It could happen to you at any time and, from the moment the ice begins to form, your actions, and the time you take to implement them, will either keep you alive or get you killed. If you encounter icing, and the aircraft you fly is not equipped with a full compliment of de-icing gear, you’re in for a very rough ride.
MARK THESE WORDS WELL - Most general aviation encounters with icing do not end well. There are exceptions…
One student pilot encountered significant icing while on a cross-country flight in Illinois. While flying his Cessna 152 on the final leg of his trip, he noticed that his windshield had fogged over. Our pilot turned on the windshield defrost and then noticed that he was losing altitude.
He increased power, and managed to stabilize his altitude. Looking out the window, he noticed he was passing an airport, but in a critically bad decision, elected to stay on course, since his home airport was only another 10 miles ahead.
With every passing moment, more ice accumulated on his wings and airframe. He kept increasing power until he could no longer maintain altitude, even with full power. The weight of the ice, along with the deformation of the airfoil from the ice wedge, had exceeded the power available!
Fortunately for our student pilot, he was barely within range of his home airport by this time. He extended his flaps (this was a bad decision – if you are iced up, don’t do ANYTHING that could change your wing configuration – it may cause a loss of control!) and started in for his approach. His windshield was iced over, and he couldn’t see out the front of the plane, so he made shallow turns until he could see he was over the runway. He touched down with a loud bang, dumping several hundred pounds of ice from the airframe and on to the runway.
HE GOT LUCKY. It is sad to say, but this trip could have ended minutes sooner had the conditions been worse, with an uncontrolled descent into a farm field, house, or roadway.
With icing, you usually can’t tell how fast - or where - it is accumulating and there is no way of knowing when you will no longer be in control of your airplane!
IF YOU ENCOUNTER ICING
- Confess: If you are taking to ATC – TELL THEM WHAT IS HAPPENING. Request a change in altitude or course to exit the icing conditions and be sure to use the word ‘immediately’ in your request. If you live through the event, file with NASA’s Aviation Safety Reporting System for protection and so that others may learn from your mistakes.
- Turn On Your Pitot Heat: Most planes are equipped with a heated pitot tube. The last thing you need is to compromise your pitot/static system. Your pitot heat should keep your airspeed indicator working, which will help you to keep flying and not stall.
- Operate At Maximum RPM: The worst action you can take while flying in icing conditions is to slow down your prop. The reduction in RPM allows ice to accumulate down the blades - and it never accumulates in a balanced manner. Keeping the prop RPM high helps to shed ice from the prop.
- Get Down! Find the nearest airport, and land your airplane. Get the ice off, and wait for the conditions to clear to allow you to continue.
SPECIAL NOTES
IF YOU CAN’T SEE, USE A STEARMAN APPROACH: Pilots of the PT-17 Stearman have to make gentle S-turns while they taxi - the nose is so high, they can’t see what is in front of them. You can use this same approach to get to the runway, use gentle, shallow turns until you’re over the runway.
REMEMBER – CONFIGURATION CHANGES ARE ** NOT ** A GOOD IDEA: Keep the flaps stowed. If the gear is up, get it down at a higher than normal speed. Stay within the allowable range - if you can.
KEEP YOUR SPEED UP: Your airplane is no longer your airplane. It may weigh more than it has ever weighed in its life and its airfoil and aerodynamics may be completely different - and constantly changing - due to the icing. Maintain higher speeds throughout the remainder of the flight and especially during your approach. This will help avoid a stall caused by a reduction in lift/increase in your weight due to the ice.
BOTTOM LINE: An encounter with icing conditions is nothing to trifle with. If you get into icing, and are not flying a plane with a full compliment of anti-icing equipment, you need to take immediate actions to get out of those conditions. Doing the right things when you encounter icing means that you will - only slightly - increase the chance that you will survive. The best and only defense against flight into icing conditions is to LISTEN to your weather briefer and AVOID flight in icing conditions.