EASA SIB InFO-25003
Use of Liquid Water Equivalent System (LWES)
Summary
InFO 25003 is an informational document from the FAA Flight Standards Service reminding pilots and operators about the proper use of the Liquid Water Equivalent System (LWES) when operating in snow and ice conditions. It emphasizes that while LWES can provide precise weather data, pilots should also consider Meteorological Aerodrome Reports (METAR) and visual observations to ensure safe takeoff decisions. This guidance applies broadly to all aircraft operating in freezing contaminant conditions.
What Changed
InFO 25003 introduces a reminder for pilots and operators to use all available weather information tools, including METAR and visual observations, alongside LWES data. It clarifies the limitations of LWES, such as a possible 5% error rate and location discrepancies between LWES and METAR stations, urging pilots to verify LWES reports before takeoff decisions.
Why It Matters
This document matters because relying solely on LWES data without cross-checking with METAR or visual cues could lead to unsafe takeoff conditions in snow and ice environments. It helps operators and pilots improve decision-making processes, enhancing flight safety and regulatory compliance. Proper understanding and use of LWES alongside other tools reduce the risk of accidents related to freezing contaminants.
What To Do
Certificate holders should review and update their company manuals and training programs to ensure pilots understand the differences between Holdover Times and Allowance Times, correct use of Holdover Time charts, and pre-takeoff contamination checks. Training should emphasize verifying LWES data with METAR and visual observations and applying appropriate deicing procedures when LWES is unavailable. No specific compliance deadlines are stated.