Turbulence Research and Development
Figure 1. Experimental ADDS Web-based display showing in situ turbulence reports overlaid on contours of the Graphical Turbulence Guidance (GTG) turbulence forecast product.
Encounters with turbulence for commercial and general aviation aircraft pose significant safety, efficiency and workload issues. NTSB estimates that turbulence accounts for approximately 71% of all weather-related accidents and incidents involving aviation, and the cost to U.S. airlines due to injuries , cabin and aircraft damage, flight delays, and time lost to inspection and maintenance is substantial, with estimates in the $150-$500 million/year range. In order to help reduce the number and severity of turbulence encounters and the impact of turbulence on the NAS, RAL scientists are working on improving the detection and forecasting of turbulence and providing operationally useful products directly to users. This work is funded by the FAA’s Aviation Weather Research Program Turbulence Product Development Team (TPDT), and is augmented by NASA’s Advanced Satellite Aviation-weather Products (ASAP) program and the Boeing Corporation.
FY06 Accomplishments:
An automated quality control algorithm for the in-situ turbulence reports has been developed and implemented. These reports are now displayed on an Experimental ADDS website, and are used by meteorologists and dispatchers at United Airlines (see Figure 1). The Graphical Turbulence Guidance 2 product was approved as an experimental product by the Aviation Weather Technology Transfer (AWTT) Board in November 2004, and displays are available on the Experimental ADDS web site (www.weather.aero). Approval as an operational product is expected in Nov. 2006 with implementation on Operational ADDS in 2008. A real-time demonstration of the NEXRAD Turbulence Detection Algorithm (NTDA) was performed using data from 24 WSR-88D radars in the upper Midwest. A 4-D graphical product was made available to meteorologists and dispatchers via a web-based Java display, and a customized text-based graphic of in-cloud turbulence ahead was uplinked to select United Airlines aircraft (see Figure 2).
Figure 2. Left: Web-based Java display of mosaicked in-cloud turbulence detected by the NTDA operating on data from 24 radars in the upper Midwest to Northeast with overlaid aircraft tracks depicting in situ turbulence reports. Right: A sample text-based graphic generated for the cockpit uplink demonstration, showing a vertical cross-section and plan view of NTDA in-cloud turbulence detected ahead of the aircraft. (click on images to enlarge)
FY07 Plans.
The in-situ turbulence detection and reporting system will be deployed on approximately 400 aircraft operated by Southwest Airlines. Depending on funding, the in-situ algorithm may also be prototyped for selected Delta Airlines' and Northwest Airlines' aircraft. The NTDA will likely be approved and begin the transition to deployment on the nation's NEXRAD network; expanded uplink demonstrations to selected United Airlines' aircraft are also planned. Continued research and development on the mechanisms of near-cloud turbulence will continue, with emphasis on case studies to identify the turbulence-generating processes. The ultimate goal is to develop a set of rules that relate observable features of clouds to the likelihood of turbulence above or adjacent to them.