01/31/2017. Remarks by Johan Visschedijk: "Under the designation SA-550 Spectrum-One, Spectrum Aircraft Corporation at Van Nuys Airport, California, USA, extensively modified a Skymaster. Spectrum considered that this conversion of a well proven airframe would provide an aircraft suitable for such roles as air ambulance, bush country air freighter, firefighting, law enforcement, maritime support, and search and rescue. to make it suitable for a wider range of utility roles.

The forward and rear piston engines, two turbocharged 225 hp Continental TSIO-360-Ds, were replaced by a single 550 shp Pratt & Whitney Aircraft of Canada PT6A-27 turboprop in the rear, driving a Hartzell reversible-pitch pusher propeller with spinner. The nose was covered by a new structure with a large door on the starboard side, to allow easy loading from the front of items such as pipework or helicopter blades up to 19 ft (5.79 m) in length. The fuselage was lengthened by 4 ft (1.22 m), immediately forward of the wing, creating a flat-floor cabin that could accommodate up to eight passengers, or provide increased cargo capacity. A double door was incorporated in the starboard side of the fuselage to facilitate the loading and unloading of outsize cargo. The twin tail booms were lengthened, and the area of the ventral fins increased.

The prototype was a conversion of the last of 61 Reims/Cessna FTB.337G aircraft produced in France and registered N15SA the Spectrum-One was first flown on February 1, 1983. The flight test program was continued in the summer of 1983, and to enable the certification program to be completed by the last quarter of 1984, a second Spectrum-One was scheduled to fly in late 1983. However, the second prototype nor the certification did materialize.

By early 1992 the aircraft had been acquired by Basler Flight Services at Oshkosh, Wisconsin. Basler stretched the aircraft a further 2 ft 10.7 in (0.88 m) and could carry ten passengers or 257.8 cu.ft (7.30 cu.m) of cargo. Strengthening of the wing center section allowed gross weight to be raised to 5,952 lb (2,700 kg). The PT6A-27 turboprop was replaced by a 750 shp PT6A-34 and hence the conversion was introduced as the Turbo 34. Reregistered N337BF the aircraft received a new CofA on April 16, 1992 and by August 1993 the aircraft had logged more than 430 hours of testing and demonstration, however, no orders for conversions were received. Reregistered to Basler Turbo Conversions on September 17, 1998, the aircraft is on the register as of this day, although still listed as a Reims/Cessna FTB.337G."

A Span: Length: Height: Cabin volume: Max useful load: Max T/O weight: Max speed: Climb:

Spectrum 38 ft 2 in (11.63 m) 36 ft 10 in (11.23 m) 9 ft 2 in (2.79 m) 206 cu.ft (5.83 cu.m) 2,200 lb (998 kg) 4,800 lb (2,177 kg) 250 mph (402 kmh) 1,600 ft (488 m)/min

Basler 38 ft 2 in (11.63 m) 39 ft 8.7 in (12.11 m) 9 ft 2 in (2.79 m) 257.8 cu.ft (7.30 cu.m) 2,200 lb (998 kg) 5,952 lb (2,700 kg) 265 mph (426 kmh) 1,600 ft (488 m)/min