Airline pilots groups have reacted with concern over the decision not to release passengers from a hoax hijacked aircraft yesterday in the UK .

The Ryanair Boeing 737-800 with 167 passengers and six crew on board suffered a bomb threat during a 12 April Paris Beauvais-Dublin flight. A piece of paper with the threat was handed to the cabin crew. On declaring an emergency, the crew was asked to fly the aircraft to Glasgow Prestwick and en route the aircraft was escorted by three Royal Air Force Panavia Tornado F3s. At Prestwick the aircraft was isolated and, according to passengers, even the emergency services stayed clear.

However, the pilot told the police several times he had asked the authorities for permission to disembark them, but for more than 2h he was told not to.

The International Federation of Airline Pilots Associations says the International Civil Aviation Organisation security advice is that "the paramount objective is the safe release of the passengers and crew", which, ICAO says, should override any consideration relating to capturing those responsible for illegal action or threats.

A thorough search of the aircraft later found no explosive, but the incident will be taken up by pilots groups seeking clear advice on future incidents, real or hoax.

Source: Flight International