Explained: Spiralling trails over Croatia (contrails from TV relay plane)

[Trailblazer]

Videos and photos of some striking spiralling contrails have been causing a stir on social media in April 2024:


Source: https://twitter.com/Humanbydesign3/status/1783377660229341504

https://www.instagram.com/reels/C6Jr1UOICVr/

The first clue is that road signs are visible in the video footage, including the name of a village, Tekačevo, which is in eastern Slovenia, near the Croatian border.

With the location, other social media posts could be found, including this


Source: https://twitter.com/Pedjijatar/status/1781982502384484665


Translation:
Yesterday morning above the Slovenia-Croatia border a wonderful "contrail", short for "condensation trail". The plane was circling at 28,000 feet to transmit the WRC Croatia rally signal. pictures borrowed from the Facebook page "Slovenian Aviation Portal"

The aircraft responsible was this one, registered in Belgium:

https://www.flightradar24.com/data/aircraft/oo-asl#34dd2177

It is operated by Air Service Liège, who provide TV relay coverage of the WRC rally (as seen in 2021 in Finland here, for instance)

Interesting to note that the plane was mostly flying circles over one location, and the wind blowing the trails creates the spiralling effect.

 

[Trailblazer]

Also interesting that this plane is a turboprop, which I don't usually associate with making persistent contrails.

 

[John J.]

interesting that this plane is a turboprop, which I don't usually associate with making persistent contrails

Contrails, including persistent contrails, were documented years before jets were on the scene; posted elsewhere:

https://www.metabunk.org/threads/de...-a-study-of-70-years-of-books-on-clouds.3201/

In the first post of that thread [link above] Mick West quotes "Cloud Formation by Supercharged Plane" from U.S. Air Service July 1921- over a century ago.
This was the type of plane responsible, a Packard-Le Père LUSAC-11. (There's a good chance this is the actual plane):

Two months after the report about the "cloud formation", the same pilot (Lieutenant John A. Macready) broke the world altitude record in the aircraft pictured
https://en.wikipedia.org/wiki/Packard-Le_Père_LUSAC-11

(Did some minor editing).

This is the item from U.S. Air Service, July 1921, from https://commons.wikimedia.org/wiki/File:Contrail_1921.jpg

Also from Mick's post, a 1943 book about clouds (the aeroplanes referred to would be propeller aircraft):

Sky over London in 1940; USAAF B-17s in WW2.

I feel the "very persistent" quote from 1943 is significant; "chemtrail" CT believers often claim, without evidence, that contemporary contrails must be materially different to "historic" contrails "because they last longer".

 

[Mick West]

Interesting to note that the plane was mostly flying circles over one location, and the wind blowing the trails creates the spiralling effect.

You see that in my old simulator:
https://contrailscience.com/contrail-simulations/
(uncheck the "Intersection" box in lower left)