Low-cost cockpit weather options gaining popularity

 - October 8, 2007, 10:43 AM

Bringing datalink weather information into the cockpit has never been easier or more affordable. A variety of newly available low-cost terrestrial and satellite uplink services are allowing buyers of relatively inexpensive cockpit multifunction displays to add special receivers and antennas and gain access to continuously updated terminal reports, forecasts, winds aloft, sigmets, airmets and Nexrad radar images.

While perhaps not quite a Weather Channel for the cockpit, low-cost weather datalink, a relatively recent advance for general aviation, nevertheless is a milestone that rivals in importance the introduction of airborne weather radar more than 40 years ago. Where radar can provide a right-now, tactical look at areas of rain and storm cells nearby, datalink offers a blend of both strategic and tactical views, giving pilots regularly updated reports and Nexrad images from stations all along their route of flight.

Such services can be used to view weather at the destination or, in a pinch, to pick through a line of worsening storms. Updates are issued every few minutes, meaning the weather the pilot is seeing on the display is usually never more than five or 10 minutes old, good enough for most types of general aviation flying. And if you’ve got datalink capability coupled with weather radar, all the better.

For this report, AIN chose to look at four of the most popular aviation multifunction displays available on the market and their respective datalink services’ offerings. In the accompanying story on this page is a further in-depth look at one of the fastest growing weather data providers, Orbcomm.

Avidyne FlightMax EX500
The FlightMax EX500 cockpit display from Lincoln, Mass.-based Avidyne is claimed to be the first MFD on the market with an integrated datalink transceiver. According to the manufacturer, the EX500 provides high-resolution depictions of weather on the moving-map page along with text METARs in plain English. The Avidyne unit can also send temporary flight restriction updates and provide a graphical display of active TFRs on the map page.

When originally announced, annual subscription prices for FlightMax weather services over the Orbcomm network were expected to cost between $349 and $599 per year.
Since then, Avidyne has expanded the concept of “narrowcast” weather, whereby customers pay for only what they use. Claimed pricing per hour of use is about $3, based on “message units” that cost 15 cents each. Downloading one Nexrad image takes about one message unit, so cost to the user will depend on just how often new pages are uplinked. The downside to low-earth orbit satellite systems is that data rates are slow.

Bendix/King KMD 550/850
Unlike satellite-based services, weather information for Bendix/King’s KMD 550/850 MFDs is sent through a network of Honeywell ground stations. These Flight Information Service-Broadcast (FIS-B) signal stations, most of them placed at avionics shops, uplink a range of free and fee-based aeronautical data. Coverage is limited by line-of-sight transmission in many areas to above 5,000 feet unless near an FIS-B station.

As part of an FAA program, Honeywell was granted use of two FIS frequencies to broadcast weather throughout much of the U.S. at a healthy 31.5 kbps. A newly designed network of 200-plus ground stations transmits the high-resolution FIS-B weather to a KDR 510 datalink receiver on board the aircraft, which is updated continuously and automatically, with virtually no effect on pilot workload, according to Honeywell.

Garmin GNS 430/530
Garmin now provides weather data to its 400- and 500-series panel-mount MFDs using its GDL 49 satellite datalink transceiver. Subscriptions to the weather service are through Echo Flight, which broadcasts its signals over the low-earth Orbcomm network on a request basis. Like other cockpit weather services, Echo Flight sends Nexrad weather data, METARs, TAFs and other information.

While the hardware price (see chart) is higher than competitors’ list prices, it is important to note that the GNS 530 used in the example includes integrated GPS receiver and navcom radio. Price for the lowest-cost option from Garmin, the GPS 400 with smaller LCD, would be about $7,000 less. List price for the GDL 49 is $3,495.

Garmin AT MX20
The weather option that has got pilots talking is WSI’s InFlight satellite service, available now for use with the Garmin AT (formerly UPSAT) MX20 multifunction display and with a variety of handheld electronic flight bag (EFB) computers. Needed additional hardware for users of the MX20 is the $4,995 AV200 receiver, which links to the WSI network for its complement of aviation weather services, well known to any pilot who’s visited FBO pilot briefing rooms, where the company’s ground terminals are commonplace.

WSI’s InFlight service offering includes its Nowrad radar mosaic, a quality-controlled version of Nexrad radar graphics and animation, as well as METARs, TAFs, sigmets and airmets. Another unique feature of the service is Echo Tops, which tracks the severity, tops and direction of major storm cells. The WSI service also provides graphical and textual displays of TFRs.