The Type 13 Aerial Troop Transport is an All Purpose Military troop transport and is employed in various situations requiring Infantry Operation. It is Your Squads main form of transportation as it is almost always used to send you on your missions. It doesn't seem to have many weapons and has been shot down at least 3 times. These missions focus around you defending the grounded chopper for a certain time.
As mentioned above you must defend the downed chopper for a certain amount of time, these missions are a pain as the suicide bombers are almost impossible to control.