Updated September 7, 2005

Datalink Weather Service Comparison

I've done some web research in preparation for a talk I gave at the American Bonanza Society Annual Convention in Dallas, TX on September 9, 2005. I've put together an Excel spreadsheet that compares the weather products from three datalink weather providers: WxWorx XM, WSI, and Bendix/King FIS. Another worksheet in the file then compares, for each service provider, which weather products can be displayed on different devices including MFD's (Avidyne FlightMax EX500, MX-20, Garmin 1000), GPS units (Garmin 430/530), and portable units (laptops, electronic flight bags, PDA's, and the Garmin 396).

To download the Excel spreadsheet, if clicking the above link does not work, try right-clicking on it and choose the "Save link as" or "Save target as".

Feel free to explore on your own. These links provide a starting point:

Weather Data Providers

WxWorx: www.wxworx.com
product specifications with update intervals: http://www.xmradio.com/weather/xmwm_productdefs.pdf
images of weather products: http://www.xmradio.com/weather/learn_about.html

WSI – product specifications and pricing
http://www.wsi.com/solutions/aviation/inflight/pricing.asp

Bendix/King Flight Information Services (FIS)
https://www3.bendixking.com/wingman/static/FIS/faq.jsp

Display Device and Software Providers

Portable devices

NAVAir: www.airgator.com
PDA, EFB and Laptop packages:
http://www.airgator.com/Saves/pricing.htm

Anywhere Map, Anywhere WX: www.controlvision.com
PDA solutions & comparison with Garmin 396:
http://www.controlvision.com/pages/awm-vs-396.aspx
EFB packages:
http://www.anywheremap.com/SearchResult.aspx?CategoryID=26

Garmin 396
http://www.garmin.com/products/gpsmap396/

Panel mounted devices

Avidyne FlightMax EX500
http://www.avidyne.com/ex500

Garmin info on GDL 69/69A (GNS 430/530, MX20, G1000)
http://www.garmin.com/products/gdl69

Bendix/King Flight Information Services (KMD 250/550/850)
https://www3.bendixking.com/wingman/static/FIS/faq.jsp

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Last updated October 12, 2004

Satellite Delivery Systems

Over the past two years, satellite systems for delivering aviation weather services to general aviation aircraft have become very usable. Prices for these systems have also dropped significantly. You can now obtain a complete handheld wireless weather solution utilizing geosynchronous satellites for under $2,000. This market continues to evolve and change rapidly.

This page deals primarily with handheld solutions. The market for panel-mount hardware is also developing rapidly but is only covered here in passing.

XM Satellite System
This is one of the least expensive systems available, while remaining extremely capable. XM aviation weather data uses the same satellites that can deliver XM Radio to your car or airplane, though you need a special receiver to get the weather data. These satellites are geosynchronous, so you have continuous coverage while flying in North America.

At this time, XM Nexrad maps can be displayed on a variety of handheld devices including PDA's running Windows software (e.g. HP/Compaq iPaq), certain Electronic Flight Bags (EFB's), and most laptops. See the WxWorx web site for portable solutions.

XM weather data can be displayed on a few panel-mount MFD's. The Avidyne FlightMax 500, available now, uses XM weather data with their "NarrowCast" service, and Garmin will be using XM weather data with their new Garmin 1000 system.

Side note about Garmin and weather data: the weather provider for the Garmin 430/530 units is Orbcomm, which utilizes a low earth orbit (LEO) satellite network that has significant limitations. Most notable is that using a LEO system, there are gaps in coverage that can last for tens of minutes, and sometimes more than an hour. You would be better served going with a geosynchronous satellite delivery system. Garmin does NOT provide geosynchronous weather data for the Garmin 430/530 and probably never will be due to the contracts they have already signed with Orbcomm. Great GPS, sub-par wx service.

Interestingly, WSI announced in the summer of 2004 that they have a unit that can display wx data from their geosynchronous satellite system on the Garmin 430/530. Garmin is not happy about this and has been trying to discourage 430/530 owners from buying into this. I would suggest researching this option carefully before purchasing.

One excellent solution for the Garmin 430/530 is to pair a 430 or 530 with the Apollo (now GarminAT) MX-20. The MX-20 can be driven by nearly any modern GPS, including a Garmin 430/530. You could then subscribe to WSI's geosynchronous weather data service, which is available for the MX-20. More information about that below... And if you want my opinion, I'd recommend using a 530 with the MX-20. The Nav-1 page on the 530 is superior to the data available on the 430. You'll enjoy the larger screen too, as well as the dedicated VOR/ILS ID, radial, and distance window, not available on the 430.

