Passive tracer

What good is a stealth aircraft if as soon as it starts firing tracers any AA gunner or other AA unit can follow the tracer track back to the aircraft and shoot it down? Well, no good at all.

Back in the days when we planned to arm the steath aircraft this was a real concern.

One answer was the PASSIVE TRACER.


An ACTIVE TRACER is burning or emitting something which can be followed.

A PASSIVE TRACER emits nothing but rather is trackable by other means.

These NORTHRUP experimentals trace by reflecting light from a laser mounted on the aircraft.

A variety of mirrors and prisms were tried. Numerous types of lasers were also tried.

“Super John” Morris “The cannon king” - Springfield Arsenal demonstrates a top secret US NAVY experimental propulsion experiment. He designed guns for the USN. Now retired. (possible joke)

That is brilliant! WOW! Necessity is the mother of invention. Thanks for posting this and the other tracer post. Totally fascinating engineering. Just incredible.

Interesting; this uses the same sort of technology as used in laser surveying, where the “stick man” holds a prism on a stick that bounces a laser back to the surveying unit.

Question: which case were these used in?

Answer: none, these never made it past the bench fixture stage where they were fired by air guns.

Those projectiles with the passive tracers are just incredibly fascinating. Really interesting stuff. I wonder if that is the same John Morris I know and purchased a few items from a while back? If so, I did not know he was a cannon designer, very cool :-)

Most likely. John retired from the US Navy and runs his “Springfield Arsenal” business in Springfield Virginia. He sells various ordnance including items which would interest you. I paid him $10 to take this photo. He would likely want to have the copyright back BUT that is not likely. I like it !

Too funny!!! Yes, I think that must be the same John then. I purchased a few really nice items from him a few years ago. Very nice guy. That pic is priceless.

John works lots of shows and does a good business on line. He does come upon some real goodies from time to time. Ebay has pretty much put him out. He likes the BIG STUFF and has a SERIOUS cannon collection.

Interesting. What was the plan to keep the burning propellant from coating the mirrors and prisms with residue, rendering the whole idea moot? I’m guessing that the idea never got that far? Super-clean propellants? I know that some of the pistol powders around these days are so clean burning, that to look inside an empty fired case, you would swear it was unfired.


Nothing declassified as of this date.