Nepal plane crash
 

Looks like he was entering a stall. Fire on the ground seems to indicate there was fuel.

Pilots, thoughts?


(Video contains moments right before the crash)
https://www.bbc.com/news/world-asia-64284366

Horrifying....

Weird. Definitely looks slow with a high angle of attack then into a stall. Not what you would expect in daytime VMC. Possibly one of the engines rolled back, got slow, then Vmc roll? Didn’t seem to snap over like you see on one of those though.

My first thought before seeing the video was a di&#ed up approach leading to an accelerated stall. Had the Kathmandu crash on my mind after seeing that episode of Air Disaster the other day. Clearly not the case here.

https://youtu.be/jyBrCjaNxOE

If needing to tighten up the turn to line up with the runway, sometimes it's tempting to kick in an extra bit of rudder.

Bad idea when close to stall speed.

An uncoordinated turn will speed up the outside wing, but slow the inside wing, potentially to the point of stalling.

Don't know what happened here, but the base-to-final turn is a critical phase of flight.

Hot, humid, high airport altitude, too slow, turning :(

No issues with any of the posts so far…excellent.

The only problem with video in crash scenarios is they show the outside of the aircraft, not the result of any number of failures happening inside the skin of the aircraft.

No competent pilot, especially an airline pilot, would put a healthy aircraft in the profile shown in the video.

That said, difficult to watch…families involved.

It looks like he landed it. How would a stall cause a crash after touch down?

Sorry, I didn’t state that very well. The crash in Kathmandu was the result of an incredibly poorly flown visual approach that the pilot tried to force onto the runway after some extreme maneuvering. He did not stall the aircraft. My first thought about this crash , short of the runway, was that it might have been caused by similar maneuvers that resulted in an accelerated stall. Seeing the video, that was clearly not the case.

Hi,

From pprune info, there are indications that pilot was oriented to land on wrong airport (there is "old" and "new" airport). She figured out late, slow and low and tried to do 90-degree turn which plane could not handle given its energy state (low & slow?). It stalled, dropped a wing and that's it. Poor people. At least it was quick. This is my worst nightmare. :(

Inside video. Those who know the area say that the fact you could see the football stadium from the window indicates that a/c was on wrong approach and likely lined up for old airport.

Warning! Inside video of crash!

<iframe width="560" height="315" src="https://www.youtube.com/embed/HHG_JDhodR4" title="YouTube video player" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share" allowfullscreen></iframe>

Most aircraft crashes are due to pilot error. This one sure looks like a pilot was way over his ability to make good decisions. A real tragedy.

We all want a Capt. Sully Sullenberger type to fly our airplane and often get Capt. Kangaroo type instead. I don't really have a solution. Some of it maybe would help if pilots were more willing to turn in fellow pilots that made incompetent decisions, but that leads to dangerous possibilities of jealous pilots reporting good pilots to get better assignments.

https://avherald.com/h?article=503c63e9&opt=0

http://forums.pelicanparts.com/uploa...1673900425.jpg

I was wrong. Yikes.

As a former pilot, I get the whole "better to die than look bad" but for the love of all named after Hindu sage Ne, wave off and go around.

Tragic...but true.:eek:

https://www.nytimes.com/2023/01/16/world/asia/nepal-yeti-airlines-crash.html

Too low and slow for the conditions. Rolled into a left turn nose up and the inside wing stalled. Tragic.

Nepal, Bangladesh, India, Sri Lanka are the short list of countries with public transportation that i do not trust (in that order).

I still don't get what happened. The video shows the plane on the ground. Did it noseplant or cartwheel?

I have flow internally in India quite a bit. Their air system is actually very modern at this point.

Yeah. That's not why i don't trust those places.

Human error and well the caste system they all use doesn't help.

Well, the caste system in India could have a negative impact on safety in India, but not in the way one might think. Because of oppression of lower castes, they have straight up quotas for jobs. So if you are filling an air traffic controller job, there is a certain percentage that have to go to lower cast people, qualified or not.

Scroll down for the final moments of flight. It does not show the impact.
https://www.bbc.com/news/world-asia-64284366

Sorry I'm a layperson. I've read the comments above and still don't understand what happened.

That left wing drops so fast. Right wing had lift until plane was sideways?

Was this the pilot's doing? Drop the left wing a bit in order to turn, speed too low so left wing stalled (and not right wing?) Maybe cut the left throttle too much and that lost the lift?

Happened so quickly. Turned into a brick. Is that what planes do? I'd have thought pilot would react to keep plane flat and we'd see the elevators flapping madly.

Pokhara isn't high altitude, its less than 3000ft.

"Density altitude" is the issue here. "Sea level", or zero altitude, is established at a nominal temperature and humidity at, not surprisingly, sea level. Raise the ambient temperature and raise the humidity, and even "sea level", right there on the water, can have "altitude" of hundreds, if not a couple thousand feet.

At 3,000 feet above sea level, in a hot and humid environment, the "density altitude" can be much, much higher than that. That's what an aircraft "sees". It "thinks" it's at, say, 20,000 feet, and behaves accordingly.

So, yeah, the "inside" wing lost lift and stalled. Lots of reasons why it would lose lift first. It's a bit obstructed by the disrupted airflow around the fuselage, and it's moving a bit slower.

She must have been well below msm or something. Almost looked like a turn into a dead engine. ATR's sure kill a lot of folks, entry level crews I guess.

Does the inside wing, port in this case, stall because it's going around a tighter radius (inside of turn) than the outside wing so the air flow is less. Or is it because of the attitude it's at when looked at from in front? If one wing has stalled, wouldn't that mean almost certainly the other wing is about to stall? Not questioning anything said so far, just trying to understand what happened.

Yes. When an aircraft is very close to stall speed, exasperated by being nose up, a left turn reduces airflow slightly over the left wing and increases airflow over the right wing inducing a L wing drop stall. Attempting to lift the wing by applying aileron makes the problem worse. It is entirely possible that they suffered a bird strike or other mechanical problem causing their approach to become unstabilized at a critical moment. They were too low to recover once the left wing dropped.

Monday morning armchair quarterback debrief- The cockpit alarms were probably screaming a stall warning. If they had gone to full power and pushed over the nose to stabilize the aircraft and go around this might have been avoided. It was the only trick left in the bag in their situation.

More in-depth detail on a wing drop stall can be found here:
https://www.aviation.govt.nz/licensing-and-certification/pilots/flight-training/flight-instructor-guide/wing-drop-stalling/

Any chance she knew a crash was coming and put it in the ditch to avoid the homes?

My understanding is that what is most intuitive, is often the opposite of what needs to happen, as you explain. Trying to pull out of it, makes the situation worse. I think the solution is often counter-intuitive and to go in the direction that seems like it could make it worse. Obviously, there's a lot more to it than that.

The news reports were giving the flight crew the benefit of the doubt and we may never know. Once the left wing dropped at that altitude I fear all flight control was lost.

Thanks for the explanation and the link. Is impressive it is a well documented thing.

I looked up the plane, it is much bigger than I thought it was and fooled my eye. I thought it was a little mountain plane but its huge and needs 1000 meters to land.

I've landed at pokhara and also at lukla before it was paved. The plane into Lukla was a turbine pilatus which has big deep wings for its size. Could feel its excess of lift even when landing at 9k feet.

This is a super sad thing. :(