The plane was carrying 67 passengers and four crew.

It is now known that 33 of the passengers were Nepalis, 32 were Bangladeshi, one was Chinese and one was from the Maldives. Among the 22 people injured, some are in a critical condition.

One of the survivors, Nepalese travel agent Basanta Bohora, described from his hospital bed what he had experienced. After a normal take-off from Dhaka, the plane had begun to behave strangely as it approached Kathmandu, he said.
"All of a sudden the plane shook violently and there was a loud bang afterwards," he was quoted as saying by the Kathmandu Post.
"I was seated near the window and was able to break out of the window," he added.
"I have no recollection after I got out of the plane, someone took me to Sinamangal Hospital, and from there my friends brought me to Norvic [Hospital]. I have injuries to my head and legs, but I am fortunate that I survived."

The aircraft was permitted to land from the southern side of the runway flying over Koteshwor, but it landed from the northern side," Sanjiv Gautam, director general of the Civil Aviation Authority of Nepal, was quoted as saying by the Kathmandu Post."We are yet to ascertain the reason behind the unusual landing."

However, US-Bangla Airlines chief executive Imran Asif has blamed Kathmandu air traffic control. "There were wrong directions from the tower. Our pilot was not at fault," he told reporters at his office in Dhaka.


Airport general manager Raj Kumar Chettri told Reuters news agency that the plane hit the airport fence before touching the ground. The pilot told flight controllers that everything was OK soon before landing, but did not reply when told his alignment was not correct, he said.

However, US-Bangla Airlines chief executive Imran Asif has blamed Kathmandu air traffic control. "There were wrong directions from the tower. Our pilot was not at fault," he told reporters at his office in Dhaka.

ATC transcripts and recordings seem to contradict that

This is what the guys flying/on ground at KTM are saying. Ok so firstly, VNKT has VFR traffic holding inside the valley. They keep the approach and go around path for the cleared approach clear of all traffic. The A/C was cleared for a VOR DME 02, it decided to circle sometime on the approach. Obvious confusion when the crew said they want to circle. That would bring the head on to the traffic behind.

They circled to the right for RW20, there’s some high terrain on left base RW20 and apparently some Wx as well. From the picture posted above, the taxiways from North to South are A, B, C, D, E. When you land RW02 and exit on B, straight ahead is the domestic apron. To put things into perspective, the a/c was over the domestic apron very low and in a steep turn. It touched down near taxiway C almost taking out Malindo who had pushed back from the international apron and came to a stop at the point marked above. The trajectory reported makes sense if you look at the picture. That part about the ATC yelling is probably when they saw it turning over the domestic apron towards the apron/ terminal and tower. Terrible day for all. Speedy recovery to all those fighting for their lives.

I have to say I’m having trouble understanding the transcript without a trace of their flightpath. Flightradar24 unfortunately stops after the hold which is to the South (extended centreline of 02). So why did ATC think they were approaching 20? Solely on the RT transmissions or from their radar (if they have it)? I wonder if they were intending to break off and fly a circle to land on 20 to avoid the tailwind but it’s a big runway and shouldn't be an issue for a turboprop. And the vis is reasonable at 7km. (Edited to say I crossed with the post above which seems to confirm they circled for 20). Why do a complicated circling approach with a 6-7kt tailwind on 02 which is 3000m? You could do that on a 747.

Listened to the 2 tapes on LiveATC. Slight differences with the transcript, e.g it is not " BanglaStar211, that would be VFR.“ but " BanglaStar211 confirm you are VFR".
and the (unintelligible) after the " request your intentions ": is "I would like to land on runway 02 "
But it does not change the overall picture. However the sound of the voice of the Captain , and the pace of delivery, would coincide with s being incapacitated , possibly Hypoxia as I indicated earlier, or another reason. But it would be easy for pilots of the airline that know him if this was his " normal" voice to clear this possibility.

But a circling approach takes quite a lot of mental capacity to perform. If you were partially incapacitated wouldn’t you just land straight ahead on the runway which is simple (02)?

Heathrow Harry

I'm with you

Is the confusion over runway 02 and its heading of 20 degrees?

just for a sidenote: both flightcrew and ATC transmissions changed from female to male when things became abnormal.

I think the confusion is initially that they are planning to approach 02 but land on 20. Later I think the pilot may just have mis-spoke under high workload as the brain easily confuses 02 with 20 (unlike 27 and 09 for instance). I think the crew were always planning to circle but didn’t communicate this well to ATC.

Seeing that hypoxia was discussed as a possible contributing cause, here´s a few words on the bleed air and pressurisation systems of the DH8D.

For most practical aspects, those systems work as on most other types. Bleed air is routed from the low or high pressure ports of the engines (automatically selected depending on power setting) via two air conditioning packs to the flight deck and cabin. Cabin pressure is then regulated via two outflow valves in the rear bulkhead; there is another outflow valve in the forward bulkhead in front of the flight deck that is only manually adjusted in case the automatic pressure regulator fails. So far, so normal.

