Norm was doing the walkaround on the Maule. It was late winter; the snow was mushy even in the morning. The Maule was on skis and tied down to the lake with ice screws used by mountain climbers. He was mumbling “carb ice” and making sure I heard it. Overly concerned, I thought.
We had spent the day before ice fishing and had feasted and slept that night in Kevin’s ice shack. Walk around done, we loaded up, started up and ran it up. Extra time on the carb heat. Norm satisfied, we took off and started our climb to 7,500 feet.
Level out, throttle, RPM and mix set.
I like my Bose noise cancelling headset, had it on and turned on. Love the way it hides the sound of the engine. Norm using the other headset, not so nice as mine, calls out “the engine is laboring, carb ice!”. Now Norm is an engine man, he’s been around engines his whole life. When Norm says the engine is laboring it must be laboring.
So, carb heat on.
When over nothing but bush and oil fields the sound of your engine choking on ice and water is uncomfortable. And just as I thought it was going to quit, she slowly started to improve and normalize.
As all pilots know, when climbing in a normally aspirated, carbureted airplane, the manifold pressure reduces. Manifold pressure also reduces when making carb ice. Hard to tell.
Hard to hear an engine labor with great noise cancelling too.
By: Grant Lakeman