If terrorists had tried last week to hijack one of the Boston-based Boeing 767s for their suicidal jihad on the World Trade Center, chances are they would have been discouraged.

The jet American Airlines used to fly passengers from Boston to Los Angeles each morning -- Flight 11 -- had mechanical problems last week that delayed flights.

"Last week that plane pulled a mechanical about two or three days out of the week," said a veteran American Airlines employee involved in Boston operations. "Why couldn't it have been this week? Why couldn't it have been yesterday?"

"What would have happened if that plane didn't actually go, you know?" the employee said. "Instead, everything was in sync, and usually we don't have everything go on such a normal schedule."

The previous week's mechanical delays were related to a jet engine and a windshield, the source says.

All 92 aboard the flight perished, along with thousands of New Yorkers in the demolished World Trade Center.