Hamam Alhammami, the co-pilot of the Dubai-Tel Aviv flydubai flight, had attacked Indian 'hero' pilot Captain Smit Machchhar with the cockpit's crash axe in a "terrorist attack", United Arab Emirates prosecutors confirmed on Saturday.

Alhammami tried to take control of the aircraft, they said.

Under international aviation regulations, a crash axe is mandatory in every commercial airliner and is kept in the cockpit for use during emergencies such as crashes. Earlier, the axes used to be stored in the main cabins, but were shifted to cockpits after the 9/11 terrorist attacks in the US 25 years ago.

An investigation is underway to determine whether the co-pilot acted as a lone wolf or has any connection with any extremist groups.

A massive disaster was averted on Wednesday when Alhammami tried to sabotage the flydubai aircraft - which was carrying over 170 passengers, including 24 children, and later stabbed Captain Machchhar, who tried to stop him.

At the time, the Boeing 737, cruising at about 34,000 feet, began dropping at roughly 23,000 feet per minute before reaching about 15,600 feet. Despite being injured, the Indian pilot unlocked the cockpit door, allowing crew and passengers to intervene and overpower the attacker.

Footage from inside the aircraft showed chaos and Captain Machchhar lying in a pool of blood, saying his co-pilot "hit" him.

While a dentist gave life-saving help to Captain Machchhar, two other relief pilots took control of the aircraft and diverted it to Saudi Arabia - where it landed safely.