Originally pioneered by the United States but dropped for political reasons, Russia, China and even Israel are pioneering stealthy combat drones (UCAV or Unmanned Combat Vehicles) with major implications for future warfare.

Less expensive than advanced stealth fighter aircraft, stealth drones can do almost anything a combat aircraft can. For cash-strapped countries, stealthy UCAVs can reduce the number of fighter aircraft needed for offensive operations, retaining combat aircraft for air defense and air superiority operations.

China’s Sharp Sword

China unveiled its Sharp Sword GJ-11 Lijian stealth combat drone at its 70th Anniversary Parade on October 1. The drone that was seen in the parade is different from the drone that previously appeared in tests.

China claims all the weapons seen in the parade are in active service, a claim that should be viewed with skepticism. So far at least, aside from some grainy photos of a GJ-11 that differs a lot from the one shown in the parade, China has not made a convincing case that its stealth drone is operational.

Russia’s Hunter Stealth UCAV

Last July, Russia’s Defense Ministry released footage of the first test of its developmental stealth combat drone, the Su-70 Okhotnik (Hunter). This is a much larger stealth platform than the Chinese GJ-11, weighing some 20 tons.

It has a 20-meter wingspan and can fly at a speed of 1,000 km/h. Right now it appears to be powered by an Al-31 turbofan engine, the same engine that is used for the Su-27 fighter jet (which requires two engines).

At the end of September, the Russian Defense Ministry provided video of the Su-70 flying with a Su-57 fighter jet and suggested that the Su-70 and the Su-57 operate cooperatively against targets.

Both the Chinese and the Russian stealth drones are based on the US X-47B. Built by Northrop Grumman for the US navy, the X-47B was intended for aircraft carrier operations. The X-47B first flew in February 2011.

The navy project was preceded by the X-45A air force experimental UCAV, which was a stealthy platform developed by Boeing’s Phantom Works. Like the navy program, it would eventually be dropped.

Instead, the US air force (with support from the CIA) developed a stealthy reconnaissance/surveillance drone known as the Lockheed-developed RQ-170. The RQ-170 was used to keep watch on the Taliban and al-Qaeda in Afghanistan and Pakistan (where it was nicknamed the Kandahar Beast) and performed still-secret missions tracking Osama Bin Laden.

During the same period, the RQ-170 was keeping tabs on Iran’s nuclear program, flying from Kandahar over Iranian territory. It was on such a mission on December 4, 2011, when Iran (perhaps with help from Russia) captured an RQ-170. This suggests that the RQ-170’s operations over Iranian territory gave the Iranians the chance to spoof the drone’s controls – real-time data links (probably by satellite) were intercepted by the Iranians/Russian, thus revealing the drone’s location.

Combat drones have different operating modes. The most common are drones that are controlled remotely by pilots (whether the pilots are located on land, at sea or in aircraft isn’t especially relevant); drones that fly semi-autonomously where their position is updated by GPS or other satellites; and drones that carry out a mission without any data link are truly autonomous.

A combat drone may or may not want to confirm its target before striking, which involves some form of data link, either a direct radio link or by satellite or aircraft relay.

The Russians appear to be using the Su-57 and its AESA (Active Electronically Scanned Array) radar to pick out the target or targets for the drone, thereby reducing the cost of expensive sensors in the drone and making it practical for a single combat jet to control many drones at the same time and to do so with the combat jet far outside of the range of enemy aircraft.

This reduces the need for high-end stealth features on the combat aircraft (which appears to be Russia’s approach) but enhances the strike characteristics of the combined (fighter/drone) force.

China’s GJ-11 is much more of a mystery. It certainly looks like a stealthy drone, but the model on parade appears to have a fully integrated engine, whereas photos of the test model are different and show the jet engine protruding from the rear of the drone (significantly compromising its stealthy character). (The engine is reportedly a version of the Shenyang WP-7, also used in the J-7 lightweight fighter.)

