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Northrop Grumman has been doing detailed design work that lays a path to air-launching its Lumberjack loitering one-way attack drone from Kratos’ stealthy XQ-58 Valkyrie uncrewed aircraft. Multiple crewed and uncrewed aircraft are being eyed as potential platforms for employing Lumberjack, which is already being tested in surface-launched modes and will have the ability to drop its own smaller precision munitions.

In a statement to TWZ today, Northrop Grumman confirmed that “Valkyrie is one of the multiple platforms we’re doing detailed design work for to ensure compatibility with Lumberjack” and that “Valkyrie is a good representation of a possible use case.” The XQ-58 is prominently featured in the Lumberjack product card available on Northrop Grumman’s website at the time of writing. It also depicts a Lumberjack launching a Hatchet miniature precision-guided glide bomb, which the company also produces, and that we will come back to later on.

Our own Howard Altman also recently had a chance to talk with Michael Bastin, Northrop Grumman’s director of programs for Lumberjack, to get a broader update on its ongoing development. The new one-way attacker was first unveiled in April at this year’s Modern Day Marine conference.

Since then, Lumber has “participated in both of the T-REX events this year. So, those are the technology, readiness, and experimentation events hosted by OUSD(R&E) [the Office of the Undersecretary of Defense for Research and Engineering, also now referred to as the Office of the Undersecretary of War for Research and Engineering],” Bastin said. “Those are really valuable for us. We got a chance to get operators to look and engage with the system, [and] actually do an end-to-end simulated mission in a relevant type of environment with a lot of capabilities that people were looking for.”

At the T-REX events, Northrop Grumman also demonstrated Lumberjack’s “ability to launch from two different styles of [ground-based] launchers, the electric rail launcher and the pneumatic launcher,” both provided by other companies, he added. “We are launcher agnostic. So we don’t really develop the launchers ourselves. We just show up to the ride.”

Bastin declined to elaborate further on the mission scenarios and the capabilities demonstrated at the T-REX events. He also acknowledged that the same kinds of launchers could be employed in shipboard scenarios, but said that Northrop Grumman’s current focus in terms of the surface-launched mode is on ground-based applications.

When it comes to current plans for air-launched applications, “Lumberjack is the size, the length anyway, of the Small Diameter Bomb. So, we’re looking to be compatible with a wide variety of aircraft, [fixed-]wing and rotorcraft, manned and unmanned,” Bastin said. “Effectively, we’re looking at anything that could carry a Small Diameter Bomb.”

“We’re designing that [Lumberjack] for multiple BRUs. So, a couple different BRU installations are compatible against that sort of Small Diameter Bomb length,” he continued, using the U.S. military-standard abbreviation for Bomb Rack Unit. “We are working with two different customer communities right now, working through large plans and experimentation for next year. So that’s part of our flight test plan that we’re developing for next year.”

The GBU-39/B Small Diameter Bomb (SDB) is a 250-pound-class precision-guided glide bomb that is just under six feet (1.8 meters) long. Northrop Grumman’s website says Lumberjack has a very similar form factor, but has a maximum gross weight of around 290 pounds.

Lumberjack’s weight is payload-dependent, which Northrop Grumman’s website says could include a “combination of kinetic and non-kinetic sub-munitions, or ISR [intelligence, surveillance, and reconnaissance] sensors.” Without any payload or fuel for its small jet engine, the core system, with its composite material structure, only tips the scales at around 79 pounds, according to the product card.

How heavy a Lumberjack might be would also impact its range in both air and surface-launched modes. So far, Northrop Grumman has only said that the system is expected to be able to fly “several hundred” nautical miles. The company has also said that it will be able to cruise at around Mach 0.3 (some 230 knots) at an altitude of 20,000 feet.

“We have done testing with both kinetic and non-kinetic [payloads],” Bastin said. “Hatchet is certainly a candidate. It’s not the only type of kind of sub-munition that we’d be interested in being able to deploy. So, as I said, if customers come with whatever kinetic effect they want, as long as it fits on the center bay, we’re capable of integrating it.”

Hatchet is a roughly six-pound precision glide bomb that Northrop Grumman currently offers with one of three guidance options: a GPS-assisted inertial navigation system (INS), INS-only, and dual-mode GPS/INS and semi-active laser guidance. Versions that use GPS-assisted INS and INS-only can only be employed against static target coordinates. Laser guidance allows for the engagement of moving targets as long as they can be lazed either by the launching platform or another offboard source.

Each Hatchet has a three-pound high-explosive warhead, which Northrop Grumman claims is of an advanced type that is 50 to 80 percent as lethal as a 500-pound-class bomb, depending on the target type. Point-detonating, delayed, and air-bursting fuze options are available.

From the start, Hatchet has been presented as particularly well-suited as an armament option for drones because of its size. Multiple uncrewed aircraft have already been demonstrated as launch platforms for these munitions.

When it comes to munition options for Lumberjack, “there’s a variety [of other options] out there. I mean, everything from things like Hatchets to integrating existing artillery shells or custom kinetic effects,” Bastin noted. “So different customers have different interests in terms of what their target is and what their payload would want to be in terms of the kinetic effectiveness against their target.”

Lumberjack is being developed with modularity and adaptability, potentially even under field conditions, in mind. Another company, Palantir, is providing an artificial intelligence and machine learning (AI/ML) infused software backend to help with the rapid integration of now payloads and other capabilities, as well as help with “maintenance and reducing operator burden.”

In any configuration, Lumberjack already offers the ability to reach target areas at standoff distances. Its ability to launch unpowered gliding payloads like Hatchet, or even potentially small powered ones, only extended its operational reach. This would all be further magnified by pairing it with an aerial launch platform like the XQ-58. The Valkyrie has its own internal payload bay, said to be able to carry at least two SDB-sized stores, and can also carry payloads under its wings. Lumberjack’s range would also help keep the launching platform further away from threats. A full operational scenario might see a Valkyrie or similar launch platform use its own survivability to get close to an especially high-threat part of the battlespace before launching a Lumberjack, which then delivers munitions into the highest risk area. This could even involve taking out hostile air defense assets that threaten the launching aircraft.

Lumberjack can also make use of its range for other purposes, including launching kinetic or non-kinetic attacks on geographically separated targets during a single sortie, as well as just loitering in a particular area. Equipped with a stand-in jamming capability and/or sensor packages, the drones could be used to form temporary force protection picket lines, and do so rapidly.

There is also a cost factor, with Lumberjack’s design being focused on a low unit cost and producibility, with a heavy emphasis on commercial and modified commercial components. Another firm, ESAero, which specializes in rapid prototyping and rapid manufacturing, is also working with Northrop Grumman on this design.

“For every pallet that I would ship a fixed number of Small Diameter Bombs on, we can ship the same number of lumberjacks on, but each lumberjack performs multiple effects, multiple missions, and can go on multiple vehicles,” Bastin explained. “So it helps drive down that cost, as I said, within a Lumberjack, because we designed it with open architecture and a very modular center bay.”

Northrop Grumman previously told TWZ that it is targeting between a “cost per effect” of $75,000 to $100,000 for Lumberjack, somewhat nebulous figures that factor in things beyond basic unit price. It is also worth noting here that while Lumberjack is intended to be a one-way system when used operationally, work is being done to improve its recoverability when used in training. Being able to reuse the drones for training, as well as test and evaluation activities, would also offer cost advantages.

It’s interesting to note here that the XQ-58 is at the low end of the cost range for loyal wingman-type drones, also now commonly referred to as Collaborative Combat Aircraft. Kratos is separately continuing to expand and evolve its Valkyrie family as its customer base grows. The U.S. Marine Corps notably confirmed earlier this year that it is now actively pursuing an operational capability with these drones after years of experimental work with the design.

Lumberjack otherwise reflects a flurry of development, especially in the United States, of longer-range one-way attack munitions, as well as other systems that increasingly blur the lines between traditional drones and cruise missiles, as well as decoys.

If Northrop Grumman keeps to its current test schedule, we may get actual looks at Lumberjacks launched from XQ-58s and/or other aircraft in the coming year.

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A long-range kamikaze drone that U.S. firm Kratos is working on together with Taiwan’s National Chung-Shan Institute of Science and Technology (NCSIST) is set to make its maiden flight early next year. The jet-powered Chien Feng IV (Mighty Hornet IV) will feature artificial intelligence (AI) enabled systems and is being developed with a particular eye toward use as an anti-ship weapon. It could also be employed against targets on land and act as a decoy.

