The Braking Action of Deicing Fluid

[Chesty Morgan]

Today Manchester ATIS was giving "23R wet with deicing fluid" and it got me thinking.

Where do we stand with performance figures? All we can use is the wet perf. but is it really good enough, has a runway covered in deicing fluid got the same braking action as a runway wet with your bog standard water? Or is it close enough for us to not give a damn about?

Just curious really but I'd be interested in any comments or experience.

[Deep and fast]

Anyone know it's water equivilent depth?

D and F

[howflytrg]

some aircrews are using specially issued performance figures while MAN sort their act out. Other operators with certain ac types eg 145's have stopped their crews using 23R/05L and this is a real pain!!!!!! .......name me a runway in the uk which had to be de-iced today but did not have a single trace of rubber on it??? When will MAG sort it?? I've had enougth of backtracking 05 R and having to wait at least 30 mins to do so. :ugh:

[bushbolox]

Simple.
It doesnt have an equivalent depth because its wet.
The clue is in the word wet. Not slush , not snow, not equivalent anything , just wet.So the condition of the runway is wet. It may be wet due to icing fluid and not water but it is still classified as wet. Performance category wet etc etc etc.Its also grooved which could be dry in some books.
IE not contaminated.
Now if any of you run off the end in the next 3 or 4 months in your 145s due to this fluid please refer the judge to the term Runway wet and provide your lawyers with copies of the rlevant publications vis a vis runway category and classification for performance.
Not actualy pure rain water. Its still wet, there isnt a new category or contaminant here or there would be a runway state report with the depth and type of contaminant.

End of whinging.Now stop turning this industry into the Human rights act and get on with it.
As for a 145 limited at man because of a bit of fluid...do me a favour....:E:ok::}

[PEI_3721]

Re “23R wet with deicing fluid”
Does the message refer to runway deicing fluid, which should have known friction characteristics, or is it a warning that aircraft de icing fluid has been shed on the runway which could significantly decrease the friction at the ‘stop’ end?

If the former, and the friction approximates to wet, then how much ‘wet’; the friction equivalent of 2.9 mm of water may not be contaminated, but it does not contribute to good stopping performance.
Furthermore, as above, what are the characteristics of any fluid on top of rubber (runway slippery when wet?), and what are the characteristics of aircraft de icing fluid on top of runway de icing fluid, IIRC they are not the same chemically.

[Deep and fast]

Not off the end of the runway that bothers me bushbolox, it's off the side in a stonking crosswind!

I think JAR ops allows wet on a grooved runway to be considered dry, but only if your ops manual states so.

As for the wet question ie no eq depth would you want to land on a runway covered in oil! The contaminant is always a concern. I know I am taking it to the extreme but crews should never be in any doubt about perf or you will get slaughtered in the subsequent board of enquiry.

Manchester no prob but Aberdeen is a little more restrictive.

D and F :8

[TeachMe]

Chesty,

"bog standard water"

Why would anyone care about the friction co-efficient of some cheap perfume?

:E (sorry ... I had to...)

[fleecy]

howflytrg,

Was the limitation at MAN caused rather by the runway assessment:

'may be slippery when wet'?

This should appear on NOTAM. It's triggered when the minimum friction level drops below 0.5 using a Mu-Meter or 0.55 using a grip tester. It's up to the Operator to request further information from the Authority and promulgate to Aircrew. Until that info was given, restrictions may have had to be put in place.

Same thing happened at Heathrow a while back.

[Conan The Barber]

As this site now resides in the refuge of the Puritans, you should not be surprised.

I can only imagine the shock, horror and crosses being made when such ungodly language was discovered.

[tubby linton]

I operated into Man on the 10th and overheard the following conversations from numerous departing aircraft to ATC:
"AC xxxx-What is the braking action on 23R?
ATC-you will have to phone this number 0161xxx xxxxx for an answer."
Five minutes later-"AC xxxx Requesting 23L for departure."
The runway 23R was declared as wet with de-cing fluid on the atis and also as being slippery when wet.No braking actions were offered to landing aircraft.Should a braking action have been offered or was it not offered as it was unmeasurable on the slippery bits?

[PEI_3721]

Re “Should a braking action have been offered or was it not offered as it was unmeasurable on the slippery bits?”

We must be careful with terms and definitions associated with this subject:
ICAO ‘braking action’ is a description, and ranges from ‘Good’ to ‘Poor’, the US in particular has differing terms; all of these are associated with a measured runway friction.
The UK appears to use ‘runway braking action’ as being the friction measurement.

UK AIP AD1.1.1 states:-
15.8 When a runway is contaminated by water (ie more than 3 mm), wet snow or slush, a braking action report will not be available due to the limitations of existing friction measuring equipment …

Thus, the reported circumstances suggest that the aerodrome operator has interpreted the conditions as ‘contaminated’ (friction not measured or not reportable).

However, in ICAO terms a descriptive braking action could be given if available.
I suggest that an aerodrome operator would be reluctant to do this without a friction measurement. Therefore, all that might be available is a PIREP, which if available, might not be very reliable for take off depending on the location of the de-icing fluid and the ‘slippery when wet’ sections of the runway – rubber deposits?.

Overall, this suggests that operators should use contaminated performance data.
This might be the conclusion from additional information provided by the aerodrome operator (and how is that determined?) …, but its always the aircraft operator’s responsibility – the pilot’s responsibility!

[tubby linton]

The problem I have with this situation is that aircraft intending to depart 23R were invited to call a telephone number to an unspecified person to discuss what was the braking action on the runway.Aircraft landing did not have this option.Also the contamination was not caused by precipitation but by deliberate spraying of an un-specified de-icing fluid onto the runway surface.The aircraft that had called this number all elected to use 23L for departure.The airport operator should have cleaned 23Rof this contamination as precipitation was not forecast.This is probably the first time in my 25 years of flying that I have ever seen a runway deliberately contaminated!I would be interested to hear what the content of these telephone calls was.I heard a Monarch and a Cathay both being given this number.
The runway is notamed as being slippery when wet with precipitation of H2O in its various forms but its characteristics with it being covered in de-icing fluid is an area that has probably never been evaluated.The logic of spraying this runway must be called into question.It must also be asked if the rubber deposits on this runway are ever going to be cleared.
I was in a heavy jet so 23R is not particularly long if contaminated.I also question why an ILS was not insatlled on 23L when it was built.If we had slid off the end of 23R who should be blamed?Should it be me for landing on a sprayed runway that was slippery or the airport operator for spraying in the first place?
Does anybody know what type of fluid Manchester were using?