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Monthly Archives: September 2013

OK, it is fair to say that the low cost carriers are seeing their methods replicated, particularly in short-haul, so that could be your first thought. But actually I refer to safety trends. In the never-ending battle of man versus machine, occasionally versus ground (a battle which we ironically sometimes try to win using yet another machine), who is winning?

Draw your own conclusions with statistics recently published at skybrary.aero.

In global terms, the accident rate has been declining steadily ever since the 1950s. In 2000, the concern was that, even with that encouraging trend, the growth of the airline industry would result in an absolute increase in the number of fatal accidents occurring each year. Some categories of accident were proving to be a particular challenge. In the late 1990s, the Flight Safety Foundation’s campaign to reduce controlled flight into terrain (CFIT) accidents, which included their Approach and Landing Accident Reduction (ALAR) tool kit, appeared initially to have achieved some success. However, in 1999-2001 the CFIT rate started to rise again, causing concern in the flight safety world. Then, the widespread introduction of TAWS began to make a real impact on the number of CFIT accidents, and the decline in the accident rate resumed.

Improvements in overall safety, and the reduction in the accident rate seen in the period 2002-2007 can be attributed to safety enhancements made possible by digital technology such as FDMACASTAWS, etc but in recent years it appears that the accident rate has again levelled out.

For large commercial airliners, a small number of accidents account for the majority of fatalities each year.

This refers to (and explains in more detail) enhancements such as:

  • FDM: Flight Data Monitoring. Flight parameters are downlinked from the aircraft and analysed against limits – throwing up ‘red flags’ where aircraft or operator limitations are exceeded. Can be used to analyse trends and investigate safety reports, as well as identify deliberate violations.
  • ACAS: Airborne Collision Avoidance System. Often referred to as TCAS (Traffic Collision Avoidance System). If something in the system, be it air traffic control, the autopilot, the weather or the pilots, screw up, this will identify airborne threats to the aircraft – i.e. warn of an impending collision which you might have missed.
  • TAWS: Terrain Awareness and Warning System. Often called GPWS or Ground Proximity Warning System. Warns you if you are, in the estimation of the system, likely to hit the ground in an abnormal manner.

So what is the point in mentioning the above safety enhancements, which have been around for some time now?

Let’s think about what they are protecting us against. It can be said that FDM acts significantly in identifying trends towards wilful violation of limitations by operating crew, such as continuing an unstable approach unstable below 500ft, and is a disincentive. Trends identified with FDM can be addressed through training i.e. by improving awareness. ACAS and TAWS also act to improve situational awareness which may be degraded through distractions, abnormal situations, fatigue or lack of proficiency.

These tools are acting as a sixth-sense to identify threats we might have missed. In the case of FDM, if being used for investigation of safety reports then the threat may be hidden in the trend (e.g. a trend towards continuing unstable approached below 500ft may suggest a lack of awareness of the fact that this is the single highest contributory factor in runway excursion events). If being used to stop violation of operational limits then the threat is in the lack of awareness of why those limits exist. These tools are eyes and ears which acts to keep us safe when ours, be it our actual eyes and ears or be it our own sixth sense built up from experience of real life and/or training, do not.

Now if the accident rate has levelled out, what is the problem with these tools? They have helped to reduce it, but at some stage we will no doubt start to rely on these tools too much. It has been said that wearing seatbelts, having airbags and improving the design of cars has not, long-term, improved personal safety since it has invoked a sense of invincibility amongst drivers and lead to more risk-taking than previously.

Perhaps we just get used to the system, however safe it may be? That would mean our complacency is directly proportional to how safe we feel. That being the case, one has to ask the question… how safe do you feel? And why?