SANTIAGO, Chile—The number of accidents involving business jets and turboprops world-wide is more than five times that of commercial jets this year, highlighting the challenges facing accident-prevention experts in improving safety for private and charter aviation.
Through nearly 10 months of 2012, more than 140 people have died in crashes in eight business jets and 13 commercially operated propeller aircraft, or turboprops, says the Flight Safety Foundation, a nonprofit group.
Only four accidents involving major passenger jets have been recorded world-wide, a record low rate of one crash per roughly 10 million flights over the period (there were 14 such jet crashes last year). Still, those crashes, which each involved more passengers, killed more than 320 people.
The data, presented at a global aviation-safety conference in Santiago, Chile, this week mark "the first year since I've been doing this presentation there were more business jet accidents than world-wide [passenger] jet accidents," said Jim Burin, the foundation's director of technical programs. The foundation has been compiling the report for 13 years.
Safety experts say the data mean more effort should be shifted to upgrading training, maintenance and government oversight at the lower end of commercial aviation in order to improve the segment's safety. Those efforts are particularly needed in the developing world, where airports are less advanced and air-traffic control systems are less reliable, experts said.
The ICAO, a United Nations body responsible for overseeing aviation safety, places more emphasis on regularly scheduled jets than smaller flights, said Nancy Graham, a senior official of the International Civil Aviation Organization.
"Perhaps we need to adjust our focus," she said.
Apart from the sheer number of accidents, safety experts increasingly say turboprops, which carry fewer passengers and weigh a fraction of Airbus or Boeing jets, support the vast majority of business activity in parts of the developing world, raising the probability an accident will involve a smaller plane.
Propeller-powered planes often transport employees and material for mining firms, oil drilling operations and other natural-resource companies to remote regions. Traditionally, such flights have been conducted under less local and international scrutiny that those of bigger passenger jets
Critics say extra attention to turboprops is long overdue.
Compared with jet fleets, "those planes typically have less experienced pilots, their flight simulators are not as advanced and they don't have the same level of automation" or onboard safety protections, according to Dai Whittingham, chief executive of the UK Flight Safety Committee, which helps airlines, pilots and government agencies share safety information.
With crash rates for passenger jets improving dramatically, "the average person automatically assumes the other parts of aviation are equally safe," according to Kevin Hiatt, chief operating officer of the safety committee. But the rise in smaller-plane crashes "sort of crept up on us," he said.
So now the foundation and its supporters "will look deeper into the issue to identify trends and relevant factors."
The active fleet of business jets and turboprops together basically equals the roughly 20,000 Western-built jets currently in service worldwide, according to the foundation's updated analysis. Between 2007 and 2011, on average there were nearly 16 passenger jet crashes annually.
With only four jet accidents through this week and slightly more than two months until the end of the year, Mr. Burin said 2012 appears headed to set a new safety standard for jetliners.
