I bring you a weekly bite-sized chunk of the science behind helicopter human factors and CRM in practice, simplifying the complex and distilling a helicopter related study into a summary of less than 500 words.
TITLE:
Safety in high-risk helicopter operations: The role of additional crew in accident prevention.
WHAT?
This study examines accident causes in high-risk helicopter operations—specifically external load and aerial application (crop spraying) flights—and evaluates how additional team members (in flight or on ground) contribute to accident prevention.
WHERE?
Conducted in Maastrict, Netherlands, based on US accident data, using records from NTSB online database.
WHEN?
Analysis covers accidents from 1995–2005 for external load operations and 1998–2005 for aerial application operations, making the data over 20 years old. The study itself was published in 2009.
WHY?
External load and aerial application flights are inherently dangerous: they involve low altitudes, confined areas, heavy or specialised loads, and on-site refuelling. They are mostly independent, small operations in single engine, single pilot helicopters. The study aimed to understand accident patterns and identify how crew interactions can reduce risks.
HOW?
Researchers extracted 142 aerial application and 120 external load helicopter accident reports from the NTSB database. They refined the database’s classifications by coding accident narratives for causes, flight phases, and rotor strikes.
FINDINGS:
From analysis of 142 accidents in aerial application flights it was found 44% were caused by in-flight ‘pilot error’, 23% by mechanical failures, and 21% by pre-flight errors. Common issues included fuel mismanagement, hoses or ties left attached during preflights, and wire strikes.
From analysis of 120 external load accidents. 40% were caused by mechanical failures, 29% pre-flight errors, 22% in-flight ‘pilot error’. Frequent causes included dynamic rollovers, cable entanglement, and rotor strikes (32.5%). Ground crew contributed to accidents in some cases, including 4 fatalities.
Across both types of operations, pilots were highly experienced (averaging around 10,000 flight hours). Accidents often occurred during high-risk phases: load pick up/drop off for external loads, refuelling/reloading departure for aerial application. The use of additional crew (especially ground crew) could have mitigated risks in many of these accidents by contributing to improved lookout, risk-management, and cross-checks. However, in some cases increased ground crew presence also introduced risks..
SO WHAT?
The study highlights a safety paradox: ground crews and additional pilots can prevent accidents but also introduce further risks to life. The authors argue that better training, more clearly defined roles, and risk and safety management involving both flight and ground crew could significantly improve outcomes in high-risk operations such as these. Aircraft cost and weight constraints limit dual-pilot configurations, but improving ground crew support could offer benefits to safety and accident prevention.
REFERENCE:
de Voogt, A. J., Uitdewilligen, S., & Eremenko, N. (2009). Safety in high-risk helicopter operations: The role of additional crew in accident prevention. Safety Science, 47(5), 717–721. https://doi.org/10.1016/j.ssci.2008.09.009
competentaviators.com 