Investigation Summary
The accident occurred during Operation Sahayogi Haat, the U.S. military's relief effort following the devastating 7.8-magnitude earthquake in Nepal. Vengeance 01 had arrived in the country on May 5 and was one of three Hueys assigned to the mission. On May 12, after picking up five injured civilians and two Nepalese soldiers, the crew faced a critical decision regarding their return flight to Kathmandu. To expedite the transport of the wounded, they chose a direct path over high, unfamiliar terrain rather than a longer, safer route. During this transit, the helicopter was caught in rapidly developing clouds or lifted into IMC by rising air currents. Deprived of visual ground references in the steep, forested mountains, the crew was unable to maneuver clear of the terrain. The wreckage was located three days later, approximately 8 miles north of Charikot at an elevation of roughly 11,000 feet.
Final Conclusions
The investigation attributed the crash to the crew's decision to fly a direct route over unfamiliar and rugged terrain under unstable weather conditions. This decision was driven by a real or perceived urgency to provide medical treatment to the injured civilians on board. The aircraft entered instrument meteorological conditions (IMC), leading to a loss of visual reference and subsequent impact with the ground.
Video Analysis
No video analysis linked for this case file yet.
Systems & Failure Modes
Visual Flight Rules (VFR)
The set of regulations under which a pilot operates an aircraft in weather conditions generally clear enough to allow the pilot to see where the aircraft is going. The crew lost these references when enveloped by clouds.
Instrument Meteorological Conditions (IMC)
Weather conditions that require pilots to fly primarily by reference to instruments. The crew's entry into IMC in mountainous terrain led to the fatal impact.
Interesting Facts
- 01The crash site was located in rugged, forested terrain at high altitude north of Charikot.
- 02The aircraft was part of Marine Light Attack Helicopter Squadron 469 (HMLA-469).
- 03Thirteen people were killed: six U.S. Marines, two Nepalese soldiers, and five Nepalese civilians.
- 04The crew was operating under Visual Flight Rules (VFR) but encountered rapidly developing clouds.
- 05The U.S. Embassy in Kathmandu renamed its Heritage Room to 'Vengeance Hall' in honor of the crew.
Safety Actions & Advisories
Operational Risk Management Review
The investigation highlighted the risks of 'urgency-based' decision making where the perceived need for speed in medical evacuations can lead to choosing higher-risk flight paths.