[st4lz]

Belarussian aircraft informed crew about tough conditions in Smolensk airport - rather old, soviet military airfield - which after that was closed in case of heavy fog and the plane redirected to Minsk or Moscow. Unfortunately, the pilots decided to land anyway, even though three approaches to landing failed.

In fact Tu-154 was aged, but after solid and expensive modernization. For now it looks like a mistake of a pilot connected with really bad weather conditions.

[adrianwaj]

in a thick fog, did not reach the runway but instead hit the treetops and fell apart

Bad avionics. A Boeing would've been alright.

[maigret]

You can't tell before an extensive investigation will have been done. Was the ILS active? Were there some navigation instrument failing? Was there a mechanical problem at this time on the aircraft? Was it just some human error (involved in 80% of aircraft accidents)? It's just too early to draw conclusions.

[jwr]

There is no ILS at this airport. That was a visual approach with almost zero visibility.

These aircraft are old, but have received extensive maintenance and upgrades, so a mechanical failure isn't likely. What you have to remember, though, is that a Tu-154 does not climb as well as a modern jet. So an aborted landing is much more dangerous, as you don't have enough engine power to climb quickly.

The pilot made four landing attempts (these are the best of pilots, so I suspect he was told to), the last one being fatal. Also, I don't expect a sane pilot to try to make a turn at low altitude right after an aborted landing, so the stories about the plane being in a turn probably mean the plane was already in a stall and falling.

Also, the runway at this airport is very short for the Tu-154 even at the best of times, so the pilot would have to touch down at the very beginning of the runway. In a dense fog that is extremely difficult.

It's a sad day. We might never know what really happened on board, but I strongly suspect that the pilots did not want to proceed and that either the presidential staff or one of the generals on board told the pilots to land anyway.

[maigret]

I had the opportunity to discuss that with a pilot who uses to land in Russia in different airports and explained us NDB landings in Russia. The pilot made only one landing attempt that failed, the other ones are the standard procedure in Russia where ATC take you down step by step in the traffic pattern - make you flight 3 or 4 circuits round over the runway. Also the captain didn't have much hours of flights compared to his years of experience - a common pattern in the east countries who don't have much money for military aircrafts expenses. It looks like a flying error at the end, he maybe have turned over the trees (probably because the NDB wasn't on the runway centerline), and was too low too early... Investigation will tell more hopefully.

[adrianwaj]

Thanks. If the wing tip clipped a tree it was because the plane was turning. Assuming it wasn't windy, but foggy as stated, good avionics should've calculated that the tip would hit the ground, and good avionics would've detected trees. As such, a sound would've gone off to warn the pilot not to turn, or stop half way through a turn.

I could be wrong, but the pilot had already tried several times to land, and he was flying manually, and probably a good pilot, and there may have been a freak tree in terms of height, but I reckon he just didn't have modern enough instruments to help him avoid the crash.

[jwr]

I'm sorry, but you seem to know little about avionics. There are no 'tree detectors'.

No sane pilot would try a turn at this altitude, and the pilot knew very well what the altitude was because he had just aborted a landing attempt. It wasn't a turn, it was likely a stall.