This was a treat, My first real engineering job was working on Flight Computer system for the Tacit Rainbow back in 1988. Very secret program, didn't even use that name but a letter and number code. Little side note, We found more information about the program from Aviation Week & Space Technology than from our Security Bulletins.

Worth noting is that at the time of this weapons development: The reason the Soviets were so terrified of this weapon is due to the intelligence provided by a guy named Adolph Tolkachev. He was a lead designer of Soviet radars and SAMs at Phazotron, and give us arguably the greatest intelligence in Cold War history; detailed information of Soviet radar frequencies and signal processing, including the Crown Jewel "war reserve modes". By the time they caught him it was too late; he gave us everything and it would take years to completely redesign their signal processing. He's worth reading about.

The first I heard of Tacit Rainbow was in the early 90's. It was among a list of munitions being adapted for use on the M270 MLRS. 30 years ago. It's neat seeing the M270 and it's younger brother HIMARS being still so important in the business of war.

This appears to be one of the most honest, creditable and informative military hardware info channels on KZfaq. Thanks Alex, for the professional and studious approach you give to your channel. Keep up the amazing effort!

Always wondered what happened to the TACIT Rainbow and now I found out. Thank You for letting me know. During my time in the Marines working TACP for 1/5 1975 tob 1987 there were a bunch of new weapons we were instructed on and alot of them were never adopted for various reasons. As a ground controller we had to know about the weapons we were working with and it's capabilities because sometimes we called danger close for friendly troops in enemy contact. We called Air Strikes, Naval Gunfire, Artillery, and Medivacs.

in-depth. keen, and beautifully structured. This video now resides in the anils, of what, all of History will remember.

Thank you for the information. Was at Korat AB working on EB & RB-66 while watching WW at work. Was TDY from Minot AFB for 6 months in spring 72 when our sqdn. commander got shot down on BAT-21 but SEALs went & got him out. In 1973 took ANALQ-119 pods from my base in UK to Korat for 1st F4 WW successful experiment. That was when SR-71 came. Lots of flat head screws!

Thanks for covering the AGM-136 A Tacit Rainbow project. I was a USAF project officer in the TR SPO (System Program Office) in 1986-1989.

Back in the 90's we had a game called Megafortress, based on "Flight of the Old Dog" by Dale Brown. Basically it was an incredibly enhanced B-52 with an enhanced bunch of munitions to go with. It specifically featured the AGM-136 just as you describe it, and feature-accurate (and many other air-launched weapons), and I really enjoyed the (simulated) tactical use of this weapon! That's when I first learned of the AGM-136.

Thank you for sharing this video. My father was involved in the first drones back in the '70s, and he was in the airforce stationed at Offutt AFB, serving as the Chief of Reconnaissance at SAC Headquarters. There is a display at the Museum showing the Drone he was a part of. He would travel to Point Mugu, California, to test it on many occasions. Thanks again. Felix

I appreciate your actual narration as much as the information.

Outstanding presentation, my friend. I appreciate your honesty and your avoiding the sensationalism which often drives so many of the KZfaq military presentations. Thank you again for your work and Merry Christmas, my friend!

Alex, I truly do enjoy these videos and your voice-overs. You have become my go-to source of this kind of info.

Really happy to see you cover Tacit Rainbow... Have heard of it but never seen a video covering it like this.

You know there is a saying in the military.. "By the time you know about it we got something way better!"

I have been involved in the Military Air Power all my life and find this type of content very interesting. Keep up the good work.

I loved this video. As a USAF veteran, I still managed to learn a few things. Very well researched. Much appreciated

The pilotless drone being wheeled out at 4:30 is the Jindivik (Aboriginal for ‘the hunted one’), an Australian radio-controlled drone developed in 1952.

Another fascinating ARM was Side-ARM, a modified Sidewinder missile fitted to the Apache, capable of killing SAM search/tracking/guidance radars. Sadly, all of the war stocks were used up in ODS, and there's been no replacement offered.

