What is a potential consequence of improperly applying de-icing fluid?

Improperly applying de-icing fluid can lead to significant safety risks, specifically the potential for ice formation on the aircraft. De-icing fluids are designed to mix with snow or ice to effectively remove it from the aircraft's surfaces, thereby minimizing ice accumulation that can adversely affect aerodynamics. If the fluid is not applied correctly—whether due to improper dilution, incorrect application techniques, or using the wrong type of fluid—the desired aerodynamic surfaces can still remain contaminated with ice or snow. This residual ice can create serious drag, alter lift characteristics, and ultimately result in hazardous flying conditions, such as reduced control or increased stall risk during flight. Therefore, ensuring correct application of de-icing fluid is crucial for maintaining aircraft safety and performance during winter weather operations.