The PA-31 Navajo is a family of cabin-class, twin-engine aircraft designed and built by Piper Aircraft using Lycoming engines for the general aviation market.
In the mid-1960s, an aircraft of this
... size was sorely needed and founder William T. Piper requested the type be developed. Targeted at small-scale cargo and feeder liner operations and the corporate market, the aircraft was a success. It continues to prove a popular choice, but due to greatly decreased demand across the general aviation sector in the 1980s, production of the PA-31 ceased.
[Text and Photo provided by: http://en.wikipedia.org/wiki/Piper_PA-31_Navajo ]