As a USAF ECM systems, Maintainer, Supervisor and Instructor from 1978-1992 You are on the right track with your conclusion. Just because a program is shuttered or disbanded does not mean the knowledge is lost or the improvements do not go on. . That second word in the naming is not just at random either.

Excellent research, and great content. Fantastic mate! Well reported and presented. Happy holidays!

I was the lead Engineer in developing the system which assembled the Missile, it was fiberglass with aluminum bulkheads all glued together. It is good to finally hear about both the political issues and the technical issues leading up to the program cancellation. I always wonder what happened to the missile assembly equipment we delivered to Northrop.

Fantastic! Alex keep it up .thank you TC

Wonderful breakdown of this weapon!! 👌 thank you, very informative & great insight 👍.

As an FYI, U.S. Navy was also flying attack drones off of carriers for a brief period during WW II. Would love to see a video about them I wonder how tacit rainbow compares to the Israeli Harpy series of attack drones… Have you ever read books by Dale Brown? There’s a cruise missile in a few of his books that’s just like the one you describe towards the end of the video: AGM-177 Wolverine. Incredibly agile, it can detect and dodge incoming AA fire, be it guns or missiles as well as release chaff and flares. In addition to its own integral warhead, it has 3 payload bays allowing for a multitude of mission profiles to be carried out. The Wild Weasel version carried a mixture of miniature decoys and SFW skeets. It would be preprogrammed with the locations of enemy air defenses, fly over them and release a decoy. When said air defense system turned on its sensors to lock onto the sudden “intruder”, the Wolverine would seed the location with the skeets. When first used in combat in the book “Fatal Terrain”, a handful of Wild Weasel Wolverines blasted a massive gap in China’s air defense network

Really enjoyed this Alex. Great work. Seeing footage of SA-2's, Tor's (SA-15's) and other Russian hardware being hunted by Tacit Rainbow feeds into that entire escalation premise. Range, detection, loiter, stealth, maneuverability etc. in the world of SAM design and employment. Fascinating deep dive. You should get into the type of HARM 88 employment modes like Pre Brief, Equation of Motion etc. Would love to get your treatment on how HARMs are employed in current 4th gen designs.

My friend Charlie was a weasel pilot. He flew a F-105g. Never shot down. First in last out. 8 mid air refuelings were routine per mission. They fired a lot of harms.

Well done. Great show. Keep up the good work. T.

Many moons ago when I was serving in the US Navy, I head a guy talking about an anti radiation missile being used in Vietnam which could lock on the the signal from the magnetron instead of the antenna. If memory serves me it was referred to Iron Hand. Apparently it was developed in response to the VC's tactic of using multiple antennas to confuse anti-radiation missiles. It was described to me has having what appeared to be blisters on the lower side of the front of the missle. As the story was related to me, when ever the VC heard "Flying Iron Hand" on the air, they would shut down all their missile sites.

Great video. When I was at Texas Instruments in the mid-80s, several colleagues worked on "the other side of the wall" on Tacit Rainbow but I never found out what it was. Most of our work was on the HARM AGM-88 which was originally designed for the Navy to take out a ship's air defenses. If the enemy powered off their radar, the HARM remembered the position and movement of the radar.

Lovely 80’s style marketing photos for such a secret.

I remember first reading about the AGM136 from a NYT article in 1986. It was definitely ahead of it's time.

You kept mis-labeling the ALCM as AGM-88 when it is in fact an AGM-86B. You did state correctly once that the HARM was the AGM-88. I was a 2M051B in the USAF and was kept busy maintaining the stockpile of AGM-86's (both big boom (B) and little boom (C)).

A friend of mine worked on the AI for a loitering Tomahawk missile and predator drones for the DOD in the late 90’s. It is pretty insane what it has been able to do since the late 90s and early 2000. He was able to get them to fly a grid hunting for targets of opportunity, being able to automatically recognize vehicle shape, color. Make/model and even license plate number. It could also detect muzzle flash and identify if the vehicle shooting was friend of foe... it would alert the controller of the detection and the controller would authorize the automated strike on the vehicle. During invasions they can clear the tomahawks and drones weapons hot, if they see a target of opportunity with over a certain threshold of probability it can automatically attack without needing approval (like, there is a 98% certainty the tanks it sees are T72s, so it can automatically attack. Pretty crazy stuff.

