Resurrected Weapons: AGM-129A/B ACM

The AGM-86 Air Launched Cruise Missile was a great way to extend the service life of the B-52. Now, despite the massive Soviet air defense network, SAC’s beloved manned bombers could rain nuclear hellfire down on godless communist scum from over 1,500 nautical miles away. Perfect for keeping big, slow bombers away from fancy air defense systems. And we’ve seen the effectiveness of cruise missiles with conventional warheads many times in Iraq.

But those commies had innovations of their own. They managed to make look-down/shoot-down radars for their advanced fighters, and even had a native AWACS by the 1980s. These could spot the small AGM-86s and shoot them down. One of the key goals of SA-15 was to be able to successfully engage inbound AGM-86s.

You probably guessed the answer to the above problem: stealth. Enter the AGM-129. The Advanced Cruise Missile.1 It had modern, low observability shaping and radar-absorbent material coatings to make it as sneaky as possible. Now it could exploit imperfections in radar deployments, with a vastly reduced detection range allowing it to elude Soviet air defenses. The AGM-129 also had an improved version of the Williams F107 engine that powered the AGM-86. The newer F112 used advanced internal coatings to reduce the thermal signature of the AGM-129. It also brought large improvements in range over the AGM-86’s 1,500 nautical mile reach, though the exact range figure for the ACM remains classified.

The guidance and navigation systems were also improved, but again, remain classified. Russian sources2 give it a CEP3 of 16 meters.

The AGM-129 used the same 5-150 kiloton warhead as used on the AGM-86, the W-80. It was also only marginally longer than the AGM-86, so it could still fit in the bomb bay of a B-52. However, it was about five inches fatter, had a wingspan two feet shorter, and was more than 550 lbs. heavier. And, of course, the stealth coating requires more maintenance. Here was the ultimate standoff weapon for the venerable BUFF, just in time for the end of the Soviet Union. Production numbers were repeatedly slashed, from 2,500, to 1,460, to 1,000, and then to the final total of 460 missiles.

Higher maintenance costs would eventually doom the AGM-129 to withdrawal from service in 2012. Which is a shame, because even if you’re not big into nuclear strikes, a conventional variant4 would be very useful against nations with modern, integrated air defense systems.

Verdict: Funding Approved by the Borgundy Air Ordnance Procurement Board


  1. A very creative name. 
  2. Seriously, they are the only ones that are willing to hazard a guess. 
  3. Circular Error Probable, i.e. the size of a target that the guidance/navigation system has a 50% chance of hitting. 
  4. To the best I am able to determine, no such variant was proposed. From other conventional variants of cruise missiles, we can reckon that replacing the W-80 with high explosives would give an approximately 1,000 lb warhead. 

One thought on “Resurrected Weapons: AGM-129A/B ACM

  1. Blacktail

    The AGM-129 ACM ended up being a white elephant, and it was doomed to fail from it’s very inception. It started-off as a power fantasy of blue-suit generals, and gradually metastasized into a requirement to build the impossible, with a blank check budget, and a prohibition on government oversight (the program’s classification level was abused for the deliberate purpose of hiding it’s problems from Congress).

    I wrote an article on the ACM for Military Today, which is easily the most complete ever published on the internet (and possibly any medium);

    My web sources include Missile Threat, Designation Systems, Global Security, Forecast International, FAS, and Astronautix, and I also included several books, including “Secret Science” (Herbert N. Foerstel) and “More Bucks, Less Bang” (Dina Rasor).


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