Recently, the FAA formally announced that they would be removing a number of test questions from the Private Pilot Knowledge Test. These test questions involved topics such ADF/NDB and Medevac. They also involved a number of weather related questions concerning Radar Summary Charts, EFAS (En Route Flight Advisory Service), and TWEBs (Transcribed Weather Broadcast).
Of the weather topics, the Radar Summary Chart and TWEB products have been essentially eliminated in the Continental United States. Alaska still has TWEB products as of this writing.
This notice from the FAA got me thinking about these and some other weather products that have gone away in the last few years and what has come along to serve the same or a similar purpose. I’ll touch on the TWEB and Radar Summary Chart in this post and perhaps touch on some others in a future post.
TWEBs existed when I started flying many years ago and I’ve known about them from that early time. As a pilot and a flight instructor, I can’t recall ever listening to one over all of those years. I would generally just speak to a Flight Service or EFAS briefer instead.
TWEBs were designed to be a prerecorded location or route briefing. These recordings would be broadcast over NDB or VOR facilities and you could tune in to listen to the message. Some TWEB stations allowed you to call in via the telephone as well to listen to the recording. The broadcast would include general weather information along with hazards, local METARs, and a forecast for the respective area.
To be useful, you needed to be flying the route specified or flying a local flight at the particular location.
If you were really a glutton for punishment, the National Weather Service (NWS) also prepared a text version of the TWEB complete with lots of abbreviations for your viewing pleasure.
249 TWEB 251402 KISN-KMOT-KGFK. ALL HGTS AGL XCP TOPS. KISN-50NM E KISN TIL 00Z P6SM SKC… AFT 00Z P6SM SCT050 LCL P6SM -TSRA BKN050. 50NM E KISN-KDVL TIL 20Z P6SM SCT070… AFT 20Z P6SM SCT070 LCL SFC WNDS VRB35G45KT 3-5SM TSRA CIGS OVC030-040. KDVL-KGFK TIL 16Z P6SM SCT-BKN020 AREAS 3-5SM BR… AFT 16Z P6SM SCT040.
Self-briefings through DUAT and later Lockheed Martin Flight Service’s website (let alone a call to Flight Service) allow you to get the same information but specific to your own route. In-flight use of EFAS (Flight Watch) along with satellite and ground based weather downlink/uplink have eliminated much of the need for this prerecorded product. Additionally, the consolidation of the many FSS stations under LM FSS has made this product more difficult to keep up to date even if there hadn’t been suitable replacements.
Radar Summary Chart
The Radar Summary Chart was a great product back in its day. It was one of the few products that would give you an indication of the weather between reporting stations. It would provide information on the height of the precipitation along with the intensity of storm cells and their general speed and direction of movement. It contained a great deal of information that you need as a pilot.
Back in the days before the Internet and smart phones with live radar, this was great information in a relatively compact product that could be received by teletype and later via FAX machine. Black and images with contours for intensity told you much of what you needed to know.
There were a number of issues with the Radar Summary Chart but if you understood them, you could deal with them. First, the chart only came out once per hour. This meant that the information displayed could be out of date, especially with fast moving thunderstorm cells. People complain that the Nexrad information being supplied to our cockpits isn’t real time but compared to the Radar Summary Chart, a 10-15 minute data delay is amazingly close.
Nowadays, one would think that the radar data shown in the Radar Summary Chart would be a digital transfer from live radar screens composited onto a single chart. In its latter years this may have been the case, but for most of the life of this product it was actually compiled from a textual radar product known as a Radar Weather Report or RAREP. RAREPs were and still are an ugly product. They are tough to interpret without plotting them which is what the Radar Summary Chart did.
Here is a RAREP from today as I write this post (there is snow heading this way):
CLE 1935 AREA 8SW+ 262/20 108/11 27W
ILN 1935 AREA 6SW+ 272/19 116/10 30W
OHX 1935 AREA 2SW++ 273/125 137/110 153W
^LL41 MI1 ML31 NI1111 NO11 OL111111 PI1111 QI111121
The black and white Radar Summary Chart saw its last transmission from the NWS back in June, 2013. The FAA released a new computer testing supplement for the Sport, Recreational, and Private tests later that year with the old chart still a part of the test. Thankfully, as of February 9th, 2015, it is no longer on the test.
The NWS does have a color replacement product but it does seem to be missing some of the elements of the old chart. The new product appears to come out every half hour which is an improvement and it does show more intensity levels through color than the old. One important thing that it does not show is whether an area is blank because there are no echos or because there is no information (ie: equipment failure). Also missing is an indication of the precipitation type that was found on the old chart. Cell movement appears to be there but the symbology has changed from arrows to pennants.
In addition, nearly live radar with motion and color intensity are available from a number of resources. Most of these products unfortunately do not include precipitation height which can be an important indicator to those of us who fly. You also need to be fully aware of any limitations that the bright and shiny color radar display may have. You may not want to stake your life on the latest free app that all of your ground-bound friends are using.
For many years, change in aviation was a slow process and it really still is, but change does come and we all need to keep up. TWEBs and the black and white Radar Summary Chart both had their day. Now, they are moving on to make way for bigger and brighter things. Enjoy the ride!
- Webinar video: Flight Review – tips for getting current - September 16, 2023
- Women in Aviation 2024 Scholarships - September 1, 2023
- Flight Maneuver Spotlight: Traffic pattern entry procedures - July 24, 2023