Unit III Study Materials Control and display technologies: CRT, LED, LCD, EL and plasma panel – Touch screen – Direct voice input (DVI) – Civil and Military Cockpits: MFDS, HUD, MFK, HOTAS.

1. AE8751 - AVIONICS
Dr. K. Kannan, M.E., M.E., Ph.D.,
Professor & Head,
Department of Mechatronics Engineering
UNIT III
FLIGHT DECKS AND COCKPITS (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 III
FLIGHT DECKS AND COCKPITS (9)
• Control and display technologies
– CRT, LED, LCD, EL and plasma panel
– Touch screen
– Direct voice input
• Civil and Military Cockpits:
- MFDS
- HUD
- MFK
- HOTAS
• CO3: To explain the concept of control & display technologies
and cockpits.

4. • MFK- Multifunction Keyboard Cockpit for
Single Seat (Military)
• HOTAS (Hand on Throttle And Stick) for
Military (F16)
• HMD-Helmet Mounted Display-for Civil
Aircrafts
• HUD-Head Up displays for both military and
civil aircrafts
• HDD-Head Down Display-all modern aircrafts
Civil and Military Cockpits

5. Cockpit Display Systems
The cockpit display systems provide a visual
presentation of the information and data from the
aircraft sensors and systems to the pilot to enable
the pilot to fly the aircraft safely and carry out the
mission.
They provide the pilot, whether civil or military,
with:
• Primary flight information,
• Navigation information,
• Engine data,
• Airframe data and
• Warning information.

6. Military Cockpit Display Systems
The military pilot has also a wide array of
additional information to view, such as:
• Infrared imaging sensors,
• Radar,
• Tactical mission data,
• Weapon aiming and
• Threat warnings.

7. The pilot is able to absorb and process substantial amounts of
visual information if the information is displayed in a way
which can be readily assimilated, and unnecessary information
must be eliminated to ease the pilot’s task in high work load
situations.
A number of developments have taken place to improve the
pilot–display interaction such as
• Head up displays,
• Helmet mounted displays,
• Multi-function colour displays,
• Digitally generated colour moving map displays,
• Synthetic pictorial imagery and
Displays management using intelligent knowledge based
system
Developments in Cockpit Display Systems

8. Cockpit Control Systems
Equally important and complementary to the
cockpit display systems in the ‘man machine
interaction’ are the cockpit control system
provided for the pilot to control the operation of
the avionic systems and to enter data. The
developments in this system includes
– Multi-function keyboards,
– Multi-function touch panel displays
– Direct voice input control
– Audio warning systems
– Eye trackers

9. Display Systems
In flight, aircraft and operating crew form a “man-
machine” system loop
The role of crew is to be an active controller or
monitor in case of automated flight with the
possibility of reverting to active function
Instruments play vital role as they are means of
communication in the “man-machine” loop
Data have to displayed in best way to help crew
interpret it ,with minimum mental efforts
So, the visual information is presented to pilot on
various displays

10. Information to the Pilots
Primary flight information: Air speed, Altitude,
Vertical speed, Angle of attack, heading …..
Navigation information: Aircraft's position, Ground
speed and Track angle (Direction with respect to
true north)
Engine Data: Engine pressure ratio, RPM, exhaust
gas temperature, fuel flow,….
Warning information: data from ground proximity
system or weather radar returns
Maps: maps showing the routes, flight points have
to displayed.

11. Forms of Data Displays
Quantitative: Variable quantity is presented by
numerical value or relative position with a
pointer on graduated scale.
Qualitative: Symbolic or pictorial presentation of
data.

12. Six Basic Instruments
Six basic instruments in a light twin-engine
airplane arranged in a "basic-T". Airspeed
indicator, Artificial horizon, Altimeter, Turn
coordinator, Heading indicator (compass) and
Vertical speed indicator.

