By Richard Allen Greene
BBC News, Washington
It sounds like a stand-up comedian's joke: A nervous flier boards a plane with hand cream and a box of matches...
Intense security has become as routine as possible
But the diversion of United 923 from London to Washington - and the arrest of a passenger for interfering with the flight - was no laughing matter.
Fighter jets scrambled to escort the plane into Boston, and the media scrambled to keep up with events.
Television news showed luggage laid out neatly on the tarmac, sniffer dogs searching them for anything suspicious.
And interest in the story was intense, as the BBC News website's own statistics show.
Within two hours of the story breaking - in the middle of the afternoon, London time - it had become our top-hitting story of the day, racking up more readers than articles that had been on the site all day long.
Meanwhile, over on CNN and Fox News, experts speculated about early reports suggesting that banned items had been found on the plane.
Ordinary items now trigger a security response
Was it Vaseline? That would be cause for alarm: last week's arrests in London reportedly centred on a plan to concoct explosives from liquids or gels while a plane was in flight.
Was it a screwdriver? Even worse: the 9/11 hijackers took control of four planes with nothing more than small, sharp hand tools - and the fifth anniversary of 9/11 is looming.
Was it a note about al-Qaeda? If so, apparent proof that a terrorist had got on board.
In the end, though, it seems that the passenger at the centre of the alert had none of those items.
Whatever the exact nature of the disturbance, it tapped into some very real fears.
Consider this. As far as we know, from a security perspective the diversion of United 923 went exactly according to plan.
Cabin crew alerted the captain that there was an "unruly passenger" on board.
The captain has the final authority to divert a flight, and he exercised it, contacting air traffic control to find an alternative landing strip.
Since 11 September 2001, it is standard procedure to send fighter jets to intercept commercial flights that may have become terrorist threats.
The disruptive passenger was restrained in some way, United Airlines confirms.
That, too, should not be surprising - flight crews would hardly let a suspected terrorist remain free if they could avoid it.
So if any lessons are to be drawn from the drama of United 923, one must be that the airlines and security agencies have plans in place to handle even the merest hint of a threat.
But the mere fact that those plans exist - and that they were put into operation to deal with a 59-year-old woman with a tube of hand cream - must make one wonder if the current generation will ever again be able to regard air travel as simply a quick and easy means of getting from one place to another.