Finally, after waiting an age for takeoff clearance, you are up in the air and wriggling to make your allocated few inches as comfortable as possible. Twelve challenging hours to go. A movie is about to start and you put on the headphones. There is sound, but no picture; your entertainment terminal is faulty. With a groan, your perception of the flight ahead changes: eleven hours and 57 minutes of excruciating boredom.

Malfunctioning inflight entertainment (IFE) systems are responsible for the largest number of onboard complaints. Airlines know how important they are to passengers, especially to those on long-haul flights. So much so that collectively they spend $2 billion (£1.4 billion) a year keeping the systems up to scratch.

Having the best IFE system has become the most important marketing tool after seat size and they are the second most expensive item on an aircraft after the engines.

In the early days of flight, the only onboard entertainment offered was a selection of magazines. The introduction of larger aircraft allowed projectors to be installed and now most longhaul aircraft have individual screens for every seat.

Each leap forward has given passengers more choice of what to watch and do, but the next advance will mark possibly their biggest change. Passengers will soon be able to play their own movies, surf the internet and book hotels and tourist attractions.

The IFE market is dominated by only two companies: Panasonic of Japan and Thales of France. Despite the potentially lucrative returns, none of the other large electronics firms have moved into the market because the technology required is more expensive to develop than normal consumer gadgets.

IFE systems must be lighter, simpler and consume less energy, as well as conform to aircraft safety standards. The systems are, therefore, considerably more expensive than consumer electronics. It costs about $4 million to fit out a Boeing 777 with an IFE system and about the same again to maintain it over a five-year period.

British Airways is upgrading its antiquated IFE system to a new Thales product. BA has about 130 long-haul aircraft, suggesting a possible installation price of more than $500 million for the fleet and a further $500 million to maintain it.

Alan Pellegrini, vice-president of inflight systems at Thales, said: “The IFE is a very high profile thing to an airline. It directly touches the airline's passengers so if there is a problem the passengers tend to get very vocal about it and then the airline's chief executive gets vocal with us.”

According to Thales, which controls about 40 per cent of the IFE market worldwide, there are usually only ever a couple of seats that have malfunctioning systems per flight. Some airlines believe that the traditional system will become redundant as passengers bring onboard their own devices.

However, Thales believes that a mixed system will be needed. Mr Pellegrini said: “We want to allow passengers to plug devices into their seat using a USB port and watch their own movies on our larger screens.”

In the fight for passenger loyalty, airlines will be forced to invest in ever more sophisticated systems. Large, flat-screen televisions with internet connectivity and a movie selection comparable to a BlockBuster store are the future. Sadly, the size of the seat is likely to stay the same.

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