13. Electronics Systems Display
Glass Cockpit
1. PFD-Primary Flight Displays providing
information which are critical to flight -
1. True Airspeed, 2. Attitude, 3. Altitude, 4.
Heading, 5. Vertical speed and 6. Yaw.
1. MFD-Multi Function Displays-Providing
information on
1. Weather, 2. Navigation 3. Engine
performance for safe landing and take off
from Multiple systems

14. Electronics Systems Display
Glass Cockpit
Primary Flight Display:
The PFD is designed to improve a pilot's situational awareness by
integrating this information into a single display instead of six
different analog instruments, reducing the amount of time
necessary to monitor the instruments.
PFDs also increase situational awareness by alerting the aircrew
to unusual or potentially hazardous conditions — for example,
low airspeed, high rate of descent — by changing the colour or
shape of the display or by providing audio alerts. These LCD
units generate less heat than CRTs which is an advantage in a
congested instrument panel. They are also lighter and occupy a
lower volume.

15. Primary Flight Display

16. Multi-function display (MFD) / Navigation display (ND):
The MFD (multi-function display) displays navigational and
weather information from multiple systems. MFDs are most
frequently designed as "chart-centric", where the aircrew
can overlay different information over a map or chart.
Examples of MFD overlay information include the aircraft's
current route plan, weather information from either onboard
radar or lightning detection sensors or ground based
sensors.
MFDs can also display information about aircraft systems,
such as fuel and electrical systems . As with the PFD, the
MFD can change the colour or shape of the data to alert the
aircrew to hazardous situations.
Electronics Systems Display
Glass Cockpit

17. Electronics Flight Instrument System

18. Electronics Display Technologies
1. Size
2. Resolution-ability to adjust and distinguish
the electron beam
3. Contrast Ratio: Ratio of the brightest possible
white value compared to the darkest possible
black value
4. Dot pitch-Size of a given pixel on the screen
in millimeters.
5. Screen Contour-Variety of contours to the
front of the screen or tube

19. Electronics Display Technologies
Cathode Ray Tube
The CRT is the oldest display technology in current
aircraft use.
Thermionic device and Uses electronic beam
scanning technique
Consists of evacuated glass, electron gun ,beam
focusing and beam deflection systems
Screen coated by crystalline solid material known as
a phosphor.
CRT signals are in Rho-theta form and have to be
converted into X-Y form

20. Construction of CRT

21. Block Diagram

22. Color CRT
Radar transmitter transmits a pulse, receiver
receives return echoes in Rho-theta form.
Data is digitalised into binary form to present four
conditions.
Blank screen shows zero or low level returns
Green represent low returns(lowest rainfall rate)
Yellow represents moderate returns(moderate
rainfall rate)
Red represents strong returns(high density rainfall
rate)

23. Color CRT

24. Cathode Ray Tube
Advantages
a) They operate at any resolution, geometry and
aspect ratio without the need for rescaling the
image.
b) CRTs run at the highest pixel resolutions
generally available.
c) Produce a very dark black and the highest
contrast levels normally available. Suitable for
use even in dimly lit or dark environments.

25. Advantages
d) CRTs produce the very best color and gray-
scale and are the reference standard for all
professional calibrations. They have a perfectly
smooth gray-scale with an infinite number of
intensity levels.
e) CRTs have fast response times and no motion
artifacts. Best for rapidly moving or changing
images.
f) CRTs are less expensive than comparable
displays using other display technologies.
Cathode Ray Tube

26. Positive Features of CRT
• Full Color
• Graphics Display
• Good Resolution
• Sunlight Readable
• Dimmable
• Power Efficient
• Inexpensive
• Wide Temperature Range
• Life Span

27. Negative Features of CRT
• Requires several power supply voltages
• Requires very high voltage
• Generates magnetic fields
• Constructed with fragile glass envelope
• Heavy Weight
• Requires significant depth behind the front
panel

28. Colors and Gray Scale
• Primary Colors
• 3 bits for each primary colors
• 512 States
• 000 for black
• Color Palette
• R+G+B = White ; R+G = Yellow ;
R+B = Cyan; B+G = Magenta

29. Problems
A television display has 525 scanning lines and
aspect ratio is 4:3. What is the equivalent
resolution of the display in lines? Also find the
number of pixels in a television picture.

