Friction coefficient
Hi Guys,
Most places use 91 92 93 etc for braking action. This METAR shows Eastern Europe apt, 18150060. Please could anybody direct me to a table or something to convert the friction coefficient to braking action. Many Thanks in advance BH |
It's MOTNE code - can't remember how to decode it but Google MOTNE and you'll get lots of help.
|
Hi!
The last two digits of the Motne code is decoded as below Friction coefficient: above 40 = BA Good 35-40 = BA Medium to good 30-35 = BA Medium 25-30 = BA Medium to poor below 20 = BA Poor And if I remember correctly 99 = BA Unreliable Regards DER |
Braking Action
For information the Code is 9 for Unreliable.
That was when I used to use this system, it may have changed |
First two digits: runway designator. Last two: BA.
|
Thanks a lot guys.
So how low would it have to get before you think about/ company ops manual says you should to be diverting? I know Ryanair/Easy have a lot of routes to Eastern europe. Does this cause any regular problems? Just trying to get a bit of a feel for winter ops over in this neck of the woods. Cheers |
Not allowed when the braking action is reported as Poor which is 0.25 friction co-efficient and below.
The MOTNE code for braking action is 91 Poor 92 Medium/Poor 93 Medium and so on. 99 is unreliable. All in the Ops manual Jepp Supplememnt and pre-amble. I would guess that the 60 at the end refers to a friction co-efficient of 0.60 and therefore Good. The rest of the code seems to follow MOTNE. Runway 18, Damp, 11% - 50%, Depth less than 1mm |
Just to make sure nothing gets lost in the translation:
Runway state messagge (referred to as MOTNE above) has the following options // - not reported, runway not operational 99 - unreliable measurement 00 to 90 - friction coefficient reported 91, 92, 93, 94, 95 - braking action reported 96 to 98 - not used Conversion from FC to BA for those who need to, correctly provided by Der_dk. Tmbstory and 738 Jockey not entirely correct. For BA/FC limits (and associated cross-wind contraints!!!) use appropriate FCOM or company manuals if more restrictive. For instance LDG on poor is normally prohibited, but lading on FC 20-25 could be allowed. OTOH many realise that there is no reliable corelation between reported deceleartion measurement and ad hoc aircraft behaviour. So, for TKOF performance some only use type of deposit and depth. Sometimes the BA/FC is not reported at all in order not to provide false and liable assumtions to operators - which I understand is UK CAA stance now. I am standing by to be soon corrected on this one. :) FD. |
From the Jeppy Supplement book.
The seventh and Eighth Digits Refer to Quote from jeppy supplement. "The friction co-efficient is denoted by two digits or, if the co-efficient is not available, the braking action is denoted the two digits. So the last two digits will be in this case 60 which equal a co-eff of 0.60. or if co-eff not available the Braking action will be reported. 95 Good 94 Medium/Good 93 Medium 92 Medium/Poor 91 Poor 99 Unreliable // Not reported AD closed So do whatever your company ops manual states. You are also correct in stating the 9 refers to unreliable......if it's referenced in a snotam. But MOTNE use 99 for unreliable. |
OTOH many realise that there is no reliable corelation between reported deceleartion measurement and ad hoc aircraft behaviour. So, for TKOF performance some only use type of deposit and depth. Sometimes the BA/FC is not reported at all in order not to provide false and liable assumtions to operators - which I understand is UK CAA stance now. I am standing by to be soon corrected on this one. :) Hope it helps.. http://www.stac.aviation-civile.gouv.fr/aoswg/Proposedamendfric_DP4.doc. |
All times are GMT. The time now is 19:26. |
Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.