David Learmount/LONDON
Available statistics from the major national agencies suggest that general aviation is getting safer, even though there were more business aviation accidents last year than in 1996.
In the USA, where more than half the world's general aviation activity takes place, the accident rate for general aviation as a whole was the lowest in its history, according to the National Transportation Safety Board (NTSB). The fact that the 1997 corporate aviation accidents list (see pages 34 to 36) is longer than the previous year's by about 10%, however, cannot be explained away by a proportionate increase in business aviation activity.
Industry revival in that sector may be promising, but it is variously estimated to have resulted in traffic growth of between 0% and 5%, depending on the part of the world. Corporate and business aircraft sales are now dramatically up, but in 1997 the sales revival had not yet begun to feed noticeably into utilisation.
The unnerving part of the increase in business aviation accidents is that most of it has taken place within the USA. Accidents recorded there last year were almost double the 1996 figures for the same category. There were 50 US business aircraft accidents in 1997 - 63% of the world total for the year.
The latter figure, in itself, is not statistically extraordinary because more than 60% of business and corporate aviation activity takes place in the USA. The year-on-year increase within the USA, however, is considerable: of the 50 business aviation accidents in the USA last year, 13 were fatal. That compares with 1996, in which there were 27 US accidents, 12 of them fatal. The only consolation is that the increase in fatal accidents was small.
According to the NTSB, however, US general aviation as a whole achieved all-time lowest figures for fatal and non-fatal accident numbers and rates. Accident numbers, comparing 1996 with 1997, were down from 1,905 to 1,854; while fatal accidents reduced from 359 to 350. Accident rates per 100,000 flying hours dropped from 7.9 to 7.5, and fatal accident rates were down from 1.49 to 1.42. The fatalities total was the only figure which showed a rise, from 631 in 1996 to 646 last year.
The US Aircraft Owners and Pilots Association (AOPA), which has yet to complete its own Air Safety Foundation analysis for 1997, welcomes the NTSB figures, noting that almost all categories of general aviation flying have shown improvement - except for instructional flying which, it says, has an impressively safe record, anyway. As for an early assessment of the trends to be revealed by its Foundation report, AOPA says that most events seem to involve "the same kinds of accidents for the same old reasons", such as manoeuvring close to the ground and flying into deteriorating weather.
Certainly, the UK Civil Aviation Authority confirmed in its analysis early this year of 1997 general aviation safety, that 27% of all fatal accidents for the 15-year period to 1996 were caused by "-continued flight into adverse weather, which includes controlled flight into terrain and loss of control in instrument meteorological conditions". This was the biggest single cause of fatal accidents. As in the USA, "low aerobatics and flying" also featured high on the list with 15% of all fatal events.
For 1997, the UK CAA, however, was able to report general aviation safety figures equal to those in its best-ever year (1994) in numbers and rates. There were 10 fatal accidents and what looks like a record-breakingly low accident rate of 1.2 events per 100,000 flying hours. But, if a suspected 6% reduction in flying hours is confirmed, the rate will still be equal to the best, at 1.4. Either figure shows a singular improvement on 1996 - a decade peak with 17 fatal accidents and a fatal event rate of 2.2 per 100,000h.
The CAA, however, now feels able to describe it as "one of those random bad years". The UK has the world's best fully documented general aviation safety record, and the fact that, after a period of moving gently downward, the three-year moving average for the last 10 years has almost levelled, indicates that improvement from here will be difficult "because of the law of diminishing returns", the CAA comments.
THE SINGLE PILOT CREW
It should not be surprising that the world's most popular twin-turboprop business aircraft features often on the corporate accidents list, simply because there are so many in operation. Like the increase in the number of US accidents listed, however, the jump in the number of Raytheon Beech King Air series aircraft is surprising: there were 29 King Air accidents during 1997, compared with nine the year before.
The King Air is the kind of aircraft flown or chartered by the full range of businesses, from large to small, using widely varying operational modes, ranging from permanently employed crews of two professional pilots to the situation where the boss flies the aircraft on a private licence with no first officer. Of the King Air accidents, 18 involved single pilots, whereas all the listed jets were crewed by two.
As in 1996, pilot error is firmly established as the most frequent causal factor in all the listed business aircraft accidents. Last year there were 79 listed events, and pilot error appears to have been involved in 48 of them (61%). Fatal accidents numbered 27, and 105 persons on board died. There were more accidents in 1997, but fewer fatal accidents and fatalities compared with 1996, which showed 64 events, 33 of them fatal, and 176 deaths.
After pilot error, the next most frequent factor was "structural or systems failure" (30%), which involved undercarriage failure in 19 out of the 23 cases. Weather, controlled flight into terrain and loss of control, in that order, were the only other categories in which the number of events ran to double figures.
The Flight Safety Foundation's Approach and Landing Accident Reduction (ALAR) task force has recently identified that, among 287 commercial aviation approach and landing accidents (ALAs) in the period 1980-96, business jets were involved in 76 (26%). Factors identified in the business jet ALAs were lighting conditions (in 87% of the events) - more than 50% occurred at night; omission or an incorrect action was causal in 31%; and, in 20%, lack of "positional awareness" was involved.
Source: Flight International
