Ryanair pilots ordered to fly slower as planes are turned into billboards in bid to reverse fall in profits Two minutes added to every hour of flying cutting fuel costs by 15% Ryanair offers advertising space on planes after profits fall by a fifth Airline warns heatwave has put people off buying flights online By Rob Davies and Hugo Gye Ryanair has ordered its pilots to fly more slowly in a bid to save money on fuel after a fall in the airline's quarterly profit. Another money-making ruse from boss Michael O'Leary will see the firm's planes turned into flying billboards with adverts painted on the outside. The airline has warned that revenues are set to fall further after the heatwave across Europe deterred people from booking holidays online. Slow down! Ryanair has added two minutes to every hour of flight in a bid to save on fuel costs Slowing down Ryanair planes below 600mph adds two minutes to the average hour of flying, but has reduced the company's fuel bill by 15 per cent - and executives insist it will have no effect on flight safety. The no-frills airline, famous as much for its revenue-boosting hidden charges as its publicity stunts, will also offer businesses the chance to advertise on its fleet of 303 Boeing 737-800s. Firms will be able to place their adverts for 12 months at a time on the plane's inner and outer winglets, or on its front and rear fuselage, where plane-spotters and airport users can see them. A Ryanair spokesman said businesses were getting the chance to use "Europe's largest - and cheapest - outdoor advertising medium." Ryanair blamed a six per cent surge in fuel costs and the early Easter for a 21 per cent decline in first-quarter profit to £67million before tax. The fall, which Ryanair said was in line with its guidance to the market, came despite a three per cent increase in passenger numbers to 23.2million and a five per cent rise in revenue to £1.16billion. The company also revealed worries that its performance had dipped in recent weeks as the hot weather drew people outside and stopped them surfing the internet for holiday deals. Outspoken: The company's controversial boss Michael O'Leary is known for his bold publicity stunts Passengers due to travel on a flight which was cancelled were shocked to be told by easyJet that they would have to wait 86 years for a replacement. Customers of the budget airline who were flying from Geneva airport received an email from the company informing them that their flight had been delayed, according to the Independent. The message said: 'We are writing to inform you that your flight will depart at 11.00 local time on 29/07/2099.' EasyJet apologised for the 'significant inconvenience', and asked passengers to 'give us another chance in the future'. A spokesman for the airline admitted that the blunder was due to a 'systems error' - luckily for the company, as feeding and housing the passengers for 86 years would have cost £6million each. Ancillary revenue, the industry term for any income that doesn't come from selling seats, was up by 25 per cent to £308million, helped by a boost from extra charges for allocated seating and priority boarding, as well as higher credit card fees. The decision to allow passengers to reserve a seat for a higher price echoes rival easyJet, where the extra option has also proved a success. Ryanair has been locked in a dispute with the Competition Commission, which wants it to sell off a 29.8 per cent stake in compatriot airline Aer Lingus. It said the Commission had lost "any shred of credibility," after Ryanair put the stake up for sale but received no offers. The Commission had cited a fear that Ryanair's stake was deterring other investors from piling in, but O'Leary said the lack of interested parties showed their claim was unfounded. Ryanair branded the Commission "absurd" and "draconian" and said it expected to appeal against an anticipated order to sell the stake.