Passengers and a gravely wounded pilot averted a potential 9/11-style terror attack yesterday after a bloody tussle with a knifeman at 34,000ft.

The brave flight captain was stabbed by his co-pilot but managed to open the flight-deck door and call for help.

At which point passengers piled into the cockpit and overpowered the attacker.

The extraordinary melee on Flight FZ1073 from Dubai to Tel Aviv sent the plane hurtling towards the Saudi Arabian desert.

Israel believes the co-pilot was planning to seize the controls and crash the plane into a target in Israel, possibly a skyscraper.

Passengers and crew wrestled the knifeman to the floor before a passenger stepped in and managed to lift the Flydubai plane skywards. 

Reports suggested off-duty pilots aboard the aircraft then took over the controls. One of them was said to be British.

Israel's prime minister Benjamin Netanyahu praised the wounded pilot – named as Indian national Smit Machchhar – saying: 'Despite being stabbed and seriously injured, he fought back, resisted, opened the cockpit door, and enabled passengers and crew to overpower the attacker, preventing a catastrophic mid-air disaster.

'He saved the lives of 174 people, including Israeli citizens and other nationals.'

Bezalel Smotrich, Israel's finance minister, said: 'Whoever tried to crash a plane and murder 180 Israelis must pay as if he [is a murderer]. Him and every state or terrorist organisation that sent him [must pay].'

The Boeing 737 made an emergency landing in Saudi Arabia, where the passengers were transferred to another Tel Aviv flight.

An Israeli security source said: 'This is thought to be a 9/11 scenario where the co-pilot kills the pilot and crashes the plane inside of Israel with all the passengers, mostly Israelis.' 

The co-pilot was arrested in Saudi Arabia but his identity, intention and motive have not yet been confirmed.

Mr Netanyahu stopped short of labelling the incident a terrorist attack in a statement, referring to it only as an apparent plot 'to crash the plane with everyone on board'.

Officials are unclear on the desired target but several sources pointed to the possibility of a tower block in Tel Aviv.

Both Israeli and non-Israeli airlines had been ordered to 'ramp up' security.

The drama happened two hours into the flight which left Dubai at just after 7am local time. A handful of passengers heard a raised voice leaking from the cockpit.

Passengers, many of them suited businessmen, who had scarcely noticed their neighbours until now, began exchanging looks over uncleared breakfast trays. 

But then alarm registered in the faces of some of the flight crew. Always the time for everyone else, remarked one passenger later, 'to start freaking out'.

But by now the plane was out of control, hurtling towards the Saudi Arabian desert – falling a terrifying 14,000ft in 30 seconds, according to flight data.

Behind the cockpit's locked door, the pilot and co-pilot were wrestling – the latter having stabbed the former with a knife.

While confusion remains over the co-pilot's motivation, he appeared to have no intention of landing the aircraft at Ben Gurion Airport in Tel Aviv at 9.05am as air traffic control expected. 

The outside world first learned something was up when the alert code '7700', meaning a general emergency, was picked up by air traffic control. 

That was followed eight minutes later by a '7500' – unlawful interference or hijacking.

How the drama unspooled after that is uncertain. One passenger told Israeli media that a group of men 'burst' into the cockpit.

Aviation experts last night said the doors are normally firmly locked and reinforced. However, pilots can unlock the door from their seats. 

Last night Mr Netanyahu confirmed that the pilot opened the cockpit door, adding: 'He is a true hero.'

Yitzhak Lieber, one of the passengers who helped to restrain the terrorist, sent a video to his children, saying: 'There is a pilot who was seriously injured, they've evacuated him. We overpowered the terrorist and he is tied up.'

In the film, later posted on social media, he adds: 'It was a very difficult incident. We'll probably come home in a few hours. 

'I need to change my clothes! Everything is full of blood, we caught him... we caught the terrorist.'

Another passenger, Dr Shota Musev, a dentist, said he treated the injured pilot in midair for severe wounds to his head and cuts on his fingers. 

Dr Musev said he was one of the first passengers to reach the cockpit after the attack, and that the pilot had been thrown on the ground. 

During a meeting with Mr Netanyahu, passenger Yaniv Hayun recounted pulling back on the controls after the attacker had been subdued. 

When Mr Netanyahu asked, 'You pulled them?' Hayun replied: 'Yes, I watch Air Crash Investigation.'

The Canadian documentary series, first aired in 2003, features dramatic reconstructions of air accidents, and interviews with those involved.

