Yeti Airlines Crash, Pokhara Nepal.

Yeti Airlines Flight 691 Crash at Pokhara Nepal.

A Yeti Airlines ATR 72 crashed on approach to Pokhara airport Nepal on 15th January 2023; there were 68 on board.

The event took place as the aircraft was due to land at the new Pokhara International airport, which opened on January 1st. Video footage taken on a mobile phone shows the plane flying slowly, nose high before it rolls to the left, disappearing from view, followed by sounds of impact.

It is assumed that there will be no survivors as the majority of the passengers have been found and all are deceased. Both recorders have now been recovered, which should allow investigators to determine the cause of the crash.

There are endless possibilities that have been put forward as a cause and the video does appear to indicate that the aircraft entered an aerodynamic stall (see my current book for more information on what that is and possible causes) at low level with little time for a recovery.

This could indicate a sudden technical fault that the crew were unable to deal with, a pilot incapacitation or simply human error. The data and voice recorders will reveal the answers to those questions.

Yeti have had four fatal crashes since 2004 and Nepalese airlines are currently banned from EU airspace due to concerns over safety and training standards.

I would not point the finger at the crew at this stage as we simply do not know any more. It is appropriate however, to say that the theme of my book is the effect of culture – both national and within each airline – on safety matters as there is ample evidence to support the theory that this is the most important factor when ensuring safe flying.

Latest News 12th Feb 2023:

The investigating panel, which includes representatives from the engine manufacturer Pratt & Whitney, as well as accident investigators from France, Singapore and elsewhere; have released an interim bulletin.

They state that analysis of the recorders shows that both propellers were in the feathered position on the base leg of the approach (the point before the turn onto final approach is made) and thus the aircraft had no thrust (power) meaning that it was effectively gliding. Propellers are feathered in flight if an engine loses power in order to reduce drag. Feathering is the term used to describe a condition when the propellers blades are turned edge on to the airflow. In that position they present minimal drag but cannot produce thrust to maintain the aircraft speed.

A transport standard aircraft must be capable of flying with one of its two engines feathered but with a second propeller in that state the aircraft is a glider. It would be virtually impossible for two propellers to feather simultaneously without any input from the crew – a major and very rare fault would need to occur – and so this implies that the crew set the propellers to feather manually, although I cannot confirm that at this stage. Were they to have done so deliberately it would imply that they were trying to reduce drag, which in turn implies that both engines had stopped working normally. This would also be very unusual, although technically possible if fuel starvation were a cause for example.

It is possible that human error was a factor but until the investigators release more information, it is impossible to judge.

Preliminary Report Update 16.2.23

The investigators – Aircraft Accident Investigation Commission – have released an initial report on the crash, based on their examination of the Flight Data Recorder (FDR) and the Cockpit Voice Recorder (CVR) and it appears to indicate that the propellers were set to the Feather position by the crew. This was possibly the Pilot Monitoring (PM) who was training another captain, the Pilot Flying (PF) for the purpose of validation to operate into the new airport that had recently opened.

The recorders show that following a request for landing flap to be set by the PF, the propellers moved to the Feather position but the flaps did not move. This could suggest that the propeller levers were moved in error, instead of the flap lever. This is still conjecture at this stage but there was clearly some confusion between pilots that the engines were no longer delivering thrust, even though they were working normally. Engines cannot deliver thrust even if set to full power – which they eventually were – if the propellers are feathered, as they will not be able to provide propulsion.

Close to the time of the crash the pilots swapped roles and the Stick Shaker (a warning device to alert pilots that they are approaching a stall) activated at east twice. Loss of control followed soon afterwards.