For the last two years, Ireland has maintained a battalion of troops in Chad, as part of an international peacekeeping force. Battalions went there on four month rotations. Thus, during the last two years, some 2,500 Irish troops were deployed to Chad (a few more than once.) Only 55 had to be sent back home early (19 because of injury or illness that could not be treated in Chad, the rest because of a death or severe illness in the family).
Irish troops have done lots of peacekeeping, but Chad proved to be their biggest challenge ever. The desert and semi-desert areas they were patrolling was vast, inhospitable and full of unfamiliar diseases. Heat related disorders were a constant danger (temperatures were often over 50C/122F degrees).
The Irish troops were trying to keep bandits and various rebel gunmen from several large refugee camps. They quickly discovered that they had to get some suitable aircraft (helicopters and UAVs) to accomplish this task. They ended up leasing some Russian Mi-17 helicopters, complete with East European crews. The Irish also bought two Israeli Orbiter UAV systems, for $550,000 each. Two of their six UAVs were lost in Chad. One UAV was lost when it apparently tried to fly back to Ireland, after it lost its communications link with the operator. The Orbiter is programmed to head back to the operator if it loses its comm link. But this Orbiter apparently still had a GPS location back in Ireland in its memory, and headed there. Since Ireland is 5,000 kilometers from Chad, the Orbiter ran out of juice and landed about 4,800 kilometers short of its goal.
The last Irish troops will be leaving Chad this month.