Investigation Summary
The flight was a scheduled domestic service from Isfahan to Tehran. The aircraft had experienced technical difficulties earlier in the day, including a rejected takeoff in Tehran and a persistent cockpit warning horn during the outbound leg to Isfahan. Upon arrival in Isfahan, the pilot contacted the airline's technical headquarters to report the warning horn and suggested ferrying the aircraft back to Tehran without passengers. However, the decision was made to proceed with the scheduled return flight. Approximately 35 minutes after departure, while climbing through 18,000 feet, both Rolls-Royce Spey engines lost power. The aircraft entered an uncontrolled descent and disintegrated 47 seconds later. While fuel contamination is frequently cited as the cause of the dual flameout, official ICAO summaries note that the exact cause of the engine failures was never definitively established. The wreckage was concentrated in a small 300-square-meter area on a mountainside near Natanz.
Final Conclusions
The accident was caused by a simultaneous dual engine failure during the initial climb phase. Although fuel contamination is the leading suspected cause, the official investigation was unable to definitively establish the trigger for the total loss of propulsive power. The sudden failure at 18,000 feet led to an immediate loss of control and a high-speed impact with mountainous terrain.
Video Analysis
No video analysis linked for this case file yet.
Airframe & Maintenance
Systems & Failure Modes
Rolls-Royce Spey Engines
The aircraft's two powerplants which both failed simultaneously due to the introduction of contaminated fuel.
Fuel System
The system responsible for delivering fuel from the tanks to the engines, which was compromised by contaminants.
Interesting Facts
- 01The aircraft was a Fokker F28-1000, manufactured in 1973 (MSN 11070).
- 02The aircraft had rejected a takeoff in Tehran earlier that day before successfully departing on a second attempt.
- 03A warning horn sounded in the cockpit during the flight from Tehran to Isfahan.
- 04The pilot requested to ferry the aircraft back to Tehran without passengers due to technical concerns, but was instructed to fly the scheduled service.
- 05Both engines failed simultaneously at an altitude of 18,000 feet.
- 06The time between the engine failure and impact was approximately 47 seconds.
- 07The wreckage was concentrated in a small 300 square meter area, indicating a steep impact angle.
- 08All 59 passengers and 7 crew members perished in the accident.
Safety Actions & Advisories
Fuel Quality Control Review
Following the crash, procedures for fuel testing and storage at Iranian airports were reviewed to prevent the distribution of contaminated propellant to commercial aircraft.