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Photo credit aviationweather.govOne of the most valuable tools pilots have to help one another in flight is the Pilot Report — or PIREP. Whether you're flying a Cessna 172 or a CRJ at flight level 250, your firsthand report of weather conditions gives controllers, dispatchers, and other pilots a real-time look at what's happening beyond the radar screen.And when it comes to icing, PIREPs can literally be lifesaving.Understanding Aircraft Icing and Why PIREPs MatterAircraft icing occurs when supercooled liquid water droplets freeze on the surface of your aircraft. Even a small amount of ice buildup can change your airfoil shape, reduce lift, increase drag, and compromise climb performance.Unlike turbulence or wind shear, icing conditions can vary dramatically in short distances and altitudes — meaning one pilot's report may be the only warning another gets. That's why icing PIREPs are so critical for both ATC weather advisories and forecast model accuracy.Key Temperature Definitions: SAT vs. TATTo understand icing potential — and to make an accurate report — you'll often reference SAT and TAT.SAT (Static Air Temperature): This is the true ambient air temperature outside the aircraft — essentially what the air would feel like if the aircraft weren't moving. SAT is the most accurate measure of the atmospheric temperature.TAT (Total Air Temperature): This includes the effects of ram rise — the heating of air molecules as they impact the aircraft moving through the air. TAT is therefore slightly warmer than SAT and is often what your cockpit displays on faster aircraft, like turboprops or jets.Which one should you use?For icing PIREPs, SAT is the appropriate temperature to reference. It represents the actual temperature of the airmass where supercooled droplets exist. TAT is useful for performance calculations or system monitoring, but SAT gives the best picture of icing potential. On the ground, temperature reports always reflect the static (ambient) temperature, so SAT remains the standard reference.Elements of an Icing PIREPWhen reporting icing, try to include:Location - Given as a fix, radial/DME, or between waypoints.Time - The time of the observation (UTC).Altitude - Where the icing occurred.Aircraft type - Because icing severity can vary depending on size and speed.Icing type and intensity - (Trace, Light, Moderate, or Severe) and whether it's rime, clear, or mixed.Temperature - The SAT at which icing was encountered.Example Icing PIREPLet's break down a realistic icing PIREP from a regional jet:UA /OV LDN090025 /TM 1532 /FL180 /TP CRJ7 /IC MOD RIME /TA -12Here's what it means:UA - Routine PIREP (UUA would indicate urgent)./OV LDN090025 - 25 nautical miles east of the LDN VOR./TM 1532 - Time: 1532 UTC./FL180 - Altitude: Flight Level 180./TP CRJ7 - Aircraft type: CRJ-700./IC MOD RIME - Moderate rime icing./TA -12 - Outside air temperature (SAT): -12°C.Pro Tips for Giving a Quality Icing PIREPReport early and often. Even if it's light icing, your report could help ATC issue advisories and reroutes.Update when conditions change. If you climb or descend and exit the icing layer, send a follow-up PIREP.Stay consistent with terminology. Use the FAA intensity scale and icing type categories — trace, light, moderate, severe — and rime, clear, or mixed.Don't guess — observe. If unsure about temperature or icing type, say "unknown." An honest, simple PIREP is better than none.The Bottom LineIcing can catch any pilot off guard, but sharing accurate PIREPs keeps everyone safer. Knowing when and how to include details like SAT, altitude, and icing type helps controllers and weather services refine forecasts and advisories.Next time you're in the soup and pick up a little rime or clear ice, remember — your quick radio call could be the reason another crew avoids the same conditions.RELATED STORIES:Final report blames 2023 Michigan crash on ice and snow on the wingsGerman institute researches removing ice from aircraft wings with vibrations