When Bombardier announced development of the clean-sheet Learjet 45, Cessna had to respond quickly. The resulting Citation Excel, created by grafting a shortened Citation X fuselage onto a modified Citation Ultra wing, won no beauty contests, but it beat the sleek Learjet on cabin comfort, short field performance, passenger amenities, baggage volume and product support. The Excel and its successors outsold the Learjet 45 by better than 2 to 1.
21,500-pound MTOWs. But the 3,500 lb-thrust TFE731- 20 turbofans had little margin for growth. They later were modified to produce 3,650 lb-thrust in the automatic performance reserve mode. The boost wasn’t enough to counter the weight gain. Takeoff field distance ballooned to 4,200 feet and eventually 4,680 as maximum takeoff weights were increased. Subsequent Citation 560XL, XLS, XLS+, and XLS Gen2 models also gained weight, but they didn’t lose takeoff performance. PWC developed higher thrust versions of the PW545 so that heftier 560XL jets retained their 3,600-foot takeoff field length bragging rights. The Ascend will be the heaviest version of the 560XL, and its TOFL is 3,660 feet. So many 560XL buyers opted for the available RE100 APU that Cessna and Textron eventually wrapped it into the standard equipment list, long a feature of more expensive midsize jets. Learjet 45 buyers also wanted APUs, but it would be months after initial deliveries began before the optional RE100 became available. In 2013, Bombardier finally remedied Learjet 45’s performance and weight shortcomings with the Learjet 75. Fitted with considerably more powerful TFE731-
NBAA convention, the Cessna booth was mobbed with onlookers. Salespeople seemingly ran out of order forms and ballpoint pens. Meyer told me his sales staff had signed 111 new orders by the last day of the show. Michel corrected him. The actual order book stood at 114 purchases when the show closed that Thursday afternoon—and it climbed to 230 before first deliveries began in 1998. All aircraft gain weight during development—and the Citation Excel was no exception. Sills planned for this eventuality by choosing Pratt & Whitney Canada’s new PW545A with 4,400 lbs thermodynamic thrust capability and initially flat-rated to 3,604 lb-thrust. When the Excel gained weight, Sills asked PWC for more push and the Canadians just dialed up the fuel controls to increase it to 3,804 lb-thrust up to 82 degrees Fahrenheit, while maintaining fat operating temperature margins for reliability. When the Excel’s weight increased again, PWC turned up the wick to 3,952 lb-thrust, enabling the jet to preserve its 3,600-foot takeoff field distance and best-in- class runway performance. The Learjet 45 also gained weight during development— first 18,300 pounds, then 19,500, next 20,500, and finally
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