3 years later The Mildura report

[Derfred]

Really? I would like to be a fly on the wall when the MFO/HFO/CP asks you why you are carrying around 30 minutes of extra fuel every day given a 1% probability of fog.

The MFO/HFO/CP of my airline would not. I feel sorry for you if you work for such an airline. Perhaps that explains your attitude.

Anyway, I didn't say I would carry around 30 minutes of extra fuel every day. I said I would have a contingency.

If there was a 1% chance of fog at my destination there are several different ways it could affect the way I operated that flight. For example:

1. Preflight, I may identify alternate airports that have zero chance of fog.
2. These airports may not necessarily be destination alternates, they may be enroute alternates, or TOD alternates, for example.
3. I may identify whether there is an alternate with an ILS, if my destination does not have an ILS.
4. I may use this 1% as a trigger to seek a second opinion, such as telephoning a Company MET department, or contacting someone with local knowledge at destination.
5. I may, as you say, carry more fuel. But not according to some pre-scripted policy. The extra fuel would be whatever I calculated I needed to mitigate the risk posed by this chance of fog. It would vary depending upon many factors.
   
6. Inflight, I would definitely be paying closer attention enroute to monitoring the weather at my destination and alternates, now that my attention has been drawn to this 1% chance of a problem.
7. I may also use this trigger inflight to pro-actively seek further information through Company or ATC channels, given that we now know they are not necessarily pro-actively seeking to help me.

There are a hell of a lot of mitigations available if the chance of a problem has been brought to your attention. It doesn't have to be as simple as just sticking on more fuel.

Fog generally will take at least 20 minutes from "first sign" to closing an airport (in my experience), so I would suggest that an airport with no reported fog at TOD could generally be committed to at that point. So a TOD alternate could be considered a viable mitigator.

As I said if the met guys could use this figure it would be on there almost every day in winter, in the south of the country.

It would most certainly not be on there almost every day in winter.

Fog requires certain meteorological conditions to occur. Predicting whether or not it will occur is difficult. Predicting a chance of it occurring is not difficult. Predicting zero chance is also not difficult. The problem is that the BoM will only admit a chance when it has a high probability of occurring (30% or greater).

Given a temperature, wet bulb depression, QNH, cloud cover and wind, some days in winter will have a chance of fog. Many will have no chance of fog. There are many forecast conditions that will preclude fog, such as temperature, rain, wind and cloud. (i.e. zero chance. Not 0.00001%, zero.)

Many pilots flying early morning arrivals into these ports on these kinds of days will make our own assessment of so-called "unforecast fog" and make contingencies anyway. Many of us save costly diversions, embarrassment or worse by doing so. Often these pilot decisions require experience and local knowledge, and will vary from pilot to pilot, so a little more information from the experts at the BoM would be handy for these decisions.


What I object to is this: The BoM appears to deliberately withhold information from the pilots who along with their passengers may live or die based on this information.

Only 20% chance of fog? Shhh... don't mention it.

5 days of 20% chance of fog? Statistically speaking, one of them will very likely end up with "unforecast fog". And that's ok?

If an engineer told you you had a cracked turbine blade, but there was only a 1% chance of it failing during this flight, you wouldn't leave the ground. But somehow, with fog, less than 30% chance is not even worth a mention. That's the most amazing risk management I've ever heard.