30. Calculate how much memory is required to store
an image, which contains green, red and white
elements. The image is displayed as a one to
one aspect ratio with a rater scan of 512 lines.
Problems

31. Light Emitting Diode
Solid state device comprising forward biased p-n
junction transistor.
Current flows through the chip and emits the
light proportional to the current flow
LEDs are arranged in segments or matrix forms
in order to display certain information.
Typical displays are 7 segments ,13 segment and
16 segment displays

32. Light Emitting Diode

33. Liquid Crystal Display
Liquid crystals have properties somewhere between
solid and liquid. The orientation of molecules can be
controlled by the application of an electric field.
Types
(i) Reflective – It uses Incident light
(ii) Backlit – It uses own light source Liquid crystal
display needs a light source in order to operate.
Larger displays can be easily made which displays
several sets of information.

34. Liquid Crystal Display
Consists of two glass plates coated on their
surfaces with conducting material(polarizing
film)
Material on front plate is etched in 7 segments
displays and the back plate is common return
Space between plates is filled with liquid crystal
compound.
When low voltage and low current signal is
applied to segments, the polarization of
compound changes to reflective medium.

35. Liquid Crystal Display

36. Liquid Crystal Display System

37. Electroluminescent Displays
Electroluminescence (EL) is an optical and electrical
phenomenon where a material emits light in response to
an electric current passed through it, or to a strong electric
field.
The term "electroluminescent display" describes displays
that use traditional electroluminescent materials which is
deposited using atomic layer deposition. ELDs are a type
of Flat panel display created by sandwiching a layer of
electroluminescent material such as GaAs between two
layers of conductors. When current flows, the layer of
material emits radiation in the form of visible light.

38. The structure of a ELD is similar to that of a passive
matrix LCD or OLED display, and displays with
transparent electrodes. ELD can have a transparency
of 80%. ELD uses chip-on-glass technology, which
mounts the display driver IC directly on one of the
edges of the display. They can be embedded onto
glass sheets.
They are much more rugged and can operate at
temperatures from -60 to 105°C and can operate for
1,00,000 hours without considerable burn-in, only
losing about 80% of its initial brightness.
Electroluminescent Displays

39. EL works by exciting atoms by passing an electric
current through them, causing them to emit photons.
By varying the material being excited, the colour of
the light emitted can be changed. The actual ELD is
constructed using flat, opaque electrode strips
running parallel to each other, covered by a layer of
electroluminescent material, followed by another
layer of electrodes, running perpendicular to the
bottom layer. This top layer must be transparent in
order to let light escape. At each intersection, the
material lights, creating a pixel.
Electroluminescent Displays

40. Plasma Display
A plasma display is a video display in which each pixel
on the screen is illuminated by a tiny bit of plasma or
charged gas, somewhat like a tiny neon light.
Plasma displays are thinner than CRT displays and
brighter than LCD.
They are called "plasma" displays because the
technology utilizes small cells containing electrically
charged ionized gases, or what are in essence
chambers more commonly known as fluorescent
lamps.

41. In plasma display panels the light of each picture
element is emitted from plasma created by an electric
discharge.
The dimensions of the discharge are in the 100 micro-
meters range at a pressure of a few hundred torrs, and
the voltage applied between electrodes is in the 100-
200 V range.
Plasma Displays scale the video image of each
incoming signal to the native resolution of the display
panel.
Plasma Display

42. Plasma Display

43. Advantages
Picture quality
- Capable of producing deeper blacks allowing for
superior contrast ratio.
- Wider viewing angles than those of LCD; images
do not suffer from degradation at high angles like
LCDs.
-Less visible motion blur, very high refresh rates
and a faster response time, contributing to superior
performance when displaying content.

44. Disadvantages
Use more electrical power, on average, than an LCD
TV.
Does not work well at high altitudes above 2 km
due to pressure differential between the gases
inside the screen and the air pressure at altitude.
It may cause a buzzing noise. For those who wish to
listen to AM radio, or are amateur radio operators
(hams) or shortwave listeners (SWL), the radio
frequency interference (RFI) from these devices
can be irritating or disabling.

