Technical Weaknesses of the BM-35 and BM-70 UAVs
On May 10, Ukrainian Defense Ministry adviser Serhiy Beskrestnov revealed critical technical flaws in Russia's BM-35 and BM-70 unmanned aerial vehicles (UAVs). According to his data, manufacturing defects are so severe that over half of all BM-35 models never reach their intended targets. The most common failures include broken propellers, seized engines, or engines that stall while airborne.
Control stations for these drones are positioned on building rooftops no more than 15 kilometers from the front line. This setup limits their effectiveness, restricting the UAVs to strikes against large, stationary targets. As Beskrestnov noted,
'the defects were so widespread that more than half of the BM-35s failed to reach their targets.'
Design Features and Control Challenges
The BM-35 drone is powered by a two-stroke internal combustion engine mounted at the front. The pilot operates it via a Radiomaster controller, using goggles or a monitor for visual feedback. Video is transmitted in the 3000–3700 MHz range and received by two square patch antennas. Control signals can be sent on the 310–370 MHz and 515 MHz bands, while the adversary uses the 360 MHz band with a 10 MHz bandwidth.
Near the ground, the drone can reach speeds exceeding 200 km/h. However, despite the control channel’s resilience to interference, there have been instances of the video channel being detected at 520 MHz, which may be a harmonic of the primary video signal at 1040 MHz. Beskrestnov also highlighted a critical gap:
'we lack sufficient means to suppress analog UAV video channels.'He emphasized that the enemy employs at least five different production-grade jamming systems targeting analog video feeds, further undermining the effectiveness of Russian drones on the battlefield.
These technical shortcomings could significantly impair the Russian military’s ability to carry out its frontline missions. With such a high proportion of drones failing to complete their flights, the overall combat utility of these UAVs is now in serious doubt. The identified issues also point to potential problems in manufacturing and quality control, which may reflect broader challenges within the country’s military technology sector.
In light of these technical shortcomings, it's essential to explore how Russia's reliance on autonomous drones in Ukraine may exacerbate their operational challenges. A recent report on the deployment of autonomous drones highlights the strategic implications of these developments and the potential for increased vulnerabilities in the field.