NASA Tests Supercooled Large Droplet Icing in Icing Research Tunnel

NASA conducted a series of tests in the Icing Research Tunnel at Glenn Research Center from June 8‑11, 2026 to study supercooled large droplet (SLD) icing, a rare but dangerous phenomenon where very cold water droplets up to 2,000 µm freeze on aircraft surfaces not protected by conventional ice protection. Using the Subsonic Flight Demonstrator (SFD) and new drop‑sizing probes that detect droplets larger than 45 µm in real time, researchers measured the full droplet size spectrum and compared it with data from probes that capture smaller droplets. The campaign aims to improve engineering tools that predict icing behavior, helping U. S. industry design safer aircraft. Results will be shared with the aerospace community after analysis.