Back to XM weather data and PDA's.

A complete XM weather data system includes a display device, a GPS that must be connected to the display device, a weather data receiver, and an XM antenna for the data receiver. All of this can remain portable (this is the best solution available if you fly in multiple aircraft). Both the XM antenna and the GPS antennas can be placed on the dash board of the airplane and work well. With a bluetooth enabled display device, you could also use a bluetooth GPS (i.e. wireless), which helps cut down on cable clutter.

As is normal for geosynchronous satellite data systems, the satellites will push current data to your display device every five minutes automatically. This is the best way to get your data, as the user does not need to make a data request as is often required with LEO systems.

Check out airgator.com for bundled solutions starting at less than $2000. See WxWorx.com for information about the data and subscription fees (about $50/month).

Control Vision, Anywhere Map, AnywhereWx, Satellite phone system
A weather data solution that uses a satellite phone has been available for several years from ControlVision, the makers of AnywhereMap. The only configuration I've seen is using a Windows based PDA (e.g. HP/Compaq iPaq or similar) as the display device. If you want to use an EFB or a laptop, you'll have to investigate that yourself. A complete system would require a PDA, a GPS for the PDA (a wireless bluetooth GPS will work with an appropriate PDA), both the Anywhere Map and AnywhereWx software, and a satellite phone that is used to retrieve data on demand. Complete packages are available from ControlVision.com.

In 2004 ControlVision has made available an XM weather data solution as well. So if you like the AnywhereMap software, you now have two data solutions - satellite phone, or XM weather data.

Differences between the satellite phone option vs. an XM data provider: XM solutions at this point require a subscription to the data service which costs about $50/month. XM data is updated automatically every five minutes. With the satellite phone, data is provided only on request, and you pay for each satellite phone call. This can be a benefit if you only fly occasionally, as you may be able to keep your data costs below $50/month. However, this also makes the system slightly more complicated. If you are a computer geek, this will not be a problem. If you aren't a computer geek, the XM system is easier to set up, and easier to operate.

WSI geosynchronous satellite system
This is the only solution that can be used both with handheld devices and panel mount devices. Note that the only panel mount device that will interface with WSI at this time is the GarminAT (formerly Apollo) MX-20. This is an excellent panel mount MFD. (As of Summer 2004, you may be able to use the WSI system with a Garmin 430/530, but Garmin isn't happy about this.)

The WSI system consists of similar hardware components as the XM system, except that the data antenna needs to be mounted on the top of the aircraft. This does reduce cable clutter, but obviously only possible if you own the aircraft. If you are a renter or a CFI, this solution isn't for you.

The WSI system will interface with Windows-based PDA's, EFB's, laptops, and the panel-mounted MX-20. This could be an excellent solution if you want handheld capability now, and are considering adding an MX-20 to your panel down the road.

Also requires a data subscription, about $50/month. All details at WSI.com.

Cell Phone & Other PDA Solutions

There are numerous other solutions available for getting some type of real-time weather data in the cockpit. If you have a web-enabled cell phone or a PDA that can connect to the internet with a radio service (like CDPD) or a cellular service (like GPRS), you could potentially use it to surf the web and get weather data.

One limitation is the legality of doing this while flying. The FCC does have restrictions from using cellular devices while flying in aircraft. See discussion under "Use In Flight" below. Note that I am not a lawyer, nor a legal expert in these matters. You need to determine the legality of any such use yourself.

Another limitation is that many newer data-capable cell phones and PDA's are very low-power devices, which helps make the batteries last a long time. Owners who have tried to connect to a data service while airborne have reported significant difficulty in many cases. These devices are probably best utilized while on the ground at fuel stops or from your hangar.

The geosynchronous satellite solutions discussed in the previous section are superior in that if you use a GPS with your display device, your position will be shown in relationship to the weather. A web-enabled cell phone or PDA may be able to get weather maps, but won't show your position. Still, when I was using my Palm Vx and OmniSky modem, this information was definitely useful for making strategic weather decisions. The satellite solutions above are more capable and 100% legal.

A while back I dropped my OmniSky modem on the ramp and destroyed it. So I am no longer using a Palm Vx/OmniSky modem for weather data.

Links and content below were last updated August 6, 2002. No guarantee of its validity at this point in time.

Ron's Gadgets

I have a Palm Vx device and an OmniSky/Earthlink wireless modem. I use the OmniSky modem on the ground and in the cockpit to gather real-time aviation weather information including METAR's, TAF's, Nexrad radar pictures, and more. As a pilot, I find these tools invaluable.

There are a ton of great non-aviation applications available for wireless PalmOS devices too, which come bundled with the OmniSky modem.

