in fighter aircraft eliminates the need for
a second crew member like navigator, observer
etc., which helps in reducing the training costs.
• For Stealth technology- less visible to Radar, IR,
Sonar, and other detection methods
• A single seat fighter is lighter and costs less than
an equivalent two seat version.
• Improved aircraft performance, control and better
handling.
• Reduction in maintenance costs.
• Secure communication.

66. • Fly-by-wire communication system used for
space vehicle’s altitude and translation control.
• Sensors used in the spacecraft for obtaining
data.
• Autopilot redundancy system.
• On-board computers used in satellites for
processing the data.
NEED FOR AVIONICS
in Space System

67. INTEGRATED AVIONICS SYSTEM
The combination, interconnection and control of the
individual sub-systems so that the overall system can
carry out its tasks effectively are referred to as
integrated system.
The first major step towards integrating avionic system
was taken in 1950s with the establishment of the
weapon system concept.
The integration of avionic sub-systems in civil aircraft
was taken in 1950s with the adoption of ARINC
specifications. ARINC defines systems and equipment
specifications in terms of functional requirements and
physical dimensions and electrical interfaces.

68. INTEGRATED AVIONICS and
WEAPON SYSTEM
The Avionics and Weapon System (AWS) in any
modern day fighter aircraft enables the pilot to
perform various mission functions such as
‘Programme Evaluation Review Technique’, or
‘PERT’ networks, and ‘Critical Path Methods,
or CPM analysis’.

69. Functional Requirement of AWS
• Receive Inputs from sensors, communication
systems, Radio navigation systems, Identification
system, Missiles, Electronic counter measures
system, Pilot controls.
• Computation of required parameters for
Navigation and Fire control.
• Transferring the computed results to displays,
Audio system and weapons.
• Controlling of weapon launch / Firing.
• Control / Co-ordinate / manage sensors optimally.

70. Sensors in AWS
A device which detects or measures a physical
property and records, indicates, or otherwise
responds to it.
In AWS, the sensors includes Radars, Inertial
Navigation System, Air Data System, Forward
Looking Infrared Sensor, etc.,.

71. Communication Systems in AWS
It is a digital Data link / Voice Link system for
transmission of short messages between
aircraft and ground stations via air band radio
or satellite.

72. Radio Navigation & IFF Systems
• Tactical Air Navigation (TACAN) is a Ultra
High Frequency Navigation system.
• Identification Friend or Foe (IFF) is designed
for command and control. It identifies the
friendly targets but not hostile ones.

73. Electronic Counter Measures Systems
Radar warning receiver,
Self-protection jammer,
Offensive jammer.
Self Protection Jammer – It is used to prevent
detection by enemy radar by jamming the
signal of hostile radar

74. Parameters for
Navigation and Fire control
Navigation Algorithms are used to guide the
steer point
Fire Control Algorithms are used for aiming
Weapon and launching the Missile.

75. Integrated Modular Architecture
A real time Computer Network Airborne system
(modular architecture) consisting of various
computing modules, with different criticality levels
Features are
1. A Dedicated Avionic System
2. Full Cockpit Control and Display System
3. Acoustic Warnings and tones to Crew
4. Autonomous Navigation system’
5. Full Plant Management feature
6. Monitoring and Diagnostic features.

76. AVIONIC SUBSYSTEMS

77. AVIONIC SUBSYSTEMS
• The subsystems of Avionics are Navigation,
Communication and Surveillance.
• Navigation is the field of study that focuses on the
process of monitoring and controlling the movement of
a craft or vehicle from one place to another.
• Communication is the art of conveying meanings from
one entity or group to another through the use of
mutually understood signs, symbols and semiotic rules.
• Surveillance is the process of monitoring the behavior
for the purpose of managing or directing.

78. AVIONICS SYSTEM DESIGN
Starting point for designing a digital avionics system is
a clear understanding of the mission requirements.
The three stages of avionics system design are:
Conceptual design
Preliminary design
Detailed design

79. Conceptual design considerations
• What will it do?
• How will it do?
• What is the general arrangement of parts?
The end result of conceptual design is an artist’s
or engineer’s conception of the vehicle /
product.
Example: Clay model of an automobile.

80. Preliminary design considerations
• How big will it be?
• How much will it weight?
• What engines will it use?
• How much fuel or propellant will it use?
• How much will it cost?

81. Detailed design considerations
• How many parts will it have?
• What shape will they be?
• What materials?
• How will it be made?
• How will the parts be joined?
• How will technology advancements (e.g.
lightweight material, advanced airfoils,
improved engines, etc.) impact the design?

82. DESIGN and TECHNOLOGY
Specific things to be considered while designing an
Avionics Systems are,
(i) Functional Requirements
(ii) Cost
(iii) Required Safety level
(iv) Selection of Design
- Allocation of functions to sub-systems
- Identification of failure modes and its effects
(v) Implementation, Testing and Evaluation
(vi) Validation
(vii) Reliability
(viii) Flexibility
(ix) Weight and (x) Power

83. System Architectures
Centralized
– Signal conditioning and computations are done by
computers in an avionics bay and the signals are
transmitted over one way data bus.
Advantages:
Simple design,
Software can be written easily.
Disadvantages
Long data buses are required,
Possibility for damage.

84. System Architectures
Federated
Sharing of input, sensor data and computed results
over data buses.
Distributed
Multiple processors are used for computing the task
under real time basis. This Architecture is used in
modern avionics system.

85. Memory

86. Thank You