21. _Late 2000 : Atta, Jarrah, and al-Shehhi begin training on jet aircraft simulators. 22. Regional airlines are increasingly opting for faster jet aircraft that ATR doesn't make. 23. Modern jet aircraft use supercritical airfoils which decrease wave drag significantly. 24. These problems were eventually solved as jet aircraft reached transonic and supersonic speeds. 25. It operates jet aircraft as a subsidiary of Delta Air Lines. 26. Clark holds an Airline Transport Pilot rating and currently flies light jet aircraft . 27. The jet aircraft were refueled in flight by aerial tankers. 28. Many newer aircraft, especially jet aircraft , have electric trim controls. 29. The airport has parking berths for three mid-sized jet aircraft . 30. In jet aircraft , all four tracks on the voice recorder are usually miked up.