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For example, I routinely check movie times and descriptions, email, stock prices, trade stocks through E-Trade, check New York Rangers scores, find phone numbers, addresses, directions and maps to people and businesses, check the arrival time and gates of my airline flights, and look up facts in the Encyclopedia Britannica.

Following is a table of wireless modem manufacturers and what platforms are supported. More detail follows below the table. This is not necessarily a complete list. Other options do exist.

Use in flight

All of these systems work while in flight, assuming a signal is present where you are flying. Use of these devices in GA aircraft is restricted by the FAA according to FAR 91.21. Read the regulation yourself. If you are the PIC, you may allow the use of these devices under many circumstances.

Use of these devices while airborne is also restricted by the FCC. We know that cellular telephones are not to be used in flight. I honestly do not know if this restriction applies to CDPD modems. (See more details below.) The OmniSky/Earthlink and Novatel modems use CDPD technology. If you want to be conservative, it may be best to assume the use of CDPD modems in flight is not legal.

The one service I believe to be legal to use while airborne in your own aircraft is the PalmNet service (palm VII, VIIx and i705). This service uses digital pager networks to transmit data, not cellular networks. My understanding is the FCC hasn't restricted the use of digital pagers while airborne. If you have more specific information or references for any of these issues, please email me.

The very basics of CDPD

The OmniSky/Earthlink and Novatel devices work very differently than cell phones: they transmit data using CDPD (Cellular Digital Packet Data). A regular cell phone requires a continuous connection to a cell tower for the duration of a call. The cell system is designed so your phone can only see one or two cell towers at a time while on the ground. This is important because your phone is tying up one channel on every cell tower it sees. When you use a cell phone from an aircraft, the phone can see many towers, maybe ten, twenty or more. Since you are now tying up a channel on all those towers, this limits the total number of phone calls possible on the cellular network. You are using an excessive number of channels and preventing other cellular users from connecting.

CDPD service is different in that the data is transmitted in a burst of packets. When you tell your CDPD enabled Palm Pilot to get some weather data, it looks for an available data channel, sends a brief request for information, then gets off the channel. When the internet sends back a reply, the channel re-opens, transmits the data to your Palm Pilot, then turns off again. This arrangement means that your device is connected to the network only for a few moments at a time, allowing many users to share a single data channel.

Software

You must install some software on the PalmOS device to make the modem work. This software comes bundled with the modem.

To get weather information you need to install additional software called web-clipping applications. There are three decent web-clipping applications that relate to aviation information. Web-clipping applications are small apps you install on the Palm that get specific information from a web site. Since the Palm Pilot screen is small, the web-clipping apps go to a particular web site and format the relevant information so it is easy to read on Palm devices. In essence you are seeing a subset of the information available if you visited the site from your home computer, but it is much more efficient. Note that web-clipping apps only work on PalmOS devices. They do not work on Windows CE devices.

With a wireless Windows CE device you surf the web just like you do from home. This means you don't need any special software to get aviation data, and you can go to any web site you want, not just ones for which web-clipping applications have been written. The downside to the Windows CE devices are initial cost for hardware, monthly internet access cost (both of which are more expensive than for the Palm devices) and download time, which generally takes longer (because you are downloading the "normal" version of every web site, not a subset of data optimized for slow connection speeds for viewing on small screens).

The three aviation weather web-clipping apps I use are described below. Links to the appropriate web sites where you can download the web-clipping applications are provided in the column to the right.

The Cheapbastards web-clipping application allows you to view nexrad radar pictures, get un decoded METAR's, TAF's and Pilot Reports, and look up the registered owner of any US aircraft by tail number. The nexrad radar pictures are great, though 20 to 30 minutes old. Good enough for the big picture.

The FBOweb web-clipping application allows you to retrieve METAR's and TAF's (un-decoded text only) and do N-number searches, like the CheapBastards software. It goes far beyond anything else with the rest of its features though! You can track any IFR flight, civilian or airline. You will see a US map with the location of the aircraft, and a text display of the aircraft's altitude, speed, destination, and flight-planned ETA. The flight tracking functions require a $9.95/month subscription fee.

You can also get information about US airports, similar to the text information in the government's Airport/Facility Directory. Phone numbers and frequencies are sometimes available for FBO's at the airport. Not all FBO's are included yet.

If you have a DUAT account, FBO web gives you the ability to store flight plans on the FBOweb.com web site (this must be done from a PC internet connection). You can then file the pre-stored flight plans from your PDA. Handy if you fly a few routes on a regular basis.

