[Alan Dunne]

Hi all

I would normally resist joining forum discussions, however what I witnessed yesterday over the skies of Dublin and Wicklow did appear highly unusual.

I witnessed what appeared to be a white unmarked plane releasing enormous amounts of thick trails which lasted for hours.

This can be dismissed using compartmentalisation, however can someone please explain why the plane turned around and proceeded to make large X's in the sky. There where four large X's (made by the same plane) over South Dublin yesterday morning and 2 large X's near the Dublin Mountains yesterday afternoon. They took several hours to dissipate.

Anyone?

[Alan Dunne]

@ Ken.

I'm not sure about this forum, but it's common to have to create a flickr account to create a link to post pics on forums.

You right click over the image in flickr (and select copy image) then use the URL button to link it when your posting your reply.

Maybe there's an easier way though?

I'd be interested to see your images. Did you manage to get the large X's?[/img]

[mr crow]

Cirrus or CI are high level cloud made up of ice crystals 20,000 ft >
cirrocumulus and some cumulonimbus (CB) or thunder storm clouds also falls into that group.
For cumulus activity to occur you 1st needs an unstable atmosphere and some form of lifting to to raise the to air higher level which will then adiabatically cool it to its due point, which will then start to form a cloud.


Large amounts of hot air and water vapour are exhausted by jet engines. 1 kg of fuel produces about 1.5 kg of water vapour.
Hot exhaust gases reduce relative humidity, but released water vapour increases it. As the exhaust mixes with ambient air, the course of events depends on the temperature, pressure and humidity of the ambient air. In general, the air behind the aircraft is supersaturated. At higher air temperature heating from the exhaust prevents supersaturation. If the air is cold saturation occurs. The trails are called contrails, (engine exhaust trails).
If the ambient air is of high relative humidity, the trails will be extended. Soon the freezing droplets will turn into ice crystals and the contrails become diffuse Cirrus clouds. If the ambient air is saturated in relation to the ice crystals, the contrail DOES NOT EVAPORATE but remains as a Cirrus cloud in the sky

You can also get condensation trails forming at the wing tip caused by the reduction in Air pressure which then reduces the air temperature and adiabatically cools it to its due point to form a condensation trail.

Also If you were to look at the winds aloft for today you would see the the wind speed at FL240(24,000ft) is 0kts yip zero, wind calm...
NO BIG MYSTERY REALLY!!

[Alan Dunne]

Mr Crow.

That does not explain why the same plane was making large X's in the sky from morning to evening?

[Alan Dunne]

Also,

It was noticeble that the lenghty trail dissipation rate was only occuring with this one particular plane. This was not the case with pretty mucj every other plane in the sky yesterday.

[alphaLaura]

Photos?

[mr crow]

Alan Dunne,

Aircraft fly at different Flight levels = Different wind speed and directions.
What do you want to hear

[Alan Dunne]

What apart from wiki- explainations for cumulus clouds?..........

........can you tell me if it's normal for an unmarked plane to spend day making Large X's in the sky from early morning to late evening?

[Bump]

I don't know what's going on, but I reckon Eddie Goggins is in on it!



For the love of God, will you conspiracy theorists get a life!!

[captain slow]

Oh this is getting good

Large white unmarked aircraft doing big X's in the sky over dublin.....thats brilliant
On so many levels thats implausible .....with the volumes of traffic around dub ATC could never approve such manouvres either at low or high altitudes.
If the aircraft is painting/spraying big X's in the sky presumably using its engines how does it stop painting when it comes to each end of the two arms of the X otherwise it would be an X within the circle.....oh yes probbaly some dark area 51/alien technology allows this to happen. Perhaps its aliens using X to mark the spot for the coming invasion

Oh perhaps the X you see are the crossing tracks by different aircraft as dub is one of the busiest junctions in the sky in europe.

As for the umarked white aircraft they are marked just not visble when viewed form the ground looking up and most aircraft especially large jets are painted white for various reasons like to prevent differential heating on the composite airframes and as anyone knows white paint is the cheapest. So you probbqaly saw lots of different white bodied jets criss-crossing in the sky.

This is great stuff tho.....very entertaining

[Alan Dunne]

Oh this is getting good

Large white unmarked aircraft doing big X's in the sky over dublin.....thats brilliant
On so many levels thats implausible .....

And yet, our sky was full of large X's all day yesterday?

It was a large plane, it did not turn in a circle to make the X's. It flew off and then returned. not a different plane. The exact same plane...........all frickin' day.

I could see the plane was

A) Unmarked
B) The same plane flying backwards and forwards

because I was using my mates binoculars.

[Alan Dunne]

For what it's worth, I do not believe in little green men.........

[alphaLaura]

If you had binoculars then: How many engines had the aircaft? Can you describe the plane in greater detail? Can you guesstimate its altitude?

[Bump]

If the plane was a large white unmarked plane how could you distinguish it from all the other large white planes that make up 90% of the commercial traffic over Ireland?

If the aircraft was flying off (out of sight) and returning how could you be sure it was the same one?!

The whole concept of this occurring is implausible on so many levels.

Someone lock this thread, it's getting ridiculous.

[Alan Dunne]

If the plane was a large white unmarked plane how could you distinguish it from all the other large white planes that make up 90% of the commercial traffic over Ireland?

If the aircraft was flying off (out of sight) and returning how could you be sure it was the same one?!

The whole concept of this occurring is implausible on so many levels.

Granted, i'm not an aviation nerd like yourselves. However as "implausible" as it sounds. There were four large X's over south Dublin yesterday morning.......a criss-crossed trail from a plane........at the same height.

So dweebs........tell me......Is it normal to have flight paths that criss-cross on the same level?

The plane which was creating this criss-crossed trails "appeared" identical to my untrained laymans eye. Interestingly, all the other planes visible yesterday which were not leaving lenghty trails where obviously distinct from what appeared to be the same plane.