The story
In 1979 Piper restyled the Arrow with a T-tail and a 14-inch longer fuselage, and offered it with a turbocharged Continental TSIO-360-FB as the Turbo Arrow IV. The turbo version outsold the normally aspirated Arrow IV: 888 Turbo Arrow IVs were built by 1987, against 479 Arrow IVs. The last ones were 1990 models, after which Piper went back to conventional-tail Arrows without turbos.
Aviation Consumer credits the T-tail to Piper's styling engineers, who decided in 1979 that the Turbo Arrow should have one.
Quick answers
How do you identify a PA-28RT-201T Turbo Arrow IV?
A low-wing Piper single with retractable gear and a T-tail is an Arrow IV. The Turbo Arrow IV wears its own turbo cowling, but from the ground the turbo and non-turbo Arrow IV are hard to tell apart, so the registration is the reliable check. The Seminole has the same T-tail look but two engines.
What does a PA-28RT-201T Turbo Arrow IV sound like?
A smooth six-cylinder growl, deeper than the four-cylinder Arrows.
How many people does the PA-28RT-201T Turbo Arrow IV carry?
Typical configuration: 1 pilot + 3 passengers.
When did the PA-28RT-201T Turbo Arrow IV first fly?
Its first flight was in 1978.
How many PA-28RT-201T Turbo Arrow IVs have been built?
888+ built.
How rare is a PA-28RT-201T Turbo Arrow IV in Bogey?
COMMON. Everyday traffic. You will catch plenty of these, and every first catch still counts. Your first PA-28RT-201T Turbo Arrow IV catch is worth 25 points.

