Aviation authorities are just as vital to maintaining the public's trust in the airlines as the carriers and the manufacturers
An assumption of good airworthiness standards and proper safety oversight is made by two main groups of people who use aircraft: the travellers and the crews. The assumption comes from trust in the system that produces and operates aircraft.
If this trust were to be degraded a little, not even to the level of mistrust but merely to passive resignation, the system would be damaged in the same way that political analysts believe democracy is being hurt by loss of trust in politicians and politics. For democracy, a sense of resignation means that fewer turn up to vote. The aviation industry, particularly the airlines, can ill afford to lose the trust they have, because it would mean that fewer passengers turn up to board.
The trust comes from the assumption that a certificated aircraft or piece of equipment is judged safe when it is new according to exhaustive tests that prove it meets carefully considered specified standards incorporating safety margins. But it is not always as simple as that. Certificators of new equipment, for example, especially if it uses new technology with which little operational experience has been gained, can be guilty of optimism. There is an understandable tendency to see that potential leading-edge technology - especially avionics - offers long- term safety improvement, and to accept that teething problems or glitches on the way to better safety are a price we have to pay. And with luck the glitches will not have serious consequences. This is a difficult area to deal with if the industry is to advance, but the European Joint Aviation Authorities, with its Future Hazards programme, is attempting to anticipate the sorts of problems that certificators must expect when they are examining new ideas and equipment. This is an important programme.
But certification responsibilities do not stop with first-time manufacture. Air travellers have a right to assume that "the authorities" which set standards will, if something is proven inadequate in service, ensure it is replaced with better equipment. Often their expectations are met, provided airlines comply with the advice in a company service bulletin (SB), or when an aviation authority airworthiness directive (AD) makes an improvement compulsory. But sometimes the company or the authority holds back from taking action, and the decision not to act is not always done following a cost-benefit analysis. When this happens it is usually impossible to work out how or why a reasonable, logical decision was never made.
There have been two recent relatively minor examples of events that illustrate the issue. An escape slide inflation hose for pre-1983 Boeing 747 classics was known to be faulty for 19 years before an event occurred in 2002 at New York Kennedy Airport that caused the US National Transportation Safety Board (NTSB) to investigate and recommend issue of an AD. In 1983, slide manufacturer BF Goodrich, after several early slide operation problems, had issued an SB to operators and from then on Boeing installed modified slide hoses in all new-build aircraft, but did not issue an SB itself until the Kennedy incident.
Also recently, the NTSB determined that electronic attitude director indicators (EADI) blacked out when an Embraer Brasilia manoeuvred violently during recovery from an icing encounter, depriving the crew of orientation information in the recovery. Bench tests of the equipment from the incident aircraft have revealed that its EADIs did not perform to specification, but also that the routine tests carried out on new-build equipment did not test it to specification. It would be difficult to explain to an airline passenger how an authority set performance limitations and then did not check the system that checks the approved equipment's ability to meet them.
There is a long list of decisions that never got made, some even following fatal accidents. In addition there is the touchy question of just how far and for how long grandfather rights for old but still-in-production designs should protect them from having to meet the standards set for aircraft certificated since then.
The potential effect is gradually to erode the trust that the travelling public has in the total system for ensuring they are safe when they fly. Despite a general belief that air travel is safe, when something goes wrong passengers are often left feeling puzzled, especially if it becomes clear that a fault has been known about for a long time. It is important that embattled airlines keep their safety standards high, but it is equally vital that the certificating authorities work not only to retain their credibility, but to improve it.
Source: Flight International
