thanks for the replies...
When I first saw it I thought (the same way as OZ DXB) that the snow will be up to 48 & 49 mm (0149) from 01mm up to 49mm.
But in the decoding tables I researched, I could not find 49 as a possible answer/number for the upper limit of snow rwy coverage.
tt Depth of deposit
00 = <1mm
01 = 1mm etc
thru’ to
90 = 90mm
91 = not used
92 = 10cm
93 = 15cm
94 = 20cm
95 = 25cm
96 = 30cm
97 = 35cm
98 = 40cm or more
99 = Runways non operational due snow or clearance
// = Not measurable or not significant
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so it has to be friction coefficient:
BB Friction coefficient / Braking action
28 = Friction coefficient 28%
35 = Friction coefficient 35%
or
91 = Braking action poor
92 = Braking action med/poor
93 = Braking action medium
94 = Braking action med/good
95 = Braking action good
99 = Figures unreliable
// = not reported e.g. runway closed
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My common sense would react as, "if I see a coefficient of friction of 0.49 (almost half) the the distances (TO and Landing) should be doubled.... well it is not like that... (I thought that my girlfriend was difficult to understand!) I guess I will have to review my atpl books about the coefficient of friction....
I have just looked at the Operational Procedures JAA book and I found another table....
In this case, a coefficient of friction of 0.49 means braking action is good,
> 0.40 is good. (or code 5)
0.39 - 0.36 is medium good (or code 4)
0.35 - 0.30 is medium (or code 3)
0.29 - 0.26 is medium poor (or code 2)
0.25 and below... is poor (or code 1)
reading unreliable (-) or (9)...
and the winner is: COEFFICIENT OF FRICTION!!
Now, due to my lack of experience in cold operations, I would appreciate if someone shares his/her own experience operating in contaminated runways.
Like how would you react on a poor coefficient of friction? company procedures, etc...
Thanks again...
Cheers,
AirGus.-