The airport runway was closed for nearly two hours during Tuesday’s blackout after all emergency power supplies failed to kick in, Times of Malta has learnt.

The Malta International Airport’s apron, which encompasses the landing strip and holding bay, was not visible to pilots for some 25 minutes as the runway lighting failed to go back on.

This is the first time this has ever happened.

The strip, however, was not reopened for a further 90 minutes after one generator came back online, because Malta Air Traffic Control personnel insisted on carrying out safety tests before reopening the runway.

The temporary blackout forced four planes to be diverted to Sicily, while a number of other flights were also delayed from taking off.

An airport source told Times of Malta that the airport has initiated an internal inquiry to establish why the back-up supplies failed to kick in immediately.

He explained that the airport was connected to Enemalta by two separate circuits which had never gone offline simultaneously before.

“This was a series of unfortunate events which are highly unlikely to repeat themselves,” the source said.

The airport is meant to be provided with a provisional power supply by a main generator, which kicked in as soon as the power cut happened at 7.50pm.

This, however, ran into problems related to its switchboard and shut down repeatedly, forcing the airport staff to have to resort to a second generator.

This was a series of unfortunate events highly unlikely to repeat themselves

The problems did not end there and the airport technical staff went into a frenzy when the back-up to the back-up also failed to provide an immediate supply.

Asked what had caused the malfunctions, the source ruled out any shortcomings from the airport’s end, insisting maintenance checks were carried out every six weeks.

A Malta Air Traffic Control officer, who preferred not to be named, raised concerns over the glitch in power supply.

“We cannot take risks in these situations,” the source said.

“Once we saw that there were some problems with the initial provision of power we wanted to ensure everything was in order.

“The situation was far from ideal. Can you imagine if something happened during an aerial manoeuvre,” the source added.

Steven Bonello, a passenger whose flight was forced to stop over in Catania for two hours, said he was asleep on the flight and thought he had landed in Malta when he had actually arrived in Sicily.

“When I woke up and was told what had happened I was quite surprised,” he said.

“I travel very regularly because of my work and felt quite uncomfortable to know that the airport ran into these difficulties just because of a power cut,” he added.

In a statement, the airport yesterday apologised for any inconvenience caused and assured passengers measures were being taken to rectify the situation.

It also clarified that while the runway was out of action for nearly two hours, the terminal remained fully operational throughout the night.