The Learjet 31 series of airplanes is essentially a Learjet 35 with a wing longer by 4 feet and with almost 4-foot-high winglets, instead of wingtip fuel tanks and large “delta fins” attached to the tail cone. These changes made the plane a much more docile one to fly, greatly improved field lengths and added 6 ktas to its normal cruise speed. Seats full range decreased to 1,225 nautical miles plus NBAA IFR fuel reserves.
In 1988, the Learjet 31 won its Supplemental Type Certificate (STC).
