Uninformed Flying Oblivious

The brainless lead the blind again...

...Plasma aerodynamics offers tantalizing promises of improving aircraft performance. By producing a thin layer of charged particles around an aircraft you can change the behavior of the boundary layer, significantly reducing friction. The charged layer also absorbs radar, improving stealth.

When my colleague Justin Mullins wrote about the subject for New Scientist magazine back in 2000, it seemed to be an obscure Russian technology dating from the late 70’s which the US was just beginning to examine. But it offered real benefits, with a potential drag reduction of up to 30%.

“A cut in drag of 1 per cent means you can increase an airliner's payload by about 10 per cent, or it could simply fly farther or faster,” Mullins pointed out, “Just imagine the effect this could have on cash-strapped airlines.”

The Russians seemed to be years ahead, even marketing a plasma stealth add-on device said to reduce radar returns by a factor of a hundred.

He concludes by wondering if the technology can actually work in practice.

“Either the new labs are a huge waste of time and money, or the American military knows something we don't.“

As it turns out, they certainly do.

A lot of information on stealth disappeared from the public domain decades ago when the whole subject turned black. Which was why I was surprised to find the original patent for plasma stealth still intact.

Patent 3,127,608 is called "Object Camouflage Method And Apparatus," and "relates to a method of making aircraft or other objects invisible to radar." The inventor, one Arnold L. Eldredge, describes the theoretical basis of plasma stealth accurately.

The most surprising thing is the date. The patent was filed on August 6th, 1956. The technology has been around for fifty years...

...check out Patent 4,030,098 (1962) “Method and means for reducing reflections of electromagnetic waves “ – assigned to the Secretary of the Army and the rather similar Patent 3,713,157 (1964) belonging to North American Aviation, later absorbed by Boeing – “Energy Absorption by a Radioisotope Produced Plasma”

Both of these use the same basic concept: a coating of radioactive material producing a flux of either Alpha of Beta particles ionize the air, producing the desired layer of plasma. It’s a clever solution. Radioactive paint weighs virtually nothing, does not require any power input and can be dirt cheap. One of the suggested emitters is Strontium-90, which is produced in abundance as a waste product by nuclear reactors.

It’s also quite safe. With a thin protective coating to prevent it from flaking off, the soft radiation (unlike dangerous Gamma radiation) is not a hazard to pilot or maintenance personnel. This type of material is only dangerous if inhaled or ingested...

...The radiation levels involved – 10 Curies per square centimeter – would give the plane a visible glow at night, making it a beacon to enemy air defenses.

Good grief. 10 Curies per square centimeter.

I don't know where these cowboys got their debriefing, but that's highly hazardous to be around. But this is the same D.o'D. that uses depleted uranium for munitions, so perhaps I shouldn't be surprised. But check it out: a microCurie is about 2,200,000 disintegrations per minute.

A millicurie is a nontrivial amount of radiation to work with. I know, I've been working with radionuclides every day for the last 25 years. But enough strontium 90 to glow in the dark to cover an airplane at 10 Curies per square cm... good grief... that's hot...

...So, were there any sightings of mysterious glowing U2s? A CIA report on the CIA's Role in the Study of UFOs, 1947-90 states:

According to later estimates from CIA officials who worked on the U-2 project and the OXCART (SR-71, or Blackbird) project, over half of all UFO reports from the late 1950s through the 1960s were accounted for by manned reconnaissance flights (namely the U-2) over the United States. (45) This led the Air Force to make misleading and deceptive statements to the public in order to allay public fears and to protect an extraordinarily sensitive national security project.

Why would anyone report a U2 as a UFO?

The early U-2s were silver (they were later painted black) and reflected the rays from the sun, especially at sunrise and sunset. They often appeared as fiery objects to observers below.

I leave it to those who compile statistics on flying saucers to say how many glowing UFOs were sighted under these conditions and how many appeared to be luminous on their own account. Note also the wording in Patent 3,713,157 which says that the plasma cloud produces a combination of ‘absorbtion, reflection, refraction and diffraction’ across frequencies including visible spectrum, which would certainly alter the appearance of an aircraft, perhaps to the point of making it an unrecognisable blob.

A radioactive coating would be unlikely to be applied to the entire aircraft – as Martin Streetly of Jane’s pointed out to me, this would immediately block the aircraft's own radar, communications and navigation aids. However, a coating on the locations contributing most to radar returns – inlets and wing-body junction – would have a significant effect, and a coating along the leading edge would give the desired reduction in drag. It might even be possible to have coated surfaces which could be covered or uncovered as needed...

Many have commented on a photograph of a B-2 from Edwards AFB (published in Air Forces Monthly in October 2000) in which the wing seems to be enveloped in a faint glowing cloud. This was explained by the Air Force as water vapor, but some commentators have argued that such a cloud would not form simultaneously above and below the wing.

See also the discussion and perhaps anomalous picture here.

The USAF appears to have been using plasma aerodynamics for decades. The Russians certainly know all about it , as does anyone who has bought the technology off them. According to the patents it has additional benefits too – it can muffle the noise produced by engines as well as preventing contrails from forming...

So why keep it secret if the competition's aware of it? Because it's incredibly dangerous to the user. Not the paper pushers in the Pentagon: it's slowly deadly to the pilot and the mechanics and the engineers and the troops working with it to try to protect everyone else.