Abstract:

Volcanic eruptions not only play a significant role in the Earth’s historical climate changes but also pose a serious threat to modern aviation safety. Explosive eruptions can eject volcanic ash into the atmosphere, where it is dispersed into the stratosphere by atmospheric circulation, directly endangering the safety of aircraft operations. With the successful delivery of China’s domestically produced large aircraft and potential exports to volcanically active Southeast Asia, research on the impact of volcanic ash on aviation safety holds critical practical significance for enhancing the global competitiveness of China’s aircraft and ensuring international flight safety. To address these challenges, this study aims to: (1) systematically summarize the physicochemical properties of volcanic ash; (2) comprehensively assess its interaction mechanisms with aircraft engines based on previous literatures; (3) conduct a case study using Indonesian volcanoes (Volcanic Explosivity Index VEI≥3, during 2010-2018) to evaluate the potential impact of volcanic hazards on the regional flight safety. Key findings include: (1) To prevent volcanic ash from entering aircraft engines, the monitoring and prediction of volcanic ash clouds are critical for flight route planning and selection. The accuracy of remote sensing monitoring is influenced by the composition, density, shape, and optical properties of volcanic ash. (2) Once volcanic ash is ingested by the engine, the deposition behavior of the particles influences the extent of damage to the engine. This process is affected by factors such as particle composition, density, shape, glass transition temperature, and viscosity. (3) The corrosive effect of deposited volcanic ash on thermal barrier coatings (TBCs) within aircraft engines is a critical factor affecting their service life. The associated degradation mechanism can be summarized as the infiltration of molten ash into the TBCs, followed by chemical reactions and the precipitation of new crystalline phases. Current protection strategies mainly include physical isolation to prevent infiltration, chemical sacrificial layer protection, melt crystallization protection, and the construction of special micro-nano surface structures. (4) Spatially, the viscosity of volcanic ash from VEI ≥ 3 eruptions in Indonesia between 2010 and 2018, calculated at 1200 ℃ under volatile-free conditions, are relatively similar (within 1-2 orders of magnitude), suggesting comparable spreading potential. Temporally, volcanic activity in this region during the same period posed a consistent threat to aviation safety, despite only minor fluctuations in intensity. Future efforts should focus on the following key points: (1) enhancing real-time volcanic ash monitoring technologies; (2) improving the algorithms and accuracy of dispersion models; (3) developing property-dependent deposition models for volcanic ash; (4) optimizing protective strategies for TBCs; and (5) advancing the construction of integrated experimental platforms for studying volcanic ash and aviation safety. These actions will safeguard China’s aircraft operations in volcanic zones and bolster its global market competitiveness.

Key words: volcanic ash, aviation safety, thermal barrier coatings, corrosion, Indonesian volcanic activity