Steve Fendley, president of Kratos’ Unmanned Systems Division, offered new details about the Chien Feng IV while speaking with TWZ‘s Howard Altman on the sidelines of the Air & Space Forces Association’s 2025 Air, Space, and Cyber Conference yesterday. A model of the design, which is derived from Kratos’ MQM-178 Firejet target drone, was shown to the public for the first time last week at the biennial Taipei Aerospace & Defense Technology Exhibition. NCSIST is a government-run organization in Taiwan charged with conducting advanced military research and development and test and evaluation work.

Chien Feng IV will fly “soon, early next year,” Fendley said. “The basic aircraft exists. So what we’re doing is we’re integrating mission capability.”

“Our Fire Jet performance characteristics are public, and it’s [Chien Feng IV] a little bit better, pretty much in every category, a little bit more speed, a little bit more altitude, a little bit more endurance,” Fendley added.

“The modified MQM-178’s high-speed capabilities, including a speed of Mach 0.8, high G maneuvering, and a service ceiling of greater than 35,000 feet, make it an ideal base platform for this transformation,” a press release Kratos put out last week had noted.

At the time of writing, the company’s website also says the MQM-178 can fly at altitudes anywhere between 20 and 35,000 feet, can pull turns down to -2 and up to +9 Gs, and carry around 70 and a half pounds of payload internally, as well as 35 pounds more under each wing and an additional 20 pounds in pods on each wingtip. Range and endurance figures for Firejet are not provided, but are offered for an existing derivative called Airwolf, which is configured for tactical mission sets, including acting as a ‘loyal wingman’ for crewed aircraft. Airwolf, also known as Tactical Firejet, has a stated maximum range of 400 nautical miles and a maximum endurance of 1.3 hours. Both Firejet and Airwolf are designed to be launched via pneumatic catapult, and the latter design at least can be recovered at the end of a mission via parachute.

The Chien Feng IV is “our aircraft and NCSIST, so the Taiwanese government, [their] mission systems and warhead,” Fendley said, and deferred to the Taiwanese side for more details about the latter components of the drone’s design.

A brief video on the Chien Feng IV that NCSIST released around the Taipei Aerospace & Defense Technology Exhibition, seen below, highlights an electro-optical/infrared camera system (EO/IR) in the nose, as well as an AI-driven computer and datalink, as being among the design’s features. In terms of terminal guidance, an EO/IR system would make sense as it is immune to electronic warfare and is passive in nature, meaning it doesn’t pump out signals that can alert the target to the incoming threat.

The Chien Feng IV model shown at the exhibition in Taipei was fitted with small underwing pods, which might be able to hold defensive countermeasures or other equipment, or even just more fuel. It also had an opaque nose cone, which could point to additional sensor options, such as a radar seeker.

The NCSIST video also mentions at least a degree of swarming capability, though it is unclear if Chien Feng IVs will be able to operate in a fully networked collaborative manner.

In terms of missions, Chien Feng IVs are expected to be tasked with “ship-hunting, ship-attacking, ground force-hunting, [and] ground-force attacking,” according to Kratos’ Fendley.

As noted, NCSIST has put particular emphasis on the anti-ship mission, which makes sense for Taiwan. Authorities on the island face the real prospect of the Chinese government on the mainland attempting to impose a blockade or even launch a full-scale military intervention across the Taiwan Strait. The People’s Liberation Army Navy (PLAN) and its steadily growing fleets of more capable surface warships would play a critical role in either scenario.

At the same time, the Taiwan Strait is just under 100 nautical miles across at its widest, and Chien Feng IVs with ranges of around 400 nautical miles would also be able to hold Chinese targets at risk on the mainland. At the Taipei Aerospace & Defense Technology Exhibition, NCSIST representatives said the drones could just be employed as decoys, according to a report last week from Jane’s.

If the Chien Feng IV’s AI-enabled systems give it the ability to find and engage targets in a highly autonomous manner, the drone’s capabilities could be magnified greatly in a maritime or land attack scenario, especially against moving targets. This, in turn, could present major complications for an adversary like China. TWZ previously explored in great detail how the steady infusion of AI and machine learning technology, especially when it comes to dynamic targeting and swarming, is pushing development of uncrewed aerial systems toward a revolutionary moment, broadly.

