Period Skies

[biffvernon]

It's a long time since we've had a sky not scarred by con-trails so I thought I'd record today's view from my garden as an homage to past skies and perhaps as a precursor to the future post aviation age:

 

[Schoolmarm]

Hasn't it been amazing. That is a great picture.

 

[jocelyn plummer]

Wall to wall then. How lovely. We have been sitting under clumps of clouds for the past three weeks and a beastly wind.

 

[Flyfisher]

Can't be long before we go to war with Iceland.
First they stole all our cod, then their banks lost loads of our money and now they've shut down our aviation industry. :wink:

 

[biffvernon]

Someone wrote "Dear Iceland, we said please send cash"


Some may wonder about relative CO2 emissions of volcanoes and aircraft. Here's a little visualization:

 

[Schoolmarm]

:shock:

 

[philpjuk100]

Sunrise yesterday,note the vapour trail! (probably before the flying ban) but how do they take all the pics of the volcano from the air?

 

[Flyfisher]

Regarding Biff's graphic, I remember seeing similar stuff after 9/11 closed down all US airspace.

Yep, volcanoes and Bin Laden are all doing their bit for the planet. :?

 

[Penners]

how do they take all the pics of the volcano from the air?

Easy...

 

[Flyfisher]

Stop showing off and put those wings away!

 

[Schoolmarm]

Errrrrm..helicopter?

 

[Penners]

Well, Marm, I always thought helicopters had engines. And engines have to suck in air. And sucking in air means sucking in dust.

 

[Flyfisher]

It might be something to do with jet engines specifically, which, as I understand things, run at temperatures sufficient to melt the dust into a 'glass' that coats the interior gubbings** causing the engine to fail. If you're lucky, the rapid cooling as the now-gliding 'plane descends is sufficient to cause the 'glass' covering the engine internals to shatter allowing the engine to restart, hopefully in time for a controlled landing. That seems to be what happened with that BA flight over Indonesia in the early 80's.

I suspect that piston-engines don't operate at the sort of temperatures that can 'glassify' the volcanic dust so, as long as there isn't enough dust to actually choke the engine through lack of oxygen, then they are rather more resilient.


** a technical aeronautical term meaning 'to gloss over the correct description, usually through lack of knowledge'.

 

[Penners]

I suspect that piston-engines don't operate at the sort of temperatures that can 'glassify' the volcanic dust so, as long as there isn't enough dust to actually choke the engine through lack of oxygen, then they are rather more resilient.

That's my understanding, too. However, I also understand that piston engines aren't immune to the dust - just able to operate at somewhat higher concentrations than jet engines.

Thus piston aircraft appear to be largely grounded, as well as jets.

 

[Pford75]

Well, I'm in San Francisco at the moment. Was supposed to leave Friday night...just had my Saturday night flight cancelled and first confirmed flight is Wednesday. Doing a Napa valley tour this afternoon...followed by fresh oysters....then tomorrow a walk around the Presidio.

These travel delays really are a pain :wink:

 

[Moo]

Listening to Any Answers while weeding my allotment today I heard a man who modestly conceded that he was pretty expert in these things suggesting that the manufacturers should turn their minds to building aircraft that didn't rely on the sort of engines we use today - neither jet nor propeller-driven. He mentioned some sort of aircraft that got its energy transmitted via airwaves, and said that sufficient research has been done to make it a real possibility. It would also have the benefit of being "as green as a lettuce leaf".
I'm afraid that just about sums up all I can remember of the conversation (I was doing some very concentrated fingertip weeding round my budding asparagus plants at the time) - perhaps someone else here didn't just listen to the programme but also understood it?

 

[jocelyn plummer]

It is noticeably quiet here, just 8 miles away from Luton airport, bliss infact. Also fantastic wall to wall blue just right for my Niece's wedding celebrations in a lovely North Beds village. Just getting ready to go.

 

[Penners]

Doing a Napa valley tour this afternoon

Pford - you poor chap. Oh well, you'll just have to make the best of it. :wink:

If you're in the market for a personal recommendation, here's the winery tour that I enjoyed the most:

Rutherford Hill Winery
tel. +1 707.963.1871
tel. +1 1.800.637.5681
200 Rutherford Hill Road
Rutherford, CA 94573

A lovely location with views over the valley, an interesting (and not too commercialised) tasting and tour, and if you take your own picnic there's a lovely picnic area.

 

[worms]

but how do they take all the pics of the volcano from the air?

I would imagine it is not down to specifics of the planes or the engines, but just that near to the source, the plume is still concentrated, can be seen and avoided. By the time it has travelled a few hundred miles, it is pretty much spread right across the sky.

 

[biffvernon]

Well, Marm, I always thought helicopters had engines. And engines have to suck in air. And sucking in air means sucking in dust.

Maybe it's to do with flying at a few hundred feet in clear air looking at the cloud sideways, rather than at 30000 feet straight through it.