Lessons Learned from TSB Investigations of Helicopter Accidents (1994-2003)

1. Transportation Safety Board of Canada Bureau de la sécurité des transports du Canada Lessons Learned from TSB Investigations of Helicopter Accidents (1994-2003) Joel Morley and Brian MacDonald International Helicopter Safety Symposium Montreal, QC September 26-29, 2005

2. Introduction • Average of 53 Canadian registered helicopters involved in accidents each year (range of 44 to 68) • 9.3 accidents per 100 000 flight hours

5. Method • Employed sample of occurrences investigated by TSB (N=103) • Comparison sample of military occurrences investigated (N=37) • Categorized by a team of TSB investigators (4 step process)

6. Step 1: Initial Occurrence Categorization • Power Loss • Structural Failure • Loss of Visual Reference • Struck Object • Loss of Control • Loss of Separation • Training for Emergencies • Other

8. Step 2: Examination of Proportion of Fatal to Non-Fatal Accidents • To see where greatest human cost was occurring • Determined: • Number of accidents in each category which were ‘fatal’ (1 or more fatality) • Number of lives lost in each category

11. Step 3: Further Break-down of Occurrence Categories • Examined types of events contributing to occurrences • Selected sub-categories which seemed to capture these factors • Loss of separation’, ‘training for emergencies’ and ‘other’ not sub-categorized

12. 3(a) Power Loss

13. 3(b) Structural Failure

14. 3(c) Loss of Visual Reference

15. 3(d) Loss of Control

16. 3(e) Struck Object

17. Step 4: Conclusions from Analysis What does this mean to me??

18. Conclusions – Loss of Visual Reference Accidents • #3 in frequency, #1 in human cost • 80% fatal with a total of 31 lives lost • Civil helicopter flying largely VFR • Possible counter-measures: • Awareness • Capability • Technology

19. Conclusions – Power Loss and Structural Failure Accidents (1) • Together account for 52% of sample • Improper maintenance 2nd most frequent sub-category in both • Underscores importance of efforts to understand and mitigate the factors underlying maintenance error such as: • Improved maintenance procedures • Awareness training

20. Conclusions – Power Loss and Structural Failure Accidents (2) • Power loss is most heavily populated category but produced the fewest fatal accidents • Training to handle power failures effective • Multi-engine helicopters also represented in power loss accidents

21. Conclusions – Loss of Control Accidents • Well recognized hazards • Loss of tail rotor effectiveness • Decayed rotor RPM • Dynamic roll-over • Vortex ring state • Environmental • Flight Control Obstruction • Efforts to address these hazards need to be maintained

22. Conclusions – Struck Object Accidents • All hazards represented well known • Potential counter measures could include: • Raising awareness • Revising procedures • Training in risk management

24. Snapshot of accidents investigated Hope it will help drive safety management practices Conclusion We need to devote resources to…

25. Questions???