Fullforward;
Let's face some cold and hard facts of life: it's not the first and unfortunately not the last time that a perfectly sound aircraft is CFIT. Every single time it happened, human error (and frequently criminal), played the most important role. Simple like this, no rocket science.
This is hilarious, how sure you are, that it was "a perfectly sound aircraft".
Where did you get it from?
Did you complete the investigation???
What we know is that the pilot stopped communicating with ATC
and lost control (started flying to low) seconds before crash.
Did you really ask yourself why?
Maybe they were preoccupied wits some kind of technical problem,
steering, power?
Aviate, Navigate, Communicate...
They first of all tried to stay afloat, then chat with the ATC.
There are documented cases of uncontaminated engine failures
of the Soloviev engines in IL-62, Tu-154. first of all resulting
in loss of power and eventually loss of tail controls.
(I discussed it before with links and documents quoted.)
And probably the Tu-204 accident 3 weeks ago on approach to DME,
also equipped with Soloviev engines (not RR !!!) was caused by similar
problems.
ASN Aircraft accident Tupolev 204-100 RA-64011 Moskva-Domodedovo Airport (DME)
A Tupolev 204-100 passenger jet, registered RA-64011, was destroyed when it crash-landed in a forest while on approach to Moskva-Domodedovo Airport (DME), Russia.
Weather reported about the time of the accident (23:34 UTC / 02:35 local):
UUDD 212330Z 16003MPS 0100 R14R/0450N R14L/0700U FG VV001 03/02Q1002 64290050 14290045 NOSIG= [Wind 160 degrees at 3 m/sec; 100 m visibility; vertical visibility 100 ft.; temperature 3 degrees C, dewpoint 2 degrees C; runway visual range for runway 14R: 450 m, Not changing significantly and for runway 14L: 700 m improving]
Sounds familiar ??
But it was ILS approach, native Russian crew, their home airfield.
They are also paid less than 1000 EUR, they certainly had "get-home-itis".
Fullforward, does it all mean, that the aircraft was "perfectly sound".
Your logic is stunning.