How is the problem reduced where two aircraft have the same SELCAL code?
How is the problem reduced where two aircraft have the same Selcal code? To avoid a call intended for another airplane, identical codes are assigned in widely separated parts of the world. An incoming signal with the correct code illuminates a green panel light in the Selcal Control Panel and sounds a chime.
What does ACARS stand for?
Aircraft Communication Addressing and Reporting System
ACARS is an acronym for Aircraft Communication Addressing and Reporting System. It is a data protocol defined in ARINC Specification 618, published and administered by Aeronautical Radio, Inc.
Who is the official registrar of SELCAL codes?
From that point, ARINC became the official registrar of SELCAL codes, accepting all SELCAL applications directly, as well as providing an annual report to ICAO with a summary of SELCAL usage. In 2006, the ARINC section responsible for SELCAL was re-structured into a separate company called Aviation Spectrum Resources, Inc. (ASRI).
Where does the SELCAL code go on an aircraft?
The code is received by any aircraft receiver monitoring the radio frequency on which the SELCAL code is broadcast. A SELCAL decoder is connected to each aircraft’s radio receiver.
How many SELCAL codes are there in the world?
The number of SELCAL codes registered has now increased to 35,000 SELCAL code assignments, over three times the number of available unique SELCAL code combinations. Where possible duplicate codes are assigned to aircraft operated in widely separated areas of the world, and usually do not have the same HF radio frequency assignment.
Is there a shortage of SELCAL code combinations?
Given the growth in the demand for SELCAL codes, there is a shortage of available 4-letter codes. This shortage has required re-use of the same code by more than one aircraft. The number of SELCAL codes registered has now increased to 35,000 SELCAL code assignments, over three times the number of available unique SELCAL code combinations.