The Conroy Turbo Three was a series of two Douglas DC-3

Douglas DC-3

The Douglas DC-3 is an American fixed-wing propeller-driven aircraft whose speed and range revolutionized air transport in the 1930s and 1940s. Its lasting impact on the airline industry and World War II makes it one of the most significant transport aircraft ever made...

s modified with turboprop

Turboprop

A turboprop engine is a type of turbine engine which drives an aircraft propeller using a reduction gear.The gas turbine is designed specifically for this application, with almost all of its output being used to drive the propeller...

 engines by Conroy Aircraft

Conroy Aircraft

Conroy Aircraft was a US aircraft manufacturer founded by John M. Conroy in Goleta, California in 1965 on the sale of Aero Spacelines. The company imitated Aero Spacelines' success with its Guppy aircraft by converting a Canadair CL-44 to carry oversized cargo as the Conroy Skymonster...

. The first conversion first flew on May 13, 1969. Rolls Royce Dart Mk. 510

Rolls-Royce Dart

|-See also:-Bibliography:* Gunston, Bill. World Encyclopedia of Aero Engines. Cambridge, England. Patrick Stephens Limited, 1989. ISBN 1-85260-163-9-External links:*...

 engines from a crashed Vickers Viscount

Vickers Viscount

The Vickers Viscount was a British medium-range turboprop airliner first flown in 1948 by Vickers-Armstrongs, making it the first such aircraft to enter service in the world...

 previously operated by United Airlines

United Airlines

United Air Lines, Inc., is the world's largest airline with 86,852 employees United Air Lines, Inc., is the world's largest airline with 86,852 employees United Air Lines, Inc., is the world's largest airline with 86,852 employees (which includes the entire holding company United Continental...

 were used to replace the original radial engine

Radial engine

The radial engine is a reciprocating type internal combustion engine configuration in which the cylinders point outward from a central crankshaft like the spokes on a wheel...

s. The replacement engines increased the aircraft's cruising speed from 170 mph to 215 mph. The prototype was converted into the Conroy Tri-Turbo-Three

Conroy Tri-Turbo-Three

The Conroy Tri-Turbo-Three was a Douglas DC-3 fitted with three Pratt & Whitney Canada PT6 engines by Conroy Aircraft; the third engine was mounted on the nose of the aircraft. It first flew on November 2, 1977. The cruise speed of the aircraft was increased to . The engine mounted on the nose...

The Second Turbo Three was called the Super Turbo Three because it was converted from a surplus Super DC-3. Unlike the first conversion, the Dart engines were mounted in the rear part of the engine nacelle. Due to the small diameter of the Viscount propellers, air flow was restricted by the bulky nacelles and landing gear fairings. This caused the takeoff distance to be 6000 feet, making it unappealing as a commuter aircraft. The aircraft ended up parked at Groton-New London Airport

Groton-New London Airport

Groton-New London Airport is a state-owned public-use airport located three miles southeast of the central business district of Groton, a town in New London County, Connecticut, United States...

 in Groton, Connecticut

Groton, Connecticut

Groton is a town located on the Thames River in New London County, Connecticut, United States. The population was 39,907 at the 2000 census....

 where on February 19, 1984 its cockpit was hit by a wing from a Trans American Lockheed L-100 Hercules.