8.33 kHz radio. (Trig Avionics)
Pilots flying general aviation aircraft in U.K. airspace are being urged by the UK Civil Aviation Authority (CAA) to convert their aircraft radios to 8.33 kHz spacing as soon as possible. According to a statement issued by the agency, pilots flying aircraft with non-8.33 compliant radios have been involved in several recent incidents that have caused alarm among the nation’s air traffic controllers.
Under an EU law passed in November 2016, ground stations in the U.K. and throughout Europe are now operating with 8.33 kHz receivers. The law, implementing regulation No. 1079/2012, was an airspace mandate issued to Eurocontrol by the EU to develop requirements for the coordinated introduction of air-to-ground voice communications based on 8.33 kHz channel spacing. Stations were upgraded to 8.33 kHz to relieve frequency congestion in the legacy 25 kHz band.
Europe first introduced 8.33 standards for aircraft flying above 24,000 feet in 1999, according to the National Business Aviation Association (NBAA).
“All aircraft, recreational and commercial, that need a radio have to convert to 8.33 kHz by the end of 2018,” a representative for the CAA told Avionics in an emailed statement.
CAA notes that several incidents have occurred within en route airspace and at smaller general aviation airports where pilots have been tuned to incorrect channels and unable to communicate with ground stations. There have been other incidents in which controllers experienced interference from aircraft using the wrong frequencies.
Although 8.33 kHz spaced radios are compatible with ground stations still operating on 25 kHz spacing, the reverse is not true; aircraft with 25 kHz radios cannot communicate with ground stations operating on 8.33 kHz, according to the CAA.
General aviation pilots and aircraft owners can claim a grant for up to 20% of the cost of installing a new 8.33 kHz radio under a funding agreement with the EU. The CAA has processed more than 5,500 such grants totaling more than $1.3 million to date. The application period for the grants comes to an end next month.
Aircraft still carrying radios tuned to the 25 kHz frequency in 2019 are not eligible for exemptions, according to CAA.