If airline flight safety is the issue, the US Federal Aviation Administration is almost always a world leader in developing systems to promote it. There is one area - flight operations quality assurance (FOQA) - however, in which it has long wanted to advance, but has been immobilised by circumstances beyond its control.

Now, having run a successful three-year FOQA operational trial in co-operation with four of the USA's major airlines, the FAA's Administrator Jane Garvey believes that she has enough goodwill and evidence of its effectiveness to win over the majority of US carriers. They have been withholding the crucial component needed to make FOQA work: their trust in the system. US airlines fear the legal implications of collecting accurate digital data about their own operations because, although they would gather it for the purpose of detecting system faults and correcting them, it could be used against them after an accident by the regulator or by litigants.

The worst indictment that an accident investigation report can contain is that the accident was "waiting to happen". Except in cases where safety principles have been wantonly disregarded, the operator who has suffered a preventable accident either cannot have known that the risk existed, or had not understood the extent of the risk. Lawyers, however, will have no sympathy for an airline that was clearly unaware of a weak point, whether in maintenance, aircrew training or operational procedures.

Knowledge of a risk is the key to flight safety. Until recently, however, that knowledge had been almost entirely confined to that gained, retrospectively, from the study of accidents and serious incidents. A far better system, involving a diagnostic, preventive approach, has been available since the mid-1970s, but in the early days it required a high level of expertise and a complex infrastructure to make it work.

Since the early 1990s, however, the advent of digital flight data recorders (DFDRs) and powerful, user-friendly, desktop digital data processing has provided aviation - military as well as civil - with the means to detect weaknesses and risks before they become accidents. Many non-US airlines already use such a system, downloading DFDRs or quick access recorders (QARs) after every flight and using the information diagnostically, both for engine health monitoring and for operational performance assessment. Until recently one of the problems has been that most of the data streams recorded simply tell the airline that everything is working as it should. Now, however, desktop computers loaded with turnkey software packages - which the airlines can customise if they wish - can sift the data for exceedances, providing warnings of those "accidents waiting to happen".

So the technology exists and the system has achieved operational maturity. Anyone who doubts that can look to the experience of the UK Civil Aviation Authority, which conceived the principles while visually analysing reams of non-digital FDR output during its certification of the Boeing 707, and then of automated landing systems, during the 1960s. The system went digital in the 1970s when the CAA launched a programme called Special Event Search and Master Analysis (SESMA) with the then state-owned British Airways. Now SESMA's descendants, improved by modern DFDRs, QARs and desktop analysis tools, are in the hands of airlines and industry.

The FAA's hope is that all US carriers, not just those who took part in the FOQA trial, will see what FOQA can do to improve their operations, their safety, and to lower their costs. The crucial component needed to make the system work, however, is trust between the airlines and the regulator. Garvey has made it clear that FOQA data will not be used in enforcement action "except in egregious cases". The FOQA system will collapse if the FAA is seen to betray its trust.

Meanwhile, the agency says, the realisation is dawning on the airlines that, in litigation, they are now as likely to be charged with having an accident because they did not have a FOQA system as they are to have their own data subpoenaed and used against them.

Source: Flight International