Image caption The airport says it is subject to delays outside its control

Belfast International Airport has some of the worst flight delays to popular destinations among UK airports.

Some 38,000 out of 199,000 international flights from UK airports to popular destinations were delayed between June and September 2016.

Northern Ireland's biggest airport was second only to London Gatwick.

One in five flights to popular holiday destinations from UK airports are delayed by more than 30 minutes, BBC analysis found.

Most were from London airports - Luton, Stansted, Gatwick and Heathrow.

The route from Belfast to Burgas in Bulgaria was the sixth most-delayed service in the summer of 2016.

A spokesperson said Belfast International Airport staff did all they could to minimise delays.

"Our on-time performance is generally very good, but sometimes we, too, fall victim to things that are outside our control," said the spokesperson.

"There is congested airspace in London and across Europe and it is clear there is a need to make improvements in aviation infrastructure.

"Like Gatwick, we are also at the mercy of repeated strike action on the Continent."

The BBC analysed Civil Aviation Authority data from 25 airports. The data does not cover flights that were cancelled.

BBC England's data unit found:

International flights from UK major airports were delayed by an average of 21 minutes last summer.

The longest delay was a chartered flight from Manchester to Dusseldorf, which was delayed by 779 minutes, or almost 13 hours, last September.

Gatwick Airport experienced the most flight delays last summer, with 30% - or 107,825 - of all flights from that airport recorded to be delayed by over 30 minutes.

Our analysis also found that delays across all airports were more likely to take place in June, compared to the other summer months.

Three-quarters of the 40 most delay-prone popular routes out of the UK last summer were to European countries. Popular routes are defined as those that ran at least one flight a day on average.

The non-European destinations with high numbers of delays were Ghana, Canada, US, Israel, Ukraine and Pakistan.

The most delay-afflicted route was from Heathrow to Accra, Ghana. 85 out of 122 - or 70% - of flights on this route were delayed by over 30 minutes last summer.

How to claim compensation

Under EU law, you have the right to claim compensation if your flight arrives at its destination over three hours late. EU law covers flights departing from or arriving to an EU country.

You can claim compensation if the delay was the fault of the airline, such as aircraft problems or flight crew being unavailable, according to the Civil Aviation Authority.

However, delays caused by extreme weather, airport or air traffic control employee strikes, airport closures or other extraordinary circumstances are not eligible for compensation.

Even if you cannot claim compensation, your airline must provide you with care and assistance.

Care and assistance include a reasonable amount of food and drink and accommodation if delayed overnight, as well as transport to and from the accommodation.

If you end up paying for any of the above yourself, the CAA recommends keeping every receipt and not spending more than is reasonable.

Advice on claiming compensation and a standard letter are available on the CAA website.

A spokesman for Gatwick said the airport would continue to do everything possible to prevent delays occurring.

"Repeated strike action on the continent over recent years and heavily congested airspace above parts of Europe and London, have led to a significant increase in the number of delays caused by wider air traffic control issues outside Gatwick's control," he added.

"Gatwick has more flights to Europe than any UK airport and is impacted disproportionately by events on the continent."

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