Interpilot air-to-air communication
In accordance with regional agreements, 123.45 MHz is the designated air-to-air VHF communications channel. Use of this channel will enable aircraft engaged in flights over remote and oceanic areas out of range of VHF ground stations to exchange necessary operational information and facilitate the resolution of operational problems (AIP GEN 3.4). Contingency procedures (e.g TIBA, Mandatory Broadcast Procedures) are referenced in AIP GEN 3.3-9