As noted in TWZ‘s past reporting on the Chien Feng IV, massed attacks involving these drones would also compel the PLA to expend commensurate amounts of anti-air interceptors, putting additional strain on Chinese air defenses. More capable interceptors would also be required to engage the higher-flying jet-powered attackers.

Taiwan is also now pushing to significantly expand its inventory of various lower-tier kamikaze drones, including in cooperation with U.S. defense contractor Anduril. This is in line with a larger strategy that American officials have discussed for helping to defend the island from any future Chinese intervention, which has been called “Hellscape” in the past. What is envisaged is the Taiwanese military heavily saturating the air and waters around the island with relatively low-cost uncrewed platforms.

NCSIST also reportedly has an eye toward exporting Chien Feng IV. There is certainly growing global interest in long-range kamikaze drones, driven heavily by observations of their use on both sides of the ongoing war in Ukraine. Attacks by Iran and its regional proxies on Israel and ships in the Red Sea, as well as targets in and around the Middle East, have also underscored the value of this kind of capability. Back in 2019, TWZ called out a then-unprecedented drone and missile attack that Iranian-backed Houthi militants in Yemen launched against Saudi Arabia as a sign of things to come.

“I would say that our recent program with Taiwan, I’m going to call as a spin off of, sort of a combination of Apollo and Athena,” Kratos’ Fendley also told TWZ yesterday.

Fendley did not further elaborate. Details about the Apollo and Athena programs remain limited, but the company has previously told TWZ that they are aimed at the European market. The possibility is now raised that one or both of those designs could be long-range kamikaze drones, or at least be capable of being employed in that role.

Kratos is otherwise pursuing new opportunities globally. This includes a partnership with Airbus on a version of the stealthy XQ-58 Valkyrie drone for the German Luftwaffe. Kratos has now sold two XQ-58s to Airbus, which are expected to start flying in Germany next year following the integration of new mission systems, according to Fendley. The Valkyrie has already been flying for years in a largely experimental role with the U.S. Air Force and the U.S. Marine Corps. The Marines are now in the process of transitioning their XQ-58 efforts to an operational capability.

“Many, many domestic and international customers, who I’m going to say have been at the interest level, have transitioned to the we’re ready to do something level,” Fendley added, speaking more generally. “So, think some Asian countries, think some European countries, and the timeline is in, I would say the next 24 months, you’re going to see those happen pretty quickly.”

When it comes to the Chien Feng IV, specifically, more details may continue to emerge as Kratos and NCSIST get closer to the planned first flight next year.

Contact the author: [email protected]

Kratos has confirmed it is working together with Taiwan’s National Chung-Shan Institute of Science and Technology (NCSIST) on a derivative of its jet-powered MQM-178 Firejet target drone called the Chien Feng IV. The Chien Feng IV is said to be eyed primarily as a lower-cost, longer-range kamikaze drone, and NCSIST is reportedly looking toward potential export opportunities along with sales to the Taiwanese military.

United Daily News in Taiwan was the first to report on the Chien Feng IV this past weekend, citing comments from NCSIST. A government-owned organization, NCSIST conducts advanced military research and development and test and evaluation work. The drone is set to make its official public debut at the biennial Taipei Aerospace & Defense Technology Exhibition next month.

“We can confirm the exciting partnership” with NCSIST and that the Chien Feng IV “is a derivative of the MQM-178 system,” Steve Fendley, president of Kratos’ Unmanned Systems Division, told TWZ. “Development started early this year and is progressing rapidly.”

“We expect that by the end of this year, we will receive a sole-source contract for the Kratos Airwolf tactical jet drone, which could lead to a production contract in late 2026,” Kratos’ CEO Eric DeMarco had also said during a quarterly earnings call earlier this month.

Airwolf, also referred to as Tactical Firejet, is based on the MQM-178 design, as well.

DeMarco’s “comment was tied to two opportunities, this partnership [with NCSIST] being one of them,” Fendley also told TWZ.

Fendley declined to provide more details about Chien Feng IV, saying that more information would come at the exhibition in Taipei in September. United Daily News‘ report also offered few specifics, but said that NCSIST had described the drone as being able to serve as a “low-cost cruise missile.”

The Firejet/Airwolf family offers a logical starting place for a Chien Feng IV drone that skirts the increasingly blurry line between longer-range kamikaze drones and cruise missiles, as well as decoys.

