Yeti AT72 at Pokhara on Jan 15th 2023, lost height on final approach, both propellers went into feather
Last Update: February 15, 2023 / 17:36:38 GMT/Zulu time
Incident Facts
Date of incident
Jan 15, 2023
Classification
Crash
Airline
Yeti Airlines
Flight number
YT-691
Departure
Kathmandu, Nepal
Destination
Pokhara, Nepal
Aircraft Registration
9N-ANC
Aircraft Type
ATR ATR-72-200
ICAO Type Designator
AT72
A Rescue Operation was in progress.
Nepal's CAA (CAAN) reported the aircraft carried 65 passengers and 4 crew, amongst them 53 Nepalis, five Indians, four Russians, four Irish, two Koreans, an Argentinian and a French and published a manifest with the names (Editorial comment: ? this does not add up with 69 people on board). Later the day the CAA corrected their previously corrected version (from 68+4 to 65+4) again to 68 passengers and 4 crew. There were 53 Nepalese, 5 Indian, 4 Russian, 2 Korean, 1 Australian, 1 Argentinian, 1 Irish and 1 French citizen plus the crew on board. 68 bodies were recovered from the crash site.
On Jan 16th 2023 the CAAN reported (correcting their earlier statement) 66 bodies were recovered so far. In the afternoon local Nepal time the CAAN added, that 69 bodies have been recovered, 41 have been identified so far.
On Jan 17th 2023 the CAAN reported that 70 of the 72 bodies have been recovered. 41 bodies have already been identified, 22 have been handed to their families.
On Jan 18th 2023 the CAAN reported that 71 of the 72 bodies have been recovered. The FDR and CVR have been handed to the investigation commission, that is being supported by foreign investigators (BEA, ATR, EASA) who travelled to Pokhara this Wednesday Jan 18th 2023.
On Jan 31st 2023 the Canadian TSB reported they have assigned an accredited representative to participate in the investigation and stated: "The TSB’s accredited representative, along with a technical advisor from Pratt & Whitney Canada, will coordinate the exchange of technical and safety information regarding the engines, which were designed and manufactured in Canada, and assist Nepal with the investigation. The accredited representative will also travel to Singapore to attend the download of the flight recorders, which is set to take place on 28 January 2023."
By Jan 31st 2023 Medical Services report that it is still unclear how many bodies were recovered from the crash site, they have results that may indicate more bodies than known so far have been recovered, only after the DNA analysis is completed there will be certainty. In the meantime Nepal's army using sniffer dogs are still searching for the missing remains.
On Feb 6th 2023 Nepal's AIC reported that both flight data and cockpit voice recorders were successfully read out in Singapore. According to first analysis of the flight data recorders both propellers of the aircraft went into the feather position. The reason for the feathering of both propellers is still being determined, human factors as well as technical factors are still under investigation.
Nepal Rescue Coordination Center (NRCC) in Kathmandu reported 68 bodies were recovered so far. The search for remaining 4 occupants is still on going. The search was interrupted during the night from 15 to 16th January.
On Jan 16th 2023 the NRCC reported the flight data recorder has been recovered from the crash site and been forwarded to the Nepalese army which is going to hand the blackbox over to the investigation team. 35 of the 66 bodies have been identified so far.
On Jan 17th 2023 the NRCC reported both flight data and cockpit voice recorders were recovered (the airline confirms this, however, there is no confirmation from the CAAN yet).
Nepal's government assigned an accident investigation commission. The French BEA is going to participate in the investigation.
On Feb 15th 2023 Nepal's AAIC (Aircraft Accident Investigation Commission) released their preliminary report summarizing the sequence of events:
On 15 January 2023, an ATR 72-212A was operating scheduled flights between Kathmandu (VNKT) and Pokhara International Airport (VNPR). The same flight crew operated two sectors between VNKT to VNPR and VNPR to VNKT earlier in the morning. The accident occurred during a visual approach for runway 12 at VNPR. This was the third flight by the crew members on that day. The flight was operated by two Captains, one Captain was in the process of obtaining aerodrome familarization for operating into Pokhara and the other Captain being the instructor pilot. The Captain being familarized, 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).
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. But during the later phases of flight crew requested and received clearance from ATC to land on Runway 12.
At 10:51:36, the aircraft descended (from 6,500 feet at five miles away from VNPR 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 surface movement at that time. Instead, the propeller rotation speed (Np) of both engines decreased simultaneously to less than 25%1 and the torque (Tq) started decreasing to 0%, which is consistent with both propellers going into the feathered condition. On the cockpit voice recorder (CVR) area microphone recording, a single Master Caution chime was recorded at 10:56:36. 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%. When propellers are in feather, they are not producing thrust.
When both propellers were feathered, the investigation team observed that both engines of 9N-ANC were running flight idle condition during the event flight to prevent over torque. As per the FDR data, all the recorded parameters related to engines did not show any anomaly. At 10:56:50 when the radio altitude callout for five hundred feet3 was annunciated, another “click” sound was heard. The aircraft reached a maximum bank angle of 30 degrees at this altitude. The recorded Np and Tq data remained invalid. 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 after the “click” sound, the aircraft was at the initiation of its last turn at 368 feet AGL, the highpressure turbine speed (Nh) of both engines increased from 73% to 77%.
It is noted that the PF handed over control of the aircraft to the PM at 10:57:18. At 10:57:20, 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 warning the crew that the aircraft Angle of Attack (AoA) increased up to the stick shaker threshold.
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, sound of impact was heard in the CVR. The FDR and CVR stopped recording at 10:57:33 and 10:57:35 respectively.
Pokhara's new International Airport was opened on Jan 1st 2023 to replace the old domestic Airport.
The position of the crash site according to the preliminary report: N28.1975 E83.985
Incident Facts
Date of incident
Jan 15, 2023
Classification
Crash
Airline
Yeti Airlines
Flight number
YT-691
Departure
Kathmandu, Nepal
Destination
Pokhara, Nepal
Aircraft Registration
9N-ANC
Aircraft Type
ATR ATR-72-200
ICAO Type Designator
AT72
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