Volpar (Beechcraft) Turbo 18Beech Model 18s fitted with the Volpar MkIV tricycle undercarriage and powered by two 705-hp Garrett TPE331-1-101B turboprop engines, flat-rated to 605 horsepower , driving Hartzell HC-B3TN-5 three-bladed, reversible-pitch, constant-speed feathering propellers