Kratos says the 10.8-foot-long MQM-178 with its wingspan of 6.5 feet can carry around 70 and a half pounds of payload internally, as well as nearly 35 pounds more under each wing and an additional 20 pounds in pods on each wingtip. It can get up to speeds of 0.69 Mach, as well as fly at altitudes anywhere between 20 and 35,000 feet. Designed as a target to fire air-to-air and surface-to-air missiles at during training and testing events, Firejet can pull turns down to -2 and up to +9 Gs. The drone is launched via catapult, but no mention is made of it being designed to be recoverable.

Airwolf has the same physical dimensions and general mode of operation as Firejet, but has a reworked internal arrangement to better allow it to be configured for tactical mission sets, including acting as a ‘loyal wingman’ for crewed aircraft. Kratos says it is recoverable via parachute and has a maximum range of 400 nautical miles and a maximum endurance of 1.3 hours.

Kratos’ website also describes Airwolf as being “low signature,” but does not offer specifics. On top of its relatively small size to begin with, the drone’s carbon fiber composite construction would help its radar cross-section. Route planning involving a low-level flight profile masked by terrain features could also help it evade detection.

With all of this in mind, the MQM-178-derived Chien Feng IV could possibly be configured for other roles beyond one-way attack, including electronic warfare and communications signal relay.

Even from what little is known about the Chien Feng IV now, it reflects broader trends globally. Just in the past few years, the ongoing war in Ukraine, attacks by Houthi militants in Yemen on ships in and around the Red Sea and targets in Israel, and fighting between Iran and Israel have underscored the value of and threats posed by long-range kamikaze drones. Jet-powered types have already begun to emerge, offering further boosts in capability and presenting new challenges for defenders, as TWZ has highlighted in the past. Armed forces around the world, including the U.S. military, are taking notice. Something of an industrial arms race to create new modular, relatively cheap, and small uncrewed aerial systems has now emerged, particularly in the United States.

United Daily News‘ report this past weekend said that NCSIST had stressed that there was no commitment yet from any branch of Taiwan’s armed forces to buy Chien Feng IVs. At the same time, the organization said that it could be a valuable companion to traditional cruise missiles in Taiwanese service, like the Hsiung Feng IIE (HF-2E).

With help from the U.S. government, Taiwan has been working to significantly expand its arsenal of one-way-attack drones, as well as other uncrewed aerial and maritime systems, in the past few years. There has been a certain degree of additional openness with regard to this cooperation from U.S. defense contractors recently. Earlier this month, Anduril very publicly announced the opening of an office in Taiwan and expanded cooperation with NCSIST, all with a heavy focus on its ALTIUS line of drones, which can be configured as loitering munitions and for other roles. The U.S. government approved the sale of nearly 300 ALTIUS 600M-V loitering munitions to Taiwan last year.

For Taiwan, this is part of a broader effort, which has been referred to in the past as “Hellscape,” that envisions the Taiwanese military flooding the air and waters around the island with relatively uncrewed platforms in the event of a military invasion from the Chinese mainland.

Especially if it is a relatively low-cost design, Chien Feng IV, as well as other longer-range kamikaze drones, could also offer a way to extend the Hellscape plan to attacks on targets on the other side of the Taiwan Strait. As noted, Airwolf’s stated maximum range is 400 nautical miles. The Taiwan Strait, at its widest, is some 97 nautical miles across. Massed Chien Feng IV attacks would also force Chinese forces on the mainland to expend commensurate amounts of interceptors. Higher-flying jet-powered drones would, in turn, require higher-end interceptors to be employed, as well.

In addition, United Daily News‘ report said that NCSIST had explicitly highlighted potential export opportunities for Chien Feng IV, which speaks to the growing global interest in the kinds of capabilities this drone could offer. Hurdles would exist for any direct exports from Taiwan, which occupies a complicated space when it comes to foreign relations, but a partnership with a U.S. company like Kratos could help in that regard. In 2023, reports emerged that the United States could buy retired HAWK surface-to-air missile systems from Taiwan and then transfer them to Ukraine, as another example of an indirect workaround.

More details about the Chien Feng IV are set to emerge next month at the Taipei Aerospace & Defense Technology Exhibition. However, it is already an important reflection of new and expanding ties between Taiwan and the U.S. defense industry, as well as global trends when it comes to the new, longer-range kamikaze drones.

Contact the author: [email protected]