Accident Boeing 737-524 (WL) VQ-BPS,

ASN Wikibase Occurrence # 319236

Date:	Sunday 9 February 2020
Time:	12:27
Type:	Boeing 737-524 (WL)
Owner/operator:	Utair
Registration:	VQ-BPS
MSN:	28909/2960
Year of manufacture:	1997
Total airframe hrs:	57410 hours
Cycles:	29162 flights
Engine model:	CFMI CFM56-3B1
Fatalities:	Fatalities: 0 / Occupants: 100
Aircraft damage:	Substantial, written off
Category:	Accident
Location:	Usinsk Airport (USK) - Russia
Phase:	Landing
Nature:	Passenger - Scheduled
Departure airport:	Moskva-Vnukovo Airport (VKO/UUWW)
Destination airport:	Usinsk Airport (USK/UUYS)
Investigating agency:	MAK
Confidence Rating:	Accident investigation report completed and information captured

Narrative:
Utair flight 595, a Boeing 737-524, suffered a main landing gear collapse after it touched down short of the runway at Usinsk Airport, Russia.
The aircraft took off from Moscow's Vnukovo Airport at 06:59 UTC and landed at Usinsk about 09:20 UTC (12:20 LT). It touched down in the snow, 32 meters short of the threshold of runway 13. The aircraft the it a snow bank, causing the main landing gears to separate.
The aircraft slid down the runway and came to rest on the edge, perpendicular to the runway. All occupants evacuated the aircraft safely.

The accident with the Boeing 737-500 VQ-BPS aircraft occurred during the landing as a result of a collision of the aircraft with a snow parapet 1.1 m high at a distance of 32 m to the runway threshold (within the paved section of the runway), which resulted in damage to the main landing gear and their subsequent "folding" in the process of moving along the runway.
The accident was caused by a combination of the following factors:
- the presence of contradictions in the Federal Aviation Rules for flights in the airspace of the Russian Federation, the airline's radio control system and the aircraft operational documentation regarding the need and procedure for introducing temperature corrections to the readings of barometric altimeters at low ambient temperatures;
- Failure by the operator of the Usinsk aerodrome to comply with the FAP-262 requirements for the maintenance of the aerodrome, which resulted in the presence of snow parapets on the paved section of the landing strip;
- the operator of the Usinsk aerodrome did not eliminate the shortcomings in the winter maintenance of the aerodrome, noted based on the results of the inspection by the Rosaviatsia commission on January 22, 2020;
- lack of risk assessment in the airline associated with the execution of approaches in the baro-VNAV mode in the presence of factors that impede such approaches (low ambient temperatures, snow-covered underlying surface, drifting snow (snowstorm), significant changes in the relief in front of the runway end, lack of PAPI-type lights), as well as appropriate recommendations to the crews on the specifics of such approaches, including after the transition to visual flight, and crew training;
- insufficient assessment by the crew during the preparation of the existing threats (hazard factors) and making an insufficiently substantiated decision to perform an RNAV (GNSS) approach (under the control of the autopilot in LNAV/VNAV mode) without introducing a correction for low outside air temperature in altitude overflying waypoints, which led to a flight below the established glide path;
- performing a flight along the "extended glide path" after turning off the autopilot and switching to manual piloting without attempting to enter the set glide path;
- the PIC may have had a visual illusion of a "high glide path" due to a snow-covered underlying surface, a snowstorm and the presence of a ravine directly in front of the runway end in the absence of PAPI type lights, which led to an incorrect assessment of the aircraft's flight altitude after switching to manual piloting, lack of reaction to timely and correct warnings of the co-pilot and exit to the runway end at a height significantly less than the established one.

METAR:

05:30 UTC / 08:30 local time:
METAR UUYS 090530Z 17006MPS 9000 SG OVC007 M24/M26 Q1003 R13/490534 NOSIG RMK QFE744/0993=
Wind 170 at 6 mps; 9000 m visibility, 700 ft overcast, temperature: -24°C

09:10 UTC / 12:10 local time:
SPECI UUYS 090910Z 17006G11MPS 1500 SN BLSN BKN015 M21/M23 Q0999 R13/390238 TEMPO 1000 SN BLSN RMK QFE741/0989=
Wind 170 at 6, gusting to 11 mps; 1500 m visibility in snow and blowing snow, broken clouds at 1500 ft, temperature: -21°C

Accident investigation: