In Side-by-Side helicopter system, pilots and co-pilot occupy same place and make a community about instruments. So both pilots have a great interaction and communication compared with tandem helicopter. In our previous research, we found the TSD information is effected on mission conduction greatly. We also realized the new task assignment is required. To compensate for our previous research and find the optimal task assignment in side-by-side helicopter system, we set up the second experiment. We established the scenario and did some experiment. Measuring data is performance total time, killing rate, and pilot & gunner workload data similar to before experiment 1, and this project has a purpose about finding optimal task assignment and researching strong point than Tandem system using 1 & 2 experiment totally.