A United Nations report calling for a moratorium on autonomous weapons systems that emerged Thursday cites the Navy’s Phalanx Gatling gun for ship defense as a system that should receive greater scrutiny because of its ability to automatically fire on perceived threats.

The Phalanx Close-In Weapons System (CWIS) is deployed on most Navy surface combatants and is designed to automatically detect, track and fire on anti-ship missiles or surface threats. The draft U.N. report submitted in early April and posted online this week addresses what it calls lethal autonomous robotics, or LARs.

The Phalanx Close-In Weapon System. Photo: Raytheon

The report calls for a close examination of LARs and a moratorium on their use until international rules are agreed up for deploying such systems, while acknowledging that the systems listed have “various degrees of autonomy and lethality.”

“Their deployment may be unacceptable because no adequate system of legal accountability can be devised, and because robots should not have the power of life and death over human beings,” the report said.

A Navy official, commenting on the report, said the Phalanx system is always monitored and its level of autonomy varies depending on the situation. In high threat environments, CWIS can be set to autonomous “detect to engage” mode because it is a last resort system and needs to act quickly to take out a missile closing in at “more than 10,000 miles per hour.” A human would slow the process down, putting the ship and sailors in danger, the official said.

When operating, CWIS is monitored by humans to avoid false tracks and ensure it is “tracking what it thinks it’s tracking,” the official said.

CWIS, built by Raytheon [RTN], was cited among several other systems, including Israel’s Harpy, a  fire-and-forget autonomous system to destroyer radar emitters; the United Kingdom’s Taranis jet combat drone; and the Navy’s X-47B, an unmanned aerial vehicle designed to launch off aircraft carriers.

The report recommends that the U.N. Human Rights Council call on nations to implement a moratorium on “at least the testing, production, assembly, transfer, acquisition, deployment and use of LARs until such time as an internationally agreed upon framework on the future of LARs has been established.”