Budget airline Ryanair has told its pilots to fly more slowly as rising fuel costs, an early Easter and the summer heatwave were blamed for a sharp fall in profits.

In typically tight fashion, the Irish low-cost airline has introduced the slow down to cut down its fuel bill, adding an average of two minutes to every hour’s flying time across Europe.

Accounts published on Monday also show that “add-on” fees or so-called “ancillary” items delivered a quarter of Ryanair’s revenue or £308 million; an average of £13.29 per passenger.

The airline’s profits fell 21 per cent to £67.5 ($103) million in the first quarter, as it admitted the hot weather over the last few weeks has caused a reduction in last minute bookings for summer holidays.

Howard Millar, deputy chief executive, told The Express : “We’re flying slightly slower but burning less fuel.

“While we’ve had the very good weather of the past couple of weeks, people are inclined to be out in the back garden, or out in the park, not at their desks in front of a hot computer.”

Chief executive Michael O’Leary said full-year profits were expected to remain on target and hit up to £518 million.

The airline also entered the debate over runway capacity in the South East, pouring scorn on Boris Johnson’s idea for a new airport hub in the Thames Estuary.

Mr Millar said: “Even my golden retriever knows it’s a barmy idea.

“The idea that you build all this infrastructure, replicating everything that’s at Heathrow, and stick it in the Thames Estuary – it’s just completely barmy.”

Ryanair’s “add-on” fees, which now account for a quarter of revenue, have become one of the airline’s defining features.

They recently introduced a fee of £10 ($15) to reserve specific seats, and the airline imposes a fine of £70 ($107) on passengers who forget to print their boarding passes online.

But the airline did win support last week after infants were invited to travel for free on all Ryanair flights on July 23 to mark the birth of the Duke and Duchess of Cambridge’s baby.

Photo Credit: Passengers board a Ryanair plane parked at Girona airport. Reuters