B737-400Model: Be in 300 model on the foundation again lengthen3.05 meters(lengthen of the airframe before wing1.83 meters, lengthen of the airframe after wing1.22 meters, two paragraphs of airframe in all lengthen3.05 meters) , installed end prize, the airframe after when taking off, be being protected, increase 54885 kilogram as a result of the greatest takeoff weight at the same time, undertook strengthening to wing and landing gear.