Airport bosses admit they still don’t know what has caused ’random long queues’ through security.

A £300,000 scheme is under way to reduce the queues which suddenly became a problem at Ronaldsway at the end of September.

But ports director Ann Reynolds told a Tynwald scrutiny committee she doesn’t know why the issue suddenly arose then.

Giving evidence to the environment and infrastructure policy review committee, she said: ’At the end of September when the queues started, there was no one issue that caused it. There was no change in the flights, there was no change in the scheduling, there was no change in the security processing. But we must take into account that we did have large passenger numbers. It was a record year for us.’

Pressed by committee chairman Rob Callister MHK, she said: ’I don’t think there is one key issue. I think there is a number of things.

’I know of no one thing that I could put it on to for the end of September, why that came then.’

She said some of it was about the close timing of flights using large aircraft, such as on Friday evenings where Gatwick and Bristol flights have been almost together. Sometimes it’s when we have very large airplanes rather than just the number of aircraft,’ she said.

One definite factor, she said, was that many passengers had changed over to using an app or checking in online.

She said before the ’random long queues’, and the message going out about arriving at the airport in plenty of time, some passengers were arriving just 30 to 40 minutes before take-off, as they didn’t have to wait 10 to 15 minutes to check in.

She claimed a lot of passengers are still unaware they have to put liquids in separate bags.

’The jam isn’t all about the number of passengers who are queueing - it’s also about the number of bags being re-screened because people have left liquids in bags,’ she said.

DoI chief executive Nick Black said he didn’t have the sophisticated data needed to explain exactly what caused the delays.

’We have opinions but we are short on evidence,’ he said. ’The queues may have been caused by people leaving at the last minute, they may have been caused by aircraft scheduling. Sometimes they appear to be totally random.’

He said that some days you could get through security ’incredibly smoothly’ but on others ’you are there to the point of becoming stressed, upset and worried’.

Committee member Chris Robertshaw said he was still struggling to understand how this problem had suddenly come from ’out of nowhere’.

’There seems to be suggestions there was a spontaneous change of action on the part of the public to arrive in a different way,’ he said.

His colleague Clare Bettison asked if flights have been delayed as a result of the queues.

Miss Reynolds said the handling agent would pull passengers forward. But she said some passengers had not made their flights.

A £300,000 scheme has been announced to tackle the queues by reorganising the security area with a new layout, full conveyor system with tray return and extra staffing to operate the second scanning line at busy times.

The airport director said the aim is to get passengers through central search in less than 10 minutes, no matter what flight they are on or what scheduling.

TravelWatch has criticised the security area revamp, arguing that ’throwing money at the problem is not the answer’.

During Friday’s committee hearing, Mr Callister sought assurances that the £300,000 investment was ’not just about screening off the problem’.

Infrastructure Minister Ray Harmer replied that this was ’absolutely not’ the case. He said the new layout would allow four or five passengers to prepare themselves at the same time. The committee chairman suggested that if the airport knew of the airlines’ schedules nine to 12 months in advance, it could push for flights to be ’separated out a little’. But Miss Reynolds said:’They are flying to us when they have availability for their flights.’

She said in summer easyJet flights come in from an international destination and there was every chance it could be subject to a slot delay. She said she had asked the airline to consider putting an aircraft on from a domestic route such as Inverness.