What aircraft gives off the ringed contrails?

About 5 years ago I saw the contrails with rings on it. It was down on Hatteras Island when I was down there with my family. We heard nothing, saw nothing, and it kinda just appeared. My father randomly looked up and saw this, and we were in awe because it was so spectacular. Now I would like to say that we didnt hear anything becasue the contrail was very very high. Way higher than normal commerical flights travel.

Any information would be great, such as links to other posts, webistes, etc.

Thanks
Fry

was there a Airbase or military exhebition where you were ?

There are numerous military installations thoughout the area, and military jets fly around constantly. Especially during the summer months. There is an Army Base and a Marine Camp in the same state. The Norfolk Naval Airstation is due north about 150 miles, and about 75 miles north of that is Langley Air force base. Again military jets are all over the east coast of the US doing manuvers and low flying tactical training.

To put it in perspective. Where I went to college was in Radford VA, which is directly across the state from the Norfolk Naval Base. As the crow flys I would say roughly 300-350 miles, estimated. Naval jets such as F15's and F16's would constantly fly in the area of my school. It is a mountainous area, so they were doing tactical low flying manuvers, dog fighting, etc. You could see them doing rolls, dogfight training, and other manuvers that are pretty impressive. It was always great to see and hear them coming. They used one of our dormatories, which happend to be the highest point in the area for about 100 miles, as a beacon and landmark. They would fly directly above my school, and at night once they would pass over the populated area, they would jam the throttle and afterburners would glow. It was a great sight.

Anyway my point is that the US military whether that be Army, Navy, Marines or Air Force all fly routinely around the mid atlantic region of the US.

Fry

From a few searches I just did, I came to the conclusion that these ringed contrails, as I put it, are normally refered to 'donuts on a rope'. That is exactly what I saw. Also these contrails are supposed to be linked to the Aurora project. I cant seem to find much information about this aircraft, and searches on google usually turn out to lead to the northern lights.

I would like as much information on this project that you guys can give me. This aircraft intregues me, and I am eager to learn about its capabiities and possible existance.

Thanx
Fry

This sounds like what is being reported in conjunction with a PDE.
No, not a partial differiential equation for those of you who hated math, but a 'pulse detonation engine'. I knew a research group about 2 years ago that claimed they were designing/building the first PDE. It was a small bench top engine and I think they all disbanded before it fired. I sometimes believed that previously solved concepts are handed down to primarily acedemia, almost as a test!

The Aurora is belived to have PDEs. Perhaps, but more likely a hybrid engine system IMO.

From my very quick search on what a PDE's contrail is 'supposed' to look like, I found it to be in line with what we saw. I really would like to see it again, but probably never will. Anyone have any pictures of this occurance?