The performance of recent aircraft is the main point to carry out missions with avionics equipment. Various types of antennas are installed for transmission and reception RF signals during operating avionics equipment. Therefore, it is important to lay the antenna location out considering the mission performance of the aircraft. Antenna performance is greatly affected by the aircraft fuselage ground area.
This paper presents the installation of Surion radios (VHF-FM, U/VHF-AM) antennas and the optimal position. Antenna positioning and verification were sequentially performed through 5 steps of the antenna layout process. The first stage was an analysis of other aircraft installation cases, the second stage was an antenna simulation analysis, the third stage was a communication system function and antenna coupling test on the ground, and the fourth stage was a flight test of the antenna pattern. However, in the last five stage, the long-distance flight test, the test criteria of the U/VHF-AM1 upper antenna were not met due to partial voice cut-off. Therefore, it is necessary to analyze the causes of the result and to study the solution. First, the U/VHF-AM1 upper antenna position was inappropriate, so its the position was relocated in consideration of the operating frequency characteristics. Second, the range ratio (1:20) performed in the antenna pattern flight test was not suitable for Surion. It was proposed to solve these problems that height of the antenna position increase by 18.5 cm and 1:300 (15NM) optimal range ratio for antenna pattern flight tests. Through the long-range communication flight test, the effectiveness of the proposed the way to lay out the antenna location and the evaluation criteria of the antenna performance test were verified. As a result, it is conformed that the communication antennas of the Surion were installed properly. And the results of this research is expected to be used as the standard of helicopter antenna installation and to be able to reduce the development schedule time and the cost.