Safety Investigation Report 2018:1 Factual Information/1.9/1.9.1 HF
Jump to navigation
Jump to search
SAFETY INVESTIGATION REPORT MH370 (9M-MRO)
1.9.1 High Frequency System
This aircraft was installed with Collins HFS-900 High Frequency (HF) System. The HF communication system on this aircraft uses two HF systems with a common HF antenna to transmit and receive radio frequency (RF) signals in the HF range.
The HF transceiver operates within the frequency range of 2,000 MHz to 29,999 MHz and one KHz channel spacing.
The Left Transfer bus sends 115V AC three-phase power to the Left HF communication system. The Left HF communication transceiver supplies 115V AC single phase to the Left HF antenna coupler for operational power. It also supplies 28V DC for the key interlock function. The Right HF communication system is the same as the Left, except that it uses power from the Right AC Sec 2 bus.