CAA disallowing braking action reports?
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CAA disallowing braking action reports?
Hi Guys
I was flying to Inverness today. On noticing the Braking action was // in my pre flight material I rang the tower assistant to ask what the braking action was. He informed me they don't give a braking action now as the CAA has told them not to.
Is this a new policy that I have missed? My departure airport was publishing it's braking action as were all my alternates.
Any thoughts gratefully received.
Thanks
I was flying to Inverness today. On noticing the Braking action was // in my pre flight material I rang the tower assistant to ask what the braking action was. He informed me they don't give a braking action now as the CAA has told them not to.
Is this a new policy that I have missed? My departure airport was publishing it's braking action as were all my alternates.
Any thoughts gratefully received.
Thanks
niknak
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It's the policy of many UK Airports now.
Your airline / operations department is clearly deficient in not establishing the facts on your behalf.
Braking action will not be reported when the surface contamination is wet or slush at any UK airport.
Your airline / operations department is clearly deficient in not establishing the facts on your behalf.
Braking action will not be reported when the surface contamination is wet or slush at any UK airport.
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Here's what the instructions to controllers say (and remember that all ATC does is to pass on information from the aerodrome operator):
If it's all true - and I've spoken to experts who assure me that it is - it seems sensible to me. I can understand that it may be frustrating for pilots but surely it's preferable to being given misleading information and finding yourself explaining to the Chief Pilot why you left an aeroplane on the snow off the end of the runway. And I seem to recall a number of such instances last winter around Europe.
Assessment of Braking Action
Friction tests should be made over the usable length of the runway at approximately 3 metres each side of the runway centreline. Where time does not permit this, measurements on each side of the centreline will suffice. Values for each third of the runway are to be notified in the SNOWTAM; for METAR reporting a single mean value for the whole available length should be calculated. When reports of braking action are passed to pilots via the RTF, they should be in plain language, as detailed in the middle column of the Snow and Ice Table below; and, an assessment given sequentially for each third of the runway to be used. For Example, “Estimated braking action for runway 23 is: poor, medium poor, poor”.
In conditions of slush or thin deposits of wet snow, friction measuring devices can produce inaccurate readings. The Snow and Ice Table below applies only in conditions of compacted snow or ice. Therefore, in conditions of slush, or uncompacted snow, no plain language estimates of braking action derived from those readings shall be passed to pilots. In this case, pilots shall be informed on the RTF that measurements of co-efficients of friction are unreliable in conditions of slush or thin deposits of wet snow and, consequently, braking action assessments are not available. For readings obtained under these conditions, the code number 99 shall be used in the SNOWTAM and METAR message.
The Snow and Ice Table below shows the estimated braking action of a runway against coefficient of friction when used on surfaces contaminated with compacted snow or ice. Specific numerical values are necessarily governed by the design, construction and operation of each individual type of instrument as well as the surface being tested. It follows that different devices produce different numbers for the same conditions. However, it has been shown that sufficient correlation exists between the various measuring devices used in wintry conditions for a common table of estimated braking actions to be used.
Random very high or very low friction readings may be ignored when calculating the average values. Assessment of stopway braking action should be made available on request where possible.
SNOW AND ICE TABLE
Measured or calculated co-ef of friction Estimated braking action MOTNE METAR Code
0.40 and above Good 95
0.39 - 0.36 Medium/Good 94
0.35 - 0.30 Medium 93
0.29 - 0.26 Medium/Poor 92
0.25 and below Poor 91
If for any reason the reading - 99
is considered unreliable.
Due to the possibility of deterioration between the time of friction assessment and subsequent aircraft operations, the completion time of the test runs should be reported together with estimated braking action assessment. This will enable the pilot to relate the information to the current situation. Ice patches present a particularly difficult condition when using a spot reading decelerometer; it will be evident that very misleading figures can be obtained from tests made on a surface covered with ice patches.
