NCAA Aeronautical Station Operator flashcards
NCAA Aeronautical Station Operator · Build recall with a focused review session.
32 cards. Read the term and the definition here. The deck at the top of this page is optional.
- Aeronautical mobile (R) service
- A mobile service reserved for communications relating to safety and regularity of flight, primarily along national or international civil air routes.
- Station licence content
- A document naming licensee, call sign, authorised frequencies, power, class of emission, and operating hours, required to be kept at the station.
- Certificate of proficiency
- A personal certificate issued to an operator confirming competence and stating the privileges and station classes the holder may operate.
- Wavelength formula
- Wavelength equals the speed of light divided by frequency; at 118 MHz the wavelength is approximately 2.54 metres.
- AM total power
- Total power equals carrier power multiplied by one plus half the modulation index squared; at 100 percent modulation total power is twice carrier power.
- Decibel definition
- A logarithmic ratio: 10 log of power ratio or 20 log of voltage ratio; plus 3 dB doubles power and plus 10 dB multiplies power by ten.
- Free-space path loss
- Loss in dB equals 32.44 plus 20 log distance in km plus 20 log frequency in MHz; doubling distance adds about 6 dB.
- VSWR and reflection
- Voltage standing wave ratio relates to reflection coefficient as (1 plus gamma) divided by (1 minus gamma); 2:1 VSWR reflects about 11 percent power.
- VHF radio horizon
- Line-of-sight range in nautical miles is approximately 1.23 times the square root of antenna height in feet, summed for both antennas.
- Ionospheric skywave
- HF signals refract in ionospheric layers, chiefly F2, enabling long-range communication; D-layer absorption is greater by day and favours higher frequencies.
- Half-wave dipole
- A resonant antenna about half a wavelength long with feed-point impedance near 73 ohms and gain of about 2.15 dBi in free space.
- Coaxial cable loss
- Attenuation increases with frequency and length; short low-loss runs preserve VHF transmitter power and receiver sensitivity.
- 8.33 kHz channel spacing
- A reduced VHF channel plan mandatory in designated airspace; the channel designator differs from the actual carrier frequency by an offset.
- Emergency frequencies
- VHF 121.5 MHz and UHF 243.0 MHz are guarded for distress; HF 2182 kHz and 4125/6215 kHz support long-range distress communications.
- Squelch setting
- A receiver circuit muting audio when no carrier is present; set just above the noise floor to avoid blocking weak but usable signals.
- Read-back requirement
- Mandatory repetition of runway clearances, hold-short instructions, altitude assignments, and other safety-critical instructions to confirm correct reception.
- ROGER and WILCO
- ROGER means the message was received; WILCO means received and will comply; AFFIRM means yes and NEGATIVE means no.
- Phonetic alphabet
- Standard words for letters: Alpha, Bravo, Charlie, Delta, Echo, Foxtrot, Golf, Hotel, India, Juliett, Kilo, Lima, Mike, November, Oscar, Papa, Quebec, Romeo, Sierra, Tango, Uniform, Victor, Whiskey, X-ray, Yankee, Zulu.
- UTC time transmission
- Time is sent as four digits in UTC, for example one two three zero for 12:30 UTC; date groups use six digits day-month-year.
- AFTN priority indicators
- SS for flight safety, DD for urgent, FF for flight regularity, GG for general, and KK for administrative; SS receives highest handling priority.
- AFTN date-time group
- Six digits giving day of month, hour, and minute in UTC, such as 121530 for the twelfth day at 15:30 UTC.
- AFTN address structure
- Eight-letter location indicators: four letters for the station, three for the department, and one for the service.
- NOTAM classes
- NOTAMN is a new notice, NOTAMR replaces a previous notice, and NOTAMC cancels one; each carries a serial number and location indicator.
- METAR and SPECI
- METAR is a routine aviation weather report issued at fixed intervals; SPECI is a special report issued when significant weather changes occur.
- TAF
- Terminal aerodrome forecast covering a specified period and including wind, visibility, weather, cloud, and expected changes.
- SIGMET
- A warning of hazardous weather such as thunderstorms, turbulence, icing, or volcanic ash issued for the safety of aircraft operations.
- MAYDAY signal
- The spoken distress signal transmitted three times, indicating a station is in grave and imminent danger and requires immediate assistance.
- PAN PAN signal
- The spoken urgency signal transmitted three times, concerning the safety of an aircraft or person but not requiring immediate distress assistance.
- SECURITE signal
- The spoken safety signal transmitted three times, preceding important navigational or meteorological warnings.
- Distress message content
- Includes station addressed, call sign, position, nature of distress, assistance required, and intentions, sent after the MAYDAY signal.
- Station log content
- Records date, UTC time, frequency, call signs, and summary of communications, including distress and urgency traffic, retained for the required period.
- Watchkeeping requirement
- A continuous listening watch on 121.5 MHz and assigned operational channels during published hours, with prompt response to calls.