Helicopter Safety | Common Helicopter Accident Causes

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Factors in Accidents

The most common factors related to helicopter accidents involving UK registered helicopters.

Taken from a study of the Griffin Helicopters accident database since 09 Jan 1997 the study comprises a review of 405 rotary wing accidents and incidents involving UK registered aircraft of which 386 involved helicopters and 40 were fatal.

Some accidents appear under more than one heading as often for example a loss of control in the hover can result in a tail strike , heavy landing and rollover.

This table shows details of what we assess the first event in accident was, some accident reports are pretty vague and if no directly attributable cause is specified then that accident will not be included in this table.

All Accidents [By First Events] In Progress
Mishandled Controls (22.02%) 85
Drivetrain Failure (4.66%) 18
Wire Strike (4.40%) 17
Under Investigation (3.89%) 15
Loss Of Control IMC (3.63%) 14
Maintenance Error (3.11%) 12
Collision with Ground Based Object (2.85%) 11
Engine Power Loss or Variation (2.59%) 10
Engine Failure (2.33%) 9
Tail Rotor Strike (2.33%) 9
Loss Of Control VMC (2.07%) 8
Other Weather Related (1.81%) 7
Windshear (1.55%) 6
Lightning Strike (1.55%) 6
Airframe Failure [Break Up] (1.30%) 5
Loss Of Tail Rotor Effectiveness (1.30%) 5
Smoke In Cockpit (1.30%) 5
Rotor System Failure (1.30%) 5
Spatial Disorientation (1.30%) 5
Loss of Fenestron Control (1.04%) 4
Downwash Related (1.04%) 4
Heavy Landing (1.04%) 4
Fuel Exhaustion (1.04%) 4
Carb Icing (1.04%) 4
Fouled Controls [Cockpit Item] (1.04%) 4
Electrical Fault (1.04%) 4
Windows Misted (1.04%) 4
Mid Air Collision (0.78%) 3
Dynamic Rollover (0.78%) 3
Undetermined [Investigation Complete] (0.78%) 3
Downwind Approach (0.52%) 2
Fuel System Defect (0.52%) 2
Ground Collision Involving 2 or more Aircraft (0.52%) 2
Fuel Contamination (0.52%) 2
External Load Hit Tail Rotor (0.52%) 2
Fuel Starvation (0.52%) 2
Anti Torque Failure (0.52%) 2
Vortex Ring State [Suspected] (0.52%) 2
Mast Bumping (0.52%) 2
Inadvertant Hydraulic Deselection (0.52%) 2
Vibration In Flight (0.52%) 2
Anti Torque System Defect (0.52%) 2
Control Restriction (0.52%) 2
Distraction (0.52%) 2
Manufacturing Defect (0.52%) 2
Subject of Foreign Authority Investigation (0.52%) 2
Control Friction Left On (0.26%) 1
Autorotative Descent (0.26%) 1
Collision with water (0.26%) 1
Control System Defect (0.26%) 1
Crew Incapacitation (0.26%) 1
Crew Lost (0.26%) 1
Door Detached (0.26%) 1
Birdstrike (0.26%) 1
Mishandled Malfunction (0.26%) 1
Wake Vortex Encounter [Suspected] (0.26%) 1
Turbulence Encountered (0.26%) 1
Training Rollover (0.26%) 1
SAR Specific Incident (0.26%) 1
Rotors Turning Without Pilot At Controls (0.26%) 1
Rain on Windows (0.26%) 1
Previous Overspeed (0.26%) 1
Insufficient Power Available [No Defect] (0.26%) 1
Not A Helicopter (0.26%) 1
Foreign Object Damage [FOD] (0.26%) 1
Mechanical Defect (0.26%) 1
Main Rotor Struck Tailboom (0.26%) 1
Low Rotor RPM (0.26%) 1
Landing Area Unsuitable (0.26%) 1
Inadvertant Control Application (0.26%) 1
Gauge Fault (0.26%) 1
Fuel Cap Not Fitted (0.26%) 1
Fuel Below Reserves (0.26%) 1
Overweight (0.26%) 1
Total 353

All Accidents [By All Events]
Mishandled Controls (23.32%) 90
Heavy Landing (20.21%) 78
Dynamic Rollover (11.92%) 46
Loss Of Control VMC (8.81%) 34
Tail Rotor Strike (6.74%) 26
Drivetrain Failure (4.92%) 19
Engine Failure (4.92%) 19
Wire Strike (4.40%) 17
Engine Power Loss or Variation (3.89%) 15
Loss Of Control IMC (3.89%) 15
Under Investigation (3.89%) 15
Maintenance Error (3.37%) 13
No Fault Found (3.11%) 12
Collision with Ground Based Object (2.85%) 11
Airframe Failure [Break Up] (2.59%) 10
Main Rotor Struck Tailboom (2.59%) 10
Smoke In Cockpit (2.07%) 8
Anti Torque Failure (1.81%) 7
Lightning Strike (1.81%) 7
Distraction (1.55%) 6
Downwind Approach (1.55%) 6
Insufficient Power Available [No Defect] (1.55%) 6
Loss Of Tail Rotor Effectiveness (1.55%) 6
Training Rollover (1.55%) 6
Windshear (1.55%) 6
Carb Icing (1.30%) 5
Collision with water (1.30%) 5
Fuel Starvation (1.30%) 5
Manufacturing Defect (1.30%) 5
Rotor System Failure (1.30%) 5
Vibration In Flight (1.30%) 5
Vortex Ring State [Suspected] (1.30%) 5
Downwash Related (1.04%) 4
Electrical Fault (1.04%) 4
Fouled Controls [Cockpit Item] (1.04%) 4
Fuel Exhaustion (1.04%) 4
Loss of Fenestron Control (1.04%) 4
Student Overpowered Instructor (1.04%) 4
Undetermined [Investigation Complete] (1.04%) 4
Anti Torque System Defect (0.78%) 3
Cowling detatched in flight (0.78%) 3
Fire Damage (0.78%) 3
Fuel System Defect (0.78%) 3
Inadvertant Control Application (0.78%) 3
Landing Area Unsuitable (0.78%) 3
Mid Air Collision (0.78%) 3
Over Pitching (0.78%) 3
Subject of Foreign Authority Investigation (0.78%) 3
Control Restriction (0.52%) 2
External Load Hit Tail Rotor (0.52%) 2
Foreign Object Damage [FOD] (0.52%) 2
Fuel Contamination (0.52%) 2
Ground Collision Involving 2 or more Aircraft (0.52%) 2
Inadvertant Hydraulic Deselection (0.52%) 2
Mast Bumping (0.52%) 2
Mechanical Defect (0.52%) 2
Previous Overtemp (0.52%) 2
Role Equipment Damaged (0.52%) 2
Autopilot Disengagement (0.26%) 1
Baggage Compartment Contents Lost (0.26%) 1
Birdstrike (0.26%) 1
Control Friction Left On (0.26%) 1
Control System Defect (0.26%) 1
Crew Hit By Turning Rotors (0.26%) 1
Crew Incapacitation (0.26%) 1
Crew Lost (0.26%) 1
Door Detached (0.26%) 1
Fuel Cap Not Fitted (0.26%) 1
Fuel Spillage (0.26%) 1
Gauge Fault (0.26%) 1
Hydraulic Failure (0.26%) 1
Lack Of Seat Cushion [Insufficient Pedal] (0.26%) 1
Landing Gear Retraction (0.26%) 1
Low Fuel State (0.26%) 1
Low Rotor RPM (0.26%) 1
Mishandled Malfunction (0.26%) 1
On Deck Vessel Changed Course (0.26%) 1
Overweight (0.26%) 1
Previous Overspeed (0.26%) 1
Rotated During Startup (0.26%) 1
Rotor Brake Application, Improper Procedure (0.26%) 1
Rotors Turning Without Pilot At Controls (0.26%) 1
Spurious Fire Warning (0.26%) 1
Static Rollover (0.26%) 1
Turbulence Encountered (0.26%) 1
Unidentified Noise (0.26%) 1
Unlicensed Pilot Owner On Own Property (0.26%) 1
Wake Vortex Encounter [Suspected] (0.26%) 1
Worn Bushes (0.26%) 1
Total 386