Suppose you're flying on a commercial airliner when a group of Arab men wielding weapons suddenly jump out of their seats, bound down the aisles, knock over the flight attendants and passengers trying to block their way, and then break through the cockpit door.

Which of the following two thoughts would be going through your head? 1) "Oh, no, we're all going to die!" or 2) "I'm so grateful those pilots don't have guns."

John Magaw, head of the federal Transportation Security Administration, falls in the second category. Last week, he announced that after careful review, his agency would not allow pilots to carry firearms. If a terrorist manages to invade the flight deck, however, the pilots have Magaw's permission to resist with all 10 fingers of their bare hands.

It would be nice to live in a world in which pilots never have to use guns. But in the post-Sept. 11 environment, it's obvious that in some situations, an armed pilot could come in very handy.

Critics insist that we should rely on tighter passenger screening, reinforced cockpit doors and federal air marshals. Those are all needed improvements. But they may not be enough to keep Islamic extremists from commandeering another aircraft and killing hundreds of people.

Consider: In March, we learned that an undercover test of security at 32 airports showed plenty of holes. A report by the Transportation Department's inspector general noted that baggage screeners missed 70 percent of knives, 30 percent of guns and 60 percent of simulated explosives. That was before the federal government began taking over security, but the problem is not easily solved. Current screening technology can't detect many sharp instruments or explosives.

So terrorists may be able to get knives, guns or bombs on planes. Thus armed, they may have no trouble breaching those reinforced cockpit doors. Or they might just wait until a pilot goes to the lavatory.

But won't the new air marshals be able to stop an attack? Only if they're present. The federal government currently has no more than 1,000 marshals, who never work solo, while the airlines conduct 35,000 flights per day. At best, marshals could cover 500 flights on any given day -- or one out of every 70.

Magaw, however, sees no need for another line of defense. He doesn't want pilots distracted by trying to shoot terrorists; he wants them focused on maintaining "positive control of that aircraft . . . get it on the ground as quickly as you can, regardless of what's happening back there."

That approach is sound as long as the terrorists are confined to the cabin. But if an attacker gets through the cockpit door, a gun may be the only way for the flight crew to maintain "positive control" of the aircraft. The pilots who died on Sept. 11, you may recall, didn't lose control of their planes because they were too busy loading their pistols.

Other critics say there is no place for guns on airliners, where flying bullets could hit passengers or blow holes in the fuselage, causing a crash. Then why are we putting armed marshals on board? Because it's better to take a chance on one or two passengers being accidentally shot than all of them being deliberately murdered. And given modern airplane design, Stephen Luckey of the Air Line Pilots Association (ALPA) testified recently on Capitol Hill, "virtually no danger exists that multiple gunshots could cause rapid decompression of a transport-category aircraft."

United Airlines has bought stun guns, though Magaw hasn't decided whether to allow those in the cockpit. Nonlethal means of defense sound appealing, but stun guns may not penetrate thick clothing, and they may require several hits to stop an attacker. Those could be fatal shortcomings in a hijacking.

One far-fetched fear is that experienced aviators will suddenly turn into trigger-happy cowboys. ALPA says pilots should be allowed to have guns only if they pass psychological evaluations, get 48 hours of specialized training and demonstrate great proficiency in the use of the weapon. Then, it says, they should be authorized to fire only to prevent a terrorist from interfering with the pilots or seizing control of the plane.

The great advantage of arming pilots, though, is not that they could shoot a hijacker. It's that they would deter terrorists from trying to hijack a plane at all. If all their trouble is going to lead them to the business end of a .45, Al Qaeda operatives will have a strong incentive to look for softer targets.

An armed pilot is not a perfectly risk-free option. But compare it to the dangers of unarmed pilots.

© 2000 CREATORS SYNDICATE, INC.