Rafi Ron was brought in from Israel

Computer consultant Jack Parker told BBC News Online that he had forgotten all about the Stanley knife which he had left at the bottom of his laptop bag as he packed for a cross-country trip.

Mr Parker says he took his computer bag - containing the knife - on board a Delta Air Lines flight from Boston to Dallas, where he took a connecting flight to Las Vegas, and again, the potentially deadly weapon was not spotted.

It is believed that the hijackers who flew two planes into the World Trade Center in New York on 11 September, used similar but smaller knives, known as box-cutters, to take control of the aircraft.

Both flights took off from Logan International Airport and ever since, security here has been under close scrutiny

Mr Ron arrives

The new security guru at Logan is Israeli Rafi Ron, previously head of security at Tel Aviv's Ben Gurion airport, reputed to be one of the safest in the world.

Despite highlighting the lapse of security, Mr Parker is not worried about flying back home, saying that he merely wanted to show the authorities where they had slipped up.

Passengers are now spending much longer standing in queues

His wife Laura McGee, however, feels less safe.

"I wouldn't fly right now, unless I had to," she said.

"You would think that Logan would be extra-extra careful. If they are not looking for things like that, what are they x-raying for?"

A spokesman for Massachusetts Port Authority, Phil Orlandella said that he was concerned but could not confirm the incident until investigations had been completed.

Mr Ron toured Logan airport for the first time on Friday and promised to deliver high security without what "passengers are facing in most airports in the United States today, which is long, long queues and a lot of hassle".

Asked whether the planes could have been hi-jacked if they had left an airport in Israel, he replied that the chances "would be much more limited".

He has returned to Israel where he will consider what he saw before making detailed proposals on his return to Boston, expected next week.

The 54-year-old has been in charge of security at some of the world's most high-profile potential targets: the Israeli prime minister's office and its mission to the United Nations in New York.

He also spent five years at Israel's main airport, which has never experienced a hi-jacking.

Cutting edge

The appointment of Mr Ron is only one part of a "top-to-bottom" overhaul of security at Logan airport announced by local authorities.

"Face-recognition" technology is also being considered. This digitally compares faces of passengers with a database of suspected terrorists who are likely to be using false passports.

"It is at the cutting edge of technology," said Massachusetts Port Authority chief, Virginia Buckingham.

This system sparked outcry when it was used on spectators at the Superbowl earlier this year but civil liberty activists say they may not oppose its use at airports in the wake of the suicide attacks.

Calm mood

Despite the uproar about safety, Logan airport appears perfectly normal.

Passenger numbers have declined since 11 September, with 30% fewer flights passing through but the terminal does not look deserted and there are not armed security officers lurking behind every pillar.

Hijacker Mohammed Atta took off from Logan airport

Although many Boston residents were on board the planes which flew into the Twin Towers, the city does not have the same feeling of grief, tragedy and nervousness as New York still does after six weeks, especially since anthrax was discovered in the city.

There are far fewer US flags flying from cars and in shop windows, while people talk about the latest sports results and the weather more than the suicide attacks and their aftermath.

On the streets of Boston, some people were concerned about how safe Logan airport is but most said that they were still prepared to fly as the chances of being hi-jacked remain relatively small.

"I just made reservations to fly for Thanksgiving holiday and I chose to fly out of Providence instead. I don't want to go through Boston," local resident Anne Bussman told BBC News Online.

"Not that it's not safe, it's because of the hassle of going through Logan airport with all the security restrictions," she added.

Domestic flights in the United States used to involve none of the series of checks international passengers are accustomed to.

But since 11 September, passengers have been told to arrive at the airport two hours before departure and take identity papers containing photographs with them.

"I don't really feel safe but if I had to, I would still fly," said another Bostonian, Adalgisa Jaquez.

"It could have happened anywhere, not only Boston."