Radio wave Propagation Radio Wave Transmission Radio waves propagate or travel as Ionospheric and Non-ionospheric propagation Ionospheric layer is found in the upper levels of stratosphere in atmosphere Radio waves travel or propagate with or without use of Ionosphere Non-Ionospheric propagation takes place without use of ionosphere Ionospheric propagation takes place using the ionospheric layer Non Ionospheric Propagation Non-Ionospheric propagation does not pass through Ionosphere Ground waves propagate without passing through Ionosphere Ground waves are sub-divided into Surface and Space waves Surface Waves Low, Medium and High Frequency waves from…
Author: Wg Cdr Rajagopal
Electro-Magnetic Waves (EM Wave)
Electro-Magnetic Waves Electrical and Magnetic Field in EM Waves EM waves are created by movement of Alternating current (AC) in a wire Radio aids in aviation use Electro Magnetic Waves (EM Waves) Alternating current creates a magnetic field perpendicular to electric field EM Radiation is transmitted through air if the wire is connected to an Ariel EM Radiation consists of electrical and magnetic components Electrical field in the same plane of the ariel Magnetic field perpendicular to the electrical field Electro Magnetic Spectrum EM waves has a wide spectrum with…
Flight Data Recorder – Cockpit Voice Recorder
Flight Data Recorder and Cockpit Voice Recorder Introduction to FDR Flight data recorder preserves aircraft data for accident investigation Trend analysis and trouble shooting is also done using data from FDR FDR records data for 10 to 25 hours of flight data and kept in Black box Black box is painted red or orange and is located in tail fin The container is resistant to fire, heat, shock and water damage Tail fin location reduces damage due to G forces in an accident Components of FDR Flight data recorder is…
Airborne Collision Avoidance System (ACAS)
Airborne Collision Avoidance System Introduction to ACAS Airborne collision avoidance system is called Traffic collision avoidance system TCAS II is mandatory for all commercial aircraft with 19 passengers or more TCAS II detects, assesses and warns of collision risk Warnings consist of Traffic and Resolution Advisories Traffic Advisories provide proximity traffic information only. Resolution Advisories offer maneuvering advice in the vertical plane. Principle of ACAS ACAS works on the principle of secondary radar in air to air mode Minimum requirement for ACAS are Mode A SSR transponders Frequencies used is…
Ground Proximity Warning System (GPWS)
Ground Proximity Warning System Introduction to GPWS Ground proximity warning system prevents controlled flight into terrain Warns of proximity to the terrain which are potential threats to safety Operates in height band 50 to 2450 feet, which is same as radio altimeter Automatic selection of operation mode based on flight profile Radio altimeter, Mach meter, ADC and Glidepath provide inputs Undercarriage, Flaps and Navigation systems also provide inputs Stages of GPWS Warnings GPWS warnings fall under two categories Alert is a caution which means advisory instructions. Warnings are commands which…
Warning Systems
Warning Systems Visual Warning Systems Warning systems gets inputs from GPWS, TCAS, Engine and Aircraft systems Alerts the crew to danger levels in the order of their priority Level A are red lights and require immediate attention Level B are amber lights requiring crew alertness and possible action Level C are in other colours requiring crew alertness without any action Types of Visual Warning Systems Warnings are displayed as warning flags or danger lights Electronic Flight Information System may display warnings as symbols Master warning lights are attention getters which…