Accident Boeing 747-3B3 EP-MNE,

Date:	Thursday 15 October 2015
Time:	07:18
Type:	Boeing 747-3B3
Owner/operator:	Mahan Air
Registration:	EP-MNE
MSN:	23480/641
Year of manufacture:	1986
Total airframe hrs:	92754 hours
Cycles:	17679 flights
Engine model:	General Electric CF6-50E2
Fatalities:	Fatalities: 0 / Occupants: 441
Aircraft damage:	Substantial, repaired
Category:	Accident
Location:	near Tehran-Mehrabad Airport (THR) - Iran
Phase:	Initial climb
Nature:	Passenger - Scheduled
Departure airport:	Tehran-Mehrabad Airport (THR/OIII)
Destination airport:	Bandar Abbas Airport (BND/OIKB)
Investigating agency:	AAIB Iran
Confidence Rating:	Accident investigation report completed and information captured

Narrative:
Mahan Air flight 1095 returned to land at Tehran-Mehrabad Airport, Iran after suffered an uncontained engine failure.
The aircraft, a Boeing 747-300, registered EP-MNE operated a scheduled flight from Mehrabad International Airport to Bandar Abbas Airport, carrying 19 flight crew and 422 passengers. The aircraft departed from Tehran at 07:16 hours local time.
About 07:18, while climbing through 7500 feet, the no.3 General Electric CF6-50E2 engine suffered an uncontained failure. Some parts of the engine detached and struck engine no. 4, as well as aircraft structure. The aircraft hydraulic systems no 1, 3 and 4 failed due to impact of debris from engine no.3. An emergency landing was made back at Tehran at 07:53.

Investigation revealed that the engine failure was initiated by vibration as a result of unbalance of the engine HPT module, which caused crack propagation in the low pressure turbine (LPT)

CAUSE of ACCIDENT:
The operators fault to modify the ENG# 3 with AD requirement, and ineffective action for N1 Vibration which caused uncontained engine failure.
Contributing factors:
- Insufficient operator maintenance & engineering performance
- Lack of effective monitoring in operators line maintenance
- Lack of support for engine parts and mandatory information from the manufacturer
- Lack of effective monitoring in Mahan air concerning operation, training and technical divisions.

Accident investigation: