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Accident Rates

Abnormals

The cleverest trick by someone arguing a point without facts is to use a twist of statistics to prove a point. Here is where we find accident rates and the claim pilots are letting the world down by not holding their end of the man/machine equation. Look at the chart above, accident rates have plummeted. (True). Look at the chart below, accidents caused by pilots are way up! (Not true.)


 

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Figure: US/Canadian Operators Accident Rates by Year, from Boeing Statistical Summary, pg. 17.

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Figure: Changes in accident causal factors over time, from CRM Handbook, figure 2.

The big picture falling accident rates (on the top of the page) leads one to believe we have this aviation thing figured out. The decline has been so sharp that it is undeniable that things have gotten better. While a lot of that is because we are smarter, most of it is because we are smarter at building airplanes.

An ICAO study notes that the proportion of accidents caused by humans is way up. Of course this is statistical hocus pocus. While the number of accidents has gone down, the number caused by mechanical problems has gone way down. Human issues have no place to go but up. I would argue that we as pilots have made great strides as well, but we can and should improve.

Summary by Phase of Flight

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Figure: Fatal accidents by phase of flight, from Boeing Statistical Summary, pg. 20.

Basis

The chart on the top of this page is based on the following:

[Boeing Statistical Summary, page 2.

  • The accident statistics presented in this summary are confined to worldwide commercial jet airplanes that are heavier than 60,000 pounds maximum gross weight. Within that set of airplanes, there are two groups excluded:
    1. Airplanes manufactured in the Commonwealth of Independent States (CIS) or the Union of Soviet Socialist Republics (USSR) are excluded because of the lack of operational data; and
    2. Commercial airplanes operated in military service. (However, if a military-owned commercial jet transport is used for civilian commercial service, those data will be included in this summary.)
  • The following airplanes are included in the statistics:
  • 707/720 717 727 737 747 757 767 777 787

    DC-8 DC-9 DC-10/MD-10 MD-11 MD-80/-90

    A300 A300-600 A310 A320/321/319/318 A330 A340 A380

    EMB-170/-175 EMB-190/-195

    Concorde

    L-1011

    BAC 1-11 Comet 4 Trident Caravelle Mercure CV-880/-990 VC-10 BAe 146 F-28 Avro RJ-70/-85/-100 F-70

    CRJ-700/-900/-1000

    F-100

Situational Awareness Case Studies

[Airbus Flight Operations Note, pg. 2] Situational awareness is not just a theoretical notion and is pertinent to most accident or incident cases. It is real, and its absence causes accidents. Research from the Australian Transportation Safety Board (ATSB) indicates that human factors is a contributing cause in around 70 percent of all incidents and accidents. Approximately 85 percent of incident reports include a mention of loss of situational awareness. Degraded situational awareness can lead to inadequate decision making and inappropriate actions. This is illustrated in [the table], which identifies causal factors involved in approach and landing accidents.

Factor % of Events
Inadequate decision making 74%
Omission of action or inappropriate action> 72%
Non-adherence to criteria for stabilized approach 66%
Inadequate crew coordination, cross-check and back-up 63%
Insufficient horizontal or vertical Situational Awareness 52%
Inadequate or insufficient understanding of prevailing conditions 48%
Slow or delayed action 45%
Flight handling difficulties 45%
Deliberate non-adherence to procedures 40%
Inadequate training 37%
Incorrect or incomplete pilot/controller communication 33%
Interaction with automation 20%

Causal factors in approach and landing accidents

References

Airbus Flight Operations Briefing Notes: Enhancing Situational Awareness.

Crew Resource Management: An Introductory Handbook, DOT/FAA/RD-92/26, DOT-VNTSC-FAA-92-8, Research and Development Service, Washington, DC, august 1992

Statistical Summary of Commercial Jet Airplane Accidents, Worldwide Operations 1959 - 2012, Boeing Commercial Airplanes, 2013

Revision: 20150403
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