There is also a time/distance calculator that allows you to figure the time and distance between any two airports based on pre-stored aircraft profiles. This is great when you are at work musing about how long it will take to get from here to there.

There is a web clipping app available for the fabulous ADDS web site (http://adds.aviationweather.noaa.gov) It allows access to current METAR reports in both decoded/plain-language and raw/un-decoded formats. I have not been able to locate the download for this on their web site recently, so I don't know what the scoop is. You can still find and download this web-clipping app from palmflying.com

Aviation Weather Web Clipping Apps (PalmOS only)
Cheapbastards: Nexrad radar and more
Fboweb.com: Text weather, flight tracking and more!
download site: fboweb.com web clipping application

More Web Clipping Apps
PalmFLYING.com
Has many aviation web clipping apps.
Palm.com search site
Search the word "aviation".

Comparison of Palm V vs. Palm VII/i705

These devices are similar, and essentially run the same web clipping applications. There are some differences to consider, noted here. The Palm VII/i705 is an integrated PalmOS device and wireless modem. The Palm V, or any other PalmOS device, is just a PalmOS device. The modem must be purchased separately. There are some advantages to this.

Form Factor

Since it is an integrated unit, the Palm VII/i705 is larger than the Palm V by itself. Once the OmniSky modem is mated to the Palm V, they are similar in size. An advantage to the Palm V/OmniSky combination is that in an area with no CDPD coverage, you can take the modem off and just walk around with the Palm V. Personally, I like the option of carrying just the much smaller Palm V.

Batteries

The Palm V, the OmniSky modem, and the Palm VII/i705 all have internal rechargeable batteries. They cannot be replaced (except by perhaps sending them back to the factory? Not sure about this.). Having separate batteries for the Palm V and its modem is an advantage to me. The batteries in the OmniSky modem last from one day to a week depending on how heavily one uses it. Once the OmniSky batteries are too low for use though, the Palm V keeps on ticking as its batteries last two to four weeks, even under heavy use.

With the Palm VII/i705, since there is just one internal battery, if you get the battery too low from heavy modem use (which could happen in 24 hours), you can't use the unit at all until you recharge the whole package.

TCP/IP Stack

The last major difference (in my mind) is the Palm VII/i705 does not have a true TCP/IP stack, whereas the Palm V does. To most users, this shouldn't really matter. However, if you want to run a wireless application that requires a TCP/IP stack, it won't work on the Palm VII/i705. I have a small web-clipping application on my Palm V called Ptelnet, that lets me telnet into a DUAT computer and get a full DUAT text weather briefing right on the Palm Pilot. This is not possible on the Palm VII/i705, as telnet applications require a TCP/IP stack.

Legality of use in flight

It is possible that CDPD modems are not legal to use in flight. The PalmNet service utilized by the Palm VII, VIIx and i705 may be legal. See discussion in left column.

For someone else's comparison of the Palm V vs. Palm VII for aviation use, click here.

Service Plans and Modem Options

When you buy a modem from OmniSky/Earthlink, you must also subscribe to a data service plan. As of August 2002, that costs $39.95/month for unlimited data access. If you go with the Palm VII or i705, your subscription will be through PalmNet, which costs $40-45/month for unlimited access.

At the Novatel web site, other wireless CDPD modems (non-OmniSky) are available for the Palm III and Palm V series, as well as the Palm m500. These do not come bundled with a service plan, so you must obtain service separately. Several different service plan providers are available if you take this route. Cost for unlimited access ranges from $25 to $65/month. Compare by using the links in the table above.

On a different note, it is possible to access the internet from many palm devices through a data-enabled cell phone. Keep in mind though, you can not use this setup in an airplane because you are connecting using a traditional cell phone. The following PalmOS devices can connect wirelessly to the internet with the Palm Mobile Connectivity Software: III series, V series, m515, m505, m500, m130, m125. This requires a data capable cell phone, cell service that supports wireless data functions, dial up access to an internet service provider (ISP), a way to connect the PalmOS device and the phone (a cable, or infrared connection). The Palm Mobile Connectivity Software comes included with the m-series handheld's mentioned above. It also comes bundled with the PalmOS 4.1 upgrade which you can buy for the III and V series handheld's for $30 from palm.com. I have not used this type of connectivity myself, and only provide the information as a possible alternative for you to research if you are so inclined.

Disclaimer: I am not a representative of Palm Inc., OmniSky, Earthlink, the FAA, the FCC, nor any other company mentioned on this page. I'm just into gadgets, aviation and computers. This information is provided freely. I'm also not a lawyer. Please do not construe anything mentioned here to be legally accurate. Do your own research. I'd like to assume we are all adults and are all willing to accept responsibility for our own actions.