An apparently previously unseen low-observable aircraft test shape has emerged, with initial open-source intelligence research indicating it was spotted at Lockheed Martin’s secretive Helendale radar-cross section (RCS) measurement facility. This site, located in the Mojave Desert not far from the company’s Skunk Works headquarters at Plant 42 in Palmdale, California, is among the most sophisticated of its kind and has played a key role in the development of U.S. stealth aircraft since the early 1980s. You can read all about this facility, which looks ripped from a science fiction movie, in this past feature of ours.
While we don’t know what this shape is intended to resemble, it provides a timely reminder of some of the exotic test work that’s clearly going on behind closed doors, at facilities like Helendale and others, on a number of advanced combat jet development programs that we know about, as well as more stealthy aviation work going on in the classified realm.
A short video showing the apparent test shape seems to have been first posted to the TikTok video-sharing social networking service, before being shared on other social media channels. Ruben Hofs brought it to our attention on Twitter. Hofs, who tweets as @rubenhofs, used an open-source intelligence (OSINT) comparison of buildings and foliage in the locale to determine that the video was almost certainly taken at Helendale.
The video itself shows what looks like an inverted stealth aircraft shape being transported on a flatbed trailer, while a voice asks: “What the fuck is that?” As Hofs notes, the shape of the aircraft is very different from typical “pole caps,” which are more familiar test shapes used for calibration of the pylons used in RCS tests at Helendale and other facilities.
Transporting the shape upside-down is also far from unusual for these kinds of tests, since surrogate airframes (and other test articles) are often mounted inverted on the test pylon at Helendale and other similar facilities before being exposed to electromagnetic emissions to measure their radar signature. Alongside many other test facilities, the RCS lab at Helendale occupies a large open area upon which models of aircraft and other test specimens can be mounted on poles, often either consisting of acute angles or made of a radar transparent substance. The test articles can then be exposed to emissions from various radar systems and from various aspects. This is, by its nature, a highly sensitive field of work, and security is typically tight.
The facility has underground areas into which test articles can be lowered when not in use, to hide them from prying eyes. Radar arrays, too, are mounted on hydraulic lifts so they can be raised or lowered, as well as slid into place, as required. Secure storage buildings on site also house test articles when not in use.
A test article for the BAE Systems Replica fighter jet concept inverted on an RCS test stand: