Gates Learjet 55C Specs and Description

Background/History

The Learjet 55C is one of the more highly refined developments in the long line of aircraft descended from Bill Lear’s original Lear 23, which made its first flight in October 1963. The turbojet-powered 20-series Learjets included the 28 &29 Longhorn models with their increased-span wings and winglets. These were succeeded by the turbofan-powered 35 and 36 models. The Learjet 55, which first flew in November 1979, utilized the Longhorn wing along with the Lear 35’s TFE731 turbofan engines and a new, larger fuselage. This variant was followed in 1986 by the 55B with its digital avionics and an increase in maximum takeoff weight. In 1988, the FAA granted certification for the model 55C. The 55C variant introduced the now-common delta fins to the Learjet line. These longitudinal tail surfaces provide improvements in handling and performance in addition to stall-avoidance capability, allowing elimination of the complex stick pusher system of earlier models. Auxiliary tanks give the 55C/ER and 55C/LR additional range. The Learjet 55C, built from 1989 through 1991, had a production run of just 14 aircraft before it was replaced by the P&W powered Learjet 60 in 1992.

Power

The Learjet 55C is powered by a pair of Garrett TFE731-3A-2B turbofans rated at 3,700 lbs. of thrust each. Inspection interval on the engines is 4,200 hours.

Avionics

The standard equipment package for the Learjet 55C includes the five-tube Collins EFIS-85L system with right- and left-side electronic attitude director indicators and electronic horizontal situation indicators, along with a central multifunction display. Also included as standard are the Collins AHS-85 AHRS, WXR-350 weather radar, APS-85 autopilot, and dual Pro Line 2 VHS comm and nav radios.

Design Features

The Learjet 55C is a medium-range, twin turbofan-powered business aircraft configured as a cantilever low-wing monoplane with slight leading-edge sweep. The swept horizontal and vertical stabilizers are arranged in a T-tail configuration. The retractable tricycle landing gear has dual wheels on each of the main units and a single wheel on the nose gear. The nine-foot delta fins positioned under the tail sections of later Learjets were first employed on the 55C. These fins aid in handling across the speed spectrum, significantly lower the landing speed and eliminate the need for the stick-pusher system. The wing, with its drag-reducing winglets, is adapted from the earlier “Longhorn” series Learjets, while the fuselage of the 55 series was a new, larger design, and would carry over to the follow-on 60 series Learjets..

Accomodations

The cabin of the Learjet 55C is optimized for seven or eight-passengers, but can accomodate ten in a high-density configuration. The new fuselage introduced with the 55-series provides considerably more interior space than was available in earlier Learjets. Cabin layoput typically consists of a four-place club arrangement with a single seat opposite the half-width lavatory in the aft cabin. A two-place side-facing bench seat is forward of the club, and a small galley/refreshment center is located on the forward port cabin bulkhead. External baggage compartments are located in the nose and the aft fuselage area, with an additional internal baggage area in the cabin aft of the lavatory. Cabin height is 5.7ft., cabin width is 5.9ft., and cabin length is 13.7ft.