ESDU 00018 is the third of a series of examples of the application of a method for representing - and@ if necessary@ relating - the braking performances of aircraft and ground-test machines in wet conditions. The method@ which is given in ESDU 99015@ is essentially statistical and implies there is a clearly-defined level of probability that can be deduced from test runs of an aircraft (or ground-test machine) in a given set of wetness conditions on a particular runway. If the runway macro-texture depth is known@ then the parameter that defines the variation of effective coefficient of braking friction in the given conditions can be readily calculated from a pre-determined Friction Data Base. The concept of a Friction Data Base is explained in ESDU 99015. This example uses data for the 'Mu-Meter' ground-test machine operating both on wetted runways and in self-wetting mode. The background to the tests is described@ the method of analysis is summarised and results are presented. Mu-Meter friction measurements are available from widely differing test series - to the extent that the suitability of the various results for use in predicting aircraft stopping performance can be assessed as a function of the ranges of runway wetness conditions used. The first example@ for an aircraft where an extensive set of data is available@ is given in ESDU 99016. The second example@ for an aircraft where only a limited set of data is available@ is given in ESDU 99017. If the method of ESDU 99015 is to be used to relate the braking performances of a given combination of aircraft and ground-test machine@ the procedure is comprised of two distinct phases. The first is the establishment of separate Friction Data Bases for the aircraft and for the ground-test machine. The second is to predict operational braking performance of the aircraft from day-to-day measurements from the ground-test machine.
ESDU 00018-2000 history
2010ESDU 00018-2010 Example of statistical analysis of wet runway friction: ground-test machine data
2000ESDU 00018-2000 Example of statistical analysis of wet runway friction: ground-test machine data.