45. Touch Screen
The touch screen is one of the easiest to use PC
interfaces, making it the interface of choice for a
wide variety of applications. A touch interface
allows users to navigate a computer system by
touching icons or links on the screen.
A touch screen is an input device that allows users
to operate a PC by simply touching the display
screen. Touch input is suitable for a wide variety
of computing applications. A touch screen can be
used with most PC systems as easily as other
input devices such as track balls or touch pads.

46. 1. Touch Sensor
2. Controller
3. Software Driver
Touch Screen

47. Touch Sensor
A touch screen sensor is a clear glass panel with a
touch responsive surface. The touch sensor/panel
is placed over a display screen so that the
responsive area of the panel covers the viewable
area of the video screen.
The sensor generally has an electrical current or
signal going through it and touching the screen
causes a voltage or signal change.
This voltage change is used to determine the
location of the touch to the screen.

48. Controller
The controller is a small PC card that connects
between the touch sensor and the PC. It takes
information from the touch sensor and translates it
into information that PC can understand.
The controller is usually installed inside the monitor
for integrated monitors or it is housed in a plastic
case for external touch add-ons/overlays.
Integrated touch monitors will have an extra cable
connection on the back for the touch screen.
Controllers are available that can connect to a
Serial/COM port or to a USB port .

49. Software Driver
The driver is a software update for the PC system that
allows the touch screen and computer to work together.
It tells the computer's operating system how to interpret
the touch event information that is sent from the
controller.
Most touch screen drivers today are a mouse-emulation
type driver. This makes touching the screen the same as
clicking your mouse at the same location on the screen.
This allows the touch screen to work with existing
software and allows new applications to be developed
without the need for touch screen specific
programming.

50. Types of Touch Screen
• Resistive
• Capacitive
• Surface Acoustic Wave
• Infrared LED/Optical
• Dispersive Signal Technology

51. Resistive Touch Screen
In this RTS, Electrically
conductive and
Resistive layers are
separated by thin
space. When some
objects touches this
panel, the layers are
connected at certain
point. This causes a
change in the electrical
current and sent to the
controller for
processing.

52. Capacitive Touch Screen
It is coated with a material (Indium tin oxide)
which conducts a continuous electrical current
across the sensor.

53. Surface Acoustic Wave
It uses ultrasonic waves that pass over the touch
screen panel. When the panel is touched, a
portion of wave is absorbed. This information
is send to the controller for processing

54. Infrared LED/Optical Touch Screen
In this two or more image sensors are placed
around the edges of the screen. Infrared
backlights are placed in the camera’s field of
view on the other side of the screen. A touch
shows a shadow and the sensors are used to
locate the touch.

55. Dispersive Signal Technology
Touch Screen
It uses sensors to detect the mechanical energy in
the glass due to a touch. Complex algorithms
are used to find out the actual location of the
touch. The main advantage of this type of
touch screens has excellent optical clarity.

56. Direct Voice Input
Direct voice input (DVI) (sometimes called voice
input control (VIC)) is a style of human–
machine interaction "HMI" in which the user
makes voice commands to issue instructions to
the machine.
DVI has been introduced into the cockpits of several
modern military aircraft, such as the Eurofighter
Typhoon, the Lockheed Martin F-35 Lightning II,
the Dassault Rafale and the Saab JAS 39 Gripen.

57. • DVI systems can be divided into two major categories of
functionality: "user-dependent" or "user-independent".
• A user-dependent system requires that a personal voice
template to be generated for a specific person; the template
for this individual has to be loaded onto their assigned
machine prior to use of the DVI system for it to function
properly.
• A user-independent system does not require any personal
voice template, being intended to respond correctly to the
voice of any user.
– Classified as Discrete recognition" and "continuous recognition".
Users of a discrete recognition system must pause between each
word so that the DVI system can identify the separations
between each word, while a continuous speech recognition
system is capable of understanding a normal rate of speech.
Direct Voice Input

