VFR into IMC
One of the main goals of WTIC research is to recommend a set of minimum performance recommendations for weather displays. For instance, WTIC researchers are looking for ways to highlight changing weather conditions in order to improve pilot recognition of such developments. VFR pilots should know that flying into instrument meteorological conditions (IMC) can lead to a potentially serious situation, and few pilots intend to cross that line. In reality, the transition from visual meteorological conditions (VMC) into IMC can be fairly rapid, or gradual and subtle. So anything that notifies the pilot of impending changes in visibility could be lifesaving.
Early research in this area focused on METAR symbology, with color changes to indicate the change from VFR to IFR. Researchers using displays currently on the market quickly found that there is wide variety in how different manufacturers present this information. Consequently, pilots who voluntarily participated in WTIC research sometimes missed changes in METAR symbology and continued their flight into IMC when they should have been considering changing course or diverting to an alternate airport. The study also revealed wide variance in pilot perceptions and suggested that the industry needs to find more salient ways of presenting a change to visibility conditions. In short, these results point to gaps in displays and the need for depictions to be more consistent, salient, intuitive, and effective across platforms.
Ian Johnson and Gary Pokodner help pilots see the dangers of weather encounters with the WILD simulator at Sun ‘n Fun.
What You See …
Another significant issue that WTIC research identified was that pilots do not fully understand the capabilities and limitations of Next Generation Weather Radar (NEXRAD) graphic displays.
NEXRAD is a great, long-range strategic planning tool that should be used to avoid hazardous weather areas, such as lines of thunderstorms. The mistake pilots often make is assuming that NEXRAD depictions are presented in real time, when in fact processing and transmission time can result in the image being up to 20 minutes old by the time it is displayed on a cockpit device. This lag is significant because thunderstorm cells can form and move far more quickly than your display may indicate.
To address image latency, the WTIC program is working with researchers from the Partnership to Enhance General Aviation Safety, Accessibility and Sustainability (PEGASAS), an FAA-sponsored Center of Excellence for General Aviation. PEGASAS has developed a table-top training device, the Weather Information Latency Demonstrator (WILD), which can adjust latency for any specified time interval to demonstrate the difference between the NEXRAD imagery and what the pilot sees out the window.
WTIC researchers used the WILD to examine how latencies affect a GA pilot’s weather decision-making. Among other things, they found that few pilots can accurately judge distances to clouds or to IMC conditions. Some flight training device manufacturers are now incorporating the WILD concept to help pilots understand the gap between cockpit weather graphics and out-the-window conditions, and improve pilots’ ability to detect and avoid hazardous weather events. The WTIC program has also been briefing pilots on simple triangulation techniques and methods for rough estimations of distance that have been shown to be significantly more accurate than “guessing” distance to clouds, IMC, or other hazards.
Ian Johnson with the WILD simulator.
Read on for more information about WTIC!
Ian Johnson is an engineering psychologist and human factors researcher in the FAA’s NextGen Aviation Weather Division’s Weather Technology in the Cockpit (WTIC) program. He has master’s degrees in human factors in aviation systems and aviation/aerospace safety systems from Embry-Riddle Aeronautical University. He also holds a pilot certificate for single and multi-engine airplanes.
Gary Pokodner is the program manager in the FAA’s NextGen Aviation Weather Division’s Weather Technology in the Cockpit (WTIC) program. He worked in design, reliability, development, testing, and acquisition of avionics at Aeronautical Radio, Incorporated (ARINC) for 25 years before joining the FAA in 2011 to work on aviation weather research.
This article was originally published in the March/April 2020 issue of FAA Safety Briefing magazine.