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Saturday, March 1, 2003

Weather Avoidance

From general aviation to air transport, a growing number of pilots are gaining comprehensive weather information, courtesy of advances in grahic presentation, data processing and data transmission.

James W. Ramsey

Advances in receiving and processing radar- and satellite-derived weather data, plus communications breakthroughs, are allowing critical weather information to be presented to pilots in flight – on-line and in near real time. The result: pilots can detect and display current and developing weather patterns hundreds of miles ahead of the aircraft and thus make flight plan changes to avoid hazards.

Weather service providers have joined with avionics suppliers to make this capability available to air transport, business and general aviation operators. While text weather information has been available for a number of years, graphical maps, displaying weather patterns over broad areas, are now being uplinked to the cockpit via telephony or satcom.

The only real-time cockpit weather information in flight is provided by airborne radars, which are limited in range and to an area in front of the aircraft. But the use of digital data links and communications management units (CMUs), tied into advanced cockpit displays, provides long-range, strategic weather information, updated as frequently as every five to eight minutes.

Service Providers

A host of companies have jumped into the burgeoning market for uplinked aviation weather information, but four companies stand out. The pioneer is Houston-based Universal Weather & Aviation, Inc. (no corporate connection to Tucson, Ariz.-based Universal Avionics Systems Corp.). In 1959 Universal Weather began providing weather briefings specifically for business aviation pilots, and then also communications and flight planning services. In 1996, the company entered the data link market, working directly with Universal Avionics to support that company’s UniLink communications management unit (CMU).

Universal Weather claims to be the first to offer color weather graphics in the cockpit and first to offer an Internet-based weather system on the ground. Some 450 corporate and general aviation aircraft, as well as several regional airliners and the U.S. military, use the UVdatalink service. The company does not provide data link hardware or software; it is a data link service provider. It supports airborne communications addressing and reporting system (ACARS)-type systems, including the Universal Avionics CMU and Teledyne Controls’ TeleLink CMU.

The company’s weather graphics are transmitted through any telephony or satcom system. But they are not available through VHF because of bandwidth limitations, according to Brian Allen, Universal Weather’s manager of UVdatalink sales and marketing.

If the airborne CMU uses a telephony system, the coverage area will be North America. With satcom, graphics can be requested worldwide.

"We are the only service offering weather maps for regions internationally," Allen maintains. "All other data link support systems have weather maps for North America only."

Using touch keys on the aircraft’s multifunction display (MFD), a pilot can select from eight different types of graphical weather images, including next generation radar (NEXRAD) maps, storm cell tops and movement, significant meteorological information (SIGMETS), winds and temperatures aloft, and potential icing or turbulence.

"If you were flying from New York to Los Angeles, the aircraft’s radar would be looking out ahead of you," says Allen. "But if you knew there was a cell over Phoenix and you wanted to see how it had changed, you can use the [CMU] box to pull up high-resolution images of NEXRAD radar for that station." A pilot, thus, could plan to "fly a dogleg around" a cell, he adds.

Universal Weather & Aviation employs 60 full-time meteorologists in the weather department at its Houston-based facility, which operates around the clock. Its service is "essential to smaller corporate or general aviation operators who can’t afford to purchase larger CMUs used by airlines and on large corporate jets," says Allen.

"A lot of data link systems are low-end systems that don’t have all the functionality of ACARS," he says. "They may just have broadcast weather-type system–very inexpensive for your smaller aircraft such as the [Raytheon] Beech King Air." While some larger airlines provide their own weather services, others, including regional carriers, use service providers such as Universal Weather or a competitor.

A ground-based product offered by Universal Weather allows corporate pilots to link to weather briefing databases through its Web site via a personal computer (PC) or personal digital assistant (PDA)–any computer that has Internet access. Clients subscribing to the UVdatalink service can access both graphical and text aviation weather services.

WSI

Weather Services International (WSI) claims to be the leading provider of weather data services and software to the broadcast media, aviation and energy markets. Headquartered near Boston, WSI entered the aviation market in 1980. Half of its 200 employees have meteorological backgrounds.

Some 800 fixed-base operators (FBOs), 1,200 corporate flight departments, and 95 percent of the Federal Aviation Administration’s (FAA’s) Flight Service Stations use WSI’s ground-based "Pilotbrief" service, and most major airlines also use WSI’s weather service for their preflight briefings, the company claims. "Pilotbrief Online" provides on any computer Web browser the same weather service, including graphics or text. The company also provides a product tailored for regional airlines.

WSI’s newest product, called "WSI InFlight," delivers its weather briefing services from the ground to the cockpit by broadcast satellite data link. "It broadcasts weather data continuously and automatically refreshes itself, so no pilot action is needed," says David Laubner, WSI director of marketing programs. "Whether taxiing on the runway in Florida, or at 55,000 feet over Seattle, the pilot sees the whole U.S. weather picture, including at his or her destination."

WSI’s Inflight weather product, acquired in 2002 from a Virginia development company, has been newly launched. The first non-certified version–designed for use with a portable display, like an electronic flight bag (EFB)–was shipped and installed in late December.

WSI has a "strong back order" of units from its network of avionics dealers, Laubner says. The first FAA-certified systems are expected to be available this spring and be used in conjunction with UPS Aviation Technologies’ MX20 MFD.

The WSI data link equipment consists of a Comant Industries low-profile antenna, mounted on the fuselage, and a 1-pound (0.5-kg) receiver, supplied by Sandia Aerospace. The receiver is connected to the aircraft MFD or to a portable display. No other data link equipment is required.

"In the case of an EFB, the avionics shop will install the software," says Laubner. "With the MX20 [shown left], UPS Aviation Technologies will provide the upgrade software, so it can be compatible. Just plug it into the FMS, and you are ready to go.

"On the MX20 MFD, you press the weather button, and it switches to our application. Over the U.S. base map, you can overlay radar or as many features as you want. It continues to update at five-minute cycles," Laubner adds.

Weather products available from the new system include WSI’s trademarked NOWrad radar mosaic map. This depicts areas of rain and snow, along with cell tops and movement, meteorological aeronautical reports (METARS) and terminal aerodrome forecasts (TAFs), plotted SIGMETs, and airman’s meteorological information (AIRMETs).

Graphics for InFlight are less detailed than those on the PilotBrief system. "We would rather have pilots flying heads-up, so we say our display has ‘high-glance value,’ meaning the iconography, color scheme and graphics are designed for a quick-glance, detailed picture of what is going on," Laubner explains.

WSI plans to price its subscription service at a flat rate of about $50 per month. The antenna and receiver cost $3,000 to $5,000 (excluding installation), depending on the display used. For example, an installation with an EFB-type display would cost about $3,000, while one with a MFD, such the MX20, would cost about $4,900.

"Some services that use telephone towers charge by the minute. If you fly a lot, charges can run up. With our service, you can leave the system on for hours, and it costs the same for the first minute as the last," states Laubner.

WSI plans also to offer an in-flight product called Echo Top, which can help determine a storm’s direction, speed and severity. It also will report hail, cyclones or other weather phenomena. Echo Top overlays on WSI’s radar product. Combining Echo Top with other weather products, "you can see current conditions, based on what the station is reporting, and have the weather forecast," says Laubner. "This will aid the pilot’s decision as to what to do when coming upon the destination."

For the future, WSI is looking at the VHF data market, despite current bandwidth and line-of-sight limitations posed by a system that uses ground towers to transmit and receive signal and content. Like Universal, WSI gathers its weather data from government sources and private networks. The prime government source is the National Weather Service (NWS), with its NEXRAD sites.

But WSI does not send out raw data. Before it is transmitted up to the pilot, the data is passed through an automatic quality control system to remove cloud echoes, clutter and noise.

Jeppesen

Famous for its aeronautical charts and navigational tools, Jeppesen, now a wholly owned subsidiary of Boeing, also offers a weather service. Through its office in Los Gatos, Calif., Denver-based Jeppesen operates an around-the-clock weather service that supports its corporate flight and trip-planning services, according to Mike Cetinich, product manager for weather and NOTAM (notices to airmen) services.

Satellink Technologies, of Dulles, Va., chose Jeppesen as the primary provider of weather information for its Merlin weather data link system (November 2002, page 39). Like WSI’s system, Merlin provides weather information to the cockpit, using a continuous broadcast satellite service. Merlin will use a derivative of Jeppesen’s moving map software and Jeppesen’s weather information, which overlays the map.

The weather data can be overlayed with nav aids, route structures, terrain or other displays, says Cetinich. It can be presented on an MFD, such as the MX20, or on an EFB or other portable device. Satellink expected to launch the Merlin system in January or February of 2003.

Jeppesen provides weather to general aviation subscribers, too, using its Flight Star flight map and update services. "We provide weather over a broad spectrum, from big airlines to regionals, corporate operators and general aviation," says Cetinich.

The company is looking closely at a weather product tailored for an EFB display that its parent company Boeing is developing in conjunction with Astronautics Corp. The EFB "would have all information necessary for navigation and, in addition, generate weather information that overlays that," says Cetinich.

Jeppesen also receives its weather information from government sources, notably the U.S. National Weather Service and the UK Met office in Brackness, England. It uses a large receiver dish to gather NEXRAD information from all the individual radar sites around the country to create a mosaic, and it updates the data in five-minute intervals.

Jeppesen is working with AirCell, as well, to provide weather information through either a cellular phone connection or through the Iridium satellite network. Another pipeline is being explored with family member, Connexion by Boeing. Using the Connexion 737-400 test aircraft, Jeppesen has participated in CNS/ATM (communication, navigation, surveillance/air traffic management) tests over the Gulf of Mexico, providing weather information via the Connexion broadband network.

Honeywell

Following a joint project with NASA to develop graphical weather from a ground-based data link, Honeywell is launching a weather service tailored for commercial airlines. "It is operational, and we are very close to securing our first customer," says Dan Leger, product manager for Honeywell’s WINN (Weather Information Network). The company configured the system for both domestic and international service.

Although targeted primarily for airline and air cargo operators, WINN also provides weather overlays for the interactive navigation (INAV) feature of Honeywell’s Primus Epic avionics suite for the business jet market. Two original equipment manufacturers (which Honeywell declines to identify) have ordered WINN to provide graphical weather for two bizjet models, Leger states.

Honeywell’s data center in Phoenix operates around the clock, accumulating from various sources weather information that is decompressed and then processed. Honeywell uses whatever pipeline between the data center and the aircraft is available: satellite, telephony or, potentially, VHF radio. Once on board the aircraft, the weather information is routed to a portable or dedicated display.

Honeywell’s system, unlike others, does not send images to the cockpit. Instead, the software application contained in the display device creates the images from the data received. Using the PC-based software application to produce images "allows us to create a much more effective tool for the flight deck," Leger explains. "The information flows up to the aircraft, is stored on a hard drive, and the crew can select particular data sets and overlay them."

A new weather feature offered by Honeywell, called CONV (convection), indicates the presence and severity of thunderstorm activity. Company officials say it is an advance over convection warning provided in current radar weather.

Another new Honeywell product is designed to detect clear air turbulence (CAT). While some elements are experimental, it is "probably the most attractive and sought-after product we have," says Leger. This three-dimensional data set, which shows the CAT’s severity as well as location, is being offered now, he reports.

For smaller aircraft Honeywell offers a weather service called Flight Information Service (FIS). A Bendix King product, it was designed for corporate and general aviation and differs slightly in architecture and packaging from WINN. Introduced late last year, FIS will be delivered via a network of more than 100 VHF transmitters located throughout the United States to an airborne VHF data link (VDL) receiver and cockpit MFD.

Honeywell owns and operates the VHF transmitters, which use FAA-authorized frequencies but have not yet been fully deployed throughout the United States. The VDL system is said to be capable of handling data at 31.5 kilobits per second.

In addition, Honeywell has a third, older weather product. Part of its AFIS (aircraft flight information service), this data link service offers graphical and text weather data, focusing on the bizjet and commuter market. AFIS, which has offered text weather for a number of years, began providing graphical weather two years ago.

Digital Cyclone

Several companies provide aviation weather services via mobile phone technology. An example is Minneapolis-based Digital Cyclone Inc., which offers a weather service directed to mobile phones for general aviation and corporate pilots.

Through a distribution agreement with Motorola, Digital Cyclone’s My-Cast system allows pilots to dial up a NEXRAD weather map and view METARS and TAFs along the flight path. The pilots can call up specific airport weather conditions, and the information will be displayed on the mobile phone’s 1.5-by-1.2- inch color screen. The service, available to Nextel and AT&T customers, will be available from Sprint and Verizon soon, the company says.

Data Link Providers

While WSI and Honeywell (in the case of AFIS) provide their own data link connections, other weather service providers, such as Universal Weather & Aviation Inc. and Jeppesen, rely on data link providers.

Teledyne Controls was launched in the weather reporting business through its relationship with Universal Weather. Teledyne’s TeleLink ACARS management unit provides an interface to cockpit multifunction control display units (MCDUs) that can display graphics, says Matt Wing, Teledyne’s communications and cabin products marketing director.

TeleLink can provide weather graphics to the cockpit from any telephony system, including Teledyne’s MagnaStar, while operating within U.S. borders, or from any satcom system, including the new Swift64 high-speed data connection (September 2002, page 22). The system provides graphical capability for large corporate jets and regional aircraft, "which do not have all the services available to them that commercial airlines have," says Wing. Teledyne also has data link customers who use Honeywell’s weather service, he adds.

A new second-generation TeleLink will add Ethernet capabilities to support mobile packet data services (MPDS) over the Inmarsat satellite network, using the same hardware that now supports the Swift64 service. The advantage of MPDS "is that you pay for just the data you send or receive, not for the time you are connected," says Jody Glasser, Teledyne’s senior director of advanced technology.

EchoFlight, Boulder, Colo., is the weather service provider for the Garmin system and has helped develop the data link. EchoFlight, in turn, obtains its weather information from Meteorlogic, of Burnsville, Minn.

Garmin International, Olathe, Kan., also offers a data link product that delivers aviation weather to general aviation and corporate aircraft. Garmin’s GDL 49 satellite weather data transceiver operates on a request/reply basis, sending out an aircraft request that is relayed to a ground station via satellite. The reply is presented on the aircraft’s GNS-530/430 navigation/communications display or multifunction display as a graphical overlay on a moving map.

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