January 8, 2025: Australian firm Anduril has developed a novel new anti-drone system called Roadrunner. These drones weigh 85 kg, are 1.8 meters tall and are propelled by twin jet engines with a top speed of about 700 kilometers an hour. Most other specifications and capabilities have not yet been released.

Roadrunner is a small VTOL/Vertical Take Off and Landing drone that can be used for reconnaissance and return after each mission to be reused several times. If the explosive warhead and fire control system is used, Roadrunner will operate as an explosive drone that will destroy itself when it demolishes a drone, helicopter or aircraft.

The U.S. Department of Defense has purchased 500 Roadrunners for about $400,000 each. Most of them will go to the Special Operations Command/SOCOM, which will use Roadrunner to support its Special Forces or SEAL operators. Roadrunner is transported in a box-like launch container. This container can be moved by UH-60 helicopter via a sling underneath. With a larger transport helicopter, like the CH-47, the container or containers can be carried inside the helicopter on pallets.

Roadrunner has nearly completed development and the ones purchased so far are being used by SOCOM to see how well the drone functions in an operational environment. Some may be sent to Ukraine where they can obtain some combat experience against a determined and resourceful enemy.

Many countries’ new weapons or recent upgrades of weapons and equipment are sent to Ukrainian troops, who eagerly use new equipment, weapons or munitions in combat. After action reports are sent back, often with suggestions for improvements and upgrades as well as comments on the performance of these items.

While Roadrunner is useful for reconnaissance and surveillance, using them to destroy low value targets like drones makes little sense. Going after helicopters or low flying jets is cost-effective, but there are numerous anti-aircraft systems available for that.

Over the last decade several other VTOL drone systems were developed and used in a combat environment. Israeli firm Blaze developed Spider, a lightweight battery-powered VTOL drone that can be broken down and carried in a backpack. Spiders can be assembled and ready for use within ten minutes. Compared to earlier larger, gasoline-powered VTOL drones, Spider emphasizes that the main advantage of VTOL drones compared to helicopter drones is superior speed, endurance and stability in windy conditions. VTOL drones are also easier to land safely and without damage. VTOL drones have been practical in the last few years because of advances in flight control software and enough flight time to deal with any unforeseen problems. Spider is expected to be popular with non-military customers who need a search and surveillance system that is lightweight, battery powered and easy to use with minimal training.

Earlier VTOL drones worked but were heavier, more expensive and not as user friendly. For example, in 2019 the U.S. Navy began testing the new VBAT VTOL drone. It looks like a small fixed-wing drone with a pusher rear-mounted propeller-driven gasoline/oil engine. The VBAT propeller is housed in a circular open cowling which provides a surface to vertically take off from and land on, combined with computerized flight controls similar to those that made the two-wheel self-balancing Segway scooters possible back in 2001. In other words, VBAT automatically takes off and lands at a location specified by the operator. After takeoff VBAT tips over and flies like any other fixed-wing aircraft. This way the 37.3 kg VBAT can carry a 3.6 kg payload and do it all longer and farther than current small quad-copter drones.

VBAT usually carries a gimballed day/night vidcam that can transmit video to the VBAT operator up to 72 kilometers distant. VBAT can also store flight information when it is flying missions up to 630 kilometers distant. Top speed is 80 kilometers an hour, while endurance is eight hours. VBAT is small, only 2.4 m long with a wingspan of 2.74 m and is broken down into separate components and stored in weatherproof shipping containers for storage or transport. A two-man crew can open a container and assemble VBAT, load flight parameters for an automated mission and have it ready for takeoff in 20 minutes. Different payload modules can be swapped out for ones that do mapping or terrain analysis. The onboard generator provides up to 500 watts for payload sensors. Max altitude is 4,700 meters and VBAT can handle winds of up to 48 kilometers an hour. It only needs a 3x3 meter clear area for takeoff and landing. With performance like that, the army and navy were interested when VBAT was first shown in 2018.

By 2021 VBAT was upgraded to the VBAT 128, a heavier 56.6 kg model with an 11.3 kg payload and upgrades in range, endurance and payload options. The two-man operator team for VBAT can be trained in two weeks and each VBAT, depending on how many payload modules are provided, will cost a few hundred thousand dollars. The U.S. army and navy bought some, mainly to further explore the use of this tech on ships or for land-based operations. In wartime systems like this can be put into service quickly and problems noted and fixed along the way. In peacetime the budgets are smaller and the time available for further testing and development longer.

There is competition. In 2019 a Chinese destroyer in the South China Sea was seen using a new VTOL drone off its helicopter deck. The VTOL drone was easily identified as the Chinese made SD40, a drone offered for sale to commercial users for operating over land or sea. The SD40 is small, only 40 kg and apparently intended for naval use on smaller ships like corvettes and patrol boats because Chinese destroyers use larger manned and unmanned helicopters due to their larger payloads, longer flight time and better stability in high winds, as are frequently encountered at sea. But the SD40 is a hybrid quadcopter/fixed-wing propeller-driven drone. The SD40 is a triple fuselage battery-powered quadcopter for takeoff and landing that switches to a gasoline-powered rear propeller in the larger main fuselage and proceeds as a fixed-wing aircraft once aloft. The two smaller outer fuselages each contain two of the quadcopter rotors and batteries for takeoff, landing or hovering. The 3.7 meter fixed wing provides plenty of lift and stability for level flight and a max speed of 180 kilometers an hour. Cruising speed is 100-140 kilometers an hour. Max payload is 6 kg which will handle a wide range of day/night vidcams or even a lightweight SAR or lidar radar. SD40 has an endurance of up to six hours, depending on how much hovering is done. Max altitude is 5,000 meters although normal operating altitudes are 1,000-3,000 meters. There are several VTOL designs similar to the SD40 available. The VBAT takes the concept up a level in performance but the Chinese navy has a larger budget and a greater sense of urgency

These VTOL designs are becoming more popular because they can operate off smaller ships and patrol boats and have better endurance and stability in high winds than heavier helicopter drones. The U.S. Navy gained practical experience in this when they used the 1.4-ton MQ-8B Fire Scout helicopter drone. The MQ-8B lacked the stability in bad weather and other conditions that larger helicopters can handle. The Navy bought 29 MQ-8Bs after 2009 and accumulated over 12,000 flight hours with it within a few years. The basic design was good, but it was too small.

In 2013 the navy experimented transferring the control hardware and software of the MQ-8B to a larger helicopter, a navalized Bell 407 to become the 2.7-ton MQ-8C. This provided greater stability and endurance and tripled the payload. The navy bought 36 MQ-8Cs and wanted to acquire about a hundred for use on smaller ships. That plan is on hold, mainly for budget reasons but also to see how well the VTOL drones perform. VBAT is a lot cheaper than a helicopter-based drone and may eventually replace many naval helicopter drones.

China has more options when it comes to different types of drones because it has the largest number of drone developers/manufacturers in the world and dominates the quadcopter market. The Chinese Navy has been seen testing a large variety of these commercial designs, including some similar to the MQ-8B. China also has a larger number of small warships and patrol boats than the United States and many of these can accommodate a smaller VTOL drone.