HK-4274
2021-MAR-02 · Pieri, Uror County, South Sudan

South Sudan Supreme Airlines — Flight HK-4274

A Let L-410UVP-E Turbolet crashed near Pieri Airstrip following a dual engine failure. Approximately ten minutes after departure, the aircraft suffered an initial engine failure while climbing. During the crew's attempt to return to the airstrip, the second engine failed, leading to an aerodynamic stall and a near-vertical impact. All ten people on board were killed.

Aircraft
Let L-410UVP-E
Registration
HK-4274
Phase
Takeoff (climb)
Cause
Engine Failure
Souls on Board
10
Fatalities
10
Origin → Dest
Pieri Airstrip, South Sudan → Juba International Airport, South Sudan
Report
Final

Investigation Summary

The aircraft was operating a domestic scheduled flight from Pieri to Yuai. Investigation by the South Sudan Civil Aviation Authority revealed a catastrophic sequence of mechanical failures. After the first engine failed, the crew initiated a turn to return to Pieri. During this maneuver, the remaining engine also lost power. The loss of total thrust resulted in a rapid decay of airspeed, leading to an aerodynamic stall. The aircraft crashed into an open field with very little forward momentum. Notably, the aircraft was operating under a fake Colombian registration (HK-4274), a common issue in the region's unregulated aviation sector. The airframe was the 1000th L-410 produced and had a long history of owners including Aeroflot and Business Aviation Center before being acquired by South Supreme Airlines in 2017.

Final Conclusions

The crash was caused by a dual engine failure shortly after takeoff. The initial failure of one engine was followed by the failure of the second during the emergency return to the airstrip, resulting in a stall and loss of control. The investigation also highlighted significant regulatory oversight issues, evidenced by the use of fraudulent aircraft registrations.

Video Analysis

No video analysis linked for this case file yet.

Airframe & Maintenance

Engines
Walter M601E

Systems & Failure Modes

i

Engines

Both engines failed in flight, depriving the aircraft of the thrust necessary to maintain altitude and airspeed.

i

Registration/Documentation

The aircraft operated with fraudulent registration marks (HK-4274 and TR-KSS), indicating a lack of proper regulatory oversight.

Interesting Facts

  • 01The aircraft was using a fake Colombian registration, HK-4274, which actually belonged to a different aircraft in South America.
  • 02The airframe was the 1000th Let L-410 ever manufactured.
  • 03There was no post-crash fire despite the total destruction of the airframe.
  • 04The flight was part of a multi-leg schedule: Juba to Pieri, then Yuai, then back to Juba.

Safety Actions & Advisories

Grounding of South Supreme Airlines

Following the accident, the President of South Sudan ordered the immediate grounding of South Supreme Airlines to allow for a full investigation into its safety standards and fleet documentation.

Known Controversies & Unanswered Questions

Fraudulent Registration

Reference ↗

The aircraft was found to be flying with a fake Colombian registration (HK-4274). This raised international concerns regarding the 'grey market' aviation operations in South Sudan and the lack of effective oversight by the Civil Aviation Authority.

Location

Pieri, Uror County, South Sudan · 8.0000, 30.0000

Related Cases

Case ID · south-supreme-l410-2021Last updated · Filed

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