This is a total non-sense. Sorry, but which serious terrorist would build a bomb and put it on a cargo plane from Yemen? That story stinks!
If you really wanted to hurt modern society, there are so many things to do which are much easier. Just find some local guys that put a bomb in a bag which they deposit/forget/whatever at a train station or similar, have a few of them explode and there you go. But honestly, some unimportant cargo aircraft that nobody cares about (normally)? I am not buying it...
There are no scheduled Cargo flights operating through Yemen. Both packages were flown from Sanaa to Doha in Qatar Airways A320 scheduled passenger flights. "Some unimportant cargo aircraft that nobody cares about". What a load of b****x. A bombed B747F crashing onto a highly populated town/city would be a massive publicity coup for Al Qaeda.