Transitioning Turbulence Research Into Airline Operations

Commercial and general aviation aircraft frequently encounter unexpected atmospheric turbulence. These encounters often result in rerouting of flights, and though rarely fatal, can sometimes even result in serious injury to aircraft occupants. According to the Federal Aviation Administration (FAA), turbulence is the leading cause of injuries to passengers and flight attendants in non-fatal accidents.¹ During the years 1998-2013, US air carriers had 432 significant turbulence incidents or accidents, with 225 serious injuries.² In addition, the cost to air carriers of these injuries, equipment damage and maintenance/inspection, or rerouting is substantial.  Moreover, rerouting of flights due to reported or forecast turbulence can significantly reduce National Airspace System (NAS) capacity.

Beginning in the 1990’s, the FAA’s Aviation Weather Research Program (AWRP) began research efforts at the National Center for Atmospheric Research (NCAR) to improve turbulence forecasting and reporting capabilities within the NAS.  Along with a gridded turbulence forecast product, Graphical Turbulence Guidance (GTG), a turbulence detection and reporting algorithm was developed for use on commercial aircraft. This algorithm produces an aircraft-type independent metric, Eddy Dissipation Rate (EDR), which describes the turbulent state of the atmosphere, and is the International Civil Aviation Organization’s (ICAO) standard for turbulence reporting.

The challenge is transitioning this applied research into operations. While the GTG forecast product is successfully in operations on the National Weather Service’s (NWS) Aviation Digital Data Service (ADDS) and is widely available to the aviation community, the deployment of the EDR algorithm is more difficult for a variety of reasons. There are several commercial options in addition to the open source NCAR solution which requires the airline to do a business case analysis to include deployment costs and savings from the data use.

There are also questions associated with how to best utilize and control the data. Certainly, aviation weather forecasters and airline dispatchers can use it strategically on the ground during pre-flight planning. However, ideally the data should be available to crews in the flight deck for tactical use during flight operations. Various methods of collecting, managing, distributing and using the data are under evaluation.

In 2008, the FAA and Delta Air Lines (DAL) began a series of collaborative “Proof of Concept” demonstrations to evaluate different applications of the GTG and EDR data in flight operations. These demonstrations were highly successful, and DAL now has over 12,000 pilots using a specially-designed Weather Application on tablets in the flight deck. Benefits have been documented in the areas of cabin management, better flight routing decisions, reduced fuel burn and emissions, as well as improving passenger comfort.

The FAA continues to work to transition the EDR turbulence reporting program further into NAS operations with the development of an EDR Technical Transfer package (EDR TT). This package will allow interested airlines to join the EDR reporting program with minimal assistance from NCAR. Both DAL and The Boeing Company are helping to evaluate the EDR TT for installation on a variety of aircraft. The effort is showing great promise as a means to facilitate the expansion of the EDR reporting program, both in the United States and worldwide.

¹http://www.faa.gov/passengers/fly_safe/turbulence/

²NTSB Briefing presented at Turbulence Workshop, Washington DC, September 3, 2014.