The word 'good' is used in a comparative sense and is intended to mean that generally, but not specifically, aircraft should not experience undue directional control or braking difficulties, but clearly a surface affected by ice and/or snow is not as good as a clean dry runway. However, it should be noted that a clean, dry runway almost certainly produces greater friction than is actually needed. 'Poor' will almost invariably mean that conditions are extremely slippery and probably only acceptable to aircraft needing to use little or no braking or steering. The intermediate values of 'medium/good' and 'medium/poor' have been included only to try to amplify the description when conditions are found to be medium, as the technique is too refined to be able to discriminate accurately in the narrow numerical bands as set out in the table.
The description 'good' must not be used for braking action on untreated ice but may be used, where appropriate, when ice has been gritted.
Under no circumstances is the word 'normal' to be used in describing braking action.
Friction tests should be made over the usable length of the runway at approximately 3 metres each side of the runway centreline. Where time does not permit this, measurements on each side of the centreline will suffice. Values for each third of the runway are to be notified in the SNOWTAM; for METAR reporting a single mean value for the whole available length should be calculated. When reports of braking action are passed to pilots via the RTF, they should be in plain language, as detailed in the middle column of the Snow and Ice Table below; and, an assessment given sequentially for each third of the runway to be used. For Example, “Estimated braking action for runway 23 is: poor, medium poor, poor”.
In conditions of slush or thin deposits of wet snow, friction measuring devices can produce inaccurate readings. The Snow and Ice Table below applies only in conditions of compacted snow or ice. Therefore, in conditions of slush, or uncompacted snow, no plain language estimates of braking action derived from those readings shall be passed to pilots. In this case, pilots shall be informed on the RTF that measurements of co-efficients of friction are unreliable in conditions of slush or thin deposits of wet snow and, consequently, braking action assessments are not available. For readings obtained under these conditions, the code number 99 shall be used in the SNOWTAM and METAR message.
The Snow and Ice Table below shows the estimated braking action of a runway against coefficient of friction when used on surfaces contaminated with compacted snow or ice. Specific numerical values are necessarily governed by the design, construction and operation of each individual type of instrument as well as the surface being tested. It follows that different devices produce different numbers for the same conditions. However, it has been shown that sufficient correlation exists between the various measuring devices used in wintry conditions for a common table of estimated braking actions to be used.
Random very high or very low friction readings may be ignored when calculating the average values. Assessment of stopway braking action should be made available on request where possible.
SNOW AND ICE TABLE
Measured or calculated co-ef of friction Estimated braking action MOTNE METAR Code
0.40 and above Good 95
0.39 - 0.36 Medium/Good 94
0.35 - 0.30 Medium 93
0.29 - 0.26 Medium/Poor 92
0.25 and below Poor 91
If for any reason the reading - 99
is considered unreliable.
Due to the possibility of deterioration between the time of friction assessment and subsequent aircraft operations, the completion time of the test runs should be reported together with estimated braking action assessment. This will enable the pilot to relate the information to the current situation. Ice patches present a particularly difficult condition when using a spot reading decelerometer; it will be evident that very misleading figures can be obtained from tests made on a surface covered with ice patches.
The word 'good' is used in a comparative sense and is intended to mean that generally, but not specifically, aircraft should not experience undue directional control or braking difficulties, but clearly a surface affected by ice and/or snow is not as good as a clean dry runway. However, it should be noted that a clean, dry runway almost certainly produces greater friction than is actually needed. 'Poor' will almost invariably mean that conditions are extremely slippery and probably only acceptable to aircraft needing to use little or no braking or steering. The intermediate values of 'medium/good' and 'medium/poor' have been included only to try to amplify the description when conditions are found to be medium, as the technique is too refined to be able to discriminate accurately in the narrow numerical bands as set out in the table.
The description 'good' must not be used for braking action on untreated ice but may be used, where appropriate, when ice has been gritted.
Under no circumstances is the word 'normal' to be used in describing braking action.
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Are there definitions of what constitutes "Compacted Snow" as opposed to "Dry Snow"? (We used to be able to give braking action reports for dry snow, bit this seems to have been dropped out of the CAA missives recently).
CAA seem to think that all aircraft must operate to a black-top runway - yes this is the ideal, but many airports cannot clear the runways to this, may not be allowed/able to de-ice runways etc. Many pilots are capable of landing on snow covered runways, particularly of small aircraft on long runways, but they are caught up in this 'thou shall not fly because braking action shall not be measured or passed'
CAA raises importance of giving good timely information to pilots, but then says you must not report braking action, give '//'. How is this giving more information to pilots??
Also what is the definition of a CFME?
CAA seem to think that all aircraft must operate to a black-top runway - yes this is the ideal, but many airports cannot clear the runways to this, may not be allowed/able to de-ice runways etc. Many pilots are capable of landing on snow covered runways, particularly of small aircraft on long runways, but they are caught up in this 'thou shall not fly because braking action shall not be measured or passed'
CAA raises importance of giving good timely information to pilots, but then says you must not report braking action, give '//'. How is this giving more information to pilots??
Also what is the definition of a CFME?
Last edited by Red Four; 20th Dec 2010 at 21:55.
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Silverknapper,
with respect, this 'issue' of no braking action reports (in slush and/or wet snow) is NOT new. It has been CAA policy since at least 2001 and they reissue the advice every year by FODCOM. Still, every winter we (UK ATC) get exclamations of astonishment from pilots when told 'no figures'.
DD
with respect, this 'issue' of no braking action reports (in slush and/or wet snow) is NOT new. It has been CAA policy since at least 2001 and they reissue the advice every year by FODCOM. Still, every winter we (UK ATC) get exclamations of astonishment from pilots when told 'no figures'.
DD
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I understand the issues regarding the slush case. Perhaps I didn't put my initial point across well. I am familiar with the relevant FODCOM's, in particular the recent 27/10. I can't see the case for not giving a reading on a surface of compacted or dry snow. Having operated frequently in Scandinavia and the Nordic region there is usually always a friction report, allowing operations to continue in perfectly safe conditions. With a blanket ban on friction readings in any conditions surely we are missing the opportunity to keep operating in conditions which are considered the norm in many countries. Having been passed a reading on departure today we were in a position to make an informed decision regarding our ability to depart or not.
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Silverknapper,
thanks for the clarification:
Agree!
A quick and random sample of UK airports AIP entries (including other HIAL Airports) is possibly revealing - most state : 'Braking assessment by....' (Mu-meter/grip tester etc) under those airports AD2.7 Seasonal Availability sections.
However, Inverness does not have this - is it possible they do not have friction measuring equipment? Difficult to believe but.....
DD
thanks for the clarification:
I can't see the case for not giving a reading on a surface of compacted or dry snow.
A quick and random sample of UK airports AIP entries (including other HIAL Airports) is possibly revealing - most state : 'Braking assessment by....' (Mu-meter/grip tester etc) under those airports AD2.7 Seasonal Availability sections.
However, Inverness does not have this - is it possible they do not have friction measuring equipment? Difficult to believe but.....
DD
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The issue with friction reports has been high on the agenda with the Norwegian CAA the last 5 years as well, because incidents have shown that friction measuring equipment have some limitations in certain conditions.
(To simplify: They generally show too high friction in some wet contaminations and to low frction in some dry contaminations)
The result is that Mu numbers are no longer reported to eighter a/c or ATC from the airfield ops. To accomodate for the inaccuracies in the BV-11 and Saab friction testers (As well as the useless GRT) the 1-5 scale is used, in other words reported in plain language as Poor to Good via the normal increments.
RWY inspection personell are not allowed to use numbers from the friction testers alone, but have to do a "reality check" on the condtions as well before creating the snowtam.
(Some years ago My Travel went off the end at ENTO/Torp, friction on slush or some such was reported medium, the RWY was so slippery the inspection vehicle could not keep straight when driving down the centerline......had the operator put a tiny bit of common sense into the equation......)
As of this winter just about all airports in Norway with IFR ops will generate the snowtam from the inspection veihicle via 3G or WLAN, directly onto AFTN and ATS displays, which in turn automaticly utdates ATIS for the relevant airfield. Giving the inspection crew total ownership of the reporting have drastically improved the accuracy.......no middle man to blame any more.
