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one good, one ho-hum and one bad. The good is that turning CAL up will cause the radar to detect lighter areas of precip and smaller water droplets. That’s good for a couple of reasons. First, the hazards in a thunderstorm are not confined to the core area. Extreme turbulence and large hail may be encountered well outside even the green areas of a violent storm.So, turning CAL up better reveals those fringe areas that must be carefully avoided by many miles. Second, even in a stratiform weather situation, when your concern is mostly engine and airframe ice, with CAL turned up to MAX, your radar will sometimes identify where the heaviest precip is, so you can avoid the greatest accumulation.About the ho-hum value of being able to turn CAL up; it, in effect, broadens the beam, making tilt management simpler. But, you must use more uptilt than normal. If youdon’t, the bottom of the beam will touch ground, which will turn on a feature called “Weather Attenuation Compensation; that throws the display out of calibration. Better to learn how to use tilt properly than to use the CAL control as a tilt crutch.What’s bad about flying with CAL turned up, of course, is that your radar display is out of calibration. It’s indicating that echoes are worse than fact, which will result in you widely circumnavigating even little rain showers, thus making you or your boss and passengers late for a critical meeting.The short of being able to turn the CAL up from calibrated is that it’s a useful feature on a radar if used sparingly, very sparingly. But it’s bad practice to run with the CAL turned up for more than a few sweeps. Think of it as being sort of like running with your engines over- temped all the time. Bad things are certain to happen, sooner or later.Obviously, all the above is related to using airborne radar only for weather avoidance purposes. But, in truth, weather is a secondary use for airborne radar. Smart pilots, professional pilots, use it far more for terrain mapping, and for backing up othersystemsinthea•ircraft,than for weather avoidance. That’ll be the subject for a later time. T&TMr. Trammell’s credentials are 33 years as an instructor and lecturer on airborne weather radar and con- vective storms avoidance. His clients have included most major airlines, all five military services and numer- ous government agencies, including the FAA, NASA and NTSB.His research has been exhaustive and has included more than 4,000 hours of inflight thunderstorm re- search, both in his own aircraft and from the jump seat for airline clients. He’s a pilot and CFII, with much twin and turbine experience. His monthly web site, www.radar- 4pilots.com, has been up monthly since May, 2005.Lazy Susan for360° Free Rotation.Completely hands-free from load to unload.AC TrackTech T2For larger aircraft up to 21,000 lbsThe World’s Lowest Profile, Remote-Control Aircraft TugOrder yours now! (855) 884-7222 www.acairtechnology.comMAY 2014TWIN & TURBINE • 15