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Pacific Coast Avionics Quarter Page4/C AdTweaking For MappingWith an understanding of all that, the wonderful thing about using airborne radar to confirm the navigation situation is that it’s so simple and easy (assuming a pulse string of reasonable length). You select a displayed range of 80 to 120 nm when flying below FL290 and TILT to ground paint on the outer half of the display; above FL290, use a displayed range of about 150 nm and adjust TILT to ground paint from 80 nm outward.Then. just lean back and watch the world roll by. Most of the time, you’ll find mapping in the WX mode works OK. For real precision, go to MAP, a displayed range of 50 or so nm, and tweak TILT and the CAL control (misnamed “GAIN” on most radars) up and down carefully. With many radars you’ll be amazed with the detail you can pull up.It’s best to simultaneously tweak TILT and CAL. Unfortunately, with an MFD, through which most radars are controlled today, that’s next to impossible because the CAL control is time-shared with something else.The neat thing about radar mapping is darkness or cloud doesn’t matter. And there’s the added benefit of being warned about weather that must be avoided. It’s simple; don’t try to fly into a radar shadow. A radar shadow will be a prominent black area just behind a red echo. If radar energy, traveling at the speed of light, isn’t going through that area, the extreme rain there will certainly stop you. Also, when topping weather, don’t allow any echo to intrude inside the 30-nm range, to avoid the CAT bubble of turbulence that builds just above some storms. Finally, note that when mapping with radar you get an instant notification of a radar failure. If the ground suddenly disappears or begins to jiggle, dance, change colors or anything weird like that, it’s off to the avionics shop you must take it.So, ground m•apping with your radar is a win, win, win situation. Once you’ve become skilled at radar navigation, you’ll wonder why you waited so long to get started. It’s eternal CAVU. It’s so simple, so soothing, so professional. T&TArchie Trammell’s credentials are 34 years as an instructor and lecturer on airborne weather radar and convective storms avoidance. His clients have included most major airlines, all five military ser- vices and numerous government agencies, includ- ing 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.radar4 pilots.com, has been up monthly since May 2005.16 • TWIN & TURBINEFEBRUARY 2016