A FIVE-YEAR TEST programme aimed at achieving a better understanding of how runway contaminants such as anti-icing fluid and slush can adversely affect aircraft stopping distances began in Canada on 15 January.
The first phase of the programme, which involves Transport Canada, the US Federal Aviation Administration and NASA, will assess several ground-friction measurement devices, and the performance of a Dassault Falcon 20 business jet on various contaminated runway surfaces. These tests, due to last for about ten days, will be carried out at North Bay, Ontario, as a prelude to a programme scheduled to stretch into the next century.
Four different friction instruments are being assessed in the initial tests: Transport Canada's electronic recording decelerometer; the Findlay Irvine GripTester; Norsemeter's Runar; and the Saab friction tester.
The team also aims to establish the contaminant drag and braking co-efficients for the Falcon 20, to compare the results with the theoretical data tables used by pilots. It is hoped that more accurate models of the effects of runway contaminants on continued or rejected take-off performance can be developed.
The Falcon 20, owned and operated by the National Research Council Canada, will be fitted with a wide range of instruments, including a differential global-positioning system for accurate position measurements.
The team had hoped to use a NASA-owned Boeing 737-100 or 757-200 for the tests, but it is understood these aircraft could not be dispatched because of adverse weather conditions across the eastern USA.
According to Al Mazur, chief of mechanical and energy management, safety and technical services - airports group, at Transport Canada, it is hoped that one of the NASA aircraft can be tested later, "in February or March".
The last such programme was carried out between 1983 and 1988, but NASA believes that additional testing is required for a variety of reasons:
better-instrumented test aircraft are available;
improved measurement procedures need to be evaluated;
new friction-measurement devices have been developed;
different anti- and de-icing fluids are in use;
additional water- and slush-drag data are needed by airframe manufacturers for new aircraft types.
NASA says that its participation in the North Bay tests forms part of a wider programme to study aircraft landing-gear systems, tyres, wheels and brakes, and to "...improve that hardware and find better ways for pilots to accomplish ground operations, including take-off and landing".
The US Air Force and Europe's Joint Aviation Authorities are also expected to participate in the programme as it continues.
Source: Flight International