Strange days for us in Europe. We can’t see planes in the sky. Trains, buses and other transportation networks are overloaded, people got stuck at airports and businesses loose a lot of money due to this strange phenomenon. This is something that never happened in the history of commercial aviation. Why are these ash clouds so dangerous that it basically collapsed European aviation? Is it just a hype or is it a real fear?
The story begins in 1982, when a Boeing 747 (jumbo) took off from Malaysia and headed to Perth, Autralia. When the jet passed by Java, where a volcano erupted earlier, all four engines stopped, so the pilot had to glide. At 12 000 feet he could restart the engines and managed to land safely in Jakarta, although one of the engines failed again later on the ground. According to investigators at was the volcanic ash that clogged the engines for some time.
Although this was the only incident caused by volcanic ash, obviously aviation experts were afraid to put flights at risk, therefore aviation authorities decided to close down all affected European airports.
You can read the whole story with explanations on BBC Online.
Read more on BBC Online
Although the sky seems nice and blue, and I am still not convinced that such a light concentration of ash would really harm jet engines, I guess everybody understands that it is better not to risk people’s life. It is rather surprising for me that there is noone who could answer this question and help aviation authorities in bringing the right decisions.
I would be grateful if you shared your opinions with us in a comment.
By Szafi
Airline world 
“Light Concentration” – that is the point. I’m wondering why they do not any experiments to figure out “how many ash” you need to have effects on the engines, and especially on the airspeed tube.
I’m currently stranded in Tokyo hoping to get on a flight back home to Geneva (CH). I was browsing through the news and airline companies to get information when I found this article. Do you think that the Airbus A380 flight from Singapore to Zurich could fly on Tuesday 21st? From what I’ve read so far, flights over 20’000 feet in Switzerland can fly and since it’s coming from Singapore, I thought that the super-jumbo plane should be higher than that. Plus since the plane should be the most cutting-edge plane to date, shouldn’t it be able to withstand a little bit of dust in its enormous engines?
Robert, yes, I think you’ll be able to fly to Switzerland on Tuesday. By the way if you’ll do fly can you please take some photos for us of the interior of the A380? We would be delighted to see some of them.
A.B: and there’s one more thing I forgot to mention. This volcano has been active since the 20th of March. Why did they start to panic last Thursday? This whole thing is really unclear to me.
ATW Online News Article from April 19 by Geoffrey Thomas on the same topic:
There have been 90 incidents over the last 30 years in which aircraft have encountered volcanic ash, invisible to weather radar and totally undetectable at night, and several of the encounters created very dangerous situations.
Made up of pulverized rock and glass, the ash gets into virtually every aircraft system and can paralyze engines in minutes. The ash turns molten in a jet engine’s combustion chamber and melds with moving parts like spray paint. It blasts cockpit windows, compromising visibility in seconds, and also clogs vital speed sensors, rendering an aircraft’s flight computers almost useless. (balint01: can mislead the auto-pilot similar to the Air France incident in 2009 where the ice shut the pitot tubes down) The deposits additionally coat the fuel system’s temperature sensors, creating a false and lower temperature reading that causes the automatic monitoring system to pour in more fuel. This makes the engine dangerously hot, damaging the turbine and potentially leading to a shutdown.
The two most famous encounters with volcanic ash involved 747s, one a British Airways flight over Indonesia in 1982 en route to Perth from Kuala Lumpur (balint01: mentioned in the article above) and another involving a 1989 KLM flight en route from Amsterdam to Anchorage. In both cases, all of the engines failed and eventually were restarted at much lower altitudes but later were scrapped because of the damage. The KLM 747’s environmental control system was replaced, its fuel tanks were cleaned and the hydraulic systems needed repair.
When Mt. St. Helens erupted in 1980, a 727 and a DC-8 encountered separate ash clouds. Both experienced damage to their windshields and several systems but both landed safely despite the damage.
In 1991, Mount Pinatubo on the island of Luzon in the Philippines erupted just 90 km. northwest of Manila. Over the course of several eruptions, the volcano ejected 10 cu. km. of material, making it the second-biggest eruption of the 20th century. There were 20 volcanic ash encounters with aircraft. Despite the more advanced ability to predict where ash could be found, the wide extent of the ash cloud made it difficult to avoid.
The eruption of Mt. Popocatepetl in Mexico in 1997 and subsequent intermittent eruptions forced the Mexico City airport to close multiple times for up to 24 hr.
Scientists working with the University of Iceland suggest it is a distinct possibility that the Eyjafjallajokull volcano will continue to erupt on and off for months to come, as occurred during the last eruptive period in 1821-1823.
cluttering the engines with thick ash – hmm. there were past events of this, where the plane shut down and crashed, and no one knew of it until it was too late. ash is dangerous from a mechanical standpoint more so from a vision standpoint. the question is, why haven’t they invented a way to protect the exposed engines? also, there is a scientist who has a device that predicts eruptions and detects ash in the air – why haven’t we commercialized this?
If there was a regulation in place where a certain “amount” of ash was ok, it’s not good enough as that’s not consistent with everywhere else in the sky. One area in the sky that has it a bit more dense and that’s it!
Taking risks is not an option in the aviation field.
The ash is carried by winds and eventually settles back to the earth as a thick blanket