Mu Readings

[Coool Hand Luke]

What ever happened to the simple, good, fair, poor, nil? That's alot easier to understand than a bunch of numbers that really don't mean anything unless you have a magic box to disseminate them.

Actually, MU values are (supposed to be) only reported if MU values are 40 or below. If the ATCT also receives at braking action report(s) from pilots it/they are also given to subsequent landing aircraft. In other words: you get both reports. The more information the better if you ask me.

Personally I prefer MU reports to good, fair, poor or nil reports. As you know, no one wants to be the guy the shuts an airport down by reporting braking action as nil, so crew braking action reports are often under-reported. Not to mention the EMB-120 I fly stops much easier on a contaminated runway than the Citation VII that I also fly. In other words, a good report in the EMB-120 could be a poor in the Citation VII. With a Tapley Meter or SAAB or whatever, I know what I am dealing with and it takes aircraft tire condition, aircraft types, crew technique, etc. out of the equation.

 

[SDCFI]

The first time I encountered Mu reports was in Helena, MT of all places. I liked them for two reasons 1) If there's no pilot BA reports you might get one from an airport vehicle. Do you really trust Jim Bob in his pickup to give you an accurate indication of how your airplane is going to stop? The Mu reading is a calculated measure of runway friction, not someone's opinion. 2) You get 3 readings so you can anticipate your braking and plan your touchdown accordingly based on what part of the runway has the best braking action. I say bring 'em on.

 

[Coool Hand Luke]

The first time I encountered Mu reports was in Helena, MT of all places. I liked them for two reasons 1) If there's no pilot BA reports you might get one from an airport vehicle. Do you really trust Jim Bob in his pickup to give you an accurate indication of how your airplane is going to stop? The Mu reading is a calculated measure of runway friction, not someone's opinion. 2) You get 3 readings so you can anticipate your braking and plan your touchdown accordingly based on what part of the runway has the best braking action. I say bring 'em on.

Yes. It's also important to note that those three readings are actually averages from 9 separate readings (3 each in the touchdown, midpoint and rollout zones).

For example, airport operations conducts a braking action report and finds that the touchdown MU values are 35, 31 and 33 respectively for an average of 33. This will be reported as an overall touchdown MU value of 35 as the final averaged MU value is rounded to the nearest 0 or 5 (ie. 33 reported as 35, 32 reported as 30).

 

[RedGuy]

Yes, but I still think they could be reported in a simpler manner with good, fair, poor, nil. Rather than the numbers, that's just my opinion though and now it's not as bad since it's been explained alittle better.

 

[stupidpilot]

Yes, but I still think they could be reported in a simpler manner with good, fair, poor, nil. Rather than the numbers, that's just my opinion though and now it's not as bad since it's been explained alittle better.

Looking at all the possible ways for braking action reports(Mu, skiddometer,James-branke index, Decel Meters2 etc.) The overriding theme is the bigger the number the better the braking action. They are all very similar in how they report the braking action values except for the ICAO index which reports it in whole numbers.

 

[MauleSkinner]

Yes, but I still think they could be reported in a simpler manner with good, fair, poor, nil. Rather than the numbers, that's just my opinion though and now it's not as bad since it's been explained alittle better.

Would be perfectly adequate long as your AFM listed runway requirements as "a little", "some", "a fair amount", and "lots"

Fly safe!

David

 

[RedGuy]

:laugh: Why not, that's the way I classify them!:laugh: But Since my AFM doesn't have MU numbers either it really doesn't help much. Matter of fact since Basically all the A/C I fly were built before 1977 the AFM isn't exactly a wealth of information.

 

[Freight Dawg]

This may help

Can't post the braking chart, sorry. Won't import correctly.

 

[Propnose]

Deleted

 

[Propnose]

I just got two MU reports lastnight in KMHK and KOMA!