Passenger revenue at US carriers in May fell by 26% year-over-year as the H1N1 virus further crimped the anemic demand environment.

Statistics released today by the Air Transport Association of America (ATA) show May's drastic drop follows an 18% fall in April's passenger revenue statistics.

The association says May's revenue decreases mark the seventh consecutive month of declines.

"In May the H1N1 influenza compounded an already weak demand situation, negatively impacting industry cash flow and forcing a closer look at current levels of flying," says ATA chief executive officer James May.

Continental Airlines has previously said H1N1 reduced its consolidated May revenues by $30 million while Delta Air Lines estimates it could face a revenue reduction of $125-$150 million during the first quarter driven by weak demand triggered by the virus.

US carrier passenger levels in May fell 9.5% as the average price to fly one mile fell 17.6%, according to ATA estimates.

Cargo traffic also continues to fall as revenue tone miles in April dropped 22% year-over-year - the ninth consecutive month of declines. The pacific region registered a 26% decline in cargo traffic.

Source: Air Transport Intelligence news