If you're working on your Instrument Rating, fall is when the training wheels start coming off. The days get shorter, the ceilings get lower, and for the first time in your training, the clouds you're flying through may be cold enough to hurt you.
Here's the reality most instrument students fly with: your trainer almost certainly is not certified for flight into known icing (FIKI). That means your icing strategy isn't about managing ice. It's about not picking it up in the first place, and having a plan to get out fast if you do.
Why Ice Is Such a Big Deal
Ice doesn't just add weight. It wrecks the wing.
Even a thin, rough layer on the leading edge disrupts airflow over the airfoil. The result is a nasty combination:
- Lift decreases and drag increases
- Weight increases
- Thrust decreases as ice builds on the propeller
- Stall speed rises, and the stall can come at a lower angle of attack than you're used to
Your stall warning may not save you, either. It's calibrated for a clean wing, and an iced-over sensor may not work at all. Meanwhile, the horizontal stabilizer, which is thinner than the wing, often collects ice faster than the wing does.
The Ingredients
Structural icing needs two things: visible moisture and temperatures at or below freezing where you're flying.
The water that causes trouble is supercooled: liquid droplets that stay liquid below 0°C until they hit something, like your wing, and freeze on contact. Small droplets freeze quickly into rough, milky rime ice. Larger droplets flow back before freezing, forming smooth, heavy clear ice that's harder to see and harder to shed. A blend of the two is mixed ice.
The practical translation: clouds or precipitation at or above the freezing level are icing territory until you have good information saying otherwise.
What "Known Icing" Actually Means
This is where a lot of students get tangled up.
You may hear pilots quote 14 CFR 91.527, which prohibits IFR flight into known or forecast icing without ice protection. But look at where it is: Part 91, Subpart F, which applies to large and turbine-powered multiengine airplanes. It doesn't govern your Skyhawk.
So what does? Your airplane's operating limitations. Most trainer POHs include a limitation like "flight into known icing conditions is prohibited," and 14 CFR 91.9 requires you to comply with those limitations. Add 91.13 (careless or reckless operation) and 91.103 (become familiar with all available information, including weather reports and forecasts for IFR flight), and you have the legal framework.
The FAA's definition of "known icing" is broader than many pilots assume. In a 2009 interpretation, the FAA Chief Counsel said known icing doesn't require ice actually forming on someone's wing. It's based on the total picture: forecasts, PIREPs, temperatures, and cloud information that would tell a reasonable, prudent pilot that ice is likely to form along the route and altitude. In practice, forecast icing can be known icing.
Building Your Icing Picture Before You Go
Your preflight weather briefing for an IFR flight in the fall should answer four questions:
- Where's the freezing level? It's included with G-AIRMET icing information on aviationweather.gov. (Text AIRMETs for the lower 48 were retired in January 2025, so the graphical product is now what you'll use for what pilots still call "Zulu.")
- Is moderate icing forecast? Check the G-AIRMET icing areas and any SIGMETs, along with the Aviation Weather Center's icing graphics.
- What are pilots actually reporting? PIREPs are the only real-time confirmation of icing, tops, and bases.
- Where are the tops and bases? Knowing where the clouds end tells you whether a climb or descent gets you out of them.
The Aviation Weather Handbook ([[ LINK: FAA Aviation Weather Handbook ]]) walks through each of these products and is worth keeping in your flight bag this time of year.
Your Escape Plan: A Real-World Scenario
Imagine you're planning an IFR flight across the mountains on a gray October afternoon. The cloud layer runs from 3,000 to 9,000 feet. The freezing level is 5,000 feet. Your route's MEA is 8,000 feet.
Walk through the outs:
- Descend? No. You can't go below the MEA, and 8,000 feet is 3,000 feet above the freezing level.
- Climb? Tops at 9,000 might work, but you'd be climbing through the coldest, wettest part of the cloud in a trainer that's already slowing down.
- Turn around? Maybe, but you'd be in ice the whole way back.
That's a flight with no good out, and that's a no-go.
Now change one number: the freezing level is 10,000 feet. Suddenly you're flying in above-freezing cloud at every altitude available to you. Same route, same airplane, completely different flight.
The lesson: before an IFR flight in cold weather, always know where the warm air is, and make sure you can legally get to it. If your only out requires going below the MEA, it isn't an out.
If You Start Picking Up Ice
The most important thing is to act early. A thin coat of ice on the windscreen edge or the strut is your cue to change something now, not after the next fix.
- Pitot heat on. It should already be on before you enter visible moisture near freezing.
- Tell ATC and ask for what you need: a lower altitude, a higher one, or a reroute back to the clear air you just left. If the situation is getting worse, declare an emergency. Controllers can't help with what they don't know about.
- Report it. Under 14 CFR 91.183(b), a pilot operating IFR in controlled airspace must report unforecast weather conditions encountered, and an icing PIREP helps every pilot behind you.
- Fly the airplane. Carry extra airspeed and avoid abrupt maneuvers. Follow your POH on flaps: many trainer POHs advise leaving them retracted when the tail may be iced, because flap extension can lead to a loss of elevator effectiveness.
When you give that PIREP, use the AIM's standard intensity terms (trace, light, moderate, severe) instead of "a little bit" or "heavy." Those definitions are based on rate of accumulation, not how much ice is on the airplane.
How It Shows Up on Your Checkride
Icing ties into the weather information knowledge in the Instrument Rating ACS, and examiners love scenario questions here. Expect something like: "You're at 7,000 feet in the clouds, the OAT just hit −2°C, and you're seeing ice on the strut. What do you do?" Or: "What does 'known icing' mean for this airplane?"
If you can explain the legal answer and the practical answer, you're in great shape. The ASA Instrument Oral Exam Guide and Checkride Ready both drill these scenarios the way examiners actually ask them.
The Takeaway
In a non-FIKI airplane, the best icing technique is avoidance, and avoidance starts on the ground. Know the freezing level, know where the tops are, read the PIREPs, and make sure every flight has a legal, reachable escape into warmer or clearer air. If it doesn't, the answer is simple: not today.
For more resources to support your training, visit NorthstarVFR.com.