Hazard Analysis of Remote Tower Systems using System-Theoretic Process Analysis (STPA)

Abstract

A Remote Tower System enables aerodrome control services to be provided remotely using imaging, surveillance, and communication technologies. However, interactions between controllers and digital systems may create hazards that conventional failure-oriented safety assessments may not adequately identify. This study applied System-Theoretic Process Analysis (STPA) to identify Unsafe Control Actions (UCAs) and Loss Scenarios in remote tower operations. A Control Structure was developed, and three Control Actions related to runway operations were identified, from which 20 UCAs were derived. Six UCAs were selected for detailed Loss Scenario analysis, resulting in 24 Loss Scenarios and 14 Safety Requirements. Major causal factors included inadequate feedback, inadequate control algorithms, and inadequate process models, with video latency, information inconsistencies, and insufficient procedural controls identified as specific contributing factors. The findings provide a foundation for the design, operational procedures, and safety assessment of remote tower systems in Korea.