Changing operational procedures for environmental reasons is valid, but only if risk analysis is applied to the methods proposed

Now is the time for a serious review of precisely how the world - but especially Europe - is going to tamper with aircraft operations in the name of environmental benefits. This week provides two compelling reasons.

One is a tragic controlled flight into terrain (CFIT) accident that took place when an aircraft was required to use a non-precision approach at night when there was a precision approach available. The other is the formal capitulation of the European Commission (EC) in its efforts to accelerate progress - at least in its own skies - toward phasing out aircraft at the noisy end of the Chapter 3 band.

Taking the second issue first: noisier aircraft will inevitably be subject to environmental sanctions sooner than quieter aircraft. Some of these sanctions will be local or national government rules compelling specific airports to pressurise airlines to use other than the safest approach or departure procedures.

In grudgingly accepting the International Civil Aviation Organisation (ICAO) standard on aircraft noise - which dictates that globally agreed noise standards may be challenged only on an airport-by-airport basis (not on a national or regional basis) - the EC has rolled over to the letter of the law and abandoned all attempts to follow its spirit. The sad thing is that ICAO standards and recommended practices (SARPS) are minima. If any nation, region, or bloc wants to go further than the SARPS, it should be able to, and this principle has not been challenged (so far) in respect of aircraft certification or safe operating practices.

The irony is that now in Europe - where people are particularly environmentally conscious - a rule to force them to put up with noisy aircraft is going to have the potential secondary effect of threatening safety.

Two examples of this are Zurich airport and Amsterdam Schiphol airport. The "primary cause" of the recent accident at Zurich is unlikely to be the requirement for the crew to change its approach from a precision to a non-precision procedure, but it will almost certainly be shown to be a causal factor. At Schiphol, the landing or take-off runway in use is determined not by the wind direction, but by which approach affects the fewest local people.

Aviation should not hide behind pretensions of safety to avoid accepting any operational change, but when changes are proposed they should be thought through properly, and risk analysis should be carried out. There may also be ways of changing operations while acting to mitigate or even eliminate any apparent increase in risk. For example, the installation of an instrument landing system (ILS) for Zurich's runway 28 has been under consideration, so the implementation of the new environmentally driven procedures could have waited until the ILS was in place. But they did not.

The Flight Safety Foundation's Approach and Landing Accident Reduction (ALAR) working group has established from a large statistical base that non-precision approaches increase the risk of serious accident by a multiple of between five and seven times. The Swiss and German decision-makers working on the Zurich noise abatement procedures should have known this, but they will plead that no pilot is compelled to fly an approach that he/she deems unwise under the circumstances. That is seriously disingenuous.

The real truth is that no pilot flying in instrument meteorological conditions should even be faced with this decision. It should be out of the question that any consideration justifies the raising of risk to passenger and crew lives by a factor of between five and seven.

It took ICAO a quarter of a century to move from specifying the standards for Chapter 3 to phasing out Chapter 2 aircraft. Europe can see the same thing happening with Chapter 4. The standards have been agreed, but there is no sign that the industry has any intention of specifying a date for phasing out Chapter 3 equipment, even in stages. Meanwhile, as a consequence of this procrastination, more and more local noise rules are going to affect operations in the two most critical phases of flight: early climb and the descent to land. For the genuinely worthy cause of allowing people near airports to sleep soundly, dangerous decisions may be made unless the industry is careful. The decision-makers should ask themselves how soundly they will be able to sleep after they have made decisions that could directly contribute to the death of air travellers and crew. The risk may not only be to travellers, but to those living under the glidepath in whose interest the decision-makers claim to be acting.

Source: Flight International