Dude your channel is awesome! Please keep up the great work. 👍

loved this, awesome to get a behind the scenes tour of an awesome museum!

Adding an inertial guidance system to these missiles would allow them to REMEMBER the positions of the enemy radars...even if those radars are turned off. Same for targets that are not even emitting emissions in the radar frequencies. Those targets could be "designated" by fighter aircraft in the area, using lasers or even targets picked up using visual references from orbiting satellites. I would be SHOCKED if newer versions of these missiles DID NOT have inertial systems integrated into their operation.

Really fascinating - thanks for the research. The Tacit Rainbow profile reminds me of the British Aerospace ALARM (Air launched anti-radiation missile), that could be launched direct, or - if the radar turned off - could climb to 8 miles, deploy a parachute and loiter. If the radar turned on again, it would fire a secondary engine and rain down. It was used in the both Gulf wars and Kosovo to some effect.

Thanks for an informative and entertaining video. I am always ready to learn more about new weapons systems. As of today, I am a new subscriber.

Super Video!!! Thank you for sharing it with us!

When I went to work at Northrop their was a mural with Tacit Rainbow on it and asked what that was. It its the canceled loitering....... In my opinion the problem was that to be effective, the TR would need much more computing power than available at a reasonable cost for a munition. While I was there Northrop developed the BAT missile which used cutting edge sensor and computing to be very effective in tests against armored columns. Of course with the end of the USSR the need to deploy it was gone. Today the sensors and computing power is so much better and drastically less expensive. The concept is still valid for TR, and I would not be surprised if a kit can be put on an existing drone to ferret out enemy radar.

Wild weasel pilots were some of the most tightly wound up people I have ever met. I met one at a Society of Old Crows meeting in San Diego while I was demonstrating a fast frequency hopping transceiver prototype. (Jam this, suckers! That was fun to develop,) This would be the early half of the 1970s. He paced around chain smoking and jumping at stray noises. His departure was fun to watch. As soon as he was allowed he hopped into his plane and taxied out to the runway followed by arrowing off the runway almost vertically. On the other hand one of the more laid back former military people I met in the 80s was a Wild Weasel WEO. (And that fast frequency hopping and related experience inspires thoughts of techniques that could render it far less effective. Some of them I've heard of being actively used.) {^_^}

This channel is criminally underrated

Subbed in the first 30 seconds. Can already tell this will be good 👌🏻

It seems to me you could separate the radar transmitter and receiver enough to keep the receiver safe. It would then be possible to have multiple transmitters and just turn on a new one after one was taken out of service.

I was involved on the propulsion system to a limited degree in the early 1980s. We were shocked when the DoD suddenly dropped the program. It’s actually a genius method of taking out subversive radar systems. I also worked on Tomahawk and ALCM propulsion systems. When I was in the Navy I specialized in A-7E Corsair propulsion and fuel systems. I also worked on Chukkar propulsion systems.

Some very interesting info. Keep up the great work.

Stealth Drone giving false radar signals was my favorite part.

I worked on flight test for Northrop durng this timeframe. This was a new design, plastic bird so to speak, hard to see, testing new design and fabrication techniques with difficult fuels for maximum performance. It was designed to be launched form Navy and Air Force B-52 bombers. Flight testing was done with both aircraft on radar SAM targets at NWC China Lake. We were all dissapointed the program was cancelled despite some very good potential.

Nice job! Trying to catch up while also trying to learn development history. Years ago I saw a missile at the AF Museum called the BDM-6, about which they had no placard. Also, it seems to me the MARD is conceptually related to the "Green Quail" drone/missiles carried for a time by B-52s. Any light you can shed on these or on the Fairchild Blue Goose will be appreciated. Happy New Year to you!

