Friction coefficient
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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
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
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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
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
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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
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
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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
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
Last edited by easymoney; 8th Nov 2007 at 10:44.
Only half a speed-brake
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.
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.
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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.
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.
Last edited by easymoney; 8th Nov 2007 at 14:09.
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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.