Only 34 out of 861 flight departure delays this year were caused by air traffic control fatigue breaks at Ronaldsway.

Infrastructure Minister Tim Crookall gave the figure in a written response to a Tynwald question from Douglas North MHK David Ashford.

The airport took the unprecedented step of closing the runway five times a day back in June last year as a result of staff shortages in air traffic control.

Since August, the number of fatigue breaks has reduced from five to two.

The airport’s opening hours have also come in for criticism. A pilot told passengers on an easyJet flight from Gatwick this month that it could not take off as Ronaldsway will not open late.

In his Tynwald question, Mr Ashford asked how many incoming flights were delayed or cancelled in the last three months due to ATC breaks or the early closure of the airport.

The Minister replied that Ronaldsway’s published closing time is 8.45pm and it had not closed earlier.

He said it had extended beyond this time on 75 days out of 92 in the last three months, with the average closing time of 9.16pm.

Mr Crookall said: ‘The airport regularly receives requests from our operators and airlines to extend beyond 8.45pm, most often due to operational issues or delays picked up elsewhere in the network during the day.’

He said that extensions can most often be accommodated through overtime but when that’s not possible or when an extension is limited, airlines are informed in advance.

Mr Crookall said delays and cancellations may occur elsewhere in the network, making it difficult and unreliable to calculate those directly attributable to issues at Ronaldsway.

He added: ‘Airline traffic running to schedule will very rarely be impacted directly by the two morning closures. When airline traffic is running off schedule, any delay is likely to be exacerbated.’

The total number of departure delays was 108 in January with three due to IoM ATC closure, 110 in February (eight due to ATC), 111 in March (six due to ATC), 141 in April (seven due to ATC), 147 in May (six due to ATC), 148 in June (two due to ATC) and 96 in July (two due to ATC).

Giving a presentation to last week’s Government Conference, airport director Gary Cobb said delays of less than an hour had fallen 15% January-July, compared to the same period last year and those of over an hour were down by 42%.

There had been a 41% drop in cancellations so far this year.

Mr Cobb said the airport will do extensions past 8.45pm on a ‘best-endeavour basis’. He said there were now 16 air traffic controllers, up from 14, with a target to reach 18.