Australia is extending its contract with Canada-headquarted McDonald, Detwiler and Associates for continued use of Heron remotely piloted aircraft.

One Heron, a medium-altitude long-endurance unmanned aerial vehicle, is operating at a Royal Australian Air Force in the country for training. A second is being used in Afghanistan and will be brought back to Australia by the end of the year.

Minister for Defense David Johnston said the six-year contract extension would cost about $105.6 million and would be covered by the existing Air Force budget and through a redistribution of tasks and priorities.

Extension of the contract would include portable ground control stations initially based at RAAF Woomera, maintenance, logistics and other associated items.

Johnston said retaining the Herons is part of a plan to ensure RAAF pilots maintain the skills to operate unmanned aerial systems until the introduction of the MQ-4C Triton, a high-altitude unmanned aerial system it plans to acquire from the United States.

"The Heron is a proven capability -- providing 'eyes in the sky' for our troops in the Middle East," Johnston said. "The retention the Heron following their withdrawal from Afghanistan later this year will ensure Australia remains at the forefront of this advancing technology.

"This is prudent planning for possible future defense scenarios."

The Heron is made by a division of Israel Aerospace Industries. It has a speed of 130 miles per hour, a range of 217 miles and a ceiling of 32,800 feet and an endurance of more than 50 hours.