Developing a framework for Total Apron Safety Management
Creators: name: Studic, Milena
Publisher: name: Imperial College London
Year: 2015

description: The Air Traffic Management (ATM) system is a complex socio-technical system that ensures safe, efficient and cost-effective air traffic movements on the ground and in the air. The current ATM system is saturated as a result of an everlasting growth in air travel demand, leading to delays and potential negative safety impacts. In order to meet future demand, current ATM modernisation initiatives in the European Union and the USA are developing a new concept of operations based on strategic holistic system optimisation. On the airport surface, this is achieved by optimising operations not only during the take-off, landing and taxiing phases, but also during the turnaround process on the apron. This requires the boundary of the ATM system to expand to include new elements, namely the apron. A key deficiency in current initiatives is that, while they focus on capacity, punctuality and cost-effectiveness of the apron, they do not address safety. This has potential negative impacts in terms of setting and prioritising safety targets. Unlike the rest of the aviation domain, which is aircraft-centric, the concept of apron safety is much wider and in addition to aircraft safety, it also includes occupational health and safety. Recent aviation safety statistics show that aircraft accidents attributed to ground handling operations are six times more frequent than those attributed to the ATM. Additionally, the UK Health and Safety Executive (HSE) statistics show worse safety records on the apron when compared to the construction and agricultural industries. Considering the change in the ATM system boundary and the low aviation and occupational health and safety records, the airport apron has been identified in this thesis as a new safety-critical area of the future ATM system. Therefore, a key focus of this thesis is to address current deficiencies with respect to safety management on the apron, by developing a better understanding of the processes carried out on the apron and a new framework for safety assessment, as well as recommending enhancements to existing safety management practices. In contrast to existing safety management practices that are based on a dated understanding of safety (referred to as Safety-I), which is predominantly reactive, the framework proposed in this thesis, for the first time, adopts a state-of-the-art proactive and predictive understanding of safety (referred to as Safety-II) for the apron. The thesis demonstrates for the first time that the existing linear component-based models traditionally used for modelling apron safety do not account for the system complexity. Therefore, the proposed framework develops a state-of-the-art systemic functional Total Apron Safety Management (TASM) model and a corresponding taxonomy of factors that characterise different sources of variability of ground handling services, capable of accounting for dependencies and dynamic interactions between different layers of the apron system (i.e. technological, human and organisational). The proposed functional model and taxonomy have been applied to three case studies in retrospective, prospective and system design analysis demonstrating the multi-purposive nature of the framework, particularly important under existing financial pressures. In retrospective analysis the proposed functional model and taxonomy have shown to identify systemic factors previously not found during the occurrence investigation. In prospective analysis, a new protocol for systemic and systematic hazard analysis in complex socio-technical systems (including the apron) was developed. Furthermore, a novel conceptual framework for a safety trend analysis based on the TASM framework was developed, offering a quick, simple, cost-effective analysis of large datasets. A key advantage of the TASM framework is that it is transferable to all ground handling services carried out by Ground Service Providers (GSP), airlines and/or airports.