Middle Eastern carriers Emirates and Qatar Airways are each signing for the Boeing 777X, while Flydubai is taking the re-engined 737 Max.
Emirates is signing for 150 777Xs and placing 50 purchase rights.
Qatar Airways has signed a letter of intent for 50 777Xs.
The aircraft are powered by the General Electric GE9X engine.
Flydubai will order 100 737 Max twinjets as well as 11 more 737NGs, a type the carrier already operates. The 737 Max will be powered by the CFM International Leap-1B.
Check out the latest coverage from this year's Dubai Airshow.