Runway friction testing - Articles and news items
Airport news • 15 July 2015 • Waterblasting Technologies
Every time an airplane lands, it deposits about a pound to a pound and a half of rubber on the runway. When the rubber accumulates it doesn’t just make black marks on the surface, it begins to reduce the friction needed for safe aircraft landings...
Issue 3 2015 • 2 June 2015 • Frank B Holt
As part of ASTM International Committee E17’s ongoing work to understand and develop standards for friction testing, former Chairman Frank B Holt describes the challenges and the progress being made to harmonise the measurement process across a range of devices...
Issue 6 2014 • 8 December 2014 • Belkacem Laïmouche, French Civil Aviation Technical Center
To ensure airfield safety, aerodromes should work towards a more overall pavement surface friction characteristic assessment, says Belkacem Laïmouche, Head of the Airfield Pavements Subdivision at the French Civil Aviation Technical Center...
Issue 6 2013 • 19 December 2013 • Jonathan Gerthoffert, Head of the Runway Friction Research Program at the French Civil Aviation Technical Center and Belkacem Laïmouche, Head of the Expertise of Airfield Pavements subdivision at the Civil Aviation Technical Center
Runway friction measurements are essential to airfield safety. Jonathan Gerthoffert and Belkacem Laïmouche profile the Civil Aviation Technical Center’s work into the reliability of testing methods...
Issue 2 2013 • 4 April 2013 • Paul Fraser-Bennison, Policy and Strategy Officer for Aerodrome and Air Traffic Standards, UK Civil Aviation Authority (CAA)
Paul Fraser-Bennison, Policy and Strategy Officer for Aerodrome and Air Traffic Standards at the UK Civil Aviation Authority (CAA) assesses the CAA’s latest winter operations trialAirline operators require information about factors which affect their aircraft take-off and landing performance. Much of this is readily available; the runway length; the height above sea level; the air temperature and pressure on the day; and local weather conditions. However, what is difficult to provide is an indication of how well the runway surface will perform if contaminated. When precipitation falls as snow, sleet or rain heavy enough for deposits more than 3mm deep a runway is termed ‘contaminated’ and revised performance calculations have to be used.
Issue 6 2012 • 6 December 2012 • Jonathan Gerthoffert, Programme Officer, Civil Aviation Technical Centre (France)
Certification of runway friction measuring devices is a strong commitment of the French State for the safety of aircraft operations. It ensures airport operators that devices meet the requirements in their ability to discriminate surfaces with different friction levels and their performances, and are consistent in terms of repeatability and reproducibility. It also makes measurements between different airports and service providers comparable, and ensures a uniform comprehension of the regulatory minimum friction level.The International Civil Aviation Organisation (ICAO) standards require runways to be maintained to be able to provide good friction characteristics. Self-wetting continuous friction measuring equipment is the most widely used tool to measure runway surface characteristics. However, devicedependency of results and complexity of measuring systems require regular device quality controls. Since 2006, quality controls have been carried out by the French State as part of a certification process on friction measuring devices used for maintenance purposes.
Issue 6 2011 • 8 December 2011 • Armann Norheim, Leader of the ICAO Friction Task Force (FTF)
The history of the world includes many well known inventions which have had a significant influence on technological developments. One of these is the Dynamometer, a device used for measuring force, moment of force (torque) and power. Dynamometers have been a vital and necessary component in instruments that can identify the friction developed between a tyre and the surface it acts upon.The principle used is an invention that is nearly 450 years old. The instrument indicates weight or pressure by making use of Hookes law1 of elasticity which states that “the extension of a spring is in direct proportion with the load applied to it”. In this article we will look into the history of tractive resistance within the transportation sector up to the advent of the jet aircraft. France, 1798Long before the birth of aviation, in the early 1780s Edme Régnier started the development of what came to be known as The Régnier Dynamometer2. Régnier was encouraged by two naturalists (Buffon and Guéneau of Montbelliard) who desired a device by which a man’s strength would be rendered comparable to that of another. The French revolution came, Buffon and Guéneau died and Régnier became inspector of the manufacture of portable arms. In 1796 the physician Coulomb urged Régnier to resume his work in view of the developing industry. Régnier’s Description et usage du Dynamomtre appeared in 1798.
