Preliminary 2008 accident statistics compiled by the US National Transportation Safety Board (NTSB) reveal a "mixed picture", with improvements in some sectors and higher accident rates in others.

For US-based scheduled air carriers (Part 121), there were 20 accidents in 2008, six more than in 2007, but with no passenger fatalities in either year. The yearly tally covered nearly 19 million flight hours and more than 10 million departures, down 0.5 % and 0.1% from 2007, respectively.

The NTSB defines an accident as an event in which any person on board an aircraft suffers death or serious injury, or where the aircraft receives "substantial" damage.

For non-scheduled Part 121 flights, there were three people killed last year, two of whom were on-board the aircraft. The sector accounted for 621,000 flight hours and 190,000 departures. In 2007 there was one fatality for non-scheduled flights, with roughly the same number or flight hours and departures.

Most concerning to NTSB officials for 2008 are the accident statistics for the Part 135 on-demand air taxi segment, with a fatal accident rate of 0.52 per 100,000 flight hours. The sector, which includes emergency medical services helicopters, experienced 19 fatal accidents killing 66 people, up from 43 fatalities and 14 accidents in 2007. The overall accident rate for on-demand flights was 1.52 per 100,000 flight hours, nearly the same as the 1.54 rate in 2007.

For general aviation, the accident rate was slightly up from last year, with 7.11 accidents per 100,000 flight hours compared to 6.92 in 2007. The fatal accident rate increased to 1.25 per 100,000 flight hours, up from 1.20 in 2007.

"While the overall aviation safety record in the US is among the best in the world, the 2008 accidents statistics reveal a mixed picture," says NTSB acting chairman Mark Rosenker. "We are particularly concerned with the spike in fatalities in on-demand air charter operations."

Source: Air Transport Intelligence news