WASHINGTON, March 2 (UPI) -- Air safety experts in Washington have begun to focus on aircraft maintenance instead of pilot error in their campaign to make flying safer.

While pilot error remains the top cause of deadly commercial air crashes, it has decreased dramatically in the past decade -- thanks to innovative training and modern jets with better warning systems that help pilots quickly correct what might once have been fatal mistakes.

As a result, crashes caused by pilots -- about two-thirds of all accidents from the 1960s through the mid-'90s -- fell to about half of all crashes from 1995 through 2001, USA Today reported Tuesday.

Accidents caused by maintenance errors have become the second-most likely category of accident since 1995. More than 30 percent of accidents from 1997 through 2001 were caused at least in part by maintenance mistakes.

An analysis by USA Today of data from the National Transportation Safety Board showed faulty maintenance caused an average of slightly more than one crash per 10 million flights in the 1990s.

It was the only major category of accidents that did not decline, a trend government regulators are working to halt.