Contrail Question

ok, so i saw a contrail i was unfamiliar with - a line with balls, so i snapped it

i thought you guys could tell me if it was anything or nothing

hehe.. one contrail looks linear while the other's like you describe..
maybe its a twin engine aircraft with one engine sputtering??!!
lol no..

The “balls,” or “donuts on a rope” phenomena is associated with aircraft wake turbulence patterns.

Wake turbulence can effect how a contrail grows and ages.


and



From this report


Some people claim that this type of contrail is also produced by pulse jet engines of the type used on the mythical Aurora spy plane.

www.answers.com...;jsessionid=lnlnup7vehnk?tname=aurora-aircraft&hl=contrail&sbid=lc03a

Finally, in 1998, another aircraft spotter videotaped two unusual contrails in quick succession. One of the sights appeared to be a fireball, while the other was described as "doughnuts on a rope." However, this latter bit of evidence is particularly shaky, as this sort of contrail is not all that rare with passenger airliners either.

Hope that helped.


[edit on 14-4-2005 by HowardRoark]

"Some people claim that this type of contrail is also produced by pulse jet engines of the type used on the mythical Aurora spy plane."

thats why i asked

The problem is, that the phenomena is also associated with wake vortex patterns.

Watcher where did you snap the photo?
Also I have not seen any military aircraft that I know off leave a “donut on a ripe” contrail.

Now, if you saw the airplane that made the contrails, and the contrails came out of the plane, already in the donut-on-a-rope morphology, then I suppose that would indeed indicate some sort of pulse jet engine. I don’t know what the frequency of the pulses would be or how that would relate to the speed of the aircraft. However, it seems to me that the intervals between pulses would have to be rather large, even at high speeds for distinct puffs to be formed.

On the other hand, if you observed a plane making a normal looking contrail that eventually looked like the picture above, then I would say that without a doubt that that was a perfect example of wake turbulence.

Certainly the contrail in that picture does not look all that “fresh.”

Where did you get that picture?

If you really took it, where was it? It could help out the Aurora research project.

hi guys, sorry for not replying sooner but (like most brits) ive been asleep

i was on holiday recently in the lake district (lake windermere, cumbria, england) i took 5 or 6 of these shots (all with my 20d digital slr (8 million pixels) with special photographic quality lens (sharp as a tac)

hope this might help - we heard planes going over at incredible speeds, but i atual shot this when going back to my tent - i didnt see the aircraft

www.globalsecurity.org...

Although these observations are intriguing, they are also difficult to reconcile with one another. While many observers agree on the unusual sounds created by these vehicles, a range of descriptions are provided as to the nature of these sounds. The pulsating tone emanating from these sightings has been taken as an indication of the use of some form of pulse detonation engine. Some observers report a characteristic frequency as high as 60 Hertz, while others suggest a frequency as low as 1 Hertz.
But a technical analysis of pulse detonation engines suggests that engines operating at the thrust levels associated with military aircraft would operate a between 100 and 200 Hertz (pulses per second). While doppler shifting may reconcile this value with the reported 50-60 Hertz pulsation, it is more difficult to reconcile this with the reports of a 1 Hertz pulsation.
It is also difficult to reconcile a pulse rate of 100-200 Hertz with the observed donut-on-a-rope contrails. The association of these contrails with a pulse detonation engine would seem to be predicated on the observation that each "donut" is a product of a single pulse detonation. Based on published photographs, the "donuts" appear to be approximately 100 meters apart. Assuming a detonation pulse rate of 100 Hertz, this would imply a velocity of 10 kilometers per second, or 36,000 kilometers per hour (roughly Mach 36), one- and-one-half times orbital velocity. While it is asserted that the Exotic Propulsion Aircraft is a high-speed vehicle, this is at least four times faster than the speeds normally associated with this aircraft.
In addition, a closer examination of the published photographs reveals a significant irregularity in the spacing between the donuts on the rope. This would seem to be inconsistent with the normal functioning of a pulse detonation engine.
While various assumptions might be brought forward to reconcile these observations with theory, the evidence is not obviously consistent with the presence of a pulse detonation engine.
And the unusually loud, rumbling sonic booms reported along the California coast actually have a precedent in a deep black program well prior to the 1970s era THAP. According to an historical Lockheed document, during test flights at high altitude, the Lockheed A-12 "Oxcart" (an SR-71 predecessor) would make an "ominous rumble on the ground. Thus, while the reports of unusual auditory signatures may be indicative of the existence of some type of advanced air vehicle, they do not appear to constitute conclusive evidence of the existence of an Exotic Propulsion Aircraft.

I would have to agree on the assessment of the donuts-on-a-rope contrail.
Assuming a speed of 4000 mph, and a detonation frequency of 60 Hz, that means every pulse would be evenly spaced about 100 feet apart. That doesn’t seem to correlate to that picture.

The picture is obviously of chemicals sprayed by nefarious government agents who dress in black and who cackle loudly while proclaiming "HA! Poor fools don't even know we are spraying them, apart from that Code 3 guy on ATS who seems to be on to us."

PeanutButterJellyTime says:

"If you really took it, where was it? It could help out the Aurora research project."

I'm not sure what "Aurora research project" you're talking about, but the wake-vortex contrails are pretty commonly viewed in the skies in Arizona (probably because we typically have less cloud cover than other locations).

If you like, I can take a bunch of pictures over the weekend; given the weather conditions, we should be seeing some persistent contrails over the next couple of days.

What information are you looking for? If you like, I can correlate the pictures to actual airplane flights (I assume you have Flight Explorer running as part of your project). Is there anything esle you need? Let me know what you project methodology is, including data collection and reduction, and I'll probably be able to come up with some sort of usable data.

Whoops! Double post; sorry!

[edit on 15-4-2005 by Off_The_Street]

OTS,

I'm talking about the Aurora Aircraft Research Project here on ATS. I just joined the project but some of the members have been collecting possible aurora sightings and making a timeline of them. If this one came from a possible aurora hot-spot we would be interested in it.

I've never seen a contrail like that here on the east coast. I know the 'donut on a rope' contrail is often associated with top secret aircraft using pulse-detonation engines.

To be honest, when I saw this contrail I doubted it was one of the 'donuts-on-a-rope' because of the irregular spacing of the 'puffs' (I guess they're vortices) but like I said, if it was from an area that is associated with aurora it would be worthwhile to follow up on it.

i seen a very similar trail today (east central saskatchewan) around noonish.

One interesting thing to note, There were 3 trails in the sky. Only one had the circles.

I can still see some of them, i first noticed them before noon.

Its almost 2 pm now.

Originally posted by Dulcimer
i seen a very similar trail today (east central saskatchewan) around noonish.

One interesting thing to note, There were 3 trails in the sky. Only one had the circles.

That is because the wake turbulance is different for each plane

I can still see some of them, i first noticed them before noon.

Its almost 2 pm now.

Are you sure that they are the exact same trails?

check the weather chart for your area, do you have a stalled front overhead?

In any case, so what?

I saw a cloud yesterday and my son and I watched it cross the sky.

big deal.

Clouds persist.

Contrails are made of the same things as clouds.

Therefore, contrails can persist.

yeah big deal indeed. did i say it was a big deal.