Six flights were searched, evacuated, or diverted yesterday in security-related scares during a chaotic day in the skies, leaving many passengers fretting that such sudden and drastic precautionary measures have become an inevitable fixture of air travel.
Authorities said the occurrences all on flights either departing or arriving in US cities were not linked in any way. They said five of the six scares had no connection to terrorism.
The one unresolved case involved an American Airlines Boeing 767 en route from Manchester, England, to Chicago that was diverted to Bangor at about 1 p.m. after an unspecified threat to the flight was reported.
Federal security officials refused to characterize the threat yesterday. A Federal Aviation Administration spokeswoman said only that the flight was diverted for "security reasons." Those on board said a male passenger was handcuffed and taken away in a police car.
The 166 other passengers and 12 crew members left for Chicago about 9 p.m.
The day of in-flight tensions occurred two weeks after a foiled terrorist plot in England prompted heightened security at airports and on planes, including a new prohibition of carrying on a plane containers holding liquids.
The alleged British plot was the latest in a series of scares after the Sept, 11, 2001, attacks that have created fluctuating levels of security over the last five years, with a spike in flight diversions typically occurring after each scare, said security specialists.
"I think we're in a highly sensitized state about security issues," said David Stempler, president of the Air Travelers Association, a passenger advocacy group. "This is more likely to become the new normal. It's just part of traveling. That's what we're going to have to deal with."
He said that post-9/11 logic dictated that airlines react to even hints of threats. "Better to be safe than sorry, and in this case sorry means losing a whole plane full of people," he said. "So we better be safe."
Last week, a 59-year-old Vermont woman's erratic behavior on a trans-Atlantic flight led to its diversion to Logan International Airport. She was arrested and charged with interfering with the flight crew, though her lawyer said the woman's outbursts were prompted by mental problems.
Yesterday's tally of six incidents appeared to mark a new single-day high of activity. While authorities were still investigating whether there was any terrorism link to the Bangor diversion, they concluded the others were not:
In Houston, baggage screeners found a stick of dynamite in the bag of college student Howard McFarland Fish, 21, who was arriving on a Continental Airlines flight from Argentina. As passengers were going through immigration, baggage was being inspected before the plane flew on to its final destination, Newark. The Lafayette College student told authorities he worked with explosives in the mining industry, and they were investigating.
Authorities diverted a US Airways jet headed from Phoenix to Charlotte, N.C., to Oklahoma City after a federal air marshal had to subdue a disruptive passenger who pushed a flight attendant, according to the FBI.
A Continental Airlines flight from Corpus Christi, Texas, to Bakersfield, Calif., was delayed and searched in El Paso, one of its scheduled stops, after the crew discovered a missing panel in a lavatory, authorities said.
A utility knife was found on a vacant passenger seat of a US Airways flight traveling from Philadelphia to Bradley International Airport in Connecticut, prompting state troopers to search the plane and interview passengers.
An Aer Lingus flight from New York to Dublin was evacuated during a scheduled stopover in western Ireland, following a bomb threat that turned out to be unfounded, officials said.
Representatives of US airlines said that security concerns required flight crews to err on the side of caution when evaluating whether to divert or delay a flight.
A stick of dynamite was found in a college student's checked luggage on a Continental Airlines flight from Argentina.
Scotland's Strathclyde Police defended the decision to keep all 167 passengers and five crew members inside the Ryanair plane during Wednesday's search of the cabin and baggage by explosives experts...
The good news for the airlines is that the bulk of the summer leisure-travel season has passed.
The plane landed at the Tri-Cities Regional Airport in eastern Tennessee without incident.