The Collins HFS-900D high frequency voice/data link transceiver provides a long-range data link for air transport class aircraft for fleets operating in oceanic, polar and remote land areas.The HFS-900D automatically selects the optimum communication frequency and establishes the primary data link between the aircraft and the ground station. Once the primary channel is set up and the coupler is turned on, the frequency management system continuously monitors up to 20 additional channels in the background. If the primary channel degrades to a point where it is no longer usable, the frequency management system will automatically select a new primary channel that can typically be logged onto within 32 seconds.
The HFS-900D delivers an integrated voice and data radio in a single unit with no need for an external modem and allows for maximum use of the airborne communications addressing and reporting system (ACARS). The HFS-900D is fully compatible with the CPL-920D Digital Antenna Coupler. When these two systems are combined, a system for high frequency data link (HFDL) applications is produced. The Collins HFDL system can also be paired with a single satellite communications system to provide maximum data link communication availability.