No one discusses whether truckers carrying nuclear waste should carry guns to prevent hijackings - but it might be a future topic in view of a measure approved this week to let 1,400 pilots carry guns to deter terrorists.

The U.S. House's aviation subcommittee approved the compromise measure, which was scaled back from a plan to let all commercial pilots carry guns. In addition, the bill calls for a two-year study to determine whether armed pilots endanger passengers.

A full transportation committee vote is scheduled for next week. Subcommittee Chairman John Mica (R-FL) said the aviation system is in a vulnerable state of transition and it's impossible to place air marshals on all at-risk flights.