Innovators at NASA’s Glenn Research Center have developed a new means of avoiding and mitigating icing events for aircraft flying above 14,000 feet, dramatically improving aviation safety and reducing operating costs.
Often undetectable with current radar, ice crystals in convective storm cells can produce a phenomenon referred to as “ice crystal icing,” in which ice accumulates, or accretes, in turbofan engines. Ice-crystal accretion can cause serious engine operational problems and sometimes even catastrophic engine failures. Using a combination of sensors, engine system modeling, and compressor flow analysis code, Glenn’s innovation performs real-time analysis to determine the potential of ice accretion. This analysis allows pilots to avoid potential icing while using a more direct route than would otherwise be possible. Thus, Glenn’s system reduces fuel consumption and engine wear while fulfilling the crucial objective of increasing aircraft safety.
The existence of an ice-crystal environment in the atmosphere is determined by one or more of three methods: (1) an external data monitoring system that detects ice crystals directly, (2) the control system that detects changes in key engine parameters such as the ratio of fan speed to core engine speed or fuel flow rate, and (3) advanced radar that detects ice crystals in the flight path of the aircraft. If risk of icing is present, Glenn’s tool signals the control system to modify the engine operating parameters so as to pre-emptively prevent a significant amount of accretion from occurring, or alternatively, guides the aircraft to a location where ice crystal accretion will not occur.
Standard practice has been for pilots to navigate at least 100 miles around visible storms, but with the improved accuracy provided by Glenn’s innovation, the pilot can fly as close as 20 miles to the ice-crystal environment while still maintaining enhanced safety. Since the magnitude of change to the engine operating parameters is so small (and the level of engine thrust set by the pilot remains the same), any modification will be imperceptible to both the pilot and passengers. In addition, Glenn’s system can be easily integrated into new engines or retrofitted into existing technologies.