A Continental Airlines report filed with federal safety inspectors blames the fatal November crash of a DC-9 at Stapleton International Airport on wing turbulence, a poorly plowed runway and air-traffic control errors.

Flight 1713 crashed upon takeoff during a snowstorm, killing 28 people."A combination of errors by the city of Denver and air-traffic control caused the catastrophic crash of Flight 1713," the airline concluded in the report filed last month with the National Transportation Safety Board, The Rocky Mountain News reported in Wednesday's edition.

"The evidence developed to date indicates the crash of Flight 1713 was not caused by mechanical or equipment failure, structural icing or pilot error," the report said. "Rather, the crash was caused by the aircraft encountering wing-tip vortices at a critical phase of flight."

A wing-tip vortex is turbulence resulting from an intense eddy of swirling air that fans out from the wings of airplanes, particularly wide-body planes.

In response to Continental's claim that the city did not completely clear the runway, Stapleton spokesman Richard Boulware said, "We reject that categorically. I personally sat in my office that day and watched airplanes take off from that very runway. Nobody else had any problem. Why did they? And if Continental did, the pilot had the option of choosing not to take off."

Frank Johns, air-traffic manager at Stapleton, said he hadn't seen the report. "So I don't have any specific comments, but we would probably disagree with those findings."

Continental spokesman Bruce Hicks said the NTSB has barred the airline from releasing the 54-page report.