Issue 3 2011 • 10 June 2011 • Armann Norheim, Leader of the IATA Friction Task Force (FTF)
In railroad engineering, the factor of adhesion of a locomotive is the weight on the driving wheels divided by the ‘starting tractive effort’. Adding extra power serves no purpose since there is not enough traction (adhesion, friction) to create useful work. The factor of adhesion which is 25% of the weight on drivers, corresponds to the co-efficiency of friction for steel-on-steel with an oxide surface film of μ = 0.25.Within aviation we are constantly in search of the ‘stopping tractive effort’. The term ‘braking action’ has been used to describe this. It is not an accurate description since its use is not consistent. In the U.S. the term relates to the pilot reports only, within ICAO it has been used for both pilot reports and the reporting of runway surface conditions. A letter is due to be sent out to American States requesting feedback on the subject. In due course, this may result in changes across all levels.
Issue 1 2011 • 26 January 2011 • Frank Holt, ASTM International Committee Member
ASTM International is one of the largest voluntary standards development organisations in the world-a trusted source for technical standards for materials, products, systems, and services. Known for their high technical quality and market relevancy, ASTM International standards have an important role in the information infrastructure that guides design, manufacturing and trade in the global economy.ASTM Committee E17 on Vehicle-Pavement Systems formed in 1960 to bring together many of the worlds experts in friction and develop standards for data collection, equipment design and data analysis. In December 2010 E17 celebrated its 50th anniversary at its meeting in New Orleans. The Committee celebration was attended by one of the founders of the original committee, Mr. William Goodwin, who served as a Chairman of E17 and also as Chairman of ASTM.
Issue 2 2010 • 5 April 2010 • Fredrik Nilsson, Airport Engineer, LFV Group
There are many parameters that have an impact on the aircraft traffic at an airport. Wind and runway conditions are some of the parameters needed for the pilot to calculate if he or she can take off or land at an airport. The friction value is one of the parameters used.
ASTM International is one of the largest voluntary standards development organisations in the world. It is a trusted source for technical standards for materials, products, systems and services. Known for their high technical quality and market relevancy, ASTM International standards have an important role in the information infrastructure that guides design, manufacturing and trade in the global economy.
Reporting the conditions of the critical tyre/surface in a way relevant to aircraft performance has been a long sought goal. There have been a lot of challenges for the aviation industry since the first reporting systems emerged and the regulating bodies have their role to play in achieving the goal for a global reporting system. Key players in such a reporting system are the airport ground staff collecting the information and making the assessment and the pilots making judgements based on the information given. The main regulating bodies (ICAO, FAA, and EASA) have several initiatives ongoing addressing these topics.
With today's technology, the measurement of ‘friction' can be readily and accurately determined whether it be in a vehicle engine, wheel bearing, or of more immediate attention, the interface between a moving vehicle tire and the travelled pavement surface. In regards to ground vehicle and aircraft operations, the problem is not one of accuracy but one of timeliness. Mother Nature can change a dry, high friction pavement surface into an icy, low friction surface in a matter of minutes. The ground vehicle runway friction value measured 30 minutes earlier may have no relevancy to current pavement friction conditions. Hence the importance of giving pilots the time of the friction measurement as well as the actual value.
ASTM International is one of the largest voluntary standards development organisations in the world, a trusted source for technical standards for materials, products, systems and services. Known for their high technical quality and market relevancy, ASTM International standards have an important role in the information infrastructure that guides design, manufacturing and trade in the global economy.
The IFPA was created to focus beyond engineering and manufacturing, and bring in representation as we have done with our Board of Directors: someone from the airlines (Southwest) with a pilot's perspective; someone from the manufacturing side (Boeing); and others to begin looking at runway friction testing, from the end-users’ perspective. An initial goal is to host next spring, at a new testing facility, a workshop for industry to begin working through issues and exploring standardised friction testing practices.