WASHINGTON — Airline pilots may have guns and reinforced cockpit doors, but cabin crews and passengers are still left too vulnerable, say some lawmakers and interest groups who want to arm flight attendants with the skills they need to help prevent a successful hijacking or terror attack. After the Sept. 11, 2001 (search), attacks, when box cutter-wielding terrorists hijacked and crashed four planes into the Pentagon (search), the World Trade Center (search) towers and a Pennsylvania field, much focus in Washington was placed on how to better secure airline pilots and prevent terrorists from getting into the cockpit. But what's...