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Conroy Aircraft of Santa Barbara, the developer of the Aero Spacelines Guppy oversized cargo planes, also produced a series of turboprop DC-3 conversions.
The first was the
Turbo-Three, N4700C. The Douglas airframe ID of the Turbo-Three
was 4903. It was equipped with a pair of 1,600 shaft horsepower
Rolls Royce Mk. 510 turboprops from a crashed United Airlines
Viscount. The cruise speed of the Turbo-Three was increased from
170 miles per hour to 215 milse per hour.
The Turbo-Three made its first flight with the new powerplants on May 13, 1969. It appeared at the Paris Airshow later that month. It is seen here at the Santa Barbara Airport on April 12, 1972.
The
Turbo-Three was followed by the Super-Turbo-Three, N156WC, seen
here at the Santa Barbara Airport on June 12, 1974. Its
Douglas airframe ID was 43193. The Super DC-3 had larger wings
and tail surfaces than the DC-3, and its main landing gear were
fully enclosed. Although very few Super DC-3s had been purchased
by the airlines, the Navy and Marine Corps were retiring several
R4D-8s about that time. Note the Viscount engine donor parked at
the left.
The small
diameter Rolls Royce Dart engines were grafted onto the rear
portion of the original engine nacelle. The airflow behind a
large part of the small-diameter propellers from the Viscount was
obstructed by the nacelle and landing gear fairing. The
Super-Turbo-Three required a 6,000-foot long runway, limiting its
practicality as a commuter airliner.
The Super-Turbo-Three ended up rotting at the Groton, Connecticut Airport. Its cockpit was seriously damaged when it was hit by the wing of a taxiing Trans American Lockheed Hercules on February 24, 1984.
The Super-Turbo-Three put in an appearance at
the Mojave Air Races on June 18, 1975.
The original Turbo-Three airframe was converted by John Conroy's
Specialized Aircraft Company into the Tri-Turbo-Three. It was
equipped with three 1,174-horsepower, Pratt & Whitney Canada
PT6A-45 turboprops driving five-bladed propellers. Its
registration was changed to N23SA. The cruise speed of the
Tri-Turbo-Three was increased to 230 miles per hour. The nose
engine could be shut down to increase its range at a reduced
cruise speed of 180 miles per hour.
It made its first flight with three engines on November 2, 1977 and appeared at the 1978 Farnborough Airshow. It is seen here at the Camarillo Airport on December 7, 1981.
In early May 1986 workers at the Santa Barbara Airport
accidentally ignited a fire in the cockpit of the
Tri-Turbo-Three. The cockpit section of the airplane was
destroyed in the blaze. This photograph was taken on May 9, 1986.
The wings and tail surfaces were removed from
the fire damaged fuselage of the Tri-Turbo-Three. It is seen here
in February 1987.
The Tri-Turbo-Three was re-assembled with a
replacement fuselage.
Conroy also created a single engine turboprop
conversion of Cessna 337 Super Skymaster, N1414G called the
Stolifter. The rear engine was deleted and the forward engine was
replaced with a 575-shaft horsepower Garrett AiResearch TPE
331-25A turboprop. The fuselage was extended to nearly double the
volume available for cargo. The short take-off characteristics of
the Stolifter were improved by the incorporation of a Robertson
Aircraft Corporation high-lift system. This picture was taken on
June 12, 1974.
John Conroy also developed the Pregnant and Super Guppies.
Much of the information on this page is from the book Douglas Propliners: DC-1 - DC-7, by Arthur Pearcy.
More of my photographs of Douglas DC-3s.
You can buy a 2006 calendar featuring my photographs of Douglas DC-3 Variants, taken over a span of thirty years.
A dozen photos of variants of Douglas DC-3s, taken over a span of thirty years. DC-3s pictured include:
PCA DC-3 N50CE, San Francisco International Airport, August 6, 1974
Conroy Super Turbo Three N156WC, Mojave Airport, June 20, 1975
DC-3 N25CE Puff, Santa Barbara Airport, October 1985
DC-3C N403JB Pegasus, Santa Barbara Airport, October 16, 1985
Salair DC-3C, N3FY, Santa Barbara Airport, May 25, 1988
Santa Monica Museum of Flying DC-3C N193DP, Van Nuys Airport, June 23, 2000
AC-47A N88874, Camarillo Airport, August 11, 2002
DC-3 N20TW, Edwards Air Force Base, August 19, 2005
DC-3C N814CL Mainliner O'Connor, Camarillo Airport, August 28, 2005
DC-3 N101KC Rose, DC-3C N814CL Mainliner O'Connor, DC-3C N1XP Duggy, Santa Monica Airport, December 17, 2005
Put a copy of the Douglas DC-3 Variants: 2006 Calendar in your Lulu.com shopping cart for $13.95.
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