Unit-5 Introduction to Avionic SystemCommuication systemsnavigation systems Flight Control systems Radar & Electronic Warfare Utility system for reliability and maintainability Certification

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Syllabus Commuication systemsnavigation systems Flight Control systems Radar & Electronic Warfare Utility system for reliability and maintainability Certification2

Navigation systems VOR ILS DME GPS

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Civil Aviation Communication system1. Satellite system including a constellation of satellites & A ground subsystem including networked ground stations communicating with the satellite subsystem. Airborne communication system in the aircraft transmitting to the satellite in the first frequency band's band). Airborne system receiving transmissions from the satellite subsystem in the second frequency band. Airborne system communicating with a ground based system in a third frequency band. The third frequency band is between the first frequency band and the second frequency band.4

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Communication Systems1. VHF Communication for Rx 100-150 MHz fir range 200 miles @ 20,000ft. 2. Long Range, HF communication @ 220MHz thru a long wire antenna between fuselage land fin 3. ATC transponder at the aircraft thru pulses giving the position & height to the ATC controller5

Navigation System1.2. 3. 4. 5.

Doppler Navigation: thru a Doppler radar at the aircraft thru a single pulse and finding the delay, giving ground speed and drift LORAN-using hyperbola principle using various 100 KHz TX-s and the intersections indicating the position GPS-giving position fixes from RX signals thru various global satellites Inertial Navigation-offering acceleration information on a stabilized aircraft Electronic Counter Measure-giving false signals to confuse enemy aircrafts6

Equipments for Navigation Systems1) Automatic Direction Finding-ADF giving Magnetic bearing of the aircraft for location on the map thru RMI from a Non Directional Beacon VOR-VHF Omni directional range-offering the course to the destination to the pilot on a freq of 108 Mhz-117.95 with no interference to the atmosphere DME-Distance Measuring equipment-measuring distance thru the time delay from aircraft to the beacon and back TACAN used in Military aircrafts

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Flight Control SystemsTypesFBW,FBL, distinction

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Elements of Flight Control systems1. Autopilot scheme-giving the motion of the aircraft thru accelerometer and gyro 2. Linkage 3. Actuator used to convert the signal from the autopilot to actuate the control device9

Flight Control Technologies1. Fly By Wire- FBW:Controlling the system for an airplane where controls actuated by electrical impulses, as from a computer 2. Fly by Light- FBL:Used instead of fly-by-wire for transferring data at higher speeds; FBL-immune lectromagnetic interference. Cable replaced by fiber optic cables10

Fly by wire types Fly-by-wire - a means of aircraft control using Electronic Circuits to send inputs from the pilot to the motors that move the various flight controls on the aircraft. Analog and Digital Fly by wire-No direct hydraulic or mechanical linkages between the pilot and the flight controls. Digital fly-by-wire using an electronic flight control system coupled with a digital computer to replace conventional mechanical flight controls11

Fly By Wire Features Fly-Wire-System of modern technology use computers to control all the flight operations of an aircraft. FBW extremely reliable, accurate and free from human errors. Electrical, electronic and computer systems completely replace conventional, mechanical systems required forturning the rudder or wing flaps of an aircraft. 12

Analog and Digital FBW systems FBW Analog control system eliminating the complexity, fragility and weight of the mechanical circuit of the hydromechanical flight control systems and replacing it with an electrical circuit. Analog cockpit controls now operating signal transducers which generate the appropriate commands, that are in turn processed by an electronic controller.13

Fly by Wire -Airbus A 321 cockpit

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Airbus A 321 Digital FBW Aircraft

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Digital FBW Control Pilot flying via a Computer reading position and forcing inputs from the pilot's controls and aircraft sensors Digital FBW enabling Flight Envelope Protection, increasing electronic stability Digital FBW reduce Pilot workload High reliability compared to Analog FBW16

Radar Electronic WarfarePrinciple, Types,Jamming,Communication thru jamming,ECM, EECM17

Control-Types1. 2. 3. 4. 5. 6. 7. Fire-control Surveillance Navigation Missile control air defence IFF and secondary surveillance Land-based, airborne and naval Military air traffic control18

Radar-Types1. Air Traffic Control ATC Radar 2. Tracking Radar-Surface to Air and Air to Air 3. Ballistic Missile-Military Radar 4. Satellite SAR Reconnisance

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Surveillance Radar

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ATC Radar

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Military Radar-Objectives1. Targeting fixed and movable objects 2. Striking using Radio Frequency & Infra Red Sensors 3. Prediction and measurement of Radar Cross Section-Stealth

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ELECTRONIC WARFAREPrinciple, Measures,Jamming, ECM ECCM

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Electronic Warfare-Definition Using Radio frequency or IR for determining, exploiting , reducing , or preventing enemy to use electromagnetic spectrum- called Electronic Warfare in Defense Use Directed energy or EM spectrum to attack the enemy EW applied from air, sea, land, and space by manned and unmanned systems26

Key Activity

1. Electronic Support 2. Electronic Counter Measures 3. Electronic Counter Counter Measures27

Objective

1. Electronic attack (EA), 2. Electronic Protect (EP), and 3. Electronic warfare support (ES)28

Warfare-Types1. Passive Warfare- by Earthorbiting satellites, aircraft, ships, aircrafts

2. Active Warfare-thru differentjamming techniques

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Devices used1. Towered Decoys-to avoid an incoming missile 2. Airborne POD and Internal ECM 3. Ship borne ECM 4. Battlefield ECM

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Decoy by Raytheon

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ELECTRONIC WARFAREELECTRONIC SUPPORT MEASURES ESMJAMMING ELECTRONIC COUNTER MEASURESELECTRONIC COUNTER COJNTER MEASURES ECCM

