Interesting article on UAV losses.
Human error causes most Predator crashes - Military - MSNBC.com
Herz reported that most Predator mishaps were the result of three types of human errors: inadequate skills and knowledge necessary to operate the aircraft; lack of teamwork; and lack of situational awareness.The result, Herz wrote, is that operators are less able to conduct "real-world operations." For example, he said, "lapses of judgment and lack of experience" often lead pilots to continue marginal landing approaches when it would have been better to circle around for another attempt.