Eyjafjallajökull

I think everyone who isn't living in a cave knows about this now - how one medium sized volcano in Iceland can take Europe's travel options back 100 years. This pesting volcano (excuse the language) has affected me personally, I was scheduled to fly on one of the first flights that got cancelled and now my 2 weeks off at home are very much in danger of evaporating.

There are a few reasons why this volcano is affecting travel so much more than others in the past.

1. For reasons I don't fully understand, but are related to ice and snow, the ash plume is getting propagated into the higher atmosphere - the place modern aeroplanes hang around - with stunning violence. The ash also seems to be extremely fine and lightweight which means it could remain airborne for weeks or months.
2. There is a jetstream - a high speed current of wind - located roughly over the volcano which snakes it's way towards the North sea before dying out, and there is little movement over Europe itself. Think of a strong river pouring in to a rather stagnant estuary.
3. The affects of ash are not very well documented other than the fact that they ruin gas turbine engines. As no one really knows what intensity is considered a cut off between 'safe' and 'unsafe', and there is very little data available about the actual intensity of the ash floating over Europe.

Through reading forums and news comments a lot of people are mentioning that volcanos erupt all the time in Italy, Japan, Indonesia, and aviation barely takes any notice. This is because either the volcano isn't powerful enough to propel it's ash into the atmosphere, the ash is thick enough to fall to the ground in a fairly limited radius and there are no strong winds overhead to move the ash quickly.

Until one of the three points above is removed from the equation I doubt conditions will change much in Europe - infact as the air in the "estuary" area slowly moves, and ash continues to be fed in, the volume of closed airspace will increase as the ash propagates slowly... As I doubt there will be any breakthroughs in ash knowledge in the next few days we can only hope that the wind conditions change and/or the eruption becomes less intense... But the high pressure is forecast to last well into the week.

S.

What visibility?!

It's Saturday morning, my second morning after 3 days off. I'm flying with a Captain I know well on a brand new, healthy aircraft. The sky is completely clear and the weather forecasts are optimistic ... I'm thinking this will be a good, easy day flying to Singapore via Kuching.

We board quickly and depart 10 minutes ahead of schedule and are granted unrestricted climb to FL380 and more or less direct to destination, there even is a nice 30kt tailwind pushing us along through the clear blue sky. I'm thinking this is a good start, and things can only get better right?

40 minutes later the Captain has just checked Kuching's ATIS. Visibility 200 meters, overcast 100ft. The look on his face is indescribable: "what was the forecast?!" I fumble for the weather... "unlimited visibility, CAVOK" So much for optimistic weather forecasts...

A few miles later Kuching Director confirms the conditions ... the visibility is now 600 meters but that still is below our minima of 800m. We decide to hold for a while to see if this surprise fog will burn off. As I plan the diversion I'm starting to think today isn't really a good day after all. Kuching comes into view about 50 miles ahead and it looks like a winter wonderland with the rather steep cartoonish hills poking out of a very low layer of cloud which is inconveniently sitting on the ground.

Just as we reach the holding fix the visibility increases to 800 meters (or minima) so we decide to give it a try and get vectored onto the ILS. It's still a beautiful clear day at 3000ft but instead of seeing ground when I look down I see cloud, which isn't normal.

1000ft descending on the ILS and we're still above the layer of cloud but there are holes here and there through which I can see bits of a city - the odd road, half a house, etc.

We enter the cloud at 500ft - the lowest we can descend to is 245ft before going around - and right on cue at minima there is a tiny gap in the clouds and the runway comes into sight so we continue and land, smoothly, 15 minutes ahead of schedule and I have enough time to go for a walk in the terminal and find some breakfast. Today is a good day.

Throughout the approach we were constantly seconds from holding/going-around/diverting when the weather conditions changed and allowed us to continue - as if the whole thing was a well scripted suspense novel. I only wish I had remembered to get the camera out of the bag and film it all.

S.