The U.S. Air Force has ordered five
more MQ-4 Global Hawk UAVs, at a cost of $58 million each. This is the B
version, which 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 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
The B version is supposed to be a lot more
reliable. Early A models tended to fail and crash at the rate of once every
thousand flight hours.