In a recent information for operators (InFo), the FAA cautions flight crews and ground deicing service providers to refrain from using “Table B.2.4 Amount of Fluid for Anti-Icing with Thickened Fluids” published in SAE AS6286 (Revision B) as the basis for determining if the aircraft anti-icing fluid has been applied effectively.
According to the InFo, “expected holdover times (HOT) may not be achieved if the quantities provided in table B.2.4 are used as the basis for determining adequate coverage. Table B.2.4 does not reflect new fluid formulations that increase viscosity and fluid thicknesses, requiring greater volumes of anti-icing fluid (but improve HOTs).” Revision C of AS6286 was published in March 2023 and does not contain Table B.2.4.
“Air operators and de/anti-icing service providers should familiarize themselves with the information contained in this InFO and be aware of the adequate application of anti-icing fluids to ensure the expected holdover time is achieved,” cautioned the FAA. “In particular, anti-icing fluids are to be applied so that it can completely cover the surfaces and form a uniform coating. Enough anti-icing has been applied when it can be visually confirmed that the anti-icing fluid is just beginning to run off the leading and trailing edges of the surfaces.”
Meanwhile, in a separate notice, FAA deicing program information and guidance documents are being relocated. Starting with the coming winter season, “Information contained in previous versions of this notice now resides in the general information document, located on the aircraft ground deicing web page,” said the agency. “Revisions to HOTs can now be found in the summary of changes to holdover time guidelines and associated documents for winter 2023–2024, also located on the ground deicing web page.