An-24 crash near Amderma

The An-24 crash near Amderma was an aviation accident that occurred on the night of Monday, 3 September 1979 near Amderma. An An-24B airliner of the Arkhangelsk Joint Aviation Detachment was completing a scheduled of the Aeroflot enterprise was completing a scheduled local flight A-513 on the route Arkhangelsk — Amderma, but during the approach to Amderma airport the aircraft descended significantly below the glide path and collided with a hill on the shore of the Kara Sea. Of the 43 people on board — 37 passengers and 6 crew members — 40 were killed; three survived with serious injuries.

The crash of Flight 513 became the largest aviation accident in the history of the Nenets Autonomous Okrug and the second in the history of Arkhangelsk Oblast (after the An-24 crash in Leshukonskoye).

According to the results of the investigation, the cause of the crash was the crew's gross violation of the requirements of NPP GA-78 regarding maintaining the established descent path during an approach using the OSP system at night in adverse weather conditions, which led to the airliner's premature descent.

Sequence of events

Back on 2 September 1979 at 22:21 Moscow time, flight A-513 with 37 passengers and 6 crew members departs Arkhangelsk's Talagi Airport; the flight is operated by An-24B USSR-46269, flying from Arkhangelsk to Amderma. In total there were 43 people on board: 37 passengers (32 adults and 5 children) and 6 crew members; the flight weight was exceeded by 816 kg.

The night sky over Amderma was covered by fractostratus clouds with a base of 120 metres, visibility was 8 kilometres and a light north-westerly wind was blowing. On the approach to the airport and before the start of the descent, the navigator-instructor went into the cabin, thereby placing the navigator's duties on the trainee. Landing at the airport was to be made on a magnetic heading of 74°, and the approach was performed by the shortest route, exiting at the point of the fourth turn. The airport was 26 kilometres away when the crew reported to the controller that they had reached an altitude of 600 metres, although in reality it was 480. Then, approaching the landing course line 8300 metres from the airfield, the aircraft reported entering the glide path, after which the airliner began to descend at a vertical speed of 3.9 m/s at a gliding speed of 210 km/h.

Down to a height of 250 metres the calculated approach parameters were maintained, but then at this height the crew, in violation of the OSP approach technique, did not level the aircraft off into horizontal flight, but simply increased engine power to 40° on the UPRT, although in fact the descent did not stop but only decreased to a rate of 1 m/s. Thus the An-24, flying in cloud, now began to descend below the glide path and passed the outer marker (DPRM) at a height of 155 metres, instead of the 250 metres established for this airfield. Emerging from the cloud at a height of 120 metres, the crew saw the approach lighting system lights below, but mistakenly decided that these were the lights of the start of the runway, and therefore stopped flying on instruments, switching to visual flight, reduced engine power to 28° on the UPRT and increased the vertical rate of descent.

Crash

The airliner was flying in darkness over a deserted shore, where the crew could not see any landmarks. Nevertheless, the crew continued the descent and dropped to an unacceptably low height, not attaching serious importance to the triggering of the “Dangerous altitude” warning. The trainee navigator reported: “altitude 80 metres, speed 210”, although in fact the altitude was 65 metres. Not knowing their true position, the pilots pushed the control columns “forward”, lowering the nose slightly more, and thereby increased the vertical speed to 5 m/s. 5 seconds after the previous report, the navigator reported to the pilots: “70 metres, speed 210” (actual altitude — 50 metres), and 2.5 seconds later: “60 metres, speed 210” (actual altitude — 40 metres). To line up with the landing axis, the pilots put the aircraft into a right bank of 4°.

A little over three seconds later, at 01:01 Moscow time, the An-24, flying on a heading of 80° at a speed of 206 km/h and with a vertical rate of descent of 6 m/s, at a height of 22.8 metres above the aerodrome level, crashed into a small hill 1850 metres from the start of the runway and 140 metres to the left of its centreline. The pilots probably saw the danger at the last moment and pulled the control columns “back” (the elevator at the moment of collision was deflected upward by 5.9°), but the high rate of descent and the short distance did not allow the crash to be avoided. The aircraft struck the hill first with the right wing panel, and then the lower part of the cockpit and the propellers hit the slope. The cockpit was immediately destroyed, and the right part of the wing broke. The fuselage was torn into two parts, after which the front part flipped over the left wing by 180°, flew 38 metres and crashed into the sandy shore of the Kara Sea 20—30 metres from the water. The aircraft was completely destroyed, and the scatter of the wreckage …