I'm a Russian who fled Putin's dictatorship - now I'm arming Ukraine with killer drones

Ukraine's defence industry is producing drones by the million, giving troops unprecedented firepower and exposing the weakness of Russia's traditional battlefield tactics. Among the manufacturers driving this surge is United Unmanned Systems, a western Ukraine-based firm already handling direct orders of 20,000 drones from frontline brigades.

Its founder, Sergej Sumlenny, says First Person View (FPV) drones have shifted firepower from senior commanders to platoon leaders, creating a battlefield where "any target you have - tanks, radio stations, radars, manpower - is done by drones now." For Russian-born Sergej, who fled his homeland 20 years ago, the mission to repel Vladimir Putin's invading forces is personal.

"I never had any illusion that Russia would attack Ukraine. I never had any illusion of what the Russian army does with occupied cities," he said.

United Unmanned Systems employs just a dozen staff but works through a wider network of contractors.

Its drones have been vital to the success of attacks on Russian soil.

"We have capacities in manpower, equipment, and production lines to produce up to 15,000 a month," Sergej explained.

Demand is constant, with recent orders from two frontline brigades for 20,000 drones each. USs drones have been vital to the success of attacks on Russian soil

Brigades can burn through 4,000 to 5,000 a month.

Unlike many Western-made systems, his drones are adaptable, battle-proven and underwritten by German engineering.

A 10-inch kamikaze model costs about £430, while heavier return bombers - able to carry a 152mm artillery shell - cost £8,600.

"So we just mount the shell and drop it with a precision of plus minus 50 centimetres," he said.

And this has changed the logic of war.

"If you let your drone with RPG-7 grenades fly 15 kilometres and precisely hit a tank, artillery piece, bunker or jammer, you, as a platoon leader, have firepower once only in the hands of a battalion commander," he said.

"Before, you had to wait for artillery approval. Now you can strike at will."

The implications for Russian armour are devastating.

"There is no tank in any army which can withstand hits from kamikaze drones. None," he said.

"A Main Battle Tank, such as the Challenger 2 or Leopard, can be destroyed with five drones. The usual tactic is to take out the tracks first, which renders the tank disabled."

Russia has responded with countermeasures, from jamming to cages welded on turrets.

But UUS' new "Black Widow" radio system is almost impossible to disrupt.

"With this model, almost none of our drones get jammed. We can even fly into a bunker with four or five layers of bricks and the signal is still excellent."

That reliability explains why top brigades - including the 47th Mechanised, the 225th Assault Regiment and the elite Rubizh and Azov Brigades - are customers.

"Our drones have extremely high-quality control, they are practically unjammable, and that makes them slightly more expensive. But the hit rate is high - 60 percent - and that is what counts."

Born near Moscow, Sumlenny moved to Germany in the early 2000s and worked as a political analyst in Kyiv.

He warned Berlin that Moscow would one day launch a full-scale war. "I told my supervisors, there will be war and we must arm Ukraine to the teeth. I was treated as a paranoid militaristic idiot. And then, five months later, Russia attacked."

The invasion became a turning point.

"Many of my personal friends from my six years in Ukraine were killed by Russians," he said.

"I feel it is my duty to provide Ukraine with all the equipment they need to kill every single Russian soldier now on Ukrainian soil."

That duty extends to personally delivering drones to the front.

"I spend a day with the units, sometimes two. I see what they do with them, I ask what should improve. Sometimes their suggestions are genius - like moving a switch or antenna."

At 44, Sergej admits he lives with risk - both from Russian strikes in Kyiv and from the knowledge his name is known to Moscow.

Yet he shrugs it off.

"I live on the top floor of an apartment block. I've never gone down to the basement during an air raid. I assess the odds mathematically of being hit are less than me being run over in the street," he said.

He added: "Only an armed Ukraine can stop Russia from the idea to attack.

"That was true before the invasion, and it is even truer now."