ECMDECEPTION

DENIAL

FREQIR DECOY

EMISSION

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ECM Function1. Disable enemy radar 2. Detect RF Sensor, identity their source, determine the source for optimum response called RWR-Radar Warning Rear 3. ELINT & ESM fed to RWR which protect the data on hostile system33

ECM

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Electronic Warfare include ELINT COMINT ECM Defensive Aids Suites (DAS) Land-based, naval and airborne

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ECM sub systems

ESM-Electronic Support Modul

ECMRWR

ELINT-Electronic Intelligence RWR-Radar warning Rear

ELINT

ESM36

Internal ECM

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Jamming

1.Jamming By radar thruNoise and Frequency of enemy radar and Mechanical jamming

2.Deception jamming 3.Denial38

1. Jamming Types1. Mechanical Jamming by Chaff, Corner Reflector, Decoys 2. Electronic Jamming by Spot jamming, Sweep jamming, DRFM (digital radio frequency jamming)

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1. Radar Jamming- in short Intentional emission of radio frequency signals to interfere with the operation of enemy radar by saturating their receiver with false information Two types of radar jamming: noise jamming and deception jamming Noise jamming system designed to delay or deny target detection using high power signals tuned to the same frequency of the enemy radar. Techniques for Noise Jamming include barrage, spot, swept spot, cover pulse, and modulated noise signals40

2. Deception Jamming by decision circuitry1. Predicated from the information from the enemy signals so that the signal Transmitted deceives the enemy radar or its operators 2. Done by receiving pulse from an enemy radar , circulate it through a delay line, amplify the signal , and reradiate back towards the enemy 3. Decision circuitry conclude that the target is at a greater distance than it actually is because of the deceptive pulse 41

ECCMObjective and methods

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Objective1. Methods to reduce or eliminate the effect of Electronic Countermeasures (ECM) on electronic sensors towards Aircrafts, vehicles and missiles 2. Using Infra-Red (IR) decoy flares and radar countermeasure chaff for protecting aircraft from heat soaking and radar-guided missiles43

Techniques1. Chirping or Pulse Compression, or linear frequency modulation-increasing the signal strength received by Radar RX 2. Frequency Hopping-by rapidly switching off the TX and Switching On the RX 3. Sidelobe banking- detecting the signal from the side lobe of the main antenna 4. Polarization-using a cross polarized antenna 5. Radiation homing-targetting enemies radiation source44

Raytheon ECCM System

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FBW

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Principle of FBW "Fly-by-Wire" (FBW) imply an electrically-signaled only control system. new way of sending signals from the cockpit to the other parts of the airplane signals tell a part of the aircraft (i.e., flaps, horizontal stabilizer, rudder, engines) to move a certain amount. computers read and refine the signal before letting it continue This helps the pilot in times of bad 47 weather (turbulence) and some

Boeing 7 77 using FBW

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Airbus A321 cockpit by flyby wire Digital)

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Flyby wire control systems1. Analog systems-analog computers replaced the electronic controller cockpit controls now operate signal transducers which generate the appropriate commands, that are in turn processed by an electronic controller. The autopilot is now part of the electronic controller 2. Digital systems digital fly-by-wire 50 flight control system is similar to

The Airbus A320, first airliner with digital fly-bywire controls

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Digital creases electronic stability, because the system is less dependent on the values of critical electrical components in an analog controller. The computers "read" position and force inputs from the pilot's controls and aircraft sensors. Side-sticks, center sticks, or conventional control yokes can be used to fly such an aircraft. 52

Utility System for reliability and Maintainability

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CertificationTypes, Certification need for Civil Aircraft, Software and Hardware, DO178B,54

Factors for Evaluating an Avionic System1. Capability of the avionic system 2. Reliability-meaning low maintenance cost 3. Maintainability-thru built in tests,auto trouble shooting and accessibility to hardware 4. Certficability (Civil)-tests on design and operation 5. Cost of Ownership including spares, training 55 6. Technical Risk for development

Types of Avionic System Evaluation (analysis techniques)1. Fault Tree Analysis (FTA) 2. Failure Mode & Effects Analysis (FMEA)

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Civil Transport Certification need For civil and commercial aviation we have test solutions for transponder modes A/C/S and ADS-B, ILS, VOR, DME, TCAS, HF, VHF, UHF communications, Short Range and 406MHz ELTs, weather radar and GPS system consists of a computer controller to act as the main controller of the firmware maintenance system, (FMS), the programmer unit and the circuit card interface equipment. The computer (PC) is optional and is not illustrated.The FMS 7000 can program various types of Proms, including the EPROM, Flash57

Certification1. Certification steps producing a deliverable document, code, or a test report for an avionic system or a Flight carrier 2. When the software passes all of its tests these are bound into a certification report, the avionic software is certified.58

DO178B Certification is a guidance for software development published by RTCA, Incorporated. The standard was developed by RTCA and EUROCAE. The FAA accepts use of DO-178B as a means of certifying software in avionics he FAA accepts use of DO-178B59

Software level Catastrophic - Failure may cause a crash. Hazardous - Failure has a large negative impact on safety or performance, or reduces the ability of the crew to operate the plane due to physical distress or a higher workload, or causes serious or fatal injuries among the passengers. Major - Failure is significant, but has a lesser impact than a Hazardous failure (for example, leads to passenger discomfort rather than injuries). Minor - Failure is noticeable, but has a lesser impact than a Major failure (for example, causing passenger 60 inconvenience or a routine flight plan change)

Software level

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Avionic Certification Federal Aviation Administration (FAA) certification of a new aircraft avionic system Upon activation of the system, pilots can significantly enhance visibility in poor weather --including darkness, smoke, smog, haze and other weather events--while simultaneously seeing critical flight data A unique application of Honeywell 62 International "Head Up Display"