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  • Non-Directional Radio Beacon

    Introduction:

    • The Non-Directional Radio Beacon (NDB) is a low or medium frequency radio beacon transmits non-directional signals whereby the pilot of an aircraft properly equipped can determine bearings and “home” to the station
    • The pilot, through the use of an Automatic Direction Finder, uses these signals in order to determine relative/magnetic bearing and therefore position
    • The entire system consists of:
      • Ground station
      • ADF receiver
      • Antenna:
        • Loop Antenna (Magnetic Bearing from the airplane to the station)
        • Sense Antenna (Directional Information)
        • Bearing Indicator
    • Ultimately, the Standard Service Volume dictates the reception limits of the NAVAID

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  • Emergency Locator Transmitter

    Introduction:

     

    Radar Service for VFR Aircraft in Difficulty:

    • Radar equipped ATC facilities can provide radar assistance and navigation service (vectors) to VFR aircraft in difficulty when the pilot can talk with the controller, and the aircraft is within radar coverage. Pilots should clearly understand that authorization to proceed in accordance with such radar navigational assistance does not constitute authorization for the pilot to violate CFRs. In effect, assistance is provided on the basis that navigational guidance information is advisory in nature, and the responsibility for flying the aircraft safely remains with the pilot
    • Experience has shown that many pilots who are not qualified for instrument flight cannot maintain control of their aircraft when they encounter clouds or other reduced visibility conditions. In many cases, the controller will not know whether flight into instrument conditions will result from ATC instructions. To avoid possible hazards resulting from being vectored into IFR conditions, a pilot in difficulty should keep the controller advised of the current weather conditions being encountered and the weather along the course ahead and observe the following:
      • If a course of action is available which will permit flight and a safe landing in VFR weather conditions, non-instrument rated pilots should choose the VFR condition rather than requesting a vector or approach that will take them into IFR weather conditions; or
      • If continued flight in VFR conditions is not possible, the non-instrument rated pilot should so advise the controller and indicating the lack of an instrument rating, declare a distress condition; or
      • If the pilot is instrument rated and current, and the aircraft is instrument equipped, the pilot should so indicate by requesting an IFR flight clearance. Assistance will then be provided on the basis that the aircraft can operate safely in IFR weather conditions

     

    Transponder Emergency Operation:

    • When a distress or urgency condition is encountered, the pilot of an aircraft with a coded radar beacon transponder, who desires to alert a ground radar facility, should squawk Mode 3/A, Code 7700/Emergency and Mode C altitude reporting and then immediately establish communications with the ATC facility
    • Radar facilities are equipped so that Code 7700 normally triggers an alarm or special indicator at all control positions. Pilots should understand that they might not be within a radar coverage area. Therefore, they should continue squawking Code 7700 and establish radio communications as soon as possible

     

    • Battery operated transponders react to forces (detecting a crash) and should operate for 48 hours continuously
    • Transmit on 121.5 and 243 MHz (guard) and the newer 406 MHz
      • 121.5/243 MHz are analog devices while 406 MHz is a digital transmitter encoded with owners contact and aircraft data; can transmit aircraft position and transmits a much stronger signal
      • 406 transmitters must be registered with NOAA
    • Pilots should be able to activate and deactivate the ELT manually for testing or in the event of an emergency when they have failed to activate autonomously

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  • Altimeter

    Introduction:

    • An altimeter is a type of barometer which measures vertical distance to the surface below, using pressure, radio, radar, laser, or capacitive technology
    • Measures the absolute pressure of the ambient air and displays it in terms of feet or meters above a selected pressure level
    • A squawk, also called an altimeter setting, must be issued to pilots in order for them to maintain their assigned altitude or flight level
    • These altimeter settings are measured in the pilot’s local area, and distributed via Air Traffic Control
    • For VFR flight operations there are no regulations but the pilot should exercise extra diligence in flight planning and in operating in these conditions is essential

     

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  • Automatic Dependent Surveillance Broadcast

    Introduction:

    • Automatic Dependent Surveillance-Broadcast (ADS-B) is surveillance technology being deployed throughout the National Airspace System [Figure 1]
    • Position reports are based on satellite navigation systems (aircraft to aircraft)
    • ADS-B broadcasts once per second with the aircrafts position, velocity, identification and other information
    • Also receives this information from other aircraft
    • The ADS-B system is composed of aircraft avionics and a ground infrastructure
      • On-board avionics determine the position of the aircraft by using the GNSS and transmit its position along with additional information about the aircraft to ground stations for use by ATC and other ADS-B services
      • This information is transmitted at a rate of approximately once per second

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  • Airspeed Indicator

    Introduction:

    • The Airspeed Indicator (ASI) is a Pitot-static instrument used in an aircraft to display the crafts airspeed, typically in knots
    • Airspeed indication is accomplished with the use of a thin, corrugated phosphor bronze diaphragm (aneroid) which measures Dynamic Pressure of the air between the Pitot tube (ram air) [Figure 1] and static port (static pressure) [Figure 2]
      • Dynamic Pressure: Difference between the static (ambient) air pressure and the total pressure caused by the motion of the aircraft through the air
    • The primary use of the airspeed indicator is to provide performance guidance during climb, descent, and landing

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