Aeroflot flight 6515

Aeroflot flight 6515
	An aeroflot aircraft of the same construction
Accident summary
Accident type	Loss of control
place	24 km southeast of Jemelyanovka, 10 km from the Soviet coast in Sywasch
date	October 23, 1978
Fatalities	26th
Survivors	0
Aircraft
Aircraft type	Antonov An-24 B
operator	Aeroflot
Mark	CCCP-46327
Departure airport	Stavropol Airport
Destination airport	Simferopol airport
Passengers	21st
crew	5
	Lists of aviation accidents

On October 23, 1978, an Antonov An-24 crashed on the inner-Soviet scheduled flight Aeroflot flight 6515 from Stavropol to Simferopol , killing all 26 occupants.

plane

The aircraft was a nine-year-old Antonov An-24 B with the air vehicle registration CCCP-46327, which had completed its first flight in September 1,969th

crew

The crew consisted of the flight captain , the first officer , the flight engineer , the navigator and a flight attendant .

course

The plane took off from Stavropol Airport at 6:14 p.m. Moscow time and rose to an altitude of 2,400 m . During the first half of the flight over Stavropol and the Kuban region , the weather conditions were good (light cloud cover and visibility of 10 km ) and the flight was conducted visually . However, the weather conditions worsened when reaching the airspace over Eastern Crimea (dense clouds with a cloud base of 600 to 800 m and a cloud upper limit of 3,000 to 3,500 m, winds with speeds of 60 km / h , and icing conditions). At around 7:25 p.m. Moscow time, the aircraft flew into the clouds. At this point in time, the aircraft had already been handed over to an air traffic controller at Simferopol Airport. At 19:39, the pilots reported over the Sywasch that the aircraft was flying through clouds and that there was a possibility of ice formation. A short time later, the pilots reported that one engine had failed and another 14 seconds later that the other engine had also failed. Then the radio contact broke off.

Eventually the z. The partly mud-covered wreckage of the aircraft was found one day later in Sywasch , 24 km southeast of Jemeljanowka and ten kilometers from the Soviet coast. All 26 inmates died.

root cause

During the investigation of the causes of the accident, a rescue operation in 2.5 m deep, murky water was carried out from October 24 to November 18, during which all essential components of the aircraft, including the MSRP-12-9 flight data recorder , were recovered. Using the data from the flight data recorder, it was possible to determine that the aircraft was flying at an altitude of 2450 m at a speed of 400 to 410 km / h 2–3 minutes before the occurrence of the emergency . Starting nine minutes before the end of the recording, a speed loss of 50 km / h and a reduction in oil pressure to 7 kg / cm² were recorded in the subsequent 7.5 minutes . The oil pressure loss was attributed to progressive icing of the engine air inlets and the engines themselves. Finally, it came to 19:40: 14:00, about 1½ minutes before impact, with a time interval of 3.5 seconds in the two engines to the flameout , whereupon precipitated both engines and propellers automatically into the feathered position were brought. The pilots then initiated a left turn towards the coast at a speed of 250 km / h and tried to restart the left engine. The left engine did not reach the required speed, however, and a reverse thrust was created instead, which reduced the speed to 186 km / h and the aircraft tilted 45 ° to the left. The angle of attack reached a supercritical value, making it the stall came and the aircraft into a steep spiral dive passed. The pilots pulled the control horns to operate the elevator , which increased the angular velocity , whereupon the aircraft turned 360 ° around the longitudinal axis at an altitude of approx. 500 m. Finally, at 19:41, the aircraft hit the surface at a speed of 490 km / h, a rate of descent of 90 m / s and a vertical inclination of 50 °.

The late activation of the engine deicing system by the pilots was found to be the cause of the accident . The fact that the flight manual did not take into account the situation of a double engine failure in flight and the training did not include the correct behavior in similar weather conditions (flight at night in the clouds under icing conditions) made the situation even worse.

Similar cases

A Vickers Viscount crashed under similar circumstances on Capital Airlines Flight 20 .

swell

45.26 35.1Coordinates: 45 ° 15 ′ 36 ″ N , 35 ° 6 ′ 0 ″ E