WOW -- BEST EVER KZfaq info on Military STUFF

Well researched and thought out. Bravo

I would note that many of the missiles shown on this article are not the TR in flight but rather other flight test missile of a different variety tests in the air.

Oh you’ll love the SLAM missile. Predates this and pioneered star tracking and terrain following if I recall correctly. Also had nuclear sub munitions

⚓️ Thanks Sanboxx 😎 given the high energy output of radar & the versatility of current satellite technology…. You can be assured sats are observing radar systems everywhere there may be a reason ⚓️

Nice vid about a neat historical program. Well done!!

Tacit Rainbow and it's ilke ara a class of weapon that are specifically homing missiles. But what interests me are area-scale EMP explosive devices. These can range from air-dropped free-fall bombs to mortar rounds. It's really hard to find comprehensive technical information on these. Is this a topic you could look into and do a video on?

Those F105's had extremely primitive radar warning equipment and the Vietnamese moved their installations constantly. The Shrike was a very simple anti-radiation missile with a very puny warhead. You can read many first hand accounts. The descriptions of their equipment just floored me. The bravery of pilots in Vietnam was extraordinary. Today might be the time we make Tacit Rainbow a reality. We finally have the guidance and AI technology to make it work. I would not be surprised if something like it is not in development as your video airs.

Very good research and well presented, thank you.

B-58 was the first to launch Satellite Recon- a facet of the Program

You should check out what happened to the Silent Eagle and the F-18 internal weapons pod. Or even the Genie nuclear missile.

Trained Wild Weasel pilots as part of the training/testing operations within the Nellis complex. What the public sees is easily 20+ years behind capabilities.

Flawless analysis.... Alex

Well researched…Well said….WELL DONE !!

I think you also have to remember that although it sounds good, the turning off radar was not when they saw an anti radiaton missile it was a standard cyclical practice turning on for around ~30 seconds and off for ~30 seconds, this means it's effect will be unnoticeable as it would be constantly getting close then moving away. This not to mention the development of anti drone tech that if you look at it's performance in Syria has been amazingly successful. It would probably cause an increase in non radar AA, spoofing and decoys though to get rid of the annoyance and demoralising nature of them.

Boeing Australia’s Loyal Wingman could potentially fill such a role. It’ll be interesting how that programme pans out. Also, at 4:30 it looks like an Australian Jindivik 1 target drone being wheeled out. The Jindivik was later exported to the UK and USA.

The AGM-88 does not need the targeted system to be radiating. The iraqi's used what we called blanking during the 1st gulf war and it did them little good. If the radar is transmitting and gets identified by the Agm-88(which can identify thousands of frequencies almost instantly) it's as good as dead. The Agm-88 style of warhead is designed to "frag" the radar equipment rendering it inoperable and not requiring a direct hit due to the associated equipment required to be in proximity to a radar system also getting damaged (the Aim-9 uses a similar style warhead called annular blast fragmentation). The Agm-88 is definitely older but a super effective weapon and I see it being in the arsenal for many years. You failed to mention the F-16 being used as sead platform as well. Love your videos and keep them coming!

Hope there already are a video about earliest drone-like systems which was actually used in combat.

The difference in range may be due to the launch altitude. Launch at 30K feet gives you an enormous glide path with minimal engine power. But it makes you an easy target. Launching at operational altitude makes you hard to find, but kills your range. I ran into something similar trying to get good range estimates on the original cruise missiles.

That's proper clever, especially when you think about the year this was being developed. Even today, this technology is mightily impressive. 🇬🇧🇺🇸✌✌

Just to clarify, it seems that these systems only hunt radar transmitters, not necessarily complete radar systems.

A very low cost option would be mini Blimps with enough powered flight control to stay in the target area, detect and launch a small missile at the enemy radar systems. Even if it only temporarily puts the system out of operation for a day. More than enough time for air assets to get to mission targets and also destroy these sites. Literally dozens could be launched and loiter for a day.

