Communications Theory PDF

COMMUNICATIONS THEORY  Radio Telephony (RT) and Communications VHF –COM 720 VHF radio transceiver for two way comms 118.0MHz – 136.975 MHz (25kHZ) Emergency freq- 121.5MHz VHF-NAV VHF receiver for ground based radio nav aids VOR, ILS, DME, ADF Transponder- t...

COMMUNICATIONS THEORY  Radio Telephony (RT) and Communications VHF –COM 720 VHF radio transceiver for two way comms 118.0MHz – 136.975 MHz (25kHZ) Emergency freq- 121.5MHz VHF-NAV VHF receiver for ground based radio nav aids VOR, ILS, DME, ADF Transponder- the aircraft side of secondary surveillance radar (SSR) Other Nav Aids- Fan Marker(MKR), Ground controlled approach system (GCA), Locators (L) non Directional Beacons(NDB), Terminal Area Radar (TAR)  Transmission Technique Getting ready to transmit Select desired frequency Adjust the volume Adjust the squelch Before transmitting Listen out on channel Decide what you need to say Be prepared to write down received messages if necessary To Transmit Activate press to talk one sec before beginning to one sec after Have microphone close to lips Avoid touching microphone Speak deliberately and clearly Check the Transmit button isn’t stuck after Transmitting If radio doesn’t work Continue to fly, check freq, check switches, check headset, check circuit breakers, SQUALK 7600 for comms failure, transmit intentions blind, stay in VMC, land ASAP  Phonetic Alphabet alpha bravo charlie delta ecko foxtrot golf hotel india juliet kilo lima mike november oscar papa quebec romeo sierra tango uniform victor whiskey xray yankee zulu Expressing Words and Numbers Clear, slowly and concise  Standard words and phrases Acknowledge Affirm Cleared Expedite Line up downwind Base leg Final Go round Hold Mayday Pan Radio check verify THE TRAFFIC PATTERN  Air Traffic Service Units Air Traffic Control (ATC) – indicated by place name followed by function e.g Dublin Tower. Provides control and information service, issues ATC clearances to enter/leave controlled airspace, provides a traffic info service, and alerting service for SAR. Flight Information Service (FIS)- indicated by place name followed by information. Information service only, not authorised to issue ATC clearances. No clearances are required at aerodrome operating FIS but contact should still be made. Total responsibility for safety lies with the pilot. Air/Ground radio (A/G)- indicated by place name followed by radio. Provides basic information only. Type of ATSU can vary depending on time of day- even if none available make call to info other aircraft  Controlled Airspace Control Zone- airspace around aerodrome in which ATC is provided to all flights. Surface to specified altitude Control Area- a portion of airspace in which ATC is provided. Upwards from a specified base to an upper flight level Terminal Control Area- an established Control Area in the vicinity of a major Aerodrome Airway- Control Area in the form of a corridor extending five miles each side of straight line joining places. Delineated by radio navigation aids, identified by a code (LIMA 975) Military Airspace- imposes certain restrictions  AirField and en-routeProcedures Parked Position (see page six of notes) Holding Downwind Final Runway vacated En-route - Callsign and aircraft type followed by P H A C E R ( position, heading , altitude, conditions,estimate,request) Priority messages: mayday, pan, direction finding, flight safety.flight regulatory Position reporting Callsign, position, time, level, ETA  Arrival and Traffic Pattern Procedures Before entering ATZ you should Listen to an ATIS if available Obtain an ATC route clearance if you are to enter controlled airspace Call at 15nm or 5 min flying time with call sign a/c type and PHACER Plan entry into the circuit pattern  COMMS FAILURE Transmitter only Carrier wave transmission -Single 1 second transmit for yes and 2 sec for no Transponder squawks or heading changes as requested Transit blind- someone may hear Continue assigned squawk unless told to change to 7600 or other  Receiver only comms failure Try the VHF-NAV receiver ATSU may try to transmit to you via NDB or VOR channel you are on Transmit blind- say so See and be seen On ground return to parking area yes- no-- say again---require homing ----(Morse H) manoeuvre complete _ (2 seconds) _ - - _ a further emergency (Morse X) Distress and Urgency Procedures Fly, Navigate, Communicate MAYDAY CALL Used when there is imminent danger to the pilot and/or aircraft e.g. During single pilot incapacitation Engine failure in a single engine aircraft, fire, structural damage or failure A forced landing Lost and/or extremely low on fuel Poor weather resulting in extreme danger  PAN CALL Urgent but does not require immediate assistance Nav difficulties Serious illness of pax Rough engine, electrical or tech problems Deteriorating wx See or hear another a/c in trouble Emergency change of level in controlled airspace -..- -..- -..- (XXX) 121.5 or 7700  Emergency Voice Procedure Name of airfield being addressed Your Callsign type of a/c Nature of emergency Pilot intentions Present position Altitude and heading Pilot qualifications (student etc) and other info if possible in the timeframe