1 Cougar Flight 91: Human Factors CASI-AERO Montréal, Quebec 26 April 2011 Wendy Tadros, TSB Chair

Introduction 2

Outline About the TSB History of Flight 91 Causes Key Human Factors –Flight Manuals / Emergency Procedures –Crew Knowledge –Crew Resource Management Residual Risks Recommendations 3

On Scene 4

About the TSB 5

Overview 6

The Whole Story 7

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9 A complex equation of 16 causes and contributing factors

Key Human Factors Ditching and Risk of Capsizing Flight Manual and Emergency Procedures 10

Key Human Factors (cont’d) Crew Training / Knowledge Vibrations Oil Temperature (“wet bulb”) Oil Pressure as Secondary Indicator 11

Crew Resource Management The Department of Transport require commercial air operators to provide contemporary crew resource management (CRM) training for Canadian Aviation Regulations (CARs) subpart 703 air taxi and CARs subpart 704 commuter pilots. A

Cougar CRM 13

Maintenance Procedures Australia, July 2008 S-92 loses oil from main gearbox. Cockpit warnings, crew reaction very similar to Flight 91 accident. Safe landing 7 minutes later. Pilot: lower and slower 14

Residual Risks (Certification) Main gearbox failed after 11 minutes during test. Rule includes clause that test not required if failure shown to be extremely remote. Oil cooler most likely failure route. Bypass valve added. Oil filter bowl and its fasteners not assessed. Today? There’s still only 11 minutes. 15

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Four Recommendations 1.All S-92 helicopters to meet a 30-minute run dry 2.The FAA to decide if even 30 minutes is enough time 3.Transport Canada to restrict flights where the helicopter’s flotation system is not up to the task for the sea conditions that day 4.Emergency breathing equipment on flights where survival suits are required 17

Summary 18

Questions? 19

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