Business jets make up a small percentage of UK commercial air traffic–3.5 percent–but a recent analysis of air traffic safety indicates that the rate of incidents and accidents among business jets is higher than among other types of commercial turbine aircraft flying in UK airspace.

According to Richard Schofield, head of customer affairs and safety at the UK’s
National Air Traffic Services (NATS), business jets were involved in nearly 16 percent of all level-bust incidents between January 2004 and the end of last year. During that time, according to Schofield, there were 1,260 level busts. “Of those, around 200 were business jets,” he said.

He added that the proportion of level busts involving business jets could be even higher–25 to 33 percent–if airspace in the rest of the North Atlantic is included. He noted, however, that the high percentage of incidents includes all business jets that fly through UK airspace and the North Atlantic, not just those that are registered in the UK.

Approximately 33 percent of the 200 business jet level busts in the UK were due to failure to follow standard instrument departures; 12 percent were due to altimeter setting errors; and 10 percent were incidents in which a pilot acknowledged a level change instruction but failed to make the change. Level busts made up 25 percent of all business jet incidents, Schofield said.

In addition, business jets were involved in 10 percent of gross navigational errors– where the reported position differs from the allocated route position by 25 miles or more–in the Shanwick Atlantic oceanic area. Most of that area is beyond the range of land-based radar, so air traffic controllers allocate a specific route, which is then confirmed by position reports at regular intervals by the aircraft.

The rate of runway incursions is also high among business jets. Schofield said they were involved in 9 percent of all incursions at UK airports. Heathrow Airport, which handled 477,000 flights last year, had the highest number of incursions, but Farnborough Airport had the highest rate of runway incursions among the 25,000 aircraft that used the field last year. “Heathrow is almost bound to have more ‘events’ because it is handling 20 times more traffic,” Schofield said. “But Farnborough still [had] the highest number of ‘events’ per 1,000 flights.”

According to Kevin Johnston at TAG Farnborough, there were five runway incursions between January 2004 and December last year, four of which occurred during the Farnborough Air Show. “No active aircraft were involved,” Johnston said. The other
incident occurred when a bird-scaring vehicle “infringed [on] the ILS cleared strip.”

Schofield added that statistics from the UK Civil Aviation Authority (CAA) show that the fatal accident rate for business jets is 8.5 times greater than the fatal accident rate for airliners per million flying hours. However, according to a 2005 CAA Aviation Safety Review, the actual number of fatal accidents per year on average is quite low.

In Europe, between 1995 and 2004, there was only one fatal accident involving a UK-registered business jet. Worldwide, business jets had an average of two fatal accidents per year, with 10 fatalities, as opposed to commercial jets, which had an average of 11 fatal accidents and 744 fatalities per year. The rate is high because, according to the report, business jets made up only .5 percent of the 22.5 million flight hours of UK-registered aircraft worldwide.

Schofield said that NATS “does not yet have an opinion” as to why the rate of incidents and accidents is so high among business jets. It is working with business jet trade associations and the CAA “to identify causes and then develop solutions.”