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How To Survive An Inadvertent Icing Encounter

_Night Flier_

Planning an IFR cross country in a non-icing equipped airplane during the Fall, Winter, and Spring months can be a challenge. Freezing levels can change quickly based on frontal movement and countless other factors, and even when you make it to your destination, there's no guarantee the weather will cooperate on your way home.

So what should you do if you have an inadvertent icing encounter? I've been there myself, and I can tell you it's not a good feeling. But the best thing you can do is stay calm and use your checklist. And in this case, we'll use the checklist for the Cessna 172S. (The lawyers would like me to remind you to use the checklist appropriate to your aircraft when you fly. But you already knew that...)

Keep Your Instruments Running Smoothly


You're in the soup, and ice is starting to stick to your plane. Your first priority is to keep your instruments running, and to do that, you need to make sure your pitot heat is on:

  • 1. PITOT HEAT Switch - ON

By keeping your pitot tube warm, you'll keep the ice off, and maintain a reliable airspeed indication (because nobody wants to go partial-panel in real life).

Head For Safety


Your next priority is to quickly get your plane out of its current location. That's why the checklist recommends you:

  • 2. Turn back or change altitude

The idea is simple, but the execution is a little more complex. By turning around, you fly back to where you were: ice free airspace. And by descending, you (in most cases) get yourself into warmer and less icy air.

But the problem is this: you're on an IFR flight plan, and you can't just start tearing around the sky without talking to anyone.

The first thing you should do is tell ATC what is going on, and request a lower altitude or immediate 180 turn. If they're unable to give that to you, don't wait: declare an emergency, tell ATC your intentions, and fly the plane to safer air. It might result in some paperwork after the flight, but it's much better than becoming an NTSB accident report because your airplane iced up.

Keep Your Windshield Warm

Eventually, you'll be out of the clouds. And when that happens, you'll want to see out the front of your plane. That's why the checklist tells you to heat things up in the cabin:

  • 3. CABIN HT Control Knob - ON (pull full out)
  • 4. Defroster Control Outlets - OPEN (to obtain maximum windshield defroster airflow)
  • 5. CABIN AIR Control Knob - ADJUST (to obtain maximum defroster heat and airflow)

Keep Your Engine Running

If ice is sticking to your plane, it could be causing engine problems too. This checklist is designed for a fuel injected engine that has an automatic alternate intake door, but if your plane is carbureted, you should be thinking about the probability of carb ice.

  • 6. Watch for signs of induction air filter icing. A loss of engine RPM could be caused by ice blocking the air intake filter. Adjust the throttle as necessary to hold engine RPM. Adjust mixture as necessary for any change in power settings.

Plan Your Landing

Armando G Alonso

Next up, you need to pick a place to land.

  • 7. Plan a landing at the nearest airport. With an extremely rapid ice build-up, select a suitable off airport landing site.

While the nearest airport isn't always your best option, getting yourself on the ground should be a priority.

And speaking of getting yourself on the ground, you'll want to do it a little faster than normal:

  • 8. With an ice accumulation of 0.25 inch or more on the wing leading edges, be prepared for significantly higher power requirements, higher approach and stall speeds, and a longer landing roll.
  • 9. Leave wing flaps retracted. With a severe ice build-up on the horizontal tail, the change in airflow caused by wing flap extension could result in a loss of elevator effectiveness.
  • 10. Open left window and, if practical, scrape ice from a portion of the windshield for visibility in the landing approach.
  • 11. Perform a landing approach using a forward slip, if necessary, for improved visibility.
  • 12. Approach at 65 to 75 KIAS depending upon the amount of ice accumulation.



Because the ice on your airplane will increase your stall speed and change the handling characteristics during touchdown, Cessna recommends you avoid flaring too much:

  • 13. Perform landing in level attitude.
  • 14. Missed approaches should be avoided whenever possible because of severely reduced climb capability.

File A NASA Aviation Safety Report

This last step isn't on the checklist, but it's something you should always do if you have an inadvertent run-in with ice, or anything else for that matter.

By filing a NASA Form 277B, you can prevent your license from being suspended or revoked, as long as you fall within the 4 rules of the program:

  • 1) The violation reported must have been inadvertent, not deliberate
  • 2) The violation must not have involved a crime, accident, or lack of qualification or competency on the part of the reporter
  • 3) Evidence of having filed an ASRS report within 10 days of the event's occurrence (your receipt) must be presented
  • 4) Immunity from action under the ASRS cannot have been used in the last five years.

We'll talk more about the NASA program in the future, but for now, make sure you bookmark the page and use it if something like happens to you on your next flight.

Walking Away From An Icing Encounter


Fly the plane, communicate with ATC, and follow your checklist. It's a recipe for walking away from almost any inadvertent icing encounter.

Colin Cutler

Colin is a Boldmethod co-founder, pilot and graphic artist. He's been a flight instructor at the University of North Dakota, an airline pilot on the CRJ-200, and has directed development of numerous commercial and military training systems. You can reach him at

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