The nation’s largest commercial pilots’ union said yesterday it’ll seek support from Congress to arm pilots as a last line of defense against hijackers. The extraordinary proposal came as lawmakers and the Bush administration accelerate efforts to draft plans for expanding airport and airline security in the wake of the September 11 hijackings. A union spokesperson said, “This is a radical change for airline pilots, but it’s an indication of the threat.” He said the union envisioned a voluntary program run by federal law enforcement. Again, main U.S. pilots’ union wants members, the pilots, to carry guns.