What is the SELCAL code?
SELCAL is a signaling method which can alert an individual aircraft that a ground station wishes to communicate with it. SELCAL codes are assigned to aircraft operators and not to individual aircraft. Aviation Spectrum Resources (ASRI) is the registrar of SELCAL codes worldwide.
How do I get a SELCAL code?
An individual aircraft is given a SELCAL code upon application to the SELCAL code registrar, Aviation Spectrum Resources, Inc. (ASRI). The code is technically assigned to the owner-operator of the aircraft rather than the aircraft itself; if an aircraft is sold, the new owners-operators must apply for a new code.
What is SELCAL number or codes?
SELCAL codes are made up of the various combinations of alphabetic characters represented as two pairs (for example AC-BD), with each character representing a unique audio frequency (see table at the bottom of this page).
What does the contraction SELCAL means?
What does the contraction “selcal” mean? It means selective calling. It is where the ground controller sends a special code that sounds a chime or illuminates a light to warn the pilot of an incoming message and to turn the volume up. Give two reasons why Selcal is used.
How do you test for SELCAL?
The aircraft station should contact the appropriate aeronautical station and request a pre-flight SELCAL check and, if necessary, give its SELCAL code. When primary and secondary frequencies are assigned, a SELCAL check should normally be made first on the secondary frequency and then on the primary frequency.
How many SELCAL codes are available?
The number of SELCAL codes registered has now increased to over 37,000 SELCAL code assignments, over three times the number of available unique SELCAL code combinations.
How is the problem reduced where an aircraft has the same SELCAL code?
7.7 How is the problem reduced where 2 aircraft have the same SELCAL code? Answer: Either by assigning the same code to aircraft on opposite sides of the globe or by assigning different HF channels (HF only).
What is a problem associated with very high frequency waves?
Related Topics: Frequency band. VHF waves, unlike longer waves, are not strongly reflected from the atmosphere; therefore, they do not bend readily around the Earth’s curvature and cannot be transmitted beyond the horizon. Their range is further limited by their inability to pass through hills or large structures.
What is the frequency range for very high frequency?
30 MHz to 299 MHz
Radio frequency range from 30 MHz to 299 MHz. The sub-bands most commonly used by fire are: VHF-FM Lo band: Frequency Modulation 30 MHz – 80 MHz, of which fire frequencies are between 30 MHz and 50 MHz.
How is the problem reduced where an aircraft have the same SELCAL code?
What is the purpose of very high frequency?
Very high frequency is commonly used for FM radio broadcast, two-way land mobile radio systems, long-range data communication, and marine communications, just to name a few. VHF includes radio waves from 30 MHz to 300 MHz.