Gates Learjet 55
The Lear family is one of the pioneers of private jet aviation. Learjets have brought performance and innovation to the aviation market, starting with the original Lear 23 in 1963. Introduced in 1981, the Lear 55 incorporates successful elements of former Learjets, while adding a few design modifications of its own like a larger fuselage. Although its predecessors were competitive, Lear essentially produced the 55 to contend in a growing business aircraft market, namely one with greater cabin accommodations.
The midsize cabin aircraft is the perfect combination of the 30-series’ turbofan engines and the 20-series’ “Longhorn” wing. Lear began replacing turbojet engines with turbofans starting with the Lear 35 in 1974. A pair of TFE 731-3A-2B engines powers the Lear 55, providing 3,700 lbs of thrust apiece. Inspection interval is 4,200 hours. Adapted from the 28 and 29 Longhorn models, the Lear 55 features an increased wingspan and drag-reducing winglets using higher strength aluminum.
However, engineers made huge developments in cabin space and aerodynamic capabilities. The Lear 55 fixes its engines higher on the fuselage to decrease the amount of interference drag. Also, the vertical tail’s position, 20 percent higher, enhances directional stability.
The Lear 55 can fly at a maximum operating speed of mach .81. It is capable of a high speed cruise of 458 knots, and a flight ceiling of 51,000 ft.
But the standup cabin is the aircraft’s single biggest improvement. 50 percent more cabin volume than its predecessors is enjoyed in the 55. The dimensions measure 5.7 ft high, 5.9 ft wide and 13.7 ft long. Rather than adding more seating, engineers chose to enhance the cabin’s comfort and amenities. The cabin typically accommodates seven or eight passengers in a configuration familiar to Lears: a club arrangement with a side-facing bench and an additional aft seat. A high-density configuration can seat ten. Also featured are external and internal baggage compartments, a half-width lavatory and a small galley/refreshment center. The expansion is sure to be noticed by passengers.
Although possibly upgraded through the years, the Lear 55’s typical avionics system would include dual Collins VHF20A comms, dual VIR30A navs, dual Collins TDR90 transponders, King 90A GPS, Global FMS GNS/XLS, Collins ADF 60, DME40, Collins color weather radar and TCAS.
It is a quality inherent to successful companies to be able to foresee future market demands and design an innovative aircraft accordingly. That is exactly what Lear did when introducing the Lear 55. By strategically borrowing effective elements from former aircraft and integrating new features, the Lear 55 offers exceptional performance and comfort in its class. It marks successful evolution.