A fail-safe decision-support framework for onboard greywater reuse in commercial aircraft water systems
Yasin UslugilPurpose
This paper aims to develop and apply a model-based decision-support framework for pre-adoption screening of onboard greywater reuse as a non-potable flushing option in commercial aircraft water systems.
Design/methodology/approach
This study uses framework-development research based on publicly available scientific, institutional and industry sources. Evidence from greywater reuse, aircraft lavatory hygiene, aircraft water and waste systems, fault detection, fail-safe operation and airline sustainability management is mapped into mandatory gates informed by failure mode and effects analysis (FMEA), weighted scoring dimensions and case-based directional validation.
Findings
The Fail-Safe Greywater Reuse Adoption Algorithm separates non-compensatory safety requirements from scored operational and sustainability factors. A publicly reported Boeing 777 long-haul evaluation falls within the adoption-consideration band with a Fail-Safe Greywater Reuse Adoption Algorithm score of 4.050, while an Airbus A320 short-haul scenario falls below the adoption threshold with a score of 2.275. Sensitivity checks retain the same directional separation.
Research limitations/implications
The framework is intended as a pre-adoption screening tool rather than a certification, design approval or operational validation instrument. The scoring weights, decision bands and preliminary FMEA values are literature-informed and require refinement through expert elicitation, prototype testing, airline maintenance records, route-level modelling and empirical case studies.
Practical implications
The framework helps airlines, manufacturers and maintenance stakeholders identify aircraft-route contexts where onboard greywater reuse may be operationally meaningful before committing to costly engineering or certification work. It supports early screening of hygiene, isolation, fallback, maintainability and sustainability-accounting risks, preventing water-saving claims from overriding safety and service-continuity requirements.
Social implications
Onboard greywater reuse may support more resource-conscious aviation by reducing potable-water carriage and enabling circular use of non-potable water within aircraft service systems. However, its social value depends on passenger trust, hygiene assurance, transparent communication, reliable fallback operation, operational reliability and safety expectations.
Originality/value
This paper reframes onboard greywater reuse as an aircraft-system adoption decision rather than a stand-alone water-saving measure. This paper combines aviation management, hygiene control, maintenance exposure, sustainability accounting and mechatronic fail-safe logic in one traceable screening model.