For most pilots, the attention-grabbing feature of the newest entries in the small-aircraft general aviation market, such as the Cirrus SR22, is probably their large-format cockpit displays. They’re colorful, bold and big, and they offer capabilities undreamed of in this class of aircraft even two or three years ago. But thanks to new technologies and the entrepreneurial spirit of several small companies–equally unknown until recently–a rev-olution in cockpit display concepts is under way.
And nothing better underlines this than the way weather data is currently reaching the flight deck. Until now, weather information to aircraft in flight has been provided in a number of ways and formats, with the scope and amount of detail varying with the service subscription fee. But all these services have had one thing in common: you pay a set fee, usually monthly, and they’re there whenever you need them. But they’re also there when you don’t need them. It’s much like cable TV–whether you watch for one hour or 24 hours a day, the price is the same.
Now, firms such as Avidyne, whose Entegra display system is available in several of the new small aircraft, offers weather keyed to your flight plan, and the fees start when you fire up your avionics before departure and stop the instant you shut down after landing at the destination. Power by the hour, meet weather by the minute.
It’s estimated that weather data downlinks–which also include current TFR map overlays–on a two-hour flight in winter conditions would cost between $4 and $6.
How does it work? Basically, the aircraft’s avionics package includes a small satellite transceiver, which transmits data to, and receives data from, the Orbcomm satellite constellation. Orbcomm is probably best described as an industrial satellite system that, since its first launch in 1995, now serves tens of thousands of surface vehicles, ocean vessels and other mobile users around the world from 30 low-earth-orbit (LEO) satellites circling 500 miles up. And its two-way transmissions are solely data, not voice messages, with an aircraft antenna built by Comant looking very much like a conventional VHF antenna. However, the antenna actually incorporates three separate elements for VHF, GPS and Orbcomm.
In Avidyne’s case–and others will undoubtedly adopt a similar technique–the aircraft system automatically transmits its present position when power is applied to the avionics. This data burst, which includes the user’s ID, is transmitted to the nearest satellite, which then retransmits it down to the nearest network operations center (NOC), of which there are several planned around the world. The NOC then responds with the current weather in the aircraft’s vicinity, with the content depending on the levels of service contracted for by the user, such as Nexrad, METARs and so on.
Aviation weather is a new endeavor for Orb- comm, which until now has primarily served terrestrial users. But the company sees an enormous business opportunity as advanced-technology flight systems spread through the entire general aviation fleet.
Another relatively new Orbcomm application could also offer valuable aviation benefits, especially to corporate operators. Following 9/11, small, self-powered satellite transceivers with miniature antennas are being linked to the security seals placed on containers and other cargo items under shipment. Should a seal be broken, the device immediately transmits an alert, which is directed to the shipping company and other security agencies. The technique was derived from Orbcomm’s work in monitoring unmanned facilities, such as remote oil and gas wells. There appears to be repotential to adapt the technology to aircraft, particularly corporate aircraft, which must often remain overnight in relatively insecure locations, and where an intrusion alert could be directed locally to the crew and simultaneously to the company’s flight department.
