Therefore, in conditions of slush, or uncompacted snow, no plain language estimates of braking action derived from those readings shall be passed to pilots
The Mu meter is rubish in wet conditions, alle friction devices are. Norway outlawed the reporting of friction coefficient from all types of frition testers. Since last year the field maint dept. report to ATC using the Poor, poor-medium, medium etc scale. (1-5 scale) The guys doing the test can still use the friction tester, but have to apply common sense to the results, i.e do the numbers seem plausible, and then convert to the plain language "scale)
At Torp some years back the tester gave numbers in the mid 30s, even when the inspection vehicle had trouble keeping straight down the rwy. Aircraft ended up in the RESA. Slush and friction testers donīt mix.
In the same way they report worse than actual conditions on other occation, ex: Thin layer of dry snow on sanded ice. Friction tester spits out numbers in the low 20s. 737 reports BA med-good 2 minutes later.
A frition tester does not has the same properties as the tires of a 60T airliner.
The concept of not reporting anyting at all seems a bit "novel"
