The unsuccessful attempt by a man to detonate a shoe bomb on an American Airlines flight shows how much airline security has improved since Sept. 11 - and how far it still has to go.
In one sense, the incident aboard Flight 63 underscores the depth of one new element of airline safety - the neighborhood-watch ethic that now pervades the cabins of America's aircraft.
Perhaps most notable, experts say, was the alertness of a flight attendant who whiffed the scent of sulfur from a burning match, then confronted Tariq Raja, who was apparently trying to ignite explosives concealed in his footwear.
When he resisted, passengers jumped in to help, echoing the spirit of Jeremy Glick and other air travelers who stormed the hijackers aboard the jetliner that crashed in Pennsylvania Sept. 11. Indeed, many passengers now see themselves as the last line of defense against terror in the skies.
But experts say what's also impressive is what the passengers didn't do: They didn't seem to panic, nor let the incident erupt into some sort of vigilante-like melee.
Yet the incident also shows the gaps that remain in airline security system.
"There are some very interesting and instructive lessons in this incident," says Mary Schiavo, an aviation security expert and former Department of Transportation official.
First is that the international security apparatus designed to prevent such terrorism appeared to work only partly. The man French authorities have identified as a Sri Lankan named Tariq Raja, but who American authorities are still calling "Richard C. Reed," the name that appears on his British passport, was able to board the plane.
A Dec. 11 Federal Aviation Authority warning did tell security personnel to be wary of terrorists putting weapons in their shoes. And officials in Paris reportedly denied Raja access to a trans-Atlantic flight Friday.
Yet he also apparently boarded Saturday's plane with no luggage and with just one piece of identification - a British passport issued, perhaps wrongly, three weeks ago in Belgium.
Security experts say these facts should have tipped off Paris-based security personnel who monitor passenger profiles - especially because France is a traditional base for terrorism.
"This shows that passenger profiling just isn't working," says Ms. Schiavo. Further, the fact that he was denied access to Friday's flight should have raised suspicions when he tried to fly again.
Schiavo says his methods hint at a sophisticated knowledge of security measures. But one thing may have tripped him up: Not knowing that lighting just one match on an US-based airplane - where smoking isn't allowed - would raise suspicion immediately. European airlines aren't as strict about smoking.
Flight 63 may also rekindle efforts to add bomb-sniffing dogs or bomb-detection machines at US and international airports - an expensive proposition. Outfitting airports with machines to check all baggage for bombs could cost $5 billion in the US alone. And such technology wouldn't have helped in the case of Flight 63, as most explosive-screening machines scan baggage, not people. Technology to screen individual clothing and bodies is available but is even more expensive.
"The fact is, we don't have a sort of silver-bullet technology," says Clint Oster, an aviation security expert at Indiana University in Bloomington.
In the meantime, such holes in the security system explain why passengers and crew members figure they're responsible for their own for safety.
On Flight 63, the initial confrontation, says Ms. Schiavo, may be the result of the flight attendants' unions making very clear that their members are on the front lines of cabin safety - and have to act fast and be resourceful. They even have a term for it: YOYO (You're On Your Own).
After smelling the sulfur, the attendant noticed a wire protruding from Raja's shoe. She questioned him. He bit her. She called for help. Then, as some passengers poured drinks on him, others quickly grabbed him - and tied him down with belts collected from other travelers. Two doctors on board then used items from the plane's medical kit to sedate the man.
This quick passenger-and-crew action isn't unique since Sept. 11. In October, passengers subdued a mentally unstable man who charged toward the cockpit door aboard a plane headed to Chicago.
And San Francisco resident Don Detrich recently started the Flight Watch Hijacking Resistance League, a group encouraging passengers to act to stop hijackings.
His tips include: "Prepare yourself with weapons and shields: ballpoint pens, large pieces of luggage, hard briefcases, blankets or whatever is available. A food cart can also provide an effective ram and shield.... Anarchy and confusion work in the passengers' favor."
The group is now even offering a training seminar for $350. And under a law passed recently in Washington, passengers and crew are protected from lawsuits based on actions they take to protect a plane against hijacking.
Yet some caution against any emerging vigilantism - and say crew and air marshals should be the first to deal with dangerous situations.