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Last updated: 19 October 2020
Status:Final
Date:Monday 11 July 2011
Time:11:56
Type:Silhouette image of generic AN24 model; specific model in this crash may look slightly different
Antonov An-24RV
Operator:Angara Airlines
Registration: RA-47302
C/n / msn: 57310302
First flight: 1975
Total airframe hrs:48489
Cycles:32783
Engines: 2 Ivchenko AI-24VT
Crew:Fatalities: 0 / Occupants: 4
Passengers:Fatalities: 7 / Occupants: 33
Total:Fatalities: 7 / Occupants: 37
Aircraft damage: Damaged beyond repair
Location:14 km (8.8 mls) SW of Strezhevoy (   Russia)
Phase: Landing (LDG)
Nature:Domestic Scheduled Passenger
Departure airport:Tomsk-Bogashevo Airport (TOF/UNTT), Russia
Destination airport:Surgut Airport (SGC/USRR), Russia
Flightnumber:5007
Narrative:
An Antonov An-24RV passenger plane, registration RA-47302, crashed into the Ob River, Russia, killing seven passengers.
Angara Airlines flight 5007 took off from Tomsk Airport at 10:10 local time, bound for Surgut. One hour and 26 minutes into the flight, when flying at a cruising altitude of 6000 m, the left engine's "chips in oil" light activated.
The engine parameters remained normal and the crew continued the flight. At 10:44, the captain, sensing the smell of burning in the cockpit, informed the crew about this and decided to proceed to the alternate airfield Nizhnevartovsk.
The flight was cleared to descend to 4,800 m and the left engine was put in flight idle mode. During the descent, the oil pressure in the left engine began to decrease to 3.5 kg/cm2, which was the minimum for the engine to operate.
At 10:49, the flight reached 4,800 m and the crew received further clearance to descend to 1,800 m and to fly a direct course to Nizhnevartovsk.
At 10:52, at an altitude of 3,600 m and a distance of 77 km from Nizhnevartovsk, the left engine "dangerous vibration" light illuminated At the command of the captain, the flight engineer turned off the left engine with feathering of the propeller
Visually convinced of the feathering of the left engine propeller, the captain saw flames from the engine compartment. At the same time, the fire alarm and the first stage of fire extinguishing went off. At the command of the captain, the flight engineer turned off the booster pumps and closed the stop valve of the left engine. The fire continued.
At 10:53, at a distance of 63 km from Nizhnevartovsk, the crew reported the fire to the controller. The engineer activated the second stage of firefighting but the fire was not extinguished. The captain then decided to make an emergency descent and landing on the Ob River, which he saw in a break in the clouds.
Before landing, the flight mechanic turned off the right engine and feathered the propeller. At the moment of ditching, at a speed of 240 km / h, there was a separation of the left-hand propeller and gear box. The aircraft then encountered an underwater obstacle and the lower part of the fuselage collapsed, The tail section then separated and the passenger cabin was partially flooded with water. The evacuation of passengers took place through the emergency hatch in the cockpit, as well as through the resulting break in the aft fuselage. Seven passengers were killed. Ten passengers received various injuries.

Probable Cause:

The aircraft accident involving An-24RV RA-47302 occurred during a ditching, which was performed because of a fire in the left AI-24-2 engine nacelle series number N49312005. Destruction of the aircraft with the loss of life was due to the collision of aircraft and underwater obstacles, which the crew could not anticipate and prevent.
The occurrence of the fire most likely was caused by depressurization system venting left engine failure due to the centrifugal breather CA-24 number G872VT9 with subsequent release air-oil emulsion in the engine compartment of the engine, as well as delayed engine shutdown when the crew received a warning of "shavings in the engine oil", pressure fluctuations of the left engine within ±5 kg/cm2, a burning smell and the oil pressure dropping below the limit.
Failure to inform the crew about the excessive vibration of the engine was due to the deterioration of the vibration measurement system, IV-41AM, most likely due to the changes (fluctuations) of the engine rotor speed in the process of the destruction of the bearing of the compressor rotor rear support and (or) misalignment of the IV-41AM-system which might have affected the decision of the crew to turn off the engine.
The cause of the destruction of the Rotary pointer LP-24 # G872VT9 was the destruction of the impeller due to prolonged exposure to air/oil emulsions with high compressor rotor temperature, due to the destruction of the ball bearing rear bearings.
Significant secondary damage to parts of the compressor rotor rear support site did not clearly establish the cause of the destruction of the bearing. Most likely, the destruction happened during its work with high misalignment of the rings.
Increased misalignment of the rings could be:
- as a result of adverse addition available to the mating parts back support assembly of the compressor rotor beats (within TU) with the beat bearing obtained because of his irregular installation at an average (according to technical condition) engine repairs in JSC "Aramilsky ARP";
- due to deviations from TU geometry of mating parts back support assembly of the compressor rotor.
Contributing factors of the accident, most likely, were:
- the psychological unpreparedness of the pilot in command to turn off the engine in flight due to lack of experience of actual flight with one engine inoperative;
- late detection of a fire by the crew and, as a consequence, failure to take timely measures to extinguish the fire. Due to lack of objective information to determine the cause of the late detection of a fire by the crew, a full assessment of the performance of all elements of the fire alarm system MTP-MTP-2A and 7, could not be made.

Accident investigation:
cover
Investigating agency: MAK
Status: Investigation completed
Duration: 2 years and 5 months
Accident number: Final report
Download report: Final report

Classification:
Engine fire
Ditching

Sources:
» Vesti.Ru
» Tomsk Airport
» RIA Novosti
» MAK


Photos

photo of Antonov-An-24RV-RA-47302
accident date: 11-07-2011
type: Antonov An-24RV
registration: RA-47302
photo of Antonov-An-24RV-RA-47302
accident date: 11-07-2011
type: Antonov An-24RV
registration: RA-47302
photo of Antonov-An-24RV-RA-47302
accident date: 11-07-2011
type: Antonov An-24RV
registration: RA-47302
photo of Antonov-An-24RV-RA-47302
accident date: 11-07-2011
type: Antonov An-24RV
registration: RA-47302
photo of Antonov-An-24RV-RA-47302
accident date: 11-07-2011
type: Antonov An-24RV
registration: RA-47302
photo of Antonov-An-24RV-RA-47302
accident date: 11-07-2011
type: Antonov An-24RV
registration: RA-47302
photo of Antonov-An-24RV-RA-47302
accident date: 11-07-2011
type: Antonov An-24RV
registration: RA-47302
photo of Antonov-An-24RV-RA-47302
accident date: 11-07-2011
type: Antonov An-24RV
registration: RA-47302
 

Video, social media

Map
This map shows the airport of departure and the intended destination of the flight. The line between the airports does not display the exact flight path.
Distance from Tomsk-Bogashevo Airport to Surgut Airport as the crow flies is 866 km (541 miles).
Accident location: Exact; as reported in the official accident report.

This information is not presented as the Flight Safety Foundation or the Aviation Safety Network’s opinion as to the cause of the accident. It is preliminary and is based on the facts as they are known at this time.
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