This paper proposes a reliable communication system for high air-traffic oceanic flight routes in aeronautical industry. This proposal uses a single aeronautical VHF channel with an air-to-air radio relay system based on local Ad-hoc networks. A TDMA (Time Division Multiple Access) is proposed to be used for multiple access in a wide-area where each aircraft is assigned with one time slot and kept during its presence in the system in order to transmit its own packet by itself or to relay its packets by neighbor aircrafts. By transmitting in each three frameperiods, each aircraft's position, ID and direction are all used to build a routing table at each neighbor aircraft. Several methods of relaying packets are discussed to reduce packet-loss-ratio occurred from relaying process. In addition, the method to deal with the sparseness of aircrafts in some periods of time was also proposed to make the packet-loss-ratio lower. This system is an effective way not only to allow aviation authority to give moreflights but also increase the safety by providing situational awareness frequently for all flights on the oceanic routes.