Minor error at 9:30; ALCM is the AGM-86

You should do a video about the M25, it was meant to kill troops out in the open with a killer shockwave.

Loving that end of the video music. Aldas uses that song for all his F1 videos.

Great video sir I thoroughly enjoyed it.

Many versions developed by the Israeli military long ago. Made the Syrian anti-aircraft missiles worse than useless during that Lebanon war. During the syrian war, they made them for only a few hundred dollars each. Any missle launch at a plane would start following the drone instead, taking the missle to any nearby target the Israelis wanted struck.

Joe Kennedy Jr died in one of the first attempts at an RC drone, using a B17.

Harm missiles actually have a setting that even if the radar shuts down after the missile has acquired the target, the harm will remember the location of the radar and still kill it.

A bit more information to add to my first comment. The military personnel only assisted Northrup engineers with simple tasks such as handling (the mear sight of the vehicle was classified at that time), engine tests (more on this later), loading for flight, and flight testing off the squadron's NC-130H (fomally a DC-130H; 65-0979) test bed aircraft. That said, having the access one learns certin capabilities and operational parameters. I personally never witnessed a completely loaded TER configuration, too early in development. We only had one test vehicle at a time. The main wing was a scissor swing wing to be inline with the fuselage for storage and pre-launch purposes. Wing was to deploy soon after launch (part of the software issue I assume). Our test vehicles had the main wing, vertical, and horizontal stabilizers fully deployed. The engine was to be free wheeling in flight and started with a black powder gas grain generator to both ensure proper RPM and ignition of the rather stable fuel at launch. For engine run tests, the start generator was removed (black powder is nasty, and made the engine a one time use). A bottle of compressed hydrogen was used for test spin up, and the fuel supply. This allowed for multiple test on the same engine in order to collect data and proof engine control software parameters. Several test flights were done on our range. I personally hang around the software engineer, due to my fledging interest in computers. I comfortably suspect it was the limited ability of the computer hardware at that point in time that doomed the project. The weapon system concept was a good idea. The missile was to be launched in masses, find a target and home in for a kill. Vietnamese SAM sites learned to switch or intermittently cycle the radars to defeat anti-radiation missles (AGM-45 Shrike and AGM-78s) then in use. This missile was designed to home in on a target, then loiter (fly a circle patern) at the altitude it lost the target's signal. If the target started to illuminate, homing commenced again until either the target is destroyed or weapon ran out of fuel. Swarms of these and their flight duration would technically destroy, or render radar controled AAA batteries (mobile or fixed) ineffective allowing friendly air forces to penetrated the enemy's air defenses. Shame it didn't work. I am sure this issue has been addressed with something even nastier. Done.

You like many others have placed a very high price in stealth, the radar technology to track stealth technology has existed for decades, let alone any modern technology that could do so. Rapier, an infra red guided (all be it short range) system was able to track stealth fighters during desert storm, astronomic radar tracks flecks of paint microns thick in orbit over the planet, to be avoided when launching space rockets, therefore any object traveling at speeds over 200mph (the speed of a diving peregrine, the fastest natural object, for extremely short distances) and traveling in what are relatively straight lines, or mostly straight flight lines maintaining relative airspeed, can easily be tracked by radar. The thing that is needed and probably already exists is a software system to track such objects in short bursts, potentially avoiding detection, with the in built ability to determine those that are natural i.e. changing direction and or speed or altitude rapidly, in a short distance and those that are man made i.e. maintaining a relative airspeed, altitude and relative course. I have not kept up with the latest technology to be able to say, but not doubt there are many things being researched, either way 'stealth' as you put it is not the panacea that you and most others place it to be, if the technology to combat it is not already out there it is, or at least should be in development. However nicely researched video Tacit rainbow would not be easy to research even now as it does relate to modern munitions, so well done.

Thanks for the good work, Alex! According to my sources at the time, the real Achilles Heel of the system was the rudimentary AI used to determine the identity of the primary targets, which had that miserable success rate you highlighted. There is a rumor that a live demonstration of the system resulted in not the destruction of the simulated SAM radar equipment, but rather the loss of several unoccupied Greyhound busses used to transport the big shot observers...

