Photos taken of what appear to be aircraft flying in Amarillo, Texas, earlier this month have aviation writers speculating it could be secretive military projects.

The images taken by Steve Douglass and Dean Muskett on March 10 and posted to Aviation Week’s defense blog show white contrails in the sky and one photo in black and white appears to zero in on a triangular-shaped plane.

Image source: Dean Muskett via Aviation Week

Image source: Dean Muskett via Aviation Week

Image source: Steve Douglass via Aviation Week

Image source: Steve Douglass via Aviation Week

Bill Sweetman, a senior aviation editor for Aviation Week who has covered aerospace and defense news for four decades — wrote that he and his colleagues, Graham Warwick and Guy Norris, “concur that the photos show something real.”

“This is more than a random image,” he wrote.

According to the post, three aircraft were spotted in total and Douglass apparently heard traffic voices on a radio line he was monitoring, which Sweetman thinks would suggest the planes were piloted, not flying autonomously.

While Sweetman wrote that he doesn’t know what the aircraft were, he said that by the photo, he thinks he can deduce what they aren’t.

“The photos tell us more about what the mysterious stranger isn’t than what it is. The size is very hard to determine, for example, although the image size at contrailing height suggests that it is bigger than an X-47B. However, the basic shape – while it resembles Boeing’s Blended Wing Body studies or the Swift Killer Bee/Northrop Grumman Bat unmanned air system — is different from anything known to have flown at full size, lacking the notched trailing edge of Northrop Grumman’s full-size designs,” Sweetman wrote.

Sweetman suggested that it could be a classified plane.

“One avenue of speculation is to look at gaps in the [U.S. Air Force's] line-up. One obvious example is high-precision stealth attack: The B-2 and F-22 have the ability to drop GPS-inertial weapons on coordinates generated or updated by radar, but that’s not the same as electro-optical targeting and laser guidance, which seemingly went away with the retirement of the F-117 six years ago: that technology gives you strike damage assessment as well as greater accuracy. The [air force] has also talked about “penetrating, stand-in electronic attack” as an enabler for other strike systems – and talked in the same way about penetrating intelligence, surveillance and reconnaissance, even when the Northrop Grumman RQ-180 was under development to perform that mission,” Sweetman wrote.

If this aircraft is part of a classified military program, Sweetman noted that it would be one of only a few instances where classified aircraft were exposed before being formally declassified.

” […] until the RQ-170 Sentinel was seen at Kandahar in 2007-09 there has been no such aircraft photographed before it was declassified. (And in the case of the RQ-170, the operational security people were not trying too hard),” he wrote.

(H/T: Gizmodo)