The GJ-11 has a wingspan of 14 meters, smaller than the Russian drone, and is said to carry the Chinese version of the US small-diameter bomb. The US GBU-39 is a guided 250 lb bomb.

The Chinese versions (50, 100, 250 lb) are guided bombs under the name Thunder Stone Gliding Precision Bomb (LS-PGB) and have been in service since 2006. Some of these use laser targeting. Exactly how they would be operated in the GJ-11 isn’t known.

Despite the claims, neither the Russian nor the Chinese stealth combat drones are ready for combat use. It will take a few years at least before they are perfected.

Israel’s Harop Loitering Munition

Meanwhile, Israel has a quasi-drone, quasi-loitering munition called the Harop, which was built by Israel Aerospace Industries (IAI). This is technically a stealthy loitering munition, but if its mission is aborted for any reason, the Harop can return to base.

Otherwise, the Harop is designed to crash into the target. It can support autonomous operations for six hours. Its warhead is small, only 23 kg, but the Harop is accurate. The Harop has been exported to Azerbaijan, Germany, India, Turkey and Singapore and has been used by Israel against targets in Iraq and Syria (including knocking out a Syrian Pantsir air defense system). Azerbaijan used the Harop successfully in the Nagorno-Karabakh conflict in April 2016.

Iran has also “cloned” the US RQ-170, resulting in one model called the Saeqeh (Thunderbolt), which has a piston engine, and another called the Shahed 171 Simorgh (Phoenix), which is jet-powered.

The Saeqeh was flown over Israeli territory from Syria and was shot down by an Israeli Apache helicopter. The Shahed 171 appears to be a fake and is not in production. Neither drone is really stealthy.

America’s missed UCAV opportunity

While the US has non-stealthy combat drones, most importantly the General Atomics MQ-9 Reaper, a hunter-killer drone that can carry smart bombs and Hellfire missiles, the only US stealth drone is the RQ-170, which is not suited for carrying munitions.

While the Russians and Chinese keyed their designs off of the X-47B (and maybe the X-45A), the US dropped both those programs because the US air force believed they would compete against the acquisition of F-35 stealth jet fighters. For the same reason, the US navy bailed out of the X-47B project.

This meant that the many technical breakthroughs achieved by the X-45A and X-47B were shelved, and the US air force idea of linking combat drones with combat aircraft disappeared.

Now, in 2019 – significantly behind its mean competitors – the US air force appears to be trying to revive stealthy combat drones with the XQ-58 Valkyrie. Valkyrie had its first test flight in March and a second in June.

The Valkyrie is part of what the air force calls its Skyborg Program, which seeks to link up its advanced fighter jets with stealthy combat drones like the XQ-58. The new twist is that the Valkyrie will include many artificial intelligence enhancements to make it smarter against enemy targets and defense systems.

If the program receives Congressional support, these drones should be flying possibly as early as 2023. But to get there, modifications are needed to enable the F-35 block 4 and the F-15 EX fighters to share data and information with the Valkyrie drone.

There are two reasons why the air force has finally relented and permitted the development of stealthy combat drones. The first reason is simple economics. As adversaries develop advanced sensors that can track the F-35 (recently demonstrated in Germany), the usefulness of the F-35 as a deep penetration weapon has been reduced against a major adversary.

A drone, on the other hand, especially if it is stealthy, can carry out the same penetration mission at less cost and without the risk of losing a valuable pilot or a $100 million aircraft. The second reason is economics: stealth combat jets are not only expensive, but once lost they can’t be replaced in any time frame that is acceptable in a modern combat scenario.

But the US has lost more than 15 years, and by the time Valkyrie is deployed, it will be more than 20 years since the first X-45 flew.

The US advantage is it is already well along in integrating combat operations and exploiting the latest advances in radars and other sensors. But whether Congress will support a stealthy UCAV is, as they say, still up in the air.

Also read: Can anything stop the attack drones?