Depending on the exact status of the DH8 and the supplements the airline bought from Bombardier, the exact use of the system may vary.

a. Takeoff with bleeds OFF. In this case, bleeds are selected ON at 400´AAL and then the pressurisation is scheduled as normal.

b. Takeoff with bleeds ON. This requires buying a supplement but restricts the performance a bit. The relevant supplement is not compatible with the one allowing reduced takeoff power, so a takeoff with bleeds on will be "Normal Takeoff Power" (NTOP, equals to TOGA on other types) at all times. Performance calculations require assuming an increment of 12°C on the actual OAT in this case.

Also, there is a switch on the pressurisation control panel that has been somewhat unimaginatively named the "AUTO-MAN-DUMP" switch. In Auto mode, pressure control is automatic; in MAN, it is as may be expected manual. Selecting DUMP will open the rear outflow valve and no differential pressure will show up. This switch is sometimes set to DUMP by maintenance; resetting it is part of a proper cockpit preparation. There is no indication showing the position of the switch apart from its position and the effects of the selection made. If during climb no pressurisation takes place, it will be felt in the ears (the DH8D reaches FL250 in ten minutes without any problems) and shown on the cabin pressurisation indications. Only when the cabin altitude reaches 13.500ft, there will be a triple chime, the master warning will flash and a red "CABIN PRESS" warning light will come on. This triggers memory items including donning the oxygen mask. With the switch on DUMP, the cabin will climb at the aircrafts rate; with the switch on MAN/AUTO and the bleeds forgotten in OFF, the climb rate will be substantially less.

Any DH8D pilot worth his salt knows this and has operated the switches many times. So in case the pressurisation looks and/or feels weird, a look at these 3 switches is completely logical for a not completely inexperienced crew and may even happen before any QRH is taken out.

So I dare say I´d be completely surprised if this suspicion was to hold any water.

I don’t hear any sign of incapacitation on the transcript. And the confusion with ATC and which runway they’re landing on seems a bit of a side show. That doesn’t cause an aircraft to do what it did. Although there are signs of overload and probably loss of SA towards the end but suspect it may have been a fairly normal circling approach until the final turn.

from a FR24 tweet "https://twitter.com/flightradar24/status/973145006574854144"
https://pbs.twimg.com/media/DYFNWU4W4AArpef.jpg:large
altitude profile

airport altitude 4400 ft

edit: remove obnoxious auto twitter insert
and because i can't post a simple link to twitter you will have to copy that link instead of clicking it :)

Listen to the recordings, it's confusion all the way and I don't think it's ATC that's caused it.

Was the Captain Male or female? It would be unusual for the handling pilot to make RT calls on approach. If so perhaps indicates the co-pilot was out of the loop on what was going on?

Here are the two ATC files. Note there is some overlap between the two.

http://archive-server.liveatc.net/vn...2018-0800Z.mp3

21:50 Communication with Approach

Handoff to Tower is missing

24:20 Contact with Tower

http://archive-server.liveatc.net/vn...2018-0830Z.mp3

03:20 Last communication

The female pilot sounds very clear, but the male pilot’s voice sounds slurred to me.

An early media analysis of the cause of the mishap:

https://www.aljazeera.com/news/2018/...090642034.html

As Strother Martin famously said in a movie "What we've got here is failure to communicate".

Hi all.

- In my airline, we do reduce power take off with the bleed on, no problems for that.

- And we have the cabin press warning at 9800ft.

Personally I don't believe in any hypoxia from the crew, they did more than 1hr cruise at 24000Ft, if took off with switch in the dump position, problems would have come sooner ... And I read airport is 4400ft ? So no really high ...

They just got confused with what to do, rwy 02, rwy 20, maybe did a circle to land not briefed so bringing more confusion in the cockpit
For example, FO think they will land 02, but captain start to break for the circling because of habit, or tired, ... ATC confused, crew confused, lost of visual conditions ... We know what it can lead to ...

Sadely for all those lives lost ...

It is a bit more than miscommunications I am afraid . . after all whatever the sense of the runway they was approaching it was free from obstacles and , seen the length of it, they should have made it whether it was 02 or 20. If as reported by witnesses they went over the terminal , then veered left over C in the other direction , and stalled in a steep turn , for me it is definitively more than miscommunications with ATC.

As to the Hypoxia theory, thanks for the technical explanation on the DH8. it is just that the voice and the speech delivery reminds me of this from my days in the military., where we practiced it in the decompression chamber. it could be intoxication due another source..or the guy could well speak "normally" like this .

Maybe the pilot felt uneasy with the tailwind component on 02. But hard to believe they would go to the opposite runway without giving any indication to ATC in particular after the exchange:
KTM-Tower: "BanglaStar211, wind 220 degrees seven knots, tailwind component six knots, runway 02 you're cleared to land."
BS211(female voice): "Cleared to land, BanglaStar 211.