1. Human Factors in Aircraft Accident Investigation
Dr. Dennis Vincenzi

2. Symptoms of System Flaws
Errors made by skilled experts are not root causes of accidents but symptoms of the flaws and inherent limitations of the overall sociotechnical system in which these experts work (Reason, 1990).

3. Why Do Accidents Happen?
Christopher A Hart, Acting Chair, NTSB
“Human error is always 100 percent of the cause of accidents, whether it is pilot error, maintenance error, management error, or system design error.”
It’s still human error.

4. Accident Examples and Human Error
1972 – An Eastern Air Lines L-1011 crashes in the Florida Everglades killing 101 on board.
1977 – Two aircraft collide on a runway in Tenerife killing 583 people.
1994 – A B-52 crashes during an aircraft demonstration flight at an airshow at Fairchild Air Force Base killing the pilot and 3 U.S. Air Force crew members.
2009 – A Bombardier Dash-8 Q400 experiences an aerodynamic stall and crashes into a house killing 49 people on board and 1 resident on the ground.

5. Human Factors Issues: Overview
Human Factors issues can include anything involving human participation, design, or operation.
Situational Awareness
Organizational Policies
Leadership Issues
Crew Resource Management
Aeronautical Decision Making
Automation Design
Fatigue
Physiological and Psychological Factors

6. Reason’s Model (1990)
Reason’s Swiss Cheese Model of Accident Causation
No single reason or event is responsible for an accident.
Accidents are the result of many events or factors that line up and result in notable events or accidents
Organizational, supervisory, preconditions for unsafe acts and the unsafe acts themselves can combine to create accidents and injury

7. Reason’s Model (1990)

8. 1994 Fairchild Air Force Base B-52 Crash
Lt Col Arthur “Bud” Holland
History of flight safety violations that went uncorrected
Risky behavior
Unprofessional behavior
Resulted in a fiery crash that killed the pilot and 3 crew members

9. Looking at the B-52 Crash from a Systems Perspective
Systems and Teams?
The pilot and flight crew as a team
Poor CRM
The pilot, flight crew, and aircraft as a system
Exceeding the limits of the aircraft
The pilot, flight crew, aircraft, and leadership as a broader, more comprehensive system
Risky behavior reported and documented many times
Air Force Leadership was aware of this behavior and chose to ignore them
Air Force Leadership had many opportunities to correct the problem but chose to take no action

10. End of Lecture 1