The UK CAA maintains an ‘Accident Analysis Group’ (AAG) which has been in existence since 1996 when it was the origin of UK CAA CAP 681, a review of Global Fatal Accidents between 1980 and 1996.
The third Review of Global Fatal Accidents was recently published by UK CAA in CAP 1036 - Global Fatal Accident Review 2002 to 2011 which summarises a study of worldwide fatal accidents to jet and turboprop aeroplanes above 5,700kg engaged in passenger, cargo and ferry/positioning flights for the ten-year period 2002 to 2011. The style and content of the document are similar to the previous Global Fatal Accident Review (CAP 776) but there are, however, some differences and these are outlined in Appendix A (see Further Reading).
The main findings of the study are listed below.
Worldwide Fatal Accident Numbers
There were a total of 250 worldwide fatal accidents, which resulted in 7,148 fatalities to passengers and crewmembers onboard the aircraft. The proportion of aircraft occupants killed in these fatal accidents was 70%.
There was an overall decreasing trend in the number of fatal accidents, however there was much more fluctuation in the number of fatalities per year.
The approach, landing and go-around phases accounted for 47% of all fatal accidents and 46% of all onboard fatalities. Take-off and climb accounted for a further 31% of the fatal accidents and 28% of the onboard fatalities.
Worldwide Aircraft Utilisation
In the ten-year period 2002 to 2011, the number of flights flown increased by 22%, which equates to an average annual growth of 1.9%. The equivalent values for hours flown were 36% for overall growth and 3.0% for average annual growth.
Worldwide Fatal Accident Rates
The overall fatal accident rate for the ten-year period 2002 to 2011 was 0.6 fatal accidents per million flights flown, or 0.4 when expressed as per million hours flown.
There was a decreasing trend in both the overall rate of fatal accidents and onboard fatalities.
On average, the fatal accident rate for turboprops was four times that for jets, based on flights flown, and nine times greater when using hours flown as the rate measure.
On average, the fatal accident rate for aircraft with Maximum Take-Off Weight Authorised (MTWA) below 15 tonnes was three times that for aircraft with MTWA above 27 tonnes, based on flights flown, and nine times greater when using hours flown as the rate measure.
On average, the fatal accident rate for cargo flights was eight times greater than for passenger flights, based on flights flown, and seven times greater when using hours flown as the rate of measure.
The fatal accident rate for African operators was over seven times greater than that for all operators combined. North America had the lowest fatal accident rate of all the regions.
Factors and Consequences
Over half of all fatal accidents involved an airline related primary causal factor.
The most frequently identified primary causal factor was “Flight Crew Handling/Skill – Flight handling” which was allocated in 14% of all fatal accidents. “Flight Crew Handling/Skill – Flight handling” was also the joint most commonly assigned causal factor. This generally related to events in which the aircraft was controllable (including single engine failures on twin engine aircraft), however the flight crew’s mishandling of the aircraft or poor manual flying skills led to the catastrophic outcome.
66% of all fatal accidents involved at least one airline related causal factor. In addition to “Flight handling”, “Omission of action or inappropriate action” was the joint most commonly assigned causal factor.
“Omission of action or inappropriate action” generally related to flight crew continuing their descent below the decision height or minimum descent/safety heights without visual reference, failing to fly a missed approach or omitting to set the correct aircraft configuration for take-off.
38% of all fatal accidents involved at least one airworthiness related causal factor, of which “Engine failure/malfunction or loss of thrust” was the most common.
The most frequently allocated circumstantial factor was “Poor visibility or lack of external visual reference”. In the majority of cases this circumstantial factor was assigned, the accident occurred during a period of thick fog. The second most frequently assigned circumstantial factor “Weather general” mainly referred to accidents which occurred during heavy rain/snow, high winds or icing conditions.
Nearly 40% of all fatal accidents involved some kind of loss of control, making this the most frequent type of accident. Loss of control events were broken down into four categories – following technical failure, following non-technical failure, following icing, and following unknown reasons. Of these four, non-technical failures (for example flight crew failing to correctly respond to a warning) were the predominant cause of loss of control accidents.
Roughly half of all fatal accidents in which the pilot(s) lost control following a non-technical failure resulted in a post-crash fire, making this the most common post-crash fire precursor.
Over a third of all fatal accidents involved a post-crash fire; however this was always in conjunction with, or as a result of another consequence rather than in its own right. Fires in flight were far less common, accounting for 5% of all fatal accidents.
Mid-air collisions accounted for three out of the 250 fatal accidents (1%).