Drones controlled via fiber-optic cable were initially considered some kind of ultimate solution because they cannot be suppressed by electronic warfare systems, moreover, the positions of their operators couldn't be detected by means of signal intelligence. But there is no such thing in the world as a perfect weapon, so besides the already known downsides like the expensiveness and weight of the coil and limited maneuverability, the practice has revealed one more drawback.
It was discovered by Ukrainian troops from the Ghost of Khortytsia Unmanned Systems Battalion, 15th National Guard Brigade. The official video published by this unit demonstrates that the fiber-optic cord the russian drones unwound behind them became an excellent pointer to the operators themselves.
Read more: Two Pivotal Issues Regarding Fiber-Optic FPV Drones on Modern Battlefield
Оптоволокно, звичайно, РЕБом не придушити, але ж ніхто не забороняв по ньому відслідкувати дислокацію ворожих операторів FPV і «завітати до них в гості». : ББпС «Привид Хортиці» 15 бригади Національної гвардії. pic.twitter.com/CQTcG8qVpX— НГУ (@ng_ukraine) February 17, 2025
As a result, the Ukrainian forces managed to eliminate an enemy group of five personnel using conventional radio-controlled FPV drones and finished off by explosives dropped from FPV bombers.
Apparently, the Ukrainian team managed to detect the russian hideout thanks to a coincidence. Their enemy had launched six or so fiber-optic drones flying along about the same route in the opposite direction. And the sun, which was low above the horizon, illuminated the fiber-optic threads in the view of a Ukrainian reconnaissance UAV.
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The reflections of the optical fiber give away a fairly clear direction, that is, even if it wasn't possible to visually follow the threads all the way to the operators, the vector is still obvious enough to finish the job. Upon following this vector, one could try to logically find a building or other shelter within a limited distance where the operators could be.
What's important here, it works both ways, and soon russian forces may figure it out and start or have already begun leveraging this shortcoming of drones controlled via fiber-optic threads to their benefit, too.

Read more: Ukrainian Artillery Destroys russian IFV with Precision Strike at 10 km Range in the Lyman Direction (Video)