For Release: March 15, 1996
Headquarters, Washington, DC
March 15, 1996
Langley Research Center, Hampton, VA
FAA Headquarters, Washington, DC
The safety of aircraft takeoffs and landings will be enhanced with the knowledge and operational procedures expected from a new study of winter runway friction now underway.
The five-year government/industry study, called the Joint Winter Runway Friction Measurement Program, is being led by NASA and Transport Canada with support from the Federal Aviation Administration (FAA). Also participating are organizations and equipment manufacturers from Europe and several Scandinavian countries.
The study will include braking tests with instrumented aircraft and ground vehicles in the U.S. and Canada. Results are expected to enhance safety for all ground operations and help relieve airport congestion during bad weather. Results also will help industry develop improved tire designs, better chemical treatments for snow and ice control, more reliable ground vehicle friction measuring systems and runway surfaces that minimize bad weather effects.
Flight crew recognition of less-than-acceptable reported runway friction conditions prior to the "go/no go" or the "land/go around" decision point is one of the near-term program goals.
NASA's B-737 research aircraft and Canada's National Research Council Falcon-20 aircraft completed a week-long series of landing tests earlier this month on ice-,snow- and slush-covered runways at the Jack Garland Airport in North Bay, Ontario, Canada, about 200 miles north of Toronto.
Surface conditions were artificially varied to expand the range of data collected. Many different runway friction-measuring ground vehicles -- vans, trailers and modified cars -- took readings with continuous and fixed slip devices under similar runway conditions for comparison with each other and with the braking performance of the two instrumented aircraft.
Winter runway evaluations also are planned at the Brunswick Naval Air Station, Maine. Water contamination studies are planned at NASA's Wallops Flight Facility, Wallops Island, VA, and the FAA Technical Center in New Jersey.
"Data from the program will be used to quantify exactly how much improvement has been made in measuring runway friction since we performed similar tests with the FAA a decade ago. We hope to learn enough over the course of the study to confidently recommend international guidelines for aircraft and airport ground operations in winter weather," said Thomas Yager, lead NASA engineer on the project.
Broad-based changes in the industry since the 1980s strongly suggested a follow-up to a NASA-FAA study conducted between 1983 and 1988. Improved measurement equipment, computer software and test procedures need to be evaluated. Data is also needed on new anti- and de-icing chemicals, water/slush drag effects on new aircraft types and tire construction effects on hydroplaning.
The study also was suggested by strong international support for developing a standardized set of guidelines for runway friction measurement and reporting. In spite of advances in technology and operational procedures, safe winter operations remain a challenge for airport operators, air traffic controllers, airlines and pilots who must coordinate their efforts under rapidly-changing weather conditions.
Complicating the winter weather picture is that criteria for safe operations on a given runway snow condition differ from airport to airport, due to differences in grooving and pavements. Obtaining data relating various winter runway friction numbers to aircraft stopping distance requirements would be a significant step toward the development and adoption of standardized guidelines or tables to be used by pilots.
NASA, the FAA and Transport Canada have cooperated in several ground vehicle
and instrumented aircraft studies aimed at improving aircraft ground performance in bad weather. NASA and the FAA worked together as early as the 1950s to establish early slush depth criteria for runway operations. A spin-off from later NASA aircraft hydroplaning studies resulted in the widespread practice of grooving automotive highways to improve tire traction during rainstorms.
In a modern spin-off application, much of the equipment being used to monitor runways is or will be used to measure highway pavement friction performance. In areas with high accident rates, pavement textures can be modified based on readings from ground friction measurement vehicles to improve the safety of automotive travel.
GET A GRIP. This runway traction test is part of a new study by NASA, Transport Canada and the FAA to enhance safety of airport ground operations and relieve airport congestion during bad winter weather. The five-winter study will include braking tests with ground vehicles and instrumented aircraft like this NASA B-737. This test took place on a snow-covered runway at Jack Garland Airport, North Bay, Ontario, Canada last week.
FOR AP DIRECT FROM NORTH BAY
GET A GRIP. NASA,Transport Canada and FAA researchers are taking advantage of winter snowfall in North Bay, Ontario to measure runway friction on slippery surfaces. Instrumented ground vehicles and aircraft like this NASA B-737 are being tested at Jack Garland Airport through Friday (Mar. 8). Results are expected to enhance safety and help relieve airport congestion during bad winter weather.
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