Ryanair is planning to cancel up to 50 flights every day for the next six weeks, affecting more than 285,000 passengers.

An error with allocating holiday time for its pilots means hundreds, if not thousands, of flights will not be taking off – potentially leaving the travel plans of up to 400,000 passengers in limbo.

Here’s the vital information you should know:

Which flights are cancelled?

Ryanair has confirmed that 50 flights per day (less than 2% of flights) have been cancelled for the next six weeks, but has only published a list of flights up until Wednesday 20 September.

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The budget airline is contacting people shortly before they are due to fly, sometimes just a day beforehand.

You can view the lists compiled so far on Ryanair’s website.

What are you entitled to if your flight is cancelled?

If you’re travelling with an airline based in the EU or with a non-EU based airline flying from an EU airport, you will be protected by the Denied Boarding Regulation.

The regulation states that the airline has an obligation to offer you assistance if your flight is cancelled or the delay is expected to go beyond a certain point.

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Depending the length and circumstances of your delay, you could be entitled to:

• a refund or alternative flight

• food, phone calls and accommodation

• flight cancellation compensation

However, one of the biggest gripes to emerge is the fact Ryanair has only published a list of affected flights up until Wednesday – and no one, least of all the passengers booked to fly in October know if their flight will take off on time or at all.

My flight has been cancelled – how do I get to where I need to?

You are entitled under EU rules to “rerouting, under comparable transport conditions, to your final destination at the earliest opportunity”. Unfortunately, what exactly “the earliest opportunity” means has not been properly tested and defined in court.

The Civil Aviation Authority (CAA) says airlines are obliged to book affected passengers on a rival airline “where there is a significant difference in the time that a reroute can be offered on the airline’s own services”. Again, there is no legal definition of “significant difference”.

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Travel experts say that if Ryanair does not put you on a rival airline you could buy a ticket and try to recoup the cost from Ryanair later, but there are no guarantees.

Surely Ryanair has a duty to look after its customers?

The bottom line is, yes, it does. Under EU rules, “passengers shall be offered free of charge (a) meals and refreshments in a reasonable relation to the waiting time; (b) hotel accommodation in cases where a stay of one or more nights becomes necessary”.

The airline is obliged to provide these, but if it does not, you should keep all receipts to claim back the cost later (and note that “refreshments” do not include alcohol).

The airline’s obligation extends for as long as it takes to get you to where you need to be.

How do I go about getting my money back?

You can claim for the full cost of your cancelled flight through Ryanair, here, but the airline is also obliged to pay you €250 for each passenger on a cancelled flight of up to 1,500km, rising to €400 for longer flights.

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The only way it can escape this obligation is if it informs passengers of the cancellation at least two weeks ahead – which it appears not to be in a position to do so.

Alternatively, Ryanair must give you a week’s notice and find another flight that gets you to your destination less than four hours after the scheduled time of arrival.

Lastly, the airline could give you less than a week’s notice but put you on a flight that arrives less than two hours after you were supposed to get there.

I’m due to travel in October with Ryanair, can I cancel and get my money back?

Due to the fact that Ryanair has only published a list of affected flights up until Wednesday, no one, least of all the passengers booked to fly in October, know if their flight will take off on time or at all.

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However, if you decide to pre-emptively cancel and book with someone else, there is no mechanism for a refund unless your flight is one of those cancelled – so, it’s a case of hope for the best or take a financial hit.

What about hotels and car hire?

If you have non-refundable hotel bookings or car hire, the airline is not liable. If they are part of a package holiday, bought in a single transaction, then the tour operator should refund them. Otherwise travel insurance, may cover your losses.