of Runway Friction Testing The Why and How of Runway Friction Testing by Delia Harverson Findlay Irvine Ltd. Midlothian, Scotland and Thomas J. Yager NASA Langley Research Center Hampton, VA, USA Part 1: A Brief History
runway friction testing: history What were the first Continuous reading Friction Measuring Equipments [CFMEs] ? When were they introduced
The first CFME was the Skiddometer designed in Sweden in the late 1950s
the second CFME was the designed by the UK Ministry of Defence in the early 1960s
Why were these early CFMEs developed? 1962: a Canberra lands on a winter contaminated runway ...
The first CFMEs were developed mainly for testing in winter conditions … and comes safely to a stop The first CFMEs were developed mainly for testing in winter conditions
After the Skiddometer and the MuMeter came the Saab Friction Tester which was also originally designed to measure in winter conditions
Later CFMEs were designed as much for maintenance testing as for operational testing
Is it as important to measure runway friction in summer as in winter? question Is it as important to measure runway friction in summer as in winter? YES! In rain, a runway with poor texture and rubber deposits can be just as slippery as a runway contaminated with ice and snow
An accident waiting to happen …
Most of these accidents need never have happened another question Are there more overrun accidents on wet runways or on runways contaminated with ice and snow? There are substantially more overrun accidents on wet runways Most of these accidents need never have happened
runway friction testing Nothing will guarantee that an overrun accident won’t happen at your airport … … but regular use of an approved, well maintained CFME will make it less likely
operational & maintenance testing Operational testing is carried out in natural conditions, in winter, in order to make immediate operational decisions. Maintenance testing is carried out in carefully controlled conditions, which include an exact amount of water put down in front of the measuring wheel, in order to make engineering decisions.
operational & maintenance testing Should engineering decisions ever be made on the basis of operational testing? No! Natural conditions are much too variable to provide a proper basis for engineering decisions
runway friction testing How do we ensure that maintenance friction testing is consistent … … that the same results are obtained in Lima as in London Heathrow? … in Santa Cruz as in Singapore?
runway friction testing For this, the international community depends on ICAO
runway friction testing Before we get onto ICAO’s role, two quick words about the lunch-box test … Forget it!