Airlines suffering from high fuel prices are incurring even more costs from fuel wasted by flight delays, according to a US government report. The US airline industry paid out $19bn in crew, fuel and maintenance costs as aircraft waited for late flights to arrive, said a report from the Congressional Joint Economic Committee.

Wasted fuel accounted for $1.6bn of the total amount lost according to the report, Your Flight is Delayed Again, which added that aircraft burned 740 million extra gallons of fuel thanks to delays.

However, the cost impact of delays are likely to be worst still this year as the report assumed an average 2007 price of $2.15 per gallon. Jet kerosene fuel was trading at $3.95 on May 20th, and the Air Transport Association has predicted an average cost of $3.40 this year – up 61 per cent from last year.

Over a third of delays were caused by other aircraft arriving late. "Other top reasons for delay point to a system under strain," said the report, which also found that 29 per cent of delays were due to circumstances within the airlines control, including bagging handling and fueling, while 28 per cent were due to national aviation system delays. Less than six per cent of delays were down to extreme weather.

Soaring fuel costs, coupled with environmental pressures are forcing growing numbers of airlines to address the problem and the Air Transport Association is currently pushing for the modernisation of the analogue air traffic control system, which it hopes would make air routes more efficient. The organisation's Smart Skies campaign is calling for the modernisation of air traffic systems as well as a change to existing funding programmes, which it claims unfairly subsidises corporate jets using the air traffic control system.

"We're investing millions in an RNP [Required Navigation Performance] system to outfit our entire fleet to help fly more direct routes and deliver more fuel savings" said Marilee McInnis, spokeswoman for South West Airlines, which saw net income jump to $695m in 2007 from $495 a year earlier.

Many experts believe that with jet fuel prices continuing to rise airlines have little choice but to invest in systems and approaches capable of curbing fuel use. South West's own plans were affected following the shutdown of partner ATA — one of eight airlines to shut down since the end of 2007 as the industry feels the strain of high fuel prices.

"We have hedges in place which are helping, but we're not immune," said McInnis "We're looking at every way possible to keep costs down - the industry wasn’t designed for these prices."

Earlier this year the company also announced that it will save $42m this year by cutting flight speeds – a fuel saving moves that a number of other airlines are reported to be investigating.