This page considers the rationale for weather information display and the human factors considerations in designing weather information display systems.
Safety and economic implications
Adverse weather conditions are a contributing or causal factor in approximately 20% of air accidents.1 For this reason, the accuracy and availability of weather information to aviation users can have safety implications.
Pilots need weather information that is accurate, timely, and appropriate to their activities.2 For example, weather conditions that require immediate evasive action by the flight crew, such as isolated heavy rain, microbursts, and atmospheric turbulence, require that the flight crew receive immediate and precise information about the type, position, and intensity of those conditions. This type of information must be displayed to pilots on the flight deck in a way that can be immediately identified and interpreted.
Air traffic management (ATM) users also require accurate, timely, and appropriate weather information if they are to ensure the safe movement of aircraft within controlled airspace.
For these reasons, weather information display systems in the air and on the ground need to be designed both to identify and manage a range of existing and new weather hazards, and to facilitate the role of each user in ensuring the safe operation of aircraft.
Weather also impacts aviation in terms of cost and efficiency. For example, pilots use winds aloft data in flight planning to reduce fuel consumption.
Weather information requirements
Weather information requirements, and the systems that deliver weather information, differ depending on the category of flight operation,3 and might include:
- Weather reports and forecasts
- Aircraft performance information relating to wind and temperature
- Certain communication and navigation equipment, flight instruments, thunderstorm detection equipment, or airborne weather radar equipment
- Weather reporting services en route, for forecast and adverse weather phenomena reporting.
Sources of weather information
Flight crews have access to weather information from various sources, including:
- Weather observations from the cockpit
- Weather reports from ATM
- Weather reports from other aircraft
- Weather reports from airline operations centre
- Airport meteorological information (METARS and terminal area forecasts)
- Weather data/reports reviewed pre-flight
- Weather data from data-links
- Ground weather radar
- On-board weather radar
- Other on-board weather warning systems.
Human factors of display design
Human factors issues arise in considering how the various sources of weather information can most successfully be displayed to the users of that information.
In designing weather information display systems it is necessary to meet the demands of different users, which requires an examination of the way in which they process and use weather information.
Lindholm (2010) has identified the following steps in designing such systems:4
- Identification of users and their function (the tasks they perform). For end users (pilots), weather information must be tailored for use as a decision aid. For non-end users (ATM), weather information will have different applications.
- Identification of the possible uses of weather information now and in the future. For example, a systems designer should consider the impact of automation and the effect this will have on pilot interaction with ATM and the external operating environment.
- Consideration of how weather information should be displayed to the various users, including the appropriate format and quantity of information.
- Identification of the type of information to be displayed to particular users in particular circumstances. Depending on how close they are to the aircraft, users weather information requirements will range from detailed and long-range (such as a meteorologist), to focussed and immediate (such as a pilot).
In addition, a systems designer must build a system that users will want when its capabilities are required, not a system that users want for their purposes today.5 Otherwise, there is a risk that certain information needs on the part of users will be hidden or masked in the development process, because they cannot understand the application of new technology to their current everyday operations and cannot foresee their own future needs.
Cockpit of a Lockheed U-2 reconnaissance aircraft, showing weather data overlayed
(in yellow) on the left (navigation) display. Wikicommons.6
Format of display
The format of weather information display in the cockpit, for useability by the flight crew, should have the following features:7
- Graphical depiction of adverse weather phenomena relative to the position of the aircraft.
- An indication of distance/range.
- An indication of the age (rather than the time) of the weather information.
Example of cockpit weather information display (with weather data
appearing in green, yellow, and red). NASA-FAA Industry Roundtable,
AeroSpace Technology Enterprise.8
The benefits of a graphical display include:9
- It is (usually) more quickly and easily interpreted than text
- It allows the pilot to switch between different data sources (where available) and to overlay information to form a composite view of weather conditions.
Developments in display systems
An example of a technological development in weather information display systems is the NASA-Georgia Tech Research Institute-Rockwell Collins Airborne Hazard Awareness System (AHAS),10 which has the following features:
- Combines information from aircraft sensors and data-links, and displays the combined information to pilots in graphical and textual format.
- Automatically converts incoming text and data into graphical representations.
- Automatically evaluates weather hazards (such as projected interception of thunderstorms) and alerts flight crew.
- Graphically and texturally displays both strategic (informative) and tactical (responsive) information.
- Provides pilots with greater situational awareness, reduces pilot workload, and allows weather-related navigation/diversion decisions to be made sooner.
1 According to data produced by the National Aviation Safety Data Analysis Center of the United States Federal Aviation Administration, weather was a contributing or causal factor in 4,159 of the 19,562 aircraft accidents (21.3%) between 1994 and 2003. NASDAC Review of NTSB Weather-Related Accidents, available on the Aviation Safety Information Analysis and Sharing (ASIAS) System at http://www.asias.faa.gov/aviation_studies/weather_study/studyindex.html, (accessed 14 September 2010).
2 T. A. Lindholm, 'Weather Information Presentation', in J. A. Wise et al (eds), Handbook of Aviation Human Factors (2nd edition). CRC Press, Boca Raton, 2010, p. 25-2.
3 See, for example, the FAA requirements, summarised in B. M. Keel et al, 'Aviation Weather Information Requirments Study', June 2000. NASA / Georgia Tech Research Institute, Atlanta, pp. 5 – 8. http://portal.acm.org/citation.cfm?id=887224, (accessed 13 September 2010).
4 Lindholm, ibid, p. 25-3.
5 Lindholm, ibid, pp. 25-9 to 25-10.
6 Image embedded from Wikicommons, http://upload.wikimedia.org/wikipedia/commons/1/10/U-2_Dragon_Lady_web_030410-F-0000C-004_Cockpit_USAF.jpg, (accessed 14 September 2010).
7 H. P. Stough et al, 'New Technologies for Reducing Aviation Weather-related Accidents', NASA Langley Research Center, NASA Glenn Research Center, http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20060048302_2006250471.pdf, (accessed 12 September 2010), p. 3.
8 Image embedded from NASA-FAA Industry Roundtable, AeroSpace Technology Enterprise, http://www.hq.nasa.gov/office/aero/events/showcase/safety.htm, (accessed 14 September 2010).
9 Keel et al, ibid, p. 26.
10 Sough et al, ibid, p. 3.