Report on air accident at Høyland, Hå municipality in Rogaland 30 April 2016 involving Airbus Helicopters AS 350 B3, LN-OSG
Aviation report 2018/10 eng
On 30 April 2016 an Airbus Helicopters AS 350 B3 was used in connection with a proficiency check. The flight examiner had briefed the flight. From low altitude, the candidate, by a mistake disconnected the hydraulic power and the helicopter started to rotate. The helicopter landed hard and the rotor hit the ground, but he helicopter came to a still in the upright position. No persons were injured.
The investigation has not revealed technical conditions that may have caused loss of control over the helicopter. The helicopter was operated beyond the limitations specified in the helicopter type flight manual. The loss of control occurred in low hover, which gave very small margins to correct the mistake of the candidate. As a result of the accident, a fire occurred. The helicopter's fire safety in accidents of this type is a part of the investigation, and the report has a recommendation to EASA, and a recommendation to AIRBUS / SAFRAN Helicopter Engines on this matter.
Safety recommendation
Safety recommendation SL No 2018/13T
On 30 April 2016, the AS 350 B3, LN-OSG was subject to an uncontrolled landing which caused the main rotor blades to hit the ground and into the helicopter's tailboom. The engine continued to run after the free turbine had thrown its turbine blades. The turbine blades were thrown after the engine's reduction gearbox ruptured and the free turbine was decoupled and accelerated beyond the speed it was designed to withstand. The consequence of this was that hot exhaust gases escaped from the engine into the engine compartment and there was a fire.
The Accident Investigation Board Norway recommends Airbus Helicopters, in cooperation with Safran Helicopter Engines to study technical solutions for AS 350 helicopters equipped with Arriel 2 engines, as well as other Airbus helicopter types with similar Arriel engine installations. The purpose of this study should be to find ways of reducing the risk of fire following accidents where the free turbine blades have shedded.
Safety recommendation SL No 2018/14T
On 30 April 2016, the AS 350 B3, LN-OSG was subject to an uncontrolled landing which caused the main rotor blades to hit the ground and into the helicopter's tailboom. The engine continued to run after the free turbine had thrown its turbine blades. The turbine blades were thrown after the engine's reduction gearbox ruptured and the free turbine was decoupled and accelerated beyond the speed it was designed to withstand. The consequence of this was that hot exhaust gases escaped from the engine into the engine compartment and there was a fire.
The Accident Investigation Board Norway recommends that EASA study the opportunity to mandate the solutions developed by Airbus Helicopters in cooperation with Safran Helicopter Engines.
Facts
| Location | Hå, Rogaland, Norway |
| Occurrence date | 30.04.2016 |
| ICAO Location indicator | ENZV |
| Aircraft | Airbus Helicopter AS 350 B3 Ecureuil |
| Operator | Pegasus Helicopter AS |
| Registration | LN-OSG |
| Meteorological conditions | VMC |
| County | Rogaland |
| Type of occurrence | Accident |
| Type of operation | Commercial, other |
| Category of operation | Light, helicopter (<= 2 250kg) |
| Aircraft category | Helicopter, Single-engine, Turboprop/turboshaft |
| FIR/AOR | ENSV (Stavanger ATCC) |