Runway friction testing

[West Coast]

All right all you cold WX guru's....

Is it common/allowed per ICAO to take one form of friction measurement and convert it to another via some formula? As an example convert readings derived from a Saab friction test into a MU or other type of reading for operators who may not be allowed per SOP to use the original method of testing?
Thanks

[call100]

As far as I am aware they all use the same standard. ICAO based.
In the UK you will no longer be given figures for friction tests. As they have been deemed unreliable in slush and wet snow. They are used now primarily for runway maintenance schedules.
See here....
http://www.stac.aviation-civile.gouv...ndfric_DP4.doc

[West Coast]

Interesting. How do you determine if you can depart with regard to braking effectiveness?

[Mad (Flt) Scientist]

Don't think there is a common standard.

See this discussion and especially the last post which quotes the JAA/EASA position as:

there is not, at present, a common friction index for all ground friction measuring devices. Hence it is not practicable at the present time to determine aeroplane performance on the basis of an internationally accepted friction index measured by ground friction devices.

[West Coast]

Does this preclude any type of reporting for preflight planning? Even something as subjective as a pilot report?

[call100]

No. You will be given a runway state. We can tell you what contaminants are present and an indication of the braking action i.e good, medium, poor, We will have done a test for our own peace of mind if possible and taken reports from pilots using the runway. The problem with slush and wet snow is that the figures gained from the friction testing equipment are not reliable.
Hope all this is helpfull...

[West Coast]

Thanks for the info.