Aeroflot Flight 1492

Aeroflot Flight 1492 was a scheduled domestic passenger flight operated by Aeroflot from Moscow–Sheremetyevo to Murmansk, Russia. On 5 May 2019, the Sukhoi Superjet 100 aircraft operating the flight was climbing out when it was struck by lightning. The aircraft suffered an electrical failure and returned to Sheremetyevo for an emergency landing. It bounced on landing and touched down hard, causing the landing gear to collapse, fuel to spill out of the wings, and a fire to erupt. The fire engulfed the rear of the aircraft, killing 41 of the 78 occupants.

Accident

Flight 1492 took off from runway 24C at Sheremetyevo International Airport, bound for Murmansk Airport, on 5 May 2019 at 18:03 local time (15:03 UTC). Towering cumulonimbus (thunderstorm) clouds were observed in the vicinity of the airport with a base of 6000 ft and peaking at about 29000 ft. The clouds were moving in a north-easterly direction at a speed of 40 - 45 kph. When the plane was approaching the thunderstorm zone, a 327 degree heading was selected manually at 18:07 local time (15:07 UTC), initiating a right turn earlier than it is prescribed by the КN 24Е standard instrument departure, but the crew did not request active thunderstorm area avoidance clearance. At 15:08 UTC, the aircraft was climbing through flight level 89 (around 8900 ft) when it was struck by lightning. The primary radio and autopilot became inoperative and the flight control mode changed to DIRECT – a degraded, more challenging mode of operation. The captain assumed manual control of the aircraft. The transponder code was changed to 7600 (to indicate radio failure) at 15:09 UTC and subsequently to 7700 (emergency) at 15:26 UTC while on final approach. The secondary radio (VHF2) remained operative and the crew were able to restore communication with air traffic control (ATC) and made a pan-pan call on the emergency frequency.

The aircraft stopped its climb at flight level 106 (around 10600 ft) and was guided towards Sheremetyevo by ATC. It performed a right orbit before lining up for approach to runway 24L; the crew tuned into the instrument landing system and the captain flew the approach manually. Upon capturing the glideslope, the aircraft's weight was 43.5 t, 1.6 t over the maximum landing weight. At 15:18:53 UTC, the captain attempted to contact the controller to request a holding area, but his message was not recorded by the controller's recorder. The flaps were lowered to 25 degrees, which is the recommended setting for an overweight landing in DIRECT mode. The wind was blowing from 190 degrees at 30 kn – a 50-degree crosswind – and the speed stabilised at 155 kn. Between 1100 ft and 900 ft AGL, the predictive windshear warning sounded repeatedly: "GO-AROUND, WINDSHEAR AHEAD". The crew did not acknowledge this warning on tape. Descending through 260 ft, the aircraft began to deviate below the glideslope and the "GLIDESLOPE" aural alert sounded. The captain called "advisory" and increased engine thrust, and the speed rose through 164 kn at 40 ft to 170 kn at 16 ft AGL – 15 kn above the required approach speed, although the airline's own Flight Operations Manual provides pilots with a margin of −5 to +20 kt as a criterion for stabilised approach. As he reduced the thrust to idle for the flare, the captain made several large, alternating sidestick inputs, causing the pitch to vary between +6 and −2 degrees.

The aircraft made simultaneous ground contact with all three landing gear legs 900 m beyond the runway threshold at a speed of 158 kn, resulting in a vertical acceleration of 2.55 g. Concurrently with the touchdown, in the span of 0.4 seconds, the sidestick was moved from full aft to full forward. Though the spoilers were armed, automatic spoiler deployment is inhibited in DIRECT mode and they were not extended manually. The aircraft bounced to a height of 6 ft. The captain attempted to apply maximum reverse thrust while he continued to hold the sidestick in the fully forward position. Reverse thrust and reverser door deployment is inhibited in the absence of weight on the aircraft's wheels (i.e. in flight) and the reverser doors only began to open upon the second touchdown. The aircraft lifted off the ground before the reverse door cycle was completed and reverse thrust did not activate. The second touchdown occurred two seconds after the first, nose-first, at a speed of 155 kn and with a vertical load of 5.85 g. The main landing gear weak links sheared – the weak links are designed to shear under heavy load to minimise damage to the wing – allowing the gear legs to "move up and backwards" and the wing remained intact. The aircraft bounced to a height of 15 - 18 ft. The thrust levers were advanced to take-off power – the reverser doors began to close – and the sidestick was pulled full aft in a possible attempt to go around. Thrust was not allowed to increase until the reverser doors were closed and a third impact was recorded at a speed of 140 kn and with a vertical load in excess of 5 g. The landing gear collapsed, penetrating the wing, and fuel spilled out of the wing tanks. A fire erupted, engulfing the wings, rear fuselage and empennage. Fire alarms sounded in the cockpit for the aft cargo hold and the auxiliary power unit. The aircraft slid down the runway, veered to the left and came to a standstill on the grass between two runway-adjoining taxiways with the nose facing upwind at 15:30 UTC. Power to the engines was cut at 15:31 UTC. Flight recorder data suggest that control over the engines had been lost after the final impact.

An evacuation was carried out from the front passenger doors and their slides were deployed. The first officer used the escape rope to climb out of the right cockpit window. Aeroflot claimed the evacuation took 55 seconds, though video evidence shows the slides still in use 70 seconds after their deployment. Passengers were seen carrying hand luggage out of the aircraft. The rear half of the aircraft was destroyed by the fire, which was extinguished about 45 minutes after landing.