Tzvika Manes, 48, was one of the passengers who ran to the cockpit. He told the Daily Mail: 'I ran to help them struggle with the terrorist. We handcuffed him with multimedia headphones, and I was trying to help the pilot, to bring help from another group…

'It's crazy, like the 9/11 with a happy ending. Thank God.

'This is what drove us to run into the fire, because we want to save our family and, you know… we are going to die.'

Other passengers described scenes of panic and confusion, mothers clinging to their children, overhead bins flinging open.

Hila Gaier said: 'You couldn't move, you were sucked downward.' She was flying with her partner and two daughters. 'I embraced them, told them I loved them, and we tried to practise breathing exercises,' she said.

Yasmin Abukasis said her daughter, who was on the flight, told her that a man holding a knife had forced one of the pilots on to the floor, and that there was blood everywhere.

She was talking from Ben Gurion airport. Composing herself, she explained that her daughter phoned her to say she heard screaming on the plane as a pilot called for help, adding that two other pilots took control of the plane as other passengers ran towards a man who had a knife. 

'The plane started to lose control. So all the people, they scream, they think they are going [to crash],' she said. 

One of the two 'other' pilots she mentioned was British and off duty.

According to her, without hesitation, he stepped over the terror pilot pinned to the floor, and rushed into the flight deck. 

Only when the plane settled did the terrified passengers dare to believe that they might just get out alive. 

And it was only when he landed the plane at Tabuk airport in north-western Saudi Arabia they knew they were truly safe.

Mr Manes said that his young daughter was in the toilet, and his wife accompanying her, when they heard shouting coming from the cockpit. 

An additional crew member who was also a pilot went into the cockpit, and that is when they saw the stabbed pilot, Mr Manes said. He and two other people restrained the attacker, he added.

'We jumped on him; three of us jumped on him forcefully, and we tied him up with his own zip ties and with the multimedia headphones. That is how we neutralised him – resourcefulness, and that's it.'

Mr Manes said that 'there are children and families here who have been through a very severe, highly traumatic event'.

One woman passenger described the 'very stressful' moment people realised the plane was descending. 

'We understood the pilots lost control,' she told Israeli newspaper Israel Hayom.

'There are people here with shirts covered in blood,' she said, adding: 'Now we are fine and want to return home.'

Shortly after the incident, the Israeli and Saudi Arabian air forces dispatched fighter jets, while Mr Netanyahu held urgent meetings, later speaking of 'a very serious security incident'.

He added: 'I salute these heroes who demonstrated extraordinary resourcefulness and courage. They saved many lives and prevented a major disaster.' 

Mr Netanyahu later waited inside Ben Gurion's Terminal 1 to greet the passengers after they disembarked from the replacement plane that brought them from Tabuk.

He met a passenger who Mr Netanyahu said helped to thwart the attack. In a video posted on the Prime Minister's official social media channels, he tells the bloodstained passenger Mr Hayun that he is a 'great hero'.

'I see a lion, I see a great hero,' Mr Netanyahu said after hugging the man. The premier then asked, pointing at bloodstains on the man's white shirt: 'Is that from him [the assailant]?'

'Yes. Unfortunately we did not manage to kill him, but he will take a while to recover,' Mr Hayun replied.

Mr Netanyahu then said: 'You saved not only all of the passengers on the plane; you don't know what would have happened with it. We don't know.'

Passengers were medically assessed upon landing. Health worker Aryeh Myers said a few had minor injuries.

He said: 'So far, just one required hospital treatment. He was injured in the tussle on the plane and had injuries to his wrist.

'All the passengers walked off the plane under their own steam. A couple of them had some bandaging. A number of people were very emotional and crying as they came off the plane. 

'You could sense the relief that they finally landed. Some of them told me it was great to be home and happy the ordeal was over.'

UAE based airliner Flydubai has said the reasons for the flight deck altercation remained unknown and urged 'all parties to refrain from premature speculation while authorities gather the facts'.

It was a forlorn hope. It appeared the note of caution was sounded in response to Israeli defence minister Israel Katz's inflexible certainty that the incident was an 'attempted jihadist terror attack'.

He said that 'according to the initial information in our possession, the terrorist had one intention: to crash the plane with all its passengers'. 

Meanwhile Mr Netanyahu was busy ordering security to be 'ramped up' on Israeli and non-Israeli carriers.