PDA

View Full Version : Damp/damp/damp


RMC
18th Sep 2008, 18:34
Can someone please confirm this needs to be reported on the ATIS. I was operating into a UK airfield recently. We had asked London info for the wx with an hour to go....got the ATIS as soon as it was within range ...neither mentioned the runway state.

I have always understood that no mention of runway state means it is dry.Had the aircraft been 10 % heavier we would have been outside the dry max landing weight. I asked approach to confirm the runway was dry...answer was Damp X 3! We diverted.

This runway has a history of being slippery and the C of F on a damp runway could have made the landing very interesting.

Sir George Cayley
18th Sep 2008, 20:28
If the runway was in the UK and at a certified airport and you had not received a NOTAM declaring that it "may be slippery when wet" then you may have diverted for no reason.

The airport has been windy in the past..........

Thunderstorms are a known problem here......

Damp in a number of states has no basis, try AMS. It is just visible staining of the surface.

Was the runway constructed of skid resistant material eg PFC, GMA or BBA?

What is its LDA and, for your mass, what was your LDAr?

What is the name of your Flight Ops Director and does he serve biscuits when he has a "chat" with you?

Good luck!

Sir George Cayley

G-SPOTs Lost
18th Sep 2008, 21:15
Is it not the case that a grooved runway when damp/damp/damp is considered dry for perf purposes.

Bristols runway used to be crap and very slippy

pelagic
18th Sep 2008, 22:58
I dont ever recall being asked to broadcast runway surface conditions on the ATIS other than when snow, ice or freezing fog were current weather conditions. With the UK weather as temperamental as it is, if I had to put "damp/damp/damp" out every time it actually was, then we'd never land or depart anything, cos the griptester would be permanently out on the runway!

BTW, we only broadcast runway surface conditions via ATIS when requested to by the Airport Operator (BAA).

sharpshooter41
19th Sep 2008, 07:06
Someone once told me that damp x 3 means that the R/W is divided into three portions and all the three are damp. However, I have not been able to get any written info. about it. Can anyone quote authority? I have heard this on ATIS at Manchester England.

Dani
19th Sep 2008, 07:19
It also depends on your company procedures.

All companies I know consider damp as dry for performance calculation, as long as there is no BC or BA (braking action or coefficient) is given. If ATC doesn't give you one of these two, you can safely assume that the BA is "good" and the BC is above 0.4.

It's something else if ATC tells you BC "unreliable", but mostly this is not because the runway is slippery, but because the BC is not measurable with the equipment given on the airport.

But it's also good to go on the safer side and do the divertion.

hth,
Dani

FLCH
19th Sep 2008, 11:53
Someone once told me that damp x 3 means that the R/W is divided into three portions and all the three are damp. However, I have not been able to get any written info. about it. Can anyone quote authority? I have heard this on ATIS at Manchester England.

I was under this impression too the sections were Touchdown/Mid/Rollout. I hope someone can clarify this. TIA

FullWings
19th Sep 2008, 15:10
In my book damp = dry for performance purposes, unless otherwise promulgated...

I did hear the runway being described as "moist" on approach to LGW once, accompanied by much schoolboy sniggering. :)

safetypee
19th Sep 2008, 15:46
Someone once told me that damp x 3 means that the R/W is divided into three portions and all the three are damp. However, I have not been able to get any written info. about it. Can anyone quote authority? I have heard this on ATIS at Manchester England.
See this in the UK AIP, para 15, “Runway Surface Condition Reporting“. (www.nats-uk.ead-it.com/aip/current/ad/EG_AD_1_1_en.pdf)