Strategic Approach
Current research in the FAA Aviation Weather Research Program (AWRP), which supports most of the aviation weather research within RAL, is focused on needs for three operational modes: terminal, en-route over land, and en-route over the ocean. Strategies for working in each of these areas are presented following a brief description of the nature of the problems in each.
Terminal Operations
The terminal environment includes both the airport surface and the airspace controlled by the approach and departure controllers. Many terminal weather issues have a direct impact on national flow-control activities, as they try to plan strategically to minimize weather impacts on the national system.
Surface weather-related safety and capacity issues are related primarily to visibility and winter weather, although convective weather and heavy rain can also impact surface operations, including ground crews. Visibility is an issue because visual separation is currently the primary method used for conducting ground operations. In the future, major terminals may move toward automated surface operations that do not depend on pilot vision. However, winter weather will continue to be a problem as runways, taxiways, and aircraft must be treated to remove snow and ice. Convective weather and heavy precipitation will also continue to impede ground operations because of reduced braking action and safety of ground personnel trying to work in adverse conditions, particularly lightning.
Approach and departure airspace weather issues, such as icing, turbulence, and convection, are not much different from en-route issues except that the aircraft are more vulnerable because they are flying slowly, configured for takeoff or landing, and operating very close to the ground. Weather activity that might be dealt with easily in en-route airspace becomes more difficult on approach and departure. Aircraft that are improperly deiced are vulnerable on departure. Low-level terrain-induced windshear and turbulence threaten aircraft on both departure and arrival. Likewise, low ceilings and visibilities impact both operations, although technology solutions may solve these problems for larger airports and advanced technology may mitigate effects on aircraft in the future.
En-route over Land Operations
Weather-related actions in the en-route airspace can best be divided into two categories: strategic and tactical. Strategic actions are taken as part of the traffic management program dealing with groups of aircraft while tactical actions are taken by controllers dealing directly with pilots of single aircraft, or the pilots themselves.
Strategic actions are applied to aircraft flows based upon forecasts of adverse weather. The effectiveness of these actions is strongly tied to the skill of the forecasts, and sometimes can result in counter-productive flow restrictions. Flow managers are very reluctant to use weather forecasts pro-actively because of their fear of taking unnecessary actions that reduce capacity. This remains one of the most critical areas of needed research in the future if RAL’s aviation weather research is to be relevant to the Next Generation Air Transportation System. Skill in forecasting convective weather, turbulence, and icing 2-5 h in advance must improve dramatically.
In the tactical timeframe, RAL has made significant progress in the last ten years. Still, much remains to be done. As air traffic control moves more toward automated decision-making approaches, high-resolution weather information on convection, turbulence, and icing will be integrated directly into the automated systems. Methods of representing forecast uncertainty must be included in the system to allow a risk management approach to decision making.
En-route Over the Ocean Operations
Just as in the en-route over land environment, the oceanic environment actions are also best divided into strategic and tactical categories. The primary difference from the en-route domain is that the strategic decisions require at least a fourteen-hour forecast, and the data available to make forecasts are much sparser.
The same strategic weather threats exist in oceanic airspace as do in en-route airspace, i.e. convection, turbulence, and icing. However, in oceanic airspace, volcanic ash encounters also are a daily concern for planners.
One of the difficult issues for dealing with tactical weather in oceanic airspace is the difficulty of communications with the cockpit. RAL looks forward to greatly-improved technology to solve this problem. The tactical challenge then becomes improving short-term forecasting skill toward the same levels as our CONUS skill. This will involve smart use of aircraft sensing assets along with satellite-based assets to approximate the quality of data from land-based systems. Convection, turbulence, icing, and volcanic ash clouds are the primary forecast weather hazard targets.
Five weather hazard themes – icing en-route and in the terminal area, turbulence, convective weather, ceiling and visibility, and volcanic ash – have been mapped against the operational needs and are summarized in the following table shown on the following page. For more detail on these specific R&D projects see www.ral.ucar.edu .
RAL will continue to work within the FAA Aviation Weather Research Program developing products and capabilities matched to this template of needs, at least in the near term (2-5 yr). During the next two years the AWRP will likely experience some budget reductions and re-alignment of Product Development Teams. As this occurs, work within the AWRP that is relevant to the long-term success of the NGATS will become much more important and within five years most of RAL’s aviation work will be associated with NGATS goals and specific weather needs. RAL staff will continue to work very diligently to position NCAR strategically for playing a major role in NGATS.
Convection |
Icing |
Turbulence |
C&V |
Vol. Ash |
|
Terminal |
Current wind shear, hail, turbulence, lightning and heavy rain in the terminal area |
Ground de-icing decision-making, runway plowing, in-flight icing on approach and departure |
Moderate to severe turbulence on approach and departure |
Runway, approach and departure C&V, fog initiation and dissipation, TAFs |
Runway clearing, removal of ash from aircraft |
En-Route |
0-6 h forecasts of significant convection |
Current (reported and diagnosed) and forecast (0-6 h) icing conditions, sfc-FL200 |
Current (reported) and forecast (0-12 h) turbulence, sfc - FL450 |
IFR vs. VFR flight conditions |
Volcanic ash encounters en-route |
Oceanic |
0-12 h forecasts of significant convection incl. tops |
Current (diagnosed) and forecast (0-12 h) icing conditions, sfc - FL200 |
Current (reported) and forecast (0-12 h) turbulence, sfc- FL450 |
No operational needs specified to date |
Volcanic ash encounters en-route in remote areas |
NGATS will also drive other new R&D initiatives that are not part of the current FAA, NASA, and DOD programs. Some of these are listed below.
- Use of UAVs as weather probes equipped with weather sensors
- Vulnerability of UAVs to hazardous weather and mitigation strategies
- Forecasting radiation hazards along new and existing polar routes
- Increasing terminal security by forecasting hazardous plumes
Business opportunities associated with commercializing space operations in sub-orbital and orbital modes of operation is another emerging area that will become well established by the end of the period covered by this strategic plan. This currently manifests itself in the form of commercial rocket and payload launches. The next phase is the promotion of tourism in space by first offering a half hour sub-orbital ride into space and several years later a more extensive orbital adventure. A new commercial spaceport will open in New Mexico in 2008 to begin this business. RAL will position itself for this new applications area by a) working within the NGATS JPDO to ensure that this type of operation is fully integrated and addressed, and b) working directly with the developers of the new spaceport. These new modes of flight operation – launch, sub-orbital, and re-entry – will be added to the current aviation needs matrix and cross linked to those weather hazards affecting each mode.
Other strategic approaches include continuing to work with aviation authorities worldwide to assist them in modernizing their aviation support services as RAL has done for the past fifteen years. RAL will also make a major effort to develop verification and validation techniques that provide a better evaluation of products from advanced weather systems.