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vioniCs R.C.AExceeding the standardsR.C. AvionicsTrustworthySixth PageCompetent4/C Ad35 Years ExperienceUp-Grade Specialistwww.rcavionics.com 763-398-3920Hillaero Modification CenterSixth Page 4/C AdA “Panhandle Hook” winter storm, so named because of its birthplace in the panhandle areas of Oklahoma and Texas, begins life as a relatively-shallow low pressure area. However, the strong temperature contrast, between the Gulf of Mexico maritime air mass and the frigid continental polar air mass lurking in Canada and the Dakotas, quickly results in the low deepening.On the first day, the storm begins engorging itself with large amounts of moisture from the Gulf of Mexico. The relatively warm air from the Gulf is carried northward and overruns cold air near the ground. Often, a layer of below-freezing air, normally somewhere between 1,000 to 5,000 feet thick (depending on how far north the warm front has progressed) will give rise to freezing rain as liquid precipitation from the warmer air above falls into the colder air below. This situation creates an excellent opportunity for extreme airframe icing. By the time the storm has wound up tight, the freezing rain can overwhelm even the equipment of FIKI equipped airplanes. Aircraft without anti-ice or de-ice devices are in great danger from an encounter with an energetic winter storm.Oklahoma, Arkansas and Western Tennessee, located on the south side of the low, become victims of an ice storm with an inch of ice frequently coating the power lines and trees in a few hours. An approach throughthis kind of freezing rain had better not take very long - even if you can heat the wings and tail feathers with prodigious amounts of bleed air.In Kansas, Missouri, and Illinois, the precipitation stays all snow and 5 to 8 inches fall within 8 hours. As the storm clears the area, a strong northwest wind blows the foot-deep snow into drifts and the skies rapidly clear behind the departing visitor.By the second day, the low is fully developed and is making a beeline up the Ohio River valley. A very deep low pressure area now, it begins to draw moisture from the Atlantic Ocean, a full 600 miles away, as well as the Gulf of Mexico. If the Great Lakes haven’t completely frozen over they contribute to the moisture supply as well, resulting in the low deepening even more, plus creating extremely dangerous icing conditions in cloud and close to the low. An airplane can become an ice cube in the lower parts of the atmosphere from ground level through FL250 regardless of boots and prop deice. Even heated-wing jets can get into trouble while descending to land when close to the deep low associated with these storms.What happens next depends of the path of the storm. If it heads east from southern Ohio, it will likely “bomb out” (greatly intensify) when it hits the Atlantic Ocean. It will then turn northward and become a nor’easter. Life willDouble M Aviation Sixth Page4/C Ad26 • TWIN & TURBINEFEBRUARY 2016