munich jepp chart and atis question

[jagr]

Hi all,
I just operated to Munich. Have 2 questions to ask.

1. On the munich RNAV SID jepp chart, eg 10-3V7. the heading says RNAV SID(OVERLAY). What does the word OVERLAY mean? I thought we have to overlay 10-3Q5 to get all the necessary information but does not seem like the case. All the required information is already on 10-3V7

2. During departure, it was snowing. The ATIS reported medium braking action 26R 62 64 26L 53 54
What do the number 63 64 and 53 54 mean?
Me and my crew thought that it was the braking coefficient but we looked up the ICAO definition and those number represented good braking action.
And it certainly was not depth of deposits because it was only lightly snowing and the runway was only slightly contaminated and damp with de-icing fluids.

Any help would be much appreciated

[Denti]

The numbers are friction coefficients which are indeed in the "good" part of the scale. However friction tests are run infrequently (always check the time for it, its on the ATIS), the "medium" report could be from a pilot report, however to have conflicting information is somewhat weird. Normally they report three friction coefficients per runway, not two, as well.

Can't comment on the jepp pages since we use LIDO electronic maps for some time now instead of jepp tailored booklets, however from my understanding an RNAV SID (OVERLAY) is simply a SID defined by RNAV points that is an overlay to an existing conventional SID, depending on what kind of equipment is on board and noted on your ATC flightplan you will either get the RNAV or the conventional SID.

[BOAC]

jagr - heaven only knows what they mean! I complained for years about the different methods of measuring runway friction and that often you did not know which was being used. I think there are at least 5 different Mu measuring devices.

That report does not make a lot of sense to me and I would probably 'go' on the 'medium' bit of the report if I were inbound. I would be tempted to think they were using CFRI units, but less than 55 would be 'fair' and 'medium' does not exist on that scale. As Denti says, in the EU a reading of 64 is WELL above 'good' (as is 53) using mu-meter readings and 'Medium' does exist there! Confusing, or what?

I think the best thing you can do is to ask your Ops Department to find out from EDDM - I would be interested to hear the answer!