Would it be correct to say that whilst Russian (ex-Soviet?) aircraft are not as technologically advanced as, say, Airbuses and Boeings, they are generally solid and reliable aircraft, well-suited to their operating environment?
I'm not sure I'd even agree with the assertion that they're not as technologically advanced. Russian equipment is fantastic, and in some ways more advanced than 'Western' equipment. Engine failure rates though, are on the high side.
That said, the BBC's statement that somehow US sanctions can be linked to this crash is UTTERLY
outrageous! The Iranians are free to order new Russian equipment (and some have indeed ordered TU-204s) and can procure US equipment from third parties (ie. lessors) that are more than 7 years old.