That depends on the kind and severity of the failure. You could have a full electrical failure and the plane would still fly. But when you miss a wing the rest doesn't really matter any more.

they usually do

but for unknown reasons, the passengers refused to glide and decided to plunge the plane to wilfully die.

now, since they wilfully died, there is no reason to trigger further investigations.

And supreme leader Putin will seek damages from the families of the passengers, as they destroyed his plane.

Usually, after they are shot down by air defense missiles, what’s left just crashes.