Another interesting video. Thanks, you do good work.

Great video. Merry Christmas

Of note, the Israelis deployed something like this back in the late 1980s with the Harpy (which is still in use today). Given the level of technology-sharing between the U.S. and Israel, and some odd diplomatic exchanges between the U.S. and the Israelis regarding the Harpy (the U.S. got VERY upset when the Israelis sold it to the Chinese), I would not be surprised at all if the Harpy uses technology originally developed for Tacit Rainbow, despite claims to the contrary. A problem with loitering anti-radiation missiles is that in order to have long loiter times, they generally have to be slow. If the missile is far away from the target radar when it turns on, the engagement could be over, with a friendly aircraft shot down, and the radar turned off before the slow loitering missile gets there. High speed missiles lack loiter time, but they have the speed to more realistically complete engagements before SAMs can complete theirs. The British ALARM attempted to balance the two approaches with a fast missile that could "loiter" via parachute, and then fire another rocket if a radar turned on, but this approach has not caught on, quite possibly due to the complexity of the system. The most recent approach is to equip anti-radiation missiles with additional sensors, so if a radar does turn off, the missile can still guide.

We don't have the same issue with political corruption involved with military contractors, our MP's are forbidden to get involved with any companies at all, let alone companies that are military contractors. It's a better system than yours, the US needs to clean this problem up.🇬🇧🇺🇸✌✌

When missiles get really clever, they will realise they are on a suicide mission and turn round and land on a beach somewhere haha

Awsome video!! Fantastic job!

I wonder if, some day, these loitering platforms would be able to be ultra low power and be "fueled" by rising high when they sense a loss of charge, being operated by batteries, and have solar panels or wind generation systems that could recharge toe system, so It could return home, or go on another unmanned mission. Having them be propeller driven, and using the wind to turn the engine in reverse, like a generator/alternator, recharge them might be a unique idea for the future

The past is interesting but not really misterious. IAI Harop was used heavily by Azerbaijan in their 2020 war with Armenia. Not only destroying radars but many other signal emitting systems, especially jammers. Drones were heavily used in this war and secured a victory for azerbaijan.

Great video very informative and well presented.

Very informative. Gonna subscribe

I was glad to hear u talk about remote drones. I was watching their use at White Sands proving grounds n the 1980’s. I’m still waiting to see released sum of the “other toys” that still appear to be under “secret” status. The “toys” r quite exciting, an though I would think Old by now, are terrifying to think of being improved

Two. One is "AWACS" for targeting missiles delivered to theater by aircraft. The same equipment of the later can be carried by GH. The Ryan 147 was a programmable jet drone that became functional in 1959.. and was then used under the name FireBee in Vietnam.

I was a flight test engineer on the Tacit Rainbow Combined Test Team and was a member of the aircrew that first launched a TR from the B-52. DARPA is mentioned in the video but I don't recall DARPA being involved in the program, at least not in 1986 and subsequent years when I was involved. The program started in the black world, then the existence of the program was declassified but it still was played close to the vest. It was a clever concept but nothing about it was really that exotic (no, I will not go into details). In general, the design was optimized for low cost rather than the most possible capability. TR had its share of problems during flight testing but in general it worked well. The program was planned with an aggressive and "success-oriented" schedule with no margin for error which was a set-up for failure because every little problem became a crisis. What really killed TR was the end of the Cold War. The US DoD budget cratered in the aftermath of the end of the Cold War. The USAF prioritized the B-2, F-22, and C-17, and other programs (particularly those with some problems like TR) no longer could be afforded.

Very well done!

Your insights are informative and very topical. So I always turn on captions so I can read along with the voice. What a surprise, today your audio came out in broken Russian. This leads me to wonder whether your excellent work isn’t being tampered with?

This missile is so secret, that there's even a KZfaq video about it. So secret...

Well done sir!😀

Great videos and informative!