Identifying Flight Safety Issues
In 2014, the Bureau of Safety and Environmental Enforcement (BSEE) released data indicating that numerous mishaps involving helicopter operations on or near offshore facilities on the US Outer Continental Shelf (OCS) had resulted in fatalities, injuries and substantial property damage and was a leading cause of death for offshore workers, according to the Center for Disease Control. After investigating these incidents, the National Transportation Safety Board (NTSB) determined that several mishaps were due to helicopter engine ingestion of associated petroleum gases (APG) and issued safety recommendations to the US Department of the Interior, US Coast Guard and BSEE.
Following the safety recommendations, ABS Group led an assessment to more fully understand the potential risks of APG to helicopter operations and to develop possible mitigation strategies.
Analyzing Existing Regulations and Standards
The HFE study began with an analysis of existing regulations and standards for offshore helideck construction, focused on the placement of methane vents or other sources of combustible gasses. Working with PricewaterhouseCoopers LLC, the American Petroleum Institute and the Helicopter Safety Advisory Council, ABS Group evaluated regulatory requirements and industry best practices from all major International Civil Aviation Organization participating nationalities which operate helicopters offshore.
Determining the Effect of Methane Ingestion
In coordination with manufacturers, the FAA and NTSB, ABS Group analyzed engine data to find a significant disparity between published engine manufacture methane ingestion limits and those suggested by regulatory bodies. As no prior openly available testing had been conducted in this area of engine performance research, the HFE team conducted a modeling study at the Gas Turbine Propulsion Laboratory at Texas A&M University. Statistically representative engine models were identified and tested to demonstrate the effects of methane ingestion on power output and determine the parameters hazardous to flight operations.
Evaluating Mitigation Strategies
The ABS Group HFE team also looked into various mitigation strategies such as gas monitoring technologies. Infrared area and point detector technology was assessed, and emergent hydrocarbon gas imaging technologies were found to be promising methods of early warning methane detection. Based on these data, ABS Group delivered a final report addressing the hazards of methane ingestion and suggesting methods to mitigate risk to industry workers and operations.
Guiding Safer Industry Practices
The corrective actions provided in the helicopter methane ingestion study could impact safety regulations and procedures to mitigate this potentially fatal flight safety issue. Additionally, the review of existing and emergent gas detection methodologies provides guidance for selecting a technology that best mitigates the hazard of methane ingestion.
Through this safety assessment, ABS Group has contributed findings that could have a significant impact on improving the safety and reliability of helicopter operations in the offshore environment.