Righteo, so, given all of this knowledge, I'm assuming that you blokes (Curtain & 73 ) would have not departed Perth, or Diverted to an applicable Alternate?
I have no idea what I would have done in the Newman situation because I don’t know anything about it. For all I know it wasn’t even raining when they touched down and a technical failure reduced braking effectiveness. All I’m saying is that the information Curtain posted is very important, potentially life saving information and if you are charged with the responsibility of keeping the flight safe then it is worth your time to read it and think about how you will apply it in a practical sense.
My experience is that I have always departed when dispatch criteria have been met but always plan the fuel to hold or divert if heavy rain is possible. I’ve held several times until the rain has eased at major ports but have yet to divert due heavy rain. My interpretation of all the info available only matters on my flights though. What is important to you and your passengers is your interpretation of it. If it was not subjective your OPT could decide ‘land’ or ‘don’t land’, but it is subjective and the decision is a human one.
Fair call, but what's your cut-off criteria for RF then?
I’m fortunate in that I’m comfortable with what my company has decided regarding RF.
Perhaps you have some applicable weather procedure or criteria to derive your Contaminated RWY no-go from the METAR alone?
No I don’t, ( you could develop one if you wanted). I use a combination of info from the metar, atis, and conversations with the Tower Controller and my own knowledge of the runway to be used.
I'm not trying to be recalcitrant, but if you have a workable method of ascertaining Contamination levels and braking action at uncontrolled Airports, please share.
Sorry but I just have my own personal assessment based on my own experience. What I am hoping comes from Curtains post is that pilots add a layer of conservatism on top of what their iPad says when there is significant water around. The FAA has suggested we do, but even they can’t give more specific guidance than that. If you wanted to you could set your own factors. Ie,” if there is heavy rain at the field I will add a 30% Safety margin instead of a 15% Safety margin. If that can’t be met I will hold or divert. “
Thats not what I do but it could be a starting point for the first year or two of command if you thought it was sensible.