Yep, trialed last year .. https://fireaviation.com/2018/02/27/trial-dropping-water-wildfire-night-begins-australia/ . To now - Specialist fire teams and tools used to fight blaze still burning in south-west Tasmania By Erin Cooper and Ros Lehman Updated 6 Jan 2019, 10:41am [...] Also for the first time, authorities have used a long-term retardant sprayed from the air. New guidelines have been developed to ensure potential impacts are limited. [...] https://www.abc.net.au/news/image/10686770-3x2-700x467.jpg https://www.abc.net.au/news/2019-01-05/fire-in-tasmanian-wilderness-still-not-contained/10686922