58. Direct voice input (DVI) control is a system which enables
the pilot to enter data and control the operation of the
aircraft’s avionic systems by means of speech.
The spoken commands and data are recognised by a speech
recognition system which compares the spoken utterances
with the stored speech templates of the system
vocabulary.
The recognised commands, or data, are then transmitted to
the aircraft sub-systems by means of the interconnecting
data bus
Feedback that the DVI system has recognised the pilot’s
command correctly is provided visually on the HUD and
HMD, and aurally by means of a speech synthesizer
system. The pilot then confirms the correctly recognised
command by saying ‘enter’ and the action is initiated.
Direct Voice Input

59. • Fully connected speech.
• Must be able to operate in the cockpit noise
environment.
• Vocabulary size. The required vocabulary is around
200 to 300 words.
• Speech template duration. The maximum speech
template duration is around 5 seconds.
• Vocabulary duration. The maximum duration of the
total vocabulary is around 160 seconds.
• Syntax nodes. The maximum number of syntax nodes
required is about 300.
Direct Voice Input –
Characteristics and Requirements

60. Civil and Military Cockpits
• Pilot controlling the aircraft area -Cockpit.
• Windows with a sun shield & can be opened
when aircraft on the ground
• Control column or Joystick located centrally
to Pilot for Control
Cockpit Technologies
– Fight Display Technology-PFD & MFD
– Flight Control Technology- PFC & SFC

61. Multi Function Display
MFD is a small screen (CRT or LCD) in an aircraft
surrounded by multiple buttons that can be used to
display information to the pilot in numerous ways.
MFDs originated in aviation, first in military aircraft,
and later were adopted by commercial
aircraft, general aviation, automotive use, and
shipboard use.

62. Multi Function Display
Many MFD’s allow the pilot to display their
Navigation route,
Moving map,
Weather radar,
NEXRAD
(Next Generation Radar – weather surveillance radar),
GPWS
(Ground Proximity Warning Systems) and
TCAS
(Traffic collision Avoidance Systems).

63. Multi Function Display

64. MFD will be used with a primary flight display (PFD),
and forms a component of a glass cockpit. The
advantage of an MFD over analog display is that an
MFD does not consume much space in the cockpit, as
data can be presented in multiple pages, rather than
always being present at once.
The possible MFD pages could differ for every plane,
complementing their abilities (in combat).
MFDs were added to the Space Shuttle (as the glass
cockpit) replacing the analog instruments and CRTs.
In modern automotive technology, MFDs are used in
cars to display navigation, entertainment, and vehicle
status information.
Multi Function Display

65. Moving Maps
The moving map function uses the MFD to provide a
pictorial view of the present position of the aircraft, the
route programmed into the FMS, the surrounding
airspace, and geographical features.
Moving maps offer a number of options to specify what
information is presented on the MFD and how it is
displayed.
Moving maps typically offer several different map
orientations (e.g., north up, track up), a range control
that allows you to “zoom” in and out to see different
volumes of airspace, and a means to adjust the amount
of detail shown on the display (declutter).

66. A moving map display has a variety of uses that provide
awareness of position and surroundings during almost
any phase of flight. Verification of the displayed data
with a chart accomplishes three functions:
1. Provides the practice for retention of pilot’s map
reading skills.
2. Contributes to pilot’s readiness for continued safe
navigation to a destination in the event of equipment
problems.
3. Ensures that Pilot maintain situational awareness.
Moving Maps

67. Moving Maps

68. TCAS
Currently MFD units are interfaced with either a
Mode S transponder or the Ryan TCAD to
provide a real-time display of traffic
information in both the attitude indicator and
the full-color moving map. Traffic symbols are
colour-coded to quickly recognize any traffic
at any altitude or on a possible collision course
and take action. With the optional FLIR
camera, the traffic can even be "visually"
identified.

69. Ryan's latest and most sophisticated traffic alerting
system, the TCAD 9900BX, has got certification
from FAA.
The 9900BX is an active system which interrogates
other aircraft's transponders, determines their position
and then issues a warning if a potential conflict is
predicted.
Using bottom and top antennas, the 9900BX can
simultaneously track up to 50 aircraft (it looks out 20
miles). When the system detects a threat, it gives the
pilot an audible warning, such as "Traffic! Twelve
o'clock high! Two miles!”.
TCAS

70. Terrain Awareness and Warning Systems
A terrain awareness and warning system (TAWS)
offers all of the features of a terrain display along
with a sophisticated warning system that alerts to
potential threats posed by surrounding terrain.
A terrain awareness and warning system uses the
aircraft’s GPS navigation signal and altimetry
systems to compare the position and trajectory of
the aircraft against a more detailed terrain and
obstacle database.
This database attempts to detail every obstruction
that could pose a threat to an aircraft in flight.

