Assessment on aerodynamic degradation for wing-damaged transport aircraft

Purpose Wingtip loss is an existing type of transport aircraft hazard which is a real threat to flight safety caused by a missile strike, underwing engine explosion or impact with obstructions when performing near-ground operations. The primary effect of the wingtip loss is an asymmetric rolling moment, which may result in the fatal loss of control for the aircraft. This study aims to assess whether aerodynamic degradation will cause a wing-damaged transport aircraft to lose its balance under a certain level of wing damage and if a pilot can compensate for the loss of aerodynamic force and regain the balance of the aircraft. Design/methodology/approach In this paper, experimental and numerical studies were conducted to investigate the aerodynamic characteristics of a wingtip-lost transport aircraft in landing configuration. Various levels of wing damages including wingtip, slat and flap loss were considered. The numerical simulations were performed with ANSYS Fluent. The computational fluid dynamics calculation was validated by wind tunnel tests. Findings The aerodynamic performance of the aircraft with wing-damaged condition was presented. It was revealed that the wingtip loss leads to an asymmetric rolling moment and a reduction of the lift force, which affects the balance of the transport aircraft. The methods to compensate for the lift force and the asymmetric rolling moment were investigated for a safe landing. The lateral balance cannot be maintained in cases with serious damage on the wing (larger than 53% of the semi-span) or moderate damage on the wing with loss of slats and flaps. Originality/value The nonlinear results indicate the importance of aerodynamic assessment for the sake of training pilots to properly handle the hazard situation and explore the critical facts leading to the air crash.