The TFE731 was based on the core of the TSCP700, which was specifically
developed for use as the auxiliary power unit (APU) on the McDonnell Douglas
DC-10. The design featured two important factors, low fuel consumption, and low
noise profiles which met the newly established U.S. noise abatement regulations.
The first production model, the TFE731-2 began rolling off the assembly line in
August, 1972, and was used on the Learjet 35/36 and Dassault Falcon 10, both of
which entered production in 1973.
The TFE731-3 was developed for use in the Lockheed JetStar re-engining program,
and subsequent versions of it have been used on a number of aircraft, including
the Learjet 55. The -5 model was certified in 1982, and a decade later, an
engine utilizing the TFE731-5 power section and a TFE731-3 fan was built and
designated the TFE731-4, intended to power the Cessna Citation 650 and 750
series aircraft.
The most recent version is the TFE731-50, based on the -60 used on the Falcon
900DX, which underwent its flight test program in 2005. Honeywell has developed
this engine complete with nacelle as a candidate to retrofit a number of
aircraft equipped with older engines.
Source: Wikipedia,
http://en.wikipedia.org/wiki/Honeywell_TFE731