Investigation Summary
The aircraft was performing a routine logistics and passenger transport mission, having already completed legs from Malang and Jakarta. Because the aircraft was not fitted with a flight recorder, investigators primarily relied on wreckage patterns, witness reports, and the pilot's flight history. Analysis of the wreckage revealed that the number four engine's propeller had malfunctioned before impact, indicating a mechanical failure that caused a significant loss of thrust shortly after takeoff. The aircraft was operating near its maximum takeoff weight, carrying 110 passengers and 12 crew members. This high weight, combined with the asymmetric thrust from the failed engine, made it impossible for the crew to maintain a safe climb gradient. The proximity of urban development to the runway at Soewondo Air Force Base left the crew with no margin for error; the aircraft clipped an illegal 100-foot radio tower belonging to Joy FM while attempting to turn back, which led to a total loss of control. The disaster highlighted long-standing concerns regarding the age of the Indonesian Hercules fleet and the common practice of transporting civilian family members on military logistics flights.
Final Conclusions
The investigation, led by the Indonesian Air Force (TNI-AU) with support from the National Transportation Safety Committee (NTSC), concluded that the primary cause was a mechanical failure of the number four engine propeller. The resulting asymmetric thrust at a low altitude and high takeoff weight prevented the aircraft from climbing. Contributing factors included the presence of an unauthorized radio tower in the flight path and the aircraft's age (54 years), which raised questions about maintenance and spare parts availability during previous embargo periods.
Photographic Evidence (1)
Video Analysis
Fireball Over Medan – Inside the 2015 Lockheed C-130 Hercules Crash — On June 30, 2015, a routine military logistics mission turned into one of Indonesia's deadliest aviation disasters when a C-130 Hercules crashed into a residential area in Medan.
If playback is blocked, the owner has disabled embedding — use the link above.
Airframe & Maintenance
Crew Experience
Captain
Major Sandy Permana
First Officer
Captain Pandu Setiawan
Systems & Failure Modes
Allison T56-A-7 Turboprops
The aircraft was powered by four turboprop engines; the failure of the outermost right engine (No. 4) created severe asymmetric thrust.
Propeller System
A seized propeller on engine number four was identified as the mechanical trigger for the loss of power.
Interesting Facts
- 01The aircraft was manufactured in 1961 according to maintenance records, though the Air Force Chief stated it was built in 1964.
- 02All 122 people on board were killed, along with 17 ground fatalities.
- 03The crash site was only 2 kilometers away from the 2005 crash site of Mandala Airlines Flight 091.
- 04The aircraft was not equipped with a Flight Data Recorder (FDR) or Cockpit Voice Recorder (CVR).
- 05The radio tower struck by the aircraft was later determined to be an illegal structure.
Safety Actions & Advisories
Fleet Grounding
The Indonesian Air Force grounded its entire C-130 fleet for safety inspections immediately following the accident.
Fleet Modernization
The Indonesian government announced plans to retire and replace aging military aircraft to prevent similar tragedies.
Obstacle Removal
Indonesian authorities advised the removal of illegal towers near airports that posed a danger to aviation safety.
Known Controversies & Unanswered Questions
Civilian Passengers on Military Flights
Reference ↗The presence of over 100 passengers, many of whom were civilians paying for transport, sparked debate over the legality and safety of using military logistics flights for public transport.
Location
ACCIDENT SITE · Coordinates taken from the wikipedia geotag.