South Korea's new naval drones crash seconds after launch

• South Korean suicide drones crash after launcher failure.
• Misaligned hatch sends two Korean drones into sea.
• South Korean drone prototypes plunge into sea during trial.
• Launcher defect blamed for South Korean drone crashes.
• Korean drone crash exposes costly prototype failure.

A high-profile sea trial intended to showcase South Korea’s homegrown suicide drone technology ended in embarrassment after two loitering munitions plunged into the ocean seconds after launch off the coast of Busan.

In a preliminary probe released by the Agency for Defense Development (ADD), official analysts determined that the mid-air failure was caused by a mechanical defect in the launcher system rather than a flaw in the aircraft itself.

The trial was conducted aboard the Navy’s 14,000-ton amphibious assault ship ROKS Marado. The drone was fired from the upper canister of a two-tier stacked launcher.

However, a lower left hatch door situated directly below sat out of alignment and directly in the path of the rocket booster's exhaust fumes.

How a bent door threw off the thrust

According to technical analysis conducted by the ADD, the launch blast severely deformed the misaligned hatch door in the opening fraction of a second.

Because the aircraft moves too slowly during the initial boost phase for its aerodynamic control surfaces to bite and engage flight correction, the deflection of the rocket booster's thrust threw the entire airframe out of balance.

The sudden imbalance caused excessive rightward deflection, severe attitude instability, and an immediate loss of altitude.

"The operating status of the drone and the overall system was normal," stated the ADD, noting that flight parameters were logged through wireless telemetry and cameras. "As developers, it was harder for us than anyone that a simple defect produced the worst possible outcome."
An identical trial executed on April 24 under matching parameters proceeded without incident.

Cost concerns, high political stakes

The timing of the flop comes at an awkward juncture for South Korea’s defense establishment. System development for the medium-class loitering munition—in progress since June 2024—is scheduled to finalize next month.

Defense Minister Ahn Gyu-back announced ambitious plans in June to fast-track homegrown suicide drones into service, acquiring more than 20,000 low-cost strike drones and training up to 500,000 service members in drone operations.

However, industry observers have pointed to the system's steep price tag. The prototypes cost approximately 800 million won ($580,000) each.

Even after transitioning to mass production, costs are projected to hover between 100 million and 200 million won ($75,000 to $150,000) per unit.

By comparison, Iran’s Shahed-136—which the Korean airframe design closely resembles—costs between $20,000 and $50,000.

The US LUCAS system was deployed in combat early this year at a cost of roughly $35,000 per unit.

Despite the setback, the ADD confirmed it has no immediate plans for a repeat sea trial, stating that core operational technology has already been validated and that future launch box assembly protocols will be adjusted.