In the evolving landscape of the Ukraine-Russia war, where technology races against countermeasures, Ukraine has introduced a remarkable new chapter in drone warfare: fiber-optic drones. Tethered by ultrathin cables instead of reliant on jam-prone radio frequencies, these drones are turning the tide in areas where traditional drones have lost effectiveness.

Old-School Technology Meets Modern Warfare

Amid severe shortages of artillery and the increasing success of Russian electronic warfare (EW) in jamming FPV drones, Ukrainian forces have been pushed to innovate. The result: drones that spool out fiber-optic cable as they fly, creating an unjammable, high-speed connection between pilot and drone.

In Dobropillya, one such drone crept under a concrete bridge undetected, allowing a Ukrainian pilot to identify and eliminate a Russian soldier wrapped in a red blanket. That level of precision—and ability to penetrate thick structures—is only possible due to the wired connection.

“If it wasn’t for those drones, I’m not sure what I’d be doing right now,” said a pilot from Ukraine’s 68th Brigade, known as the Dovbush Hornets, one of the most elite drone units in the Ukrainian military.

How Fiber-Optic Drones Work

At first glance, these drones look like conventional quadcopters. The difference lies in a box mounted on the drone containing a spool of fiber-optic cable—up to 20 kilometers in length—commonly used in broadband internet infrastructure. As the drone flies, the cable unspools, ensuring an uninterrupted link to the operator.

This setup allows pilots to:

• Navigate complex environments such as tunnels, bridges, and inside buildings.
• Park drones in ambush positions, waiting for enemy movement before detonating.
• Use the drones in tandem with radio-guided drones, by first destroying Russian jamming devices.

A Tactical Gamechanger on Urban and Forested Fronts

These drones are especially valuable in dense urban zones like Pokrovsk or heavily wooded areas of Donetsk. Conventional drones frequently lose signal due to interference from buildings or trees—and more so from Russian EW systems mounted on vehicles and along the 600-mile frontline.

Fiber-optic drones, however, have enabled Ukrainian troops to:

• Ambush tanks in garages and underground hangars.
• Target soldiers hiding in steel piping or behind thick walls.
• Conduct surprise strikes in basements, schools, or forest cover.

“They create an effect of terror,” said Lt. Andriy Kasianenko of the Achilles Drone Regiment. “You can be reached in buildings, in low-lying areas, anywhere.”

Innovation, Production—and a Race Against Time

Ukraine has significantly ramped up production. Sparrow Avia, one of the largest drone manufacturers in Ukraine, now produces 12,000 fiber-optic drones per month and aims to double that by the end of 2025. The factory operates in a secret location west of Kyiv, with 220 employees working around the clock.

Yet the effort faces a critical vulnerability: dependency on Chinese fiber-optic cable. “If China was to stop deliveries of this cable to us, then all fiber-optic flights in Ukraine would instantly stop,” said Sparrow Avia’s director, Nikolai.

To mitigate this, Ukraine has attacked Russia’s only known fiber-optic cable plant in Saransk twice this year, in an attempt to slow Moscow’s own drone supply.

Despite the cable’s high cost—double that of standard FPV drones—demand has skyrocketed. The company is experimenting with camouflage-colored cables to reduce visibility on the battlefield and developing faster-spooling methods to scale up production.

Limitations: Tethered Power, Tracked Risks

While highly effective, fiber-optic drones are not without problems:

• Cable breaks: High winds, rough terrain, or passing tanks can snap the cable mid-flight.
• Weight limits: The cable spool adds weight, reducing the explosive payload or battery life.
• Security risk: The cable can be traced back to the launch site, compromising operator positions.
• Environmental clutter: Leftover cables litter battlefields, with soldiers tripping over them or animals nesting in discarded lines.

“Half the time, the cable snaps mid-mission,” said one pilot known as East, part of the Achilles unit. “We have to plan every flight so civilians and even our own soldiers don’t interfere with the wire.”

To combat this, Ukrainian forces are developing mobile launch units and changing positions frequently after each mission. Some commanders even propose deploying scissor-like cable cutters across open fields to defend against Russian fiber-optic drones.

What’s Next: AI-Guided Autonomy

Looking forward, commanders like Lt. Kasianenko anticipate that fiber-optic drones are only a bridge to the next wave of drone warfare—autonomous systems powered by artificial intelligence, capable of switching frequencies or operating without operator input.

“All radio-controlled frequencies will eventually be completely jammed,” he said. “Auto-guidance systems will be the future.”

Until then, Ukraine’s battlefields—littered with the fine threads of fiber-optic cable—will continue to showcase how a seemingly retro technology is playing a cutting-edge role in the fight for survival.