Frequency Interference Leads to MQ-9A Runway Excursion in Kuwait

Casualties unknown • KUWAIT, KW

An MQ-9A Reaper was destroyed after losing its command uplink due to signal interference from another unit's ground terminal during landing rollout.

What happened

On 24 September 2020, an MQ-9A, tail number 10-4108, departed the runway surface at Ali Al Salem Air Base, Kuwait. The aircraft, which was government-owned and contractor-operated by Remotely Piloted Solutions (RPS) under the 432d Wing, was performing a landing rollout when it veered left off the prepared surface.

The mishap occurred during a period of high operational tempo where multiple aircraft were utilizing various frequencies. As the aircraft decelerated on the runway, it entered the beamwidth of a ground data terminal (GDT) belonging to another unit. This GDT was transmitting on the same uplink frequency as the aircraft's primary control link. The strength of the interfering signal prevented the aircraft from receiving necessary commands from its own ground control station. Because the nose wheel maintained the last received command—a slight left turn—the aircraft drifted off the runway. Despite attempts by the pilot to execute a full-power climb, the airspeed was insufficient to lift the aircraft before it exited the runway. The incident resulted in the total destruction of the aircraft, valued at over $42 million, though there were no injuries.

The investigation

The investigation examined the radio frequency management and coordination between units operating at the airfield. It established that a different unit had recently transitioned its downlink frequencies from SPURS to CHARGERS due to interference issues but had failed to update its paired uplink frequencies accordingly, continuing to use the MOSPORT uplink.

Investigators also looked into the communication between the 46 EATKS and RPS operators. It was found that while the aircraft was being prepared for an early landing due to forecasted high winds, there was a misunderverstanding regarding frequency availability. The investigation confirmed that the aircraft entered the concentrated narrow beam of the other unit's GDT during the rollout, which caused the loss of the command link.

Probable cause

The mishap was caused by the improper use of the MOSPORT uplink frequency by another unit following a change in frequency allocation, combined with the aircraft entering the interference beam of that unit's ground data terminal, which resulted in a loss of command uplink.

Frequently asked questions

What happened in the 2020-09-24 MQ-9 accident near KUWAIT, KW?

An MQ-9A Reaper was destroyed after losing its command uplink due to signal interference from another unit's ground terminal during landing rollout.

What aircraft was involved and where did it happen?

The accident on 2020-09-24 involved a MQ-9, registration 10-4108, operated by Air Combat Command (ACC), at KUWAIT, KW.

What was the probable cause of the accident?

The mishap was caused by the improper use of the MOSPORT uplink frequency by another unit following a change in frequency allocation, combined with the aircraft entering the interference beam of that unit's ground data terminal, which resulted in a loss of command uplink.

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