Could this be the Aurora?

I found this ht tp://ww w.draxium.com/ufo.html while researching the above mention A/C.

It also alledges that people saw a triangle shaped A/C take off in daylight from Groom. I havent heard of this before, has anyone else?

I do not think Auroa caused this. Pulse detonation engines have to fire many times a second so you would not really see rings that are spead out like that.

No luck here, it isnt Aurora.

I've come across these 'doughnuts on a rope' contrails before, but I can't think where. Incidentally, I'm pretty sure they were in reference to the Aurora, wherever I saw them.

Will see if I can find the link I visited.

Don't forget, at the speed aurora is supposed to travel at, the donut on a string effect is very possible due to the time between detinations and airspeed.

Since the pulse detonation engine fires many times a second it would seem that the "Donuts" would have to be very close togther. They are spread out and that is why I do not think it is Aurora.

PDEs firing at 60 times per second at mach 5 in the troposphere would make them about 30 yards or meters apart. The pulses per second might be lower then that, and the speed might be higher. So if you ask me those trails COULD be from a PDE engine, but i doubt they are because i am a skeptical dude.

[Edited on 15-9-2003 by kdub]

If it's not a PDE, then what is it? A pulse detonation engine can fire at lower freqeuncies, but you just won't get the thrust. Also, from the altitude, it looks like, oh, twenty to thirty thousand feet up? The Aurora has no reason to hang around at such alow altitude. Also, the air is too dense for it to be running full-on Mach 7. I believe this is the Aurora bleeding off speed, descending to initial approach (also, given te time of day in this pic - Aurora takes off at dawn). It may be doing about Mach 3 here.

Oh, from what I gather the TR-3A/B is supposed to be a subsonic, stealthy platform, separate from Aurora/ SENIOR CITIZEN or whatever you want to call it!

on second thought arnt PDE's supposed to fire sequentially and not all at once? just 12 PDEs fireing 60 times per second, one at a time would change the distance at mock 5 between them all the way down under 3 meters. and its also true that it probably isnt at mock 5 if its at 30k feet (i had no idea how high it looked in that picture, couldnt even venture a guess) so they would be even closer than that. aint a PDE. probably just some wierd turbulence from something boring creating the doughnuts.

I've stood at airports and watched 727's make exactly that pattern. It's not pulsed, it's a corkscrew shape. If you look at the 'pulses' many of them seem to lean one way.

Sorry, this is just the result of humid air and a commercial airline angine at low speed.

I`ve seen this type of shape before and I live under major flightpaths. They look far too much like ones I see regularly to convince me they are from an xcraft.

Interesting replies guys.

I used to live close to BWI Airport outside of Baltimore. My house was right under a flight route , I could look out of my window and see the contrails. I've seen many contrails that look similar to the one in the photo. So I think it might be From a regular aircraft, Maybe one of the Janet flights.

Tim

The key would be the rumbling engine noise associated with the PDEs. I've personally never seen contrails like that before, but I guess atmospheric conditions where I live don't give rise to that.

Another point: wingtip vortices: I think I can make them out in this photo. Aurora contrails are distinctive in that they don't have any.

Also: it's way too low!

originally posted by: Lampyridae
If it's not a PDE, then what is it? A pulse detonation engine can fire at lower freqeuncies, but you just won't get the thrust. Also, from the altitude, it looks like, oh, twenty to thirty thousand feet up? The Aurora has no reason to hang around at such alow altitude. Also, the air is too dense for it to be running full-on Mach 7. I believe this is the Aurora bleeding off speed, descending to initial approach (also, given te time of day in this pic - Aurora takes off at dawn). It may be doing about Mach 3 here.

Oh, from what I gather the TR-3A/B is supposed to be a subsonic, stealthy platform, separate from Aurora/ SENIOR CITIZEN or whatever you want to call it!

This thread may be two decades old, but on page 77 of his book Aurora: The Pentagon’s Secret Hypersonic Spyplane, Bill Sweetman writes:

The pulsing is a low-speed phenomenon and has no connection with pulsed detonation wave engine (PDWE) technology, which has been linked to the u “doughnut-on-a- rope” contrails that have been seen over the United States. The explanation for these contrails is still not clear.

Sweetman noted that the pulsing sound is not in anyway linked to a pulse detonation wave engine, casting doubts on suggestions by some that the "donuts-on-a-rope" contrails seen in the late 1980s and early 1990s were produced by a pulse detonation wave engine. A late 1992 issue of the FAS Public Interest Report likewise expressed considerable doubt on a Pulse Detonating Wave Engine creating those contrails based on technical analysis of this type of engine:

As much as these observations are intriguing, they are difficult to reconcile with one another. While many observers agree on the unusual sounds, they have given a wide range of descriptions as to the their nature. The pulsating tone emanating from these sightings has been taken as an indication of some form of pulse detonation engine. Some observers report a characteristic frequency as high as 60 Hertz, while others give a frequency as low as 1 Hertz.

A technical analysis of pulse detonation engines suggests that engines operating at the thrust levels associated with military aircraft would operate at 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 supposition 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.

Thus, while the reports of unusual auditory signatures maybe 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.

a reply to: Potlatch

The explanation for those contrails is atmospheric turbulence. Aurora didn’t exist then, and it doesn’t now. PDEs have never successfully pushed a large platform, let alone to mach 6+.

a reply to: Zaphod58

Warning -

The off-page link supplied in the OP attempted to infect my computer and triggered a MalwareBytes scan.
That link should be deleted.

Thanks

originally posted by: Zaphod58
a reply to: Potlatch

The explanation for those contrails is atmospheric turbulence. Aurora didn’t exist then, and it doesn’t now. PDEs have never successfully pushed a large platform, let alone to mach 6+.

I definitely agree with you. I first heard of the mythical Aurora spyplane while reading the timeline portion of the book The Timechart of Aviation History, but when Googling the web for "Lockheed Martin Aurora", I was surprised to find out that what the book calls "Lockheed Martin Aurora" was actually rumored to exist in the late 1980s and early 1990s, a few years before the SR-71 was reactivated. After reading news stories about flight tests of the X-43 and X-51 and better understanding the history of scramjet and hypersonic air-breathing aircraft development, but also seeing Lockheed Martin unveil the "SR-72" concept for a Mach 6 spyplane in 2013, it is now apparent that the putative Aurora spyplane was pure myth and legend. Add to that the fact that in a March 1998 issue of Popular Mechanics there is a brief item under the "Tech Update" about how photos of an SR-71 releasing streams of spherical puffs confirmed that the "donuts-on-a-rope" contrails were in no way generated by a pulse detonation wave engine. It's arguable if the SR-71's return to service in 1995 forced some people who believed in Aurora's existence in the first place to change their mind about these contrails being produced by a pulse detonation wave engine.