Almost half of frequent fliers fail to redeem their air miles because of frustration with terms and conditions Estimated 14 trillion air miles have never been redeemed by flyers 60% think they need to take too many flights before they can claim rewards RyanAir and EasyJet criticised because they don't run reward schemes Almost half of flyers never redeem their air miles because the terms and conditions are too restrictive, a study has found. Figures also revealed that 60 per cent of people think they need to take too many flights before they can get anything of value back. The reward programmes are designed to encourage travellers to stick with the same company each time they fly. Poor rewards: 60 per cent of travellers think they need to take too many flights before they can redeem Air Miles. British Airways' rewards scheme is largely used only by business flyers But with just 40 per cent of people who collect air miles ever redeeming them, airlines are facing calls to overhaul the schemes because they are not working. In total, there are an estimated 14 trillion points which have never been redeemed by flyers. The study also found that 79 per cent of people who travel more than seven times per year want non-travel related rewards. Loyalty programmes have changed beyond recognition since Airmiles was launched in 1988, and many experts believe that the airline industry has failed to build on early gains. Airlines don't allow flyers to redeem their airmiles or points at peak times, they expire after a period of time and they often have to spend a minimum amount. Incremental revenue experts Collinson Latitude surveyed 1,005 British flyers last year. Loyalty points: Flyers complain that it takes too long to get free trips, many have never used the points and others didn't find anything of value, the survey results show Programme: Airmiles were originally launched back in 1988 James Berry, product director, said: 'Traditional rewards programmes are not necessarily designed to accommodate the changing needs of customers as it takes too long to build up enough points. Commercial results from reward programmes are increasingly under scrutiny and just doing the same thing will not help drive incremental profitability, nor will it tackle the problem of unused points. In total, almost half of British adults flew last year, but less than one in four - 23 per cent - said they collected airline loyalty points. Jay Sorensen, president of IdeaWorksCompany, said that airlines need to expand their loyalty schemes. British Airways' loyalty programme is used largely by regular business flyers, while budget airlines like RyanAir and EasyJet don't run rewards programmes. Mr Sorensen told CNN.com: 'The UK is a bit of an enigma in the market, as their three largest airlines don't encourage people to sign up to their programs. Air France-KLM are particularly good. They have frequent promotions that allow members to redeem international awards at just half the usual miles.