In 1972, Piper added the PA-31-350 Chieftain to its range by stretching the standard Navajo fuselage by 24 inches and adding an extra rear side window to the cabin. The extra length allows for a 6-seat passenger cabin with two crew but a high density layout for ten is possible. The Chieftain is powered by a pair of 350 hp Lycoming L/TIO-540 engines.