In Feb 2015 I had posted the following:
CFM VS IAE Engines A320I find the following different characteristics between the two engine types.IAE engine takes longer to start than CFM.IAE engine as you open thrust for take off appears bit noisier than CFM.IAE has fan flutter that is why there is KEEP OUT ZONE between certain RPM when applying take off thrust while there is no such thing in CFM.IAE engine for circling approach OEI and flap3 is seven tons more weight restricted than CFM for circling.IAE engine aircraft have Flap full with flaps at 40 while CFM engine aircraft have flap full with flaps at 35. I don't know is it because engines size or shape.The question is with all this why would anybody want an IAE engine? Fuel efficiency may come to mind but these days nobody will buy fuel inefficient engine so they must be evenly matched. Is it price or any other advantage which overrides all this?