They crammed big engines under the wings in a way that it could really need a new air type certification. This is more like a new plane, with the baggage of the

They crammed big engines under the wings in a way that it could really need a new air type certification. This is more like a new plane, with the baggage of the old 737 and without the certification testing for a new plane. Yes it can fly, but it's pushing the boundaries of safety.