I would like to hear the tape instead on relying on the transcript as there are a lot of (...) and (unintelligible) , anyone can post the link ?
From what I know of KTM ( been there quite a few times) , turboprop OPS are all VFR , not sure about international ones however. But a remark by the ATC supervisor ( or coach) seems to indicate they were VFR :
KTH-Tower (different voice): “ BanglaStar211, that would be VFR.“
The METAR indicate only CBs and few, but haze/mist is very common heavily reducing visibility , especially facing sun.
I cleaned up the last part which is important ; I doubt they were all the time VMC , and making a visual approach in partial IMC appears to be problem , as to to disorientation a to which runway they were going to use . or saw in the end.
KTH-Tower: Runway is vacated, either runway 02 or 20 ?“
BS211 : we like to land on 20.“
KTH-Tower: „Okay runway 20, cleared to land.
BS211: „260 copied, cleared to land.“
KTH-Tower: „BanglaStar211, confirm you have the runway in sight?“
BS211: „Negative, Sir.“
KTH-Tower: confirm you have the runway not in sight, yet ?“
BS211: „Affirmative, we have (..) runway in sight. Requesting clear to land, Sir.“
KTH-Tower: BanglaStar211, cleared to land.“
BS211 „Cleared to land runway 02, BanglaStar212.“
KTH-Tower: „Roger, ruway 02, cleared to land, BanglaStar211.“
..
BS211(male voice): „..sir, are we cleared to land ?“
For me , it looks like there might have been another technical or physical issue (Hypoxia?) , not reported to ATC, that could explain such erratic behavior, that you could see from a solo fight in a C152 that lost VMC than from an ATPL of an International airline.