71. There are presently two classes of certified
terrain awareness and warning systems that
differ in the capabilities they provide to the
pilot:
–TAWS A and
–TAWS B.
Terrain Awareness and Warning Systems

72. TAWS A
A TAWS A system provides indications for the
following potentially hazardous situations:
1. Excessive rate of descent
2. Excessive closure rate to terrain
3. Altitude loss after takeoff
4. Negative climb rate
5. Flight into terrain when not in landing configuration
6. Excessive downward deviation from glideslope
7. Premature descent
8. Terrain along future portions of the intended flight
route

73. TAWS B
A TAWS B system provides indications of
imminent contact with the ground in three
potentially hazardous situations:
1. Excessive rate of descent
2. Excessive closure rate to terrain (per
Advisory Circular (AC) 23-18, to 500 feet
above terrain)
3. Negative climb rate or altitude loss after
takeoff

74. Terrain Awareness and Warning Systems

75. GPWS & NEXRAD
GPWS - It alerts the pilot if the aircraft is in immediate
danger of flying into an obstacle.
TCAS - It reduces the incidence of wind – air collisions
between the aircrafts.
NEXRAD – It is a network system of 160 high-
resolution S-band Doppler weather radars jointly
operated by the National Weather Service (NWS), the
Federal Aviation Administration (FAA) and the U.S.
Air Force. The NEXRAD system detects precipitation
and wind, and its data can be processed to map
precipitation patterns and movement.

76. Cockpit Weather Systems
Advanced avionics cockpit weather systems provide many of the
same weather products available on the ground and have a
variety of uses that can enhanced awareness of weather that
may be encountered during almost any phase of flight.
Radar images, satellite weather pictures, Aviation Routine
Weather Reports (METARs), terminal weather forecasts
(TAFs), significant meteorological information (SIGMETs),
Airmen’s Meteorological Information (AIRMETs), and other
products are now readily accessible at any time during flight.
Weather products provided by cockpit weather systems are
typically presented on an MFD. Some installations allow the
overlay of this data in the PFD.

77. Thunderstorms and Precipitation
Thunderstorms and precipitation are detected through
the use of radar.
In the advanced avionics cockpit, radar data can come
from one of two sources: an onboard weather radar
system or a ground weather surveillance radar
system.
Ground weather surveillance system data is transmitted
to the cockpit via a broadcast (or datalink) weather
service. Onboard weather radar and ground weather
surveillance radar systems each offer advantages and
disadvantages to the pilot. Some aircraft use a
combination of both systems.

78. Radar Data

79. Onboard Weather Radar Systems
Onboard weather radar uses an adjustable
aircraft mounted radar antenna to detect, in
real time, weather phenomena near the aircraft.
The coverage of an onboard weather radar
system is similar to a flashlight beam.

80. Onboard Weather Radar Systems

81. Ground Weather Surveillance Radar
Ground weather surveillance integrates weather
information from many ground radar stations.
The weather information collected from many
sources is then used to create a composite
picture that covers large volumes of airspace.
These composite radar images can then be
transmitted to aircraft equipped with weather
data receivers.

82. AE8751 - AVIONICS
Dr. K. Kannan, M.E., M.E., Ph.D.,
Associate Professor & Head,
Department of Mechatronics Engineering
UNIT III
FLIGHT DECKS AND COCKPITS (9)

83. Head Up Displays
The most important advancement in the visual
presentation of data to the pilot is Head Up
Display or HUD.
The HUD has enabled a major improvement in
man–machine interaction (MMI) to be achieved
as the pilot is able to view and assimilate the
essential flight data generated by the sensors and
systems in the aircraft whilst head up and
maintaining full visual concentration on the
outside world scene.

84. Head Up Displays
The display shows the artificial horizon with the aircraft making
a 3.6◦ descent, on a heading of 00◦. The left hand scale shows an
airspeed of 137 knots and the right hand scale an altitude of 880
ft.

85. A head up display projects a collimated display in the
pilot’s head up forward line of sight so that he can view
both the display information and the outside world
scene at the same time.
Because the display is collimated, the pilot’s gaze angle of
the display symbology does not change with head
movement so that the overlaid symbology remains
conformal, or stabilised, with the outside world scene.
The pilot is thus able to observe both distant outside world
objects and display data at the same time without
having to change the direction of gaze or refocus the
eyes.
Head Up Displays

86. HUD Schematic

87. Collimator
A collimator is defined as an optical system of
finite focal length with an image source at the
focal plane. Rays of light emanating from a
particular point on the focal plane exit from the
collimating system as a parallel bunch of rays,
as if they came from a source at infinity.

88. Collimator

89. Field of View
It is important to distinguish between the
instantaneous field of view (IFOV) and the total
field of view (TFOV) of a HUD as the two are not
the same in the case of the refractive type of
HUD.
The instantaneous field of view is the angular
coverage of the imagery which can be seen by the
observer at any specific instant and is determined
by the diameter of the collimating lens, D, and the
distance, L, of the observer’s eyes from the
collimating lens.

90. IFOV = 2 tan−1 (D/2L)
The total field of view is the total angular
coverage of the CRT imagery which can be
seen by moving the observer’s eye position
around. TFOV is determined by the diameter
of the display, A, and effective focal length of
the collimating lens, F.
TFOV = 2 tan−1 (A/2F)
Field of View

91. Field of View

92. Holographic HUDs
The requirement for a large FOV is driven by the
use of the HUD to display a collimated TV
picture of the FLIR sensor output to enable the
pilot to ‘see’ through the HUD FOV in
conditions of poor visibility, particularly night
operations. It should be noted that the FLIR
sensor can also penetrate through haze and
many cloud conditions and provide ‘enhanced
vision’ as the FLIR display is accurately
overlaid one to one with the real world.

93. Holographic HUDs

94. HUD Electronics

95. Military Aircraft’s HUD
The pilot freely concentrates on the outside
world during maneuvers. In combat situations
the pilot can scan for possible threats from any
direction. The combined FLIR with HUD
enables the pilot to fly at low level by night in
fair weather. This provides a realistic night
attack capability.

96. Civil Aircraft’s HUD
The HUD provides situational awareness and
increased safety in circumstances such as wind
shear or terrain/ traffic avoidance maneuvers.
If the flight path vector is below the horizon,
the aircraft is descending. Flight path vector
provides a two dimensional display of drift
angle and flight path angle. It helps the pilot to
land the aircraft safely in conditions of very
low visibility due to fog.

97. Multi-Function Keyboard
It is an avionics sub system through which the pilot interacts to
configure mission related parameters like flight plan, airfield
database, communication equipment during initialization and
operation flight phase of mission.
The MFK consist of a processor with ROM, RAM and EEPROM
memory. It is connected to one of the 1553B buses used for
data communication. The MFK has a built-in display unit and
a keyboard. It is also connected to the Multi Function Rotary
switch (MFR) through a RS422 interface.
The MFK has a built-in display unit. The display unit is a pair of
LCD based Colour Graphical Display. The Real-time
operating specifications are very stringent in such applications
because the performance and safety of the aircraft depend on
it. Efficient design of the architecture and code is required for
successful operation.

98. Multi-Function Keyboard

99. Hands on Throttle and Stick
In this buttons and switches are placed on the
throttle stick and flight control stick, allowing the
pilot to access vital cockpit functions and fly the
aircraft without removing his hands from the
throttle and flight controls.
It allows the pilot to remain focused on important
duties than looking for controls in the cockpit.
The HOTAS system can be enhanced by DVI or
HMD. This will allow the pilot to control various
systems using his line of sight, and to guide
missiles to the target by simply looking at it.

100. Hands on Throttle and Stick

101. Thank You