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 of the Griffin Helicopters accident database since 09 Jan 1997 the study comprises a review of 366 rotary wing accidents and incidents involving UK registered aircraft of which 348 involved helicopters and 35 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 (22.99%) 80
Wire Strike (4.60%) 16
Drivetrain Failure (4.60%) 16
Loss Of Control IMC (3.45%) 12
Maintenance Error (3.45%) 12
Engine Power Loss or Variation (2.87%) 10
Collision with Ground Based Object (2.87%) 10
Under Investigation (2.59%) 9
Tail Rotor Strike (2.59%) 9
Engine Failure (2.30%) 8
Other Weather Related (2.01%) 7
Loss Of Control VMC (2.01%) 7
Windshear (1.72%) 6
Lightning Strike (1.72%) 6
Airframe Failure [Break Up] (1.44%) 5
Rotor System Failure (1.44%) 5
Loss of Fenestron Control (1.15%) 4
Loss Of Tail Rotor Effectiveness (1.15%) 4
Fuel Exhaustion (1.15%) 4
Windows Misted (1.15%) 4
Carb Icing (1.15%) 4
Fouled Controls [Cockpit Item] (1.15%) 4
Electrical Fault (1.15%) 4
Smoke In Cockpit (1.15%) 4
Downwash Related (0.86%) 3
Heavy Landing (0.86%) 3
Spatial Disorientation (0.86%) 3
Mid Air Collision (0.86%) 3
Fuel Starvation (0.57%) 2
Fuel System Defect (0.57%) 2
Fuel Contamination (0.57%) 2
External Load Hit Tail Rotor (0.57%) 2
Control Restriction (0.57%) 2
Dynamic Rollover (0.57%) 2
Distraction (0.57%) 2
Anti Torque Failure (0.57%) 2
Mast Bumping (0.57%) 2
Inadvertant Hydraulic Deselection (0.57%) 2
Ground Collision Involving 2 or more Aircraft (0.57%) 2
Vortex Ring State [Suspected] (0.57%) 2
Vibration In Flight (0.57%) 2
Subject of Foreign Authority Investigation (0.57%) 2
Mechanical Defect (0.57%) 2
Crew Lost (0.29%) 1
Crew Incapacitation (0.29%) 1
Control System Defect (0.29%) 1
Undetermined [Investigation Complete] (0.29%) 1
Turbulence Encountered (0.29%) 1
Collision with water (0.29%) 1
Birdstrike (0.29%) 1
Autorotative Descent (0.29%) 1
Anti Torque System Defect (0.29%) 1
Wake Vortex Encounter [Suspected] (0.29%) 1
Control Friction Left On (0.29%) 1
Door Detached (0.29%) 1
Insufficient Power Available [No Defect] (0.29%) 1
SAR Specific Incident (0.29%) 1
Rotors Turning Without Pilot At Controls (0.29%) 1
Rain on Windows (0.29%) 1
Overweight (0.29%) 1
Foreign Object Damage [FOD] (0.29%) 1
Manufacturing Defect (0.29%) 1
Fuel Below Reserves (0.29%) 1
Fuel Cap Not Fitted (0.29%) 1
Main Rotor Struck Tailboom (0.29%) 1
Low Rotor RPM (0.29%) 1
Landing Area Unsuitable (0.29%) 1
Gauge Fault (0.29%) 1
Downwind Approach (0.29%) 1
Total 318

All Accidents [By All Events]
Mishandled Controls (24.14%) 84
Heavy Landing (22.13%) 77
Dynamic Rollover (12.36%) 43
Loss Of Control VMC (9.48%) 33
Tail Rotor Strike (7.47%) 26
Engine Failure (4.89%) 17
Drivetrain Failure (4.60%) 16
Wire Strike (4.60%) 16
Engine Power Loss or Variation (4.31%) 15
Loss Of Control IMC (3.74%) 13
Maintenance Error (3.45%) 12
No Fault Found (3.45%) 12
Collision with Ground Based Object (2.87%) 10
Main Rotor Struck Tailboom (2.87%) 10
Airframe Failure [Break Up] (2.59%) 9
Under Investigation (2.59%) 9
Anti Torque Failure (2.01%) 7
Smoke In Cockpit (2.01%) 7
Distraction (1.72%) 6
Insufficient Power Available [No Defect] (1.72%) 6
Lightning Strike (1.72%) 6
Windshear (1.72%) 6
Carb Icing (1.44%) 5
Downwind Approach (1.44%) 5
Fuel Starvation (1.44%) 5
Rotor System Failure (1.44%) 5
Vibration In Flight (1.44%) 5
Vortex Ring State [Suspected] (1.44%) 5
Collision with water (1.15%) 4
Electrical Fault (1.15%) 4
Fouled Controls [Cockpit Item] (1.15%) 4
Fuel Exhaustion (1.15%) 4
Loss of Fenestron Control (1.15%) 4
Loss Of Tail Rotor Effectiveness (1.15%) 4
Manufacturing Defect (1.15%) 4
Student Overpowered Instructor (1.15%) 4
Training Rollover (1.15%) 4
Cowling detatched in flight (0.86%) 3
Downwash Related (0.86%) 3
Fuel System Defect (0.86%) 3
Landing Area Unsuitable (0.86%) 3
Mechanical Defect (0.86%) 3
Mid Air Collision (0.86%) 3
Over Pitching (0.86%) 3
Subject of Foreign Authority Investigation (0.86%) 3
Anti Torque System Defect (0.57%) 2
Control Restriction (0.57%) 2
External Load Hit Tail Rotor (0.57%) 2
Fire Damage (0.57%) 2
Foreign Object Damage [FOD] (0.57%) 2
Fuel Contamination (0.57%) 2
Ground Collision Involving 2 or more Aircraft (0.57%) 2
Inadvertant Control Application (0.57%) 2
Inadvertant Hydraulic Deselection (0.57%) 2
Mast Bumping (0.57%) 2
Previous Overtemp (0.57%) 2
Role Equipment Damaged (0.57%) 2
Undetermined [Investigation Complete] (0.57%) 2
Baggage Compartment Contents Lost (0.29%) 1
Birdstrike (0.29%) 1
Control Friction Left On (0.29%) 1
Control System Defect (0.29%) 1
Crew Hit By Turning Rotors (0.29%) 1
Crew Incapacitation (0.29%) 1
Crew Lost (0.29%) 1
Door Detached (0.29%) 1
Fuel Cap Not Fitted (0.29%) 1
Fuel Spillage (0.29%) 1
Gauge Fault (0.29%) 1
Hydraulic Failure (0.29%) 1
Lack Of Seat Cushion [Insufficient Pedal] (0.29%) 1
Landing Gear Retraction (0.29%) 1
Low Fuel State (0.29%) 1
Low Rotor RPM (0.29%) 1
On Deck Vessel Changed Course (0.29%) 1
Overweight (0.29%) 1
Rotated During Startup (0.29%) 1
Rotor Brake Application, Improper Procedure (0.29%) 1
Rotors Turning Without Pilot At Controls (0.29%) 1
Spurious Fire Warning (0.29%) 1
Static Rollover (0.29%) 1
Turbulence Encountered (0.29%) 1
Unidentified Noise (0.29%) 1
Unlicensed Pilot Owner On Own Property (0.29%) 1
Wake Vortex Encounter [Suspected] (0.29%) 1
Worn Bushes (0.29%) 1
Total 348