Thai Air Force Territorial defense training was introduced in 2006 and available until Grade 5 by 2010 for the Royal Thai Air Force, only for students studying in polytechnic colleges within the locale of the Don Muang Royal Thai Air Force Base, Bangkok. The study will involve only about the mechanical side of the air force only. Small arms Uniform and insignia Army territorial defense students wear a khaki-green uniform and beret with the Army Reserve Command Insignia (Crossed swords under The Great Crown of Victory) on their collar, beret, and belt. Territorial defense students distinguish their school and province by the school's coat of arms on the right shoulder, and provincial badge on left breast. The name badge is sewn on the right chest. Training years and rankings Each student's training year can be distinguished by rectangular Thai Numeral ranging from 1 to 5 on a khaki-background tag. For command students, they are distinguished with colored background and pentagonal-shaped number tag. The official colorings are as follow. "Green": Squad Leader "Red": Platoon Leader "Light Blue": Company Leader In practice, the command student's ranking can go up to battalion or even regiment. These off-document ranks employ off-document insignia such as armbands with text notation. Such notations can also be employed for lower positions, as command students do not inherit their status into the Field Training. Special training About 120 fourth grade territorial defense students who pass the physical test are allowed to enter the parasail training course. Requirements are, for males, 15 pull-ups with no time limit, 47 push-ups in two minutes, 65 sit-ups in two minutes, and a one-mile run in eight minutes. Female applicants have more relaxed requirements. Battle of Tha Nang Sang Bridge On the first day of the Japanese invasion of Southeast Asia (8 December 1941), the Japanese Army sent troops to many parts of Chumphon Province. At Ma Hat Bay, the Japanese forces landed on beaches stretching from Ban Pak Nam Chumphon to Ban Kho Son. The 38th Infantry Battalion of the Royal Thai Army, about 17 km away, was too far away to intercept the initial invaders in time. As a result, roughly 100 of the reserve students and the local police force had to hold the numerically superior Japanese army at bay from positions on the west side of Tha Nang Sang Bridge until the 38th Infantry could arrive. The force of reserve