Pilots 'must have been murdered' before jets were aimed at buildings
However, there was some dispute about whether or not the terrorists themselves were experienced pilots.
They said it was "inconceivable" that the pilots, even if they were held at gunpoint, would have complied with the terrorists and crashed the jets into the towers, killing both passengers and workers inside.
According to Mike Webster, a retired British Airways pilot, the terrorists would have needed only "minimal" training to have been able to steer the aeroplanes into the World Trade Centre. He estimated that three hours on a flight simulator would have been enough to teach them the basic skills required to crash the planes.
"There is no way that a pilot would knowingly crash his plane just because someone was standing behind him with a gun," he said.
"It's more than likely that the terrorists took control of the planes and crashed them. To do this they would have needed minimal experience. They definitely would not have needed any kind of sophisticated training, like that required by an airline crew member before he is allowed to fly a plane."
A senior British Airways pilot said that any responsible pilot would have resisted orders from the terrorists to crash the jets into the World Trade Centre.
"If the pilots knew they were going to die anyway, they would have put the aircraft to the ground to minimise the number of fatalities. Pilots tend to go along with hijackers because the prime objective is the safety of passengers at all time. But in a case like this where they appear to be kamikazes, there just aren't any rules or recommendations," he said.
"It is unlikely that these terrorists had never flown a plane before. They could have been have been ex-military pilots who knew at least the basics about flying an aircraft."
Kieran Daly, editor of Air Transport Intelligence, an internet publication, said the terrorists would have needed some experience to have been able to steer the plans into the World Trade Centre.
"Flying an aircraft into a building is not as simple as it appears. This suggests that the people who did this had at least some understanding about how to handle an aeroplane," he said.
"In my opinion it's inconceivable that the pilots would have crashed the planes. If a gun was held to their head, they clearly would have resisted because either way they knew they were going to die."
Meanwhile, aviation experts said last night that airport security governing internal flights is less stringent in the United States than in Europe and hijackers would have exploited that loophole. Now American air regulators will have to completely reconsider security systems that previously have been kept to a minimum, to allow people to travel between cities with the ease of a bus service.
People accompanying or meeting passengers on domestic flights in the United States are allowed to go through security screens right up to the gate of the aircraft lane. In Europe, only passengers with tickets can pass beyond screens.
All four of the aircraft that crashed yesterday were on internal flights.
David Learmount, safety editor of Flight International magazine, said that airlines in America had rejected recommendations made by a security commission headed by Vice-President Al Gore during the previous Clinton Administration.
The commission had said that internal flights should have the same, much higher level of security surrounding international flights. In Europe, the same level of security covers both domestic and international flights.
"The airlines turned it down because they said aviation in America is like travelling on buses: people hop on and off. Everything is aimed at processing the largest number of passengers," Mr Learmount said.
The hijackers may have been able to smuggle weapons on board because airport metal detectors through which passengers pass do not detect explosives. Security tests have shown previously that it is relatively easy to for passengers to smuggle bombs on to an aircraft by strapping them to their waists.
"You can now buy guns which are extremely difficult to detect, made of plastic and other materials," Phil Butterworth-Hayes, civil aviation editor of Jane's publications, said.
He added that the fear of hijacking had receded since the 1970s and early 1980s, when it was a favourite tactic of terrorists.
Mr Baum said that the hijackers could simply have pretended to have weapons to gain access to the cockpit and no amount of physical screening would have identified them.
"You can hijack a plane with your bare hands," he said. "One person can stand up and pretend they have explosives strapped to their waist."
( Daily Telegraph, London)
- Nicole Martin in London
