Sunday, January 1, 2006
Garmin GPSMAP 396
The wunderbox that brings satellite uplink weather and radio capabilities to the cockpit
Fourteen years ago, when I met Tim Casey of Garmin International, we were at the Paris Air Show, and Carl Pascarell and I had just ferried the prototype Sino Swearingen SJ30 jet across the Atlantic to Le Bourget Airport with little more than point-and-shoot VHF radios. Like most prototypes, the first SJ30 was having its share of systems problems, and electrical glitches had burned up both of our VLF/Omegas on the eastbound crossing. By definition, we were flying IFR above 35,000 feet and needed a method of positively identifying our position for the trip back to San Antonio, Texas. " />
Perhaps the best news is the ease with which you can move between weather pages. All mode icons—GPS, Weather, XM Radio, Flights, Route, E6B, etc.—are on the far left side of the menu page. You merely select “Weather” from the menu section, then cursor right with the rocker key and page up or down through the various XM Weather products. Once the system is locked on (you’ll sometimes receive the “Waiting for Data” warning for a few minutes after startup), you can page between the data choices in seconds.
The system provides weather coverage in near real-time. At worst, NEXRAD information is no more than five minutes old. When Dr. Grider and I left Kokomo, we monitored storms over the Northern Plains states several hundred miles away and watched the weather develop and march to the southeast. On the larger scales, we could even scroll back 800 nm to the Gulf of Mexico and check the storm situation. We also interrogated the system for winds aloft at our breathable altitudes, but we could have checked for winds as high as 42,000 feet (in 3,000-foot increments) if there had been a need. This allowed us to make informed decisions about the best height for winds. You can even loop the weather, although only for a few radar sweeps because of limited memory (64 megabytes), so movement trends aren’t that evident.
In addition to high-resolution NEXRAD, satellite weather mosaic views and winds aloft, XM WX includes another dozen or more products. These include METARs, TAFs, AIRMETs, SIGMETs, along with the ever-changing TFRs, the latter an especially valuable feature at a time when the FAA is liable to establish a new TFR or extend an old one on the spur of the moment. Other XM products include Echo Tops, precip type, freezing levels, surface pressure, and city and county forecasts. There’s an electrical storm track page and a lightning strike page in case you need to monitor severe weather in the area.
The GPSMAP 396’s obvious primary benefit is its weather uplink, but the system has other talents besides weather coverage. The new Garmin portable expands on the GPSMAP 296’s TAWS capability by adding aural warnings of terrain ahead. Garmin’s awesome 30-arc second database encompasses all the standard aviation points plus all man-made or natural obstacles and a terrain data point for roughly every half-mile of North America (30 million in all). That means four terrain data points per square mile. With this much terrain information available, the new GPSMAP 396 can serve nearly the same functions as an airline TAWS at a fraction of the cost.
Additionally, the GPSMAP 396 is modestly programmable. You can choose some parameters of warning limits. If the system senses terrain within those limits, a small thumbnail box will pop up at the lower left, and you’ll hear Garmin’s British-accented Betty warn of “terrain, terrain.” The GPSMAP 396 also alarms on excessive descent rate and warns of any terrain within 500 feet with the traditional “pull up, pull up.”
Like the earlier GPSMAP 296 (see “Tech Talk: Garmin GPSmap 296,” P&P, September 2004), the GPSMAP 396 offers a vivid, color, moving-map display, but unlike the earlier model, the new system is far more resistant to wash out in bright light. It’s a full 70% brighter than the screen used on the previous model. That’s a major improvement as, despite the GPSMAP 296’s other talents, the moving-map display can become difficult to read in bright-light situations. The GPSMAP 396’s 480 x 320 display is clearly visible in virtually any light without losing map detail. Garmin says backlighting has been improved, and the new screen reduces reflectivity, but the bottom line is a more vivid, easier-reading display.
A nice combination feature of the new box and XM WX is the series of enhancements to the “nearest airports” feature. Now, when you select “Nearest,” you can interrogate for weather at each of those closest airports. If you need to divert, it’s easier to make a quick decision as to which alternate is the best choice. Similarly, the “nearest airports” feature enables another valuable asset for normal flying. The system can provide the altimeter setting at the airport closest to your current position.
Another nice feature of the GPSMAP 396 is its ability to interface with the Garmin SL30/40 navcoms. When coupled with either box, the GPSMAP 396 can display an automatic upload of communication frequencies on the standby window. If your airplane is equipped with a Garmin 330 mode-S transponder, the 396 can be coupled to the 330 to display traffic uplink, although it’s likely most 330 owners are already reading traffic through a Garmin GNS 430 or 530.
(A company called Air Gizmo has developed a clever mount that allows installing a GPSMAP 296 or 396 directly in the radio stack rather than on the yoke or on top of the panel. Although intended primarily for the homebuilt market, the Air Gizmo GPS Panel Dock could work equally well for a variety of production airplanes.)
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