(To simplify: They generally show too high friction in some wet contaminations and to low frction in some dry contaminations)
The result is that Mu numbers are no longer reported to eighter a/c or ATC from the airfield ops. To accomodate for the inaccuracies in the BV-11 and Saab friction testers (As well as the useless GRT) the 1-5 scale is used, in other words reported in plain language as Poor to Good via the normal increments.
RWY inspection personell are not allowed to use numbers from the friction testers alone, but have to do a "reality check" on the condtions as well before creating the snowtam.
(Some years ago My Travel went off the end at ENTO/Torp, friction on slush or some such was reported medium, the RWY was so slippery the inspection vehicle could not keep straight when driving down the centerline......had the operator put a tiny bit of common sense into the equation......)
As of this winter just about all airports in Norway with IFR ops will generate the snowtam from the inspection veihicle via 3G or WLAN, directly onto AFTN and ATS displays, which in turn automaticly utdates ATIS for the relevant airfield. Giving the inspection crew total ownership of the reporting have drastically improved the accuracy.......no middle man to blame any more.
CFME = Continuous Friction Measuring Equipment.
The primary purpose of CFME is the ongoing monitoring of the runway condition [wearing of the friction surface and rubber build up].
As mentioned above the rules which originated with ICAO and were implemented by the UK CAA in 2001 have been documented in ATC, Aerodrome, Flight Ops and AIS publications since that date.
Nothing new here! Catch up you boys!!
Merry Christmas
Helen
The primary purpose of CFME is the ongoing monitoring of the runway condition [wearing of the friction surface and rubber build up].
As mentioned above the rules which originated with ICAO and were implemented by the UK CAA in 2001 have been documented in ATC, Aerodrome, Flight Ops and AIS publications since that date.
Nothing new here! Catch up you boys!!
Merry Christmas
Helen
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SNOTAMS and Runway State messages in the UK are totally useless as they are either out of date or contain no useful information. CAP 493 Supplementary Instruction Number 2010/07 rams this point home. Basically says if the runway is in anyway contaminated, you will NOT be given a braking action and you are on your own. In the UK, the only reliable figures you can use are those for Wet or Dry runways and if these don't apply, don't fly.
Unfortunately, the only information really required is the braking action for runway length and crosswind limitation - and the only thing NOT given is... So the best thing you could do is suggest that you've got the airport manager's wife and kids down the back and you intend landing. If it's crap braking action, the runway will quickly become unavailable - unless of course he is greatly despised.
It would make sense to me if UK airports actually had the ability to determine Braking Actions on contaminated runways - it's done over the rest of EASA land, so how about a bit of action on the Third World island?
PM
Unfortunately, the only information really required is the braking action for runway length and crosswind limitation - and the only thing NOT given is... So the best thing you could do is suggest that you've got the airport manager's wife and kids down the back and you intend landing. If it's crap braking action, the runway will quickly become unavailable - unless of course he is greatly despised.
It would make sense to me if UK airports actually had the ability to determine Braking Actions on contaminated runways - it's done over the rest of EASA land, so how about a bit of action on the Third World island?
PM
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Goodday guys
I'm an ATC in Mongolia. I really appreciate with your posts. I have no idea about controller's action when the braking action reported "poor". May i ask pilot's intention land or to proceeding current approach?
Who will decide to landing on the slippery runways with and lower than 0.25?
I'm an ATC in Mongolia. I really appreciate with your posts. I have no idea about controller's action when the braking action reported "poor". May i ask pilot's intention land or to proceeding current approach?
Who will decide to landing on the slippery runways with and lower than 0.25?
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Goodday Sir
I have no idea about controller's action when the braking action reported "poor".
May i ask pilot's intention land or to proceeding current approach?
Who will decide to landing on the slippery runways with and lower than Mu-0.25?
I have no idea about controller's action when the braking action reported "poor".
May i ask pilot's intention land or to proceeding current approach?
Who will decide to landing on the slippery runways with and lower than Mu-0.25?
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One needs to have the airports open to give braking action reports, after last Winters shambles in the UK there seems to be no need at all for such reports! Sounds more like "If we say nothing then we are not responsible for anything which may happen" than any logic based decision.
