August 4, 2008: The U.S. Navy lent their RQ-4 Global Hawk UAV to the state of California last month, for use in monitoring the progress of massive forest and brush fires in the northern part of the state. The RQ-4 stayed in the air for nearly 24 hours, using its powerful sensors to send detailed images to those managing the effort to fight the fires.

It's not unusual for the military to contribute personnel or other resources to civilian disasters, including forest fires. But the RQ-4 was unique in that the navy is still testing this version of Global Hawk, which is equipped for maritime patrol. The RQ-4 is a long range UAV, that can reach any place in the world in 24 hours. Earlier this year, an RQ-4A made the first non-stop crossing of the Pacific, flying 12,000 kilometers, from California to Australia, in 23 hours. The Global Hawk has previously crossed the Pacific in several hops, but it always had the endurance to do it non-stop.

The U.S. Navy has found that engaging in this kind of disaster relief effort is very beneficial. First, the people being helped appreciate it, and this is good in the PR department. But the sailors and marines involved get useful experience operating in intense, and often extreme, circumstances.

A strategic reconnaissance UAV like the RQ-4, which can intensely scan land and water surfaces, is particularly useful for disaster relief. The video and still images an RQ-4 generates are transmitted via satellite to the ground, and can easily be put onto an Internet connection. This makes it easy to get the images to the people running the disaster relief. In effect, the RQ-4 is like having a photo-satellite overhead all the time.

In the last seven years, RQ-4s have flown over 20,000 hours, most of that combat missions, and many of them from Persian Gulf bases. The latest models have been able to fly 20 hour missions, land for refueling and maintenance, and be off in four hours for another twenty hours in the sky. The RQ-4 has been very reliable, with aircraft being ready for action 95 percent of the time. The U.S. Air Force has been buying them at the rate of five a year, at a cost of $58 million each.

The new B version is larger (wingspan is 15 feet larger, at 131 feet, and it's four feet longer at 48 feet) than the A model, and can carry an additional two tons of equipment. To support that, there's a new generator that produces 150 percent more electrical power. The B version is a lot more reliable. Early A models tended to fail and crash at the rate of once every thousand flight hours, mostly because of design flaws.

The first three RQ-4Bs entered service in 2006. At 13 tons, the Global Hawk is the size of a commuter airliner (like the Embraer ERJ 145), but costs nearly twice as much. Global Hawk can be equipped with much more powerful, and expensive, sensors. These more the double the cost of the aircraft. These spy satellite quality sensors (especially AESA radar) are usually worth the expense, because they enable the UAV, flying at over 60,000 feet, to get a sharp picture of all the territory it can see from that altitude.

The U.S. Air Force is stationing a squadron of seven Global Hawks on the island of Guam. These UAVs will begin arriving there next year, and undertake recon missions throughout the western Pacific. The U.S. Navy is also planning to buy Global Hawks, 44 of them, to perform maritime reconnaissance. As a result of that decision, Australia is likely to buy some as well, to monitor the vast stretches of ocean that surround the island continent. The navy RQ-4 used in northern California is the test aircraft the navy is using to see how effective the Global Hawk would be on maritime patrol missions.