Casualties unknown

2020-09-24: MQ-9 (10-4108) — Air Combat Command (ACC) — KUWAIT, KW

KUWAIT, KW

On September 24, 2020, a MQ-9 (registration 10-4108) operated by Air Combat Command (ACC) was involved in an aviation accident near KUWAIT, KW. Investigators recorded the probable cause as: The causes were (a) the Other Unit improperly using the MOSPORT uplink frequency to launch and land aircraft after the frequency allocation plan had been adjusted and distributed; and (b) during landing rollout, the mishap aircraft entered the beamwidth for… This summary draws on records from the U.S. Air Force Accident Investigation Board (AIB); 8 related events involving the same aircraft type or operator are linked below.

Sourcesthe U.S. Air Force Accident Investigation Board (AIB)Primary reportUpdated 1781081675Data APIEditorial standards

An MQ-9A (tail number 10-4108) departed the runway during landing rollout at Ali Al Salem Air Base, Kuwait after losing uplink due to interference from another unit's ground data terminal transmitting on the same frequency. The aircraft was destroyed; no injuries.

Sequence of Events

On 24 September 2020, at approximately 0433 Zulu, the mishap aircraft (MA), an MQ-9A with tail number 10-4108, was conducting a landing rollout at an airfield at Ali Al Salem Air Base, Kuwait. The MA was government-owned and contractor-operated, assigned to the 432d Wing with contractors for Remotely Piloted Solutions (RPS) flying it at the time. The mishap crew consisted of the Mishap Pilot, Mishap Sensor Operator, and Mishap Safety Observer.

During the landing, another unit's ground data terminal (GDT) and ground control station (GCS) were in use and transmitting on the same uplink frequency as the MA's uplink. The interfering GDT initially transmitted on a wide beam and later switched to a narrow beam. As the MA decelerated, it entered the beam of the interfering GDT. The MA lost uplink with its own GDT; its nose wheel maintained the last received command (slight left), causing the MA to veer left and depart the side of the runway.

Cause

The Abbreviated Accident Board President found two necessary causes: (a) the other unit improperly used the MOSPORT uplink frequency for launching and landing aircraft after the frequency allocation plan had been adjusted and distributed; and (b) during landing rollout, the MA entered the beamwidth of the other unit's GDT, causing the MA to receive two different uplink signals on the same frequency, preventing it from receiving data from its own GDT and resulting in the loss of uplink.

Damage and Injuries

The MQ-9A was destroyed. Total loss to the Government is valued at $42,520,806.00. There were no injuries or other damages.

Probable cause

The causes were (a) the Other Unit improperly using the MOSPORT uplink frequency to launch and land aircraft after the frequency allocation plan had been adjusted and distributed; and (b) during landing rollout, the mishap aircraft entered the beamwidth for the Other Unit GDT, causing the mishap aircraft to receive two different uplink signals on the same frequency, preventing it from receiving data from its own GDT and resulting in the loss of uplink.