Although not related to this accident it's noteworthy that the ATR engines are labelled 1 & 2. The original B737-200s had this labelling but later Boeing types changed to L & R, a potential source of confusion due to multiple meanings of the word 'right'. As in:
Looks like we'll have to shut it down.
Agreed - make sure we shut down the right engine.
Did Boeing managers initiate the change of labelling or was it customer airlines? And for what reason?