David Learmount/LONDON
General aviation safety is either improving slowly or has reached a point where further significant improvement is unlikely, say the national agencies which track GA safety with any accuracy. The 1998 corporate aviation accidents list shows 70 accidents, 29 of them fatal, and a total of 124 fatalities - an improvement on 1997 in which 80 accidents occurring, 26 of them fatal.
None of the major agencies admits to giving up on their programmes to improve safety awareness, but there is a palpable weariness that the same reports with the same warnings emerge every year. Even the US National Transportation Safety Board - while trumpeting about all time safety records (which it has done for the last three years) and a 3.6% improvement in the 1998 fatal accident rates compared with those for 1997 - sounds jaded in its triumph.
In the UK, the Civil Aviation Authority shows that 1998 equalled 1997 as a best-ever year, but the same - or almost identical - levels have been achieved five times in the past 10 years. That sounds like a plateau, so quoting figures has become meaningless. Improvement is the holy grail, but there are no real figures to indicate progress towards it.
There is nothing surprising about this because GA accidents, like road accidents, always seem always to have the same simple characteristics. The same could be said about military or airline accidents when they are put into broad categories, but the aircraft in both cases are more complex with potentially infinite varieties of small upsets, either technical or human factors related, which can start a critical chain of events. In the case of GA, apart from sophisticated corporate aircraft, the aeroplanes are relatively simple. In theory the pilot of a light aircraft should know, in any given situation, exactly what options are available simply because they are few.
All the nations which track GA safety are united in the judgement that continuing into deteriorating weather is the greatest cause of grief. In the corporate aviation accidents list, which records events involving more capable aircraft and, presumably, more experienced pilots, numerous aviators filed for flights under visual flight rules (VFR), presumably because of their qualifications or aircraft equipment. But soon after take off the same pilots came to grief in instrument meteorological conditions(IMC).
In some cases, from the evidence, it is difficult to believe that the pilots did not know the risk they were taking. The tables record nine accidents involving weather as a major factor, with 20 resulting fatalities. Controlled flight into terrain (CFIT) killed 57 people in 11 accidents, and the weather was not particularly bad in most of them, but IMC prevailed in them all. The concept of VMC at night, not espoused in all countries, is a trap which catches many aviators and ought to be reviewed. Good visibility exists only when there is strong moon or starlight, and even then the visual clues differ in daylight.
On 13 March last year an Aerospatiale TBM-700 pilot carried out a successful night global positioning system (GPS) satellite navigation system letdown into the visual circuit. During the night circuit, although the visibility was technically about 15km, the aircraft hit trees on a low hill while positioning to land. There was overcast and moonlight, if any, would have been limited.
GPS is a much used navigation aid in general aviation, but it can let an aircraft down into trouble. In accidents like this it is tempting to ask whether, without GPS, the pilot would have elected to make the approach attempt or to divert to an airfield with precision runway approach guidance.
NASA has been working on the concept of making use of new technology to make light aircraft cockpits so intuitive and engines so reliable that accidents will decrease. The idea is ultimately to provide the intuitive situational awareness which is being introduced in airliners in the form of enhanced ground proximity warning systems integrated with a navigation display. As the airlines have found, however, mankind finds new ways of making mistakes when provided with new technology - not only until it becomes mature, but until pilots have learned what its limitations are and have picked up user skills.
Airline pilots are more or less bound by standard operating procedures with any given level of equipment. They are less free to use a new piece of equipment, like GPS, in a way for which it was not designed. Private pilots have advice but are freer to calculate their own risks.
Neither is it so easy to persuade private pilots to learn about human factors so as to develop an awareness of their own weaknesses. Airlines and the military, meanwhile, invest in human factors instruction and concepts like crew resource management (CRM). The military has developed a version of CRM for single-pilot cockpits.
The UK CAA, having expressed its muted pleasure at good 1998 GA safety figures, resorts to group human factors, providing a checklist of actions for individual private pilots and club instructors in its GA Safety Information Leaflet. The theme is to become part of a safety team for the whole industry by persuading other pilots who are acting unwisely not to do so. The suggestions include persuading pilots:
• to take refresher training if out of practice;
• not to use out of date charts and planning data;
• to get good meteorological data;
• not to show off;
• not to press on in bad weather.
Despite worthy intentions, however, technology which brings improved situational awareness to GA pilots may now be the only way left to improve safety at anything more than a pedestrian rate. Using basically the same aircraft with the same cockpits will tend to generate the same results as today.
Source: Flight International