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| Date: | Sunday 15 January 2023 |
| Time: | 10:57 |
| Type: |  ATR 72-500 (72-212A) |
| Owner/operator: | Yeti Airlines |
| Registration: | 9N-ANC |
| MSN: | 754 |
| Year of manufacture: | 2007 |
| Engine model: | Pratt & Whitney Canada PW127 |
| Fatalities: | Fatalities: 72 / Occupants: 72 |
| Aircraft damage: | Destroyed |
| Category: | Accident |
| Location: | 2 km WNW of Pokhara International Airport -
 Nepal
|
| Phase: | Approach |
| Nature: | Passenger - Scheduled |
| Departure airport: | Kathmandu-Tribhuvan Airport (KTM/VNKT) |
| Pokhara International Airport (VNPR) | |
| Investigating agency: | Nepal AAIC |
| Confidence Rating: |  Accident investigation report completed and information captured |
Yeti Airlines flight 691, an ATR 72-500, crashed while on final approach to runway 12 at Pokhara International Airport, Nepal.
The aircraft crashed on the bank of Seti River and partially ended up in a deep gorge, killing all 72 on board.
The flight was operated by two captains, one captain was in the process of obtaining aerodrome familiarization for operating into Pokhara and the other captain being the instructor pilot. The captain being familiarized, who was occupying the left hand seat, was the Pilot Flying (PF) and the instructor pilot, occupying the right hand seat, was the Pilot Monitoring (PM).
They had operated two sectors between Kathmandu and Pokhara earlier in the morning.
The take-off, climb, cruise and descent to Pokhara was normal. During the first contact with Pokhara tower the Air Traffic Controller (ATC) assigned the runway 30 to land. At a later time, the flight crew requested and received clearance from ATC to land on runway 12.
At 10:51:36, the aircraft descended from 6,500 feet and joined the downwind track for runway 12 to the north of the runway.
The aircraft was visually identified by ATC during the approach. At 10:56:12, the pilots extended the flaps to the 15 degrees position and selected the landing gears lever to the down position. The take-off (TO) setting was selected on power management panel.
At 10:56:27, the PF disengaged the Autopilot System (AP) at an altitude of 721 feet Above Ground Level (AGL). The PF then called for "FLAPS 30" at 10:56:32, and the PM replied, "Flaps 30 and descending". The flight data recorder (FDR) data did not record any flap movement at that time.
Instead, the propeller rotation speed (Np) of both engines decreased simultaneously to less than 25% and the torque (Tq) started decreasing to 0%, which is consistent with both propellers going into the feathered condition. This was followed by a single Master Caution chime.
The flight crew then carried out the "Before Landing Checklist" before starting the left turn onto the base leg. During that time, the power lever angle increased from 41% to 44%. At the point, Np of both propellers were recorded as Non-Computed Data (NCD) in the FDR and the torque (Tq) of both engines were at 0%.
At 10:56:50 when the radio altitude callout for five hundred feet was annunciated, another 'click' sound was heard, likely the crew had inhibited the master caution light.
The aircraft reached a maximum bank angle of 30 degrees at this altitude. The yaw damper disconnected four seconds later. The PF consulted the PM on whether to continue the left turn and the PM replied to continue the turn. Subsequently, the PF asked the PM on whether to continue descend and the PM responded it was not necessary and instructed to apply a little power. At 10:56:54, another click was heard, followed by the flaps surface movement to the 30 degrees position.
When ATC gave the clearance for landing at 10:57:07, the PF mentioned twice that there was no power coming from the engines. At 10:57:11, the power levers were advanced first to 62 degrees then to the maximum power position.
It was followed by a 'click' sound at 10:57:16. One second afterwards, the aircraft was at the initiation of its last turn at 368 feet AGL, the high-pressure turbine speed (Nh) of both engines increased from 73% to 77%.
At 10:57:18 the PF handed over control of the aircraft to the PM and the PM (who was previously the PF) repeated again that there was no power from the engines. At 10:57:24 when the aircraft was at 311 feet AGL, the stick shaker was activated.
At 10:57:26, a second sequence of stick shaker warning was activated when the aircraft banked towards the left abruptly. Thereafter, the radio altitude alert for two hundred feet was annunciated, and the cricket sound and stick shaker ceased. At 10:57:32, the aircraft impacted the ground.
The Pokhara International Airport was opened on January 1, 2023 and is located to the east-southeast of the old Pokhara Airport.
The most probable cause of the accident is determined to be the inadvertent movement of both condition levers to the feathered position in flight, which resulted in feathering of both propellers and subsequent loss of thrust, leading to an aerodynamic stall and collision with terrain.
The contributing factors to the accident are:
1 High workload due to operating into a new airport with surrounding terrain and the crew missing the associated flight deck and engine indications that both propellers had been feathered.
2 Human factor issues such as high workload and stress that appears to have resulted in the misidentification and selection of the propellers to the feathered position.
3 The proximity of terrain requiring a tight circuit to land on runway 12. This tight circuit was not the usual visual circuit pattern and contributed to the high workload. This tight pattern also meant that the approach did not meet the stabilised visual approach criteria.
4 Use of visual approach circuit for RWY 12 without any evaluation, validation and resolution of its threats which were highlighted by the SRM team of CAAN and advices proposed in flight procedures design report conducted by the consultant and without the development and approval of the chart by the operator and regulator respectively.
5 Lack of appropriate technical and skill based training (including simulator) to the crew and proper classroom briefings (for that flight) for the safe operation of flight at new airport for visual approach to runway 12.
6 Non-compliance with SOPs, ineffective CRM and lack of sterile cockpit discipline.
METAR:
04:30 UTC / 10:15 local time:
VNPR METAR 0430Z 17003KT 070V190 6000 FEW025 14/09 Q1016 NOSIG
05:00 UTC / 10:45 local time:
VNPR METAR 0500Z 12005KT 080V160 6000 FEW025 14/09 Q1015 NOSIG
Accident investigation:
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|
Sources:
kathmandupost.com
Location
Revision history:
| Date/time | Contributor | Updates |
|---|---|---|
| 28-Dec-2023 15:21 | harro | Updated [Other fatalities, Damage, Narrative, Accident report] |
Corrections or additions? ... Edit this accident description
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