02/28/2015. Remarks by Johan Visschedijk: "The pictured aircraft was built as a North American NA-159 T-28A Trojan under the USAF serial 49-1587 (c/n 159-99), struck off charge it came on the civil register as N9106Z, and in the early 1960s it was converted by Hamilton to a T-28R-2 and given the new c/n 10. On June 5, 1971 the aircraft was reregistered N28DS and is still as of this day. Present owner is Robert Dulany of Fort Lauderdale, Florida, USA."
09/30/2010. Remarks by Johan Visschedijk: "The Hamilