Just after 11 am a Piper Cherokee Warrior single-engine aircraft developed engine trouble while on a training flight. The aircraft had been up about 2-hours after leaving David Wayne Hooks Airport in Tomball. The instructor, Matt Duggan, spotted a long muddy road just off Goodson Loop and SH 249, lined by a barbed wire fence and decided to attempt a landing. The wing just mere feet from the fence as the aircraft landed without any damage. The student, Laura Bigler, said she has been in the air since 10-years-old and wasn’t scared at all. Mechanics responded to the scene and we’re going to try to do a repair. It is believed to possibly been carburetor icing that caused the issue. The FAA, Magnolia Fire, and MCSO responded to the scene.
Carb ice forms because the pressure drop in the venturi causes the air to “cool,” and draw heat away from the surrounding metal of the carburetor venturi. Ice then can begin collecting on the cooled carburetor throat. This is the same principle that makes your refrigerator or air conditioner work.
Meanwhile, fuel being drawn through the fuel discharge nozzle into the airflow atomizes into very fine droplets that evaporate easily. When the fuel changes from a finely atomized liquid to a vapor it, too, cools—stripping more heat from the surrounding metal.
The result is that the carburetor’s internal temperature may drop below freezing, even on a warm day. If the ambient air contains sufficient moisture (which can be the case even in seemingly dry air), frost (carburetor ice) can form on the inside of the carburetor.