Volcanic ash and aviation

[Smurf1976]

With so many flights grounded due to the volcanic ash over NZ, Tasmania and Victoria I'm wondering if anyone knows the technical issues relating to this?

We have Virgin saying they can fly safely at lower altitude. A rougher ride apparently and I'm guessing a bit slower, but they can safely get from A to B (well, that's what they're saying...).

Meanwhile Qantas and Jetstar have suspended all flights which, in Tas at least (and no doubt NZ and Vic as well) is causing outright chaos.

Looking at the sky yesterday I would have assumed a large burnoff or fire if I hadn't known about the volcano. It was that typical "bushfire" look with high cloud (ash, smoke) and a very red sunset. So there's certainly something up there that's for sure.

Does anyone know what the truth is with aviation? Are Qantas being sensible or have they over reacted? Are Virgin taking unnecessary risks with safety? Or is their approach of flying lower a safe way around the problem? Why can't Qantas just fly lower as well?

I'm not one to advocate government regulation of everything, but when it comes to safety it seems rather odd to me that of the two major airlines in Australia one is flying and one is not flying the exact same routes. Seems rather odd to me. Does anyone know the facts on this one?

 

[medicowallet]

Apart from damage to the engines/aircraft.

Does it cost more to fly at low altitude?

 

[tech/a]

What's happened
Haven't heard anything about it in Europe
In answer to your question we flew into Heathrow in the middle of the Iceland eruption At the end of May so I had a personal interest in the topic.

It appears that certain types of dust can basically choke jet engines and caus catastrophic failure.
Other types can just chew up the turbines with the same result.
However it's widely agreed over here that most modern aircraft can fly in certain types and concentrations of ash.
Virgin and Ryan air flew test planes through the worst with no problems.

No airline can afford major damage to engines let alone a disaster so I'm happy hedging on the side of safety
It's not a hard choice in my opinion.

 

[tech/a]

Googled it thanks

 

[medicowallet]

Googled it thanks

Sorry mate, was logged off..

Interesting to see the combined effect of this and poor US lead on the stockmarket today.. might not be pretty.

 

[Aussiejeff]

Apart from damage to the engines/aircraft.

Does it cost more to fly at low altitude?

Absolutely! Depending on how flush each airline's fuel purchasing funds and rate of burn for their fleet at lower altitudes depends on how much extra increasingly expensive jet fuel they are prepared to burn to maintain low flights. Throw in a hotch-potch of individual airline Safety policies and it all adds to the confusion...

A couple of links to help with the debate....

http://answers.yahoo.com/question/index?qid=20110517161126AAgoNSH

http://answers.yahoo.com/question/index?qid=20100418004059AAUnQia

Note - I believe catching favorable jet stream tail winds is also a significant consideration not mentioned in those links. Most times on the Perth to Melbourne or Sydney flights I've been on the Capt has mentioned the boost in ground speed thanks to "favorable tail winds". Has to be an economic benefit there.

 

[Glen48]

The colder the OAT (outside air Temp ) is the more fuel efficient the engine is. There was a pommy plane which flew into a volcano one night a few yrs ago took all the paint off and lucky to land.

 

[Aussiejeff]

The colder the OAT (outside air Temp ) is the more fuel efficient the engine is. There was a pommy plane which flew into a volcano one night a few yrs ago took all the paint off and lucky to land.

Flew into a volcano and survived?

Some feat!

Sorry, Glen. Your typo was simply irresistable! LOL