Helicopter Crashes in Colombia After Ground-Based Explosive Detonation

Casualties unknown • Orito, CO

An MI-171 helicopter sustained a loss of control and subsequent destruction after an improvised explosive device detonated beneath it during an external cargo operation in Nariño.

What happened

On October 5, 2013, an MI-171 helicopter, registration HK-4770, was performing a commercial external cargo flight in the rural Alisales Canyon, Nariño. The mission, operated by Helistar S.A.S. for Ecopetrol, involved transporting 150 kilograms of cargo to landing site H13.

Due to low cloud cover, a Colombian Air Force escort helicopter was unable to continue the mission past point H-5. The pilot of HK-4770 elected to proceed alone to the destination. After performing a reconnaissance pass and confirming the presence of ground personnel and landing signals, the pilot initiated an approach to a hover at approximately 8 to 10 meters above the ground.

While in a hover, an explosive device planted on the ground detonated near the rear right side of the aircraft. The blast disrupted the airflow and caused a sudden loss of lift, leading to a loss of control. The aircraft impacted the terrain, causing the landing gear to fracture and the helicopter to roll onto its left side. All 5 crew members evacuated the aircraft unharmed. Following the crash, illegal armed groups arrived at the scene and incinerated the wreckage, resulting in the total loss of the aircraft.

The investigation

The GRIAA investigation established that the crew was fully qualified, and the aircraft was within weight and balance limits for the operation. The investigation focused on the sequence of events leading to the loss of lift and the security environment of the landing site. Investigators determined that while the pilot had coordinated with ground security analysts and confirmed the presence of military personnel in the area, the specific threat of a planted explosive was not identified.

Findings

  • The primary cause of the accident was the loss of lift caused by the detonation of an explosive device during a hover.
  • The ground personnel failed to conduct a sufficiently detailed inspection of the landing zone to identify the presence of the explosive.
  • There was a lack of effective intelligence regarding the planned terrorist actions by illegal groups in the area.
  • Low visibility and cloud cover prevented the military escort from providing necessary security coverage during the final approach.

Probable cause

The sudden loss of aerodynamic lift resulting from a ground-based explosive detonation during an external cargo hover, compounded by inadequate site inspections and insufficient security intelligence.

Frequently asked questions

What happened in the 2013-10-05 MI-171E accident near Orito, CO?

An MI-171 helicopter sustained a loss of control and subsequent destruction after an improvised explosive device detonated beneath it during an external cargo operation in Nariño.

What aircraft was involved and where did it happen?

The accident on 2013-10-05 involved a MI-171E, registration HK4770, at Orito, CO.

What was the probable cause of the accident?

The sudden loss of aerodynamic lift resulting from a ground-based explosive detonation during an external cargo hover, compounded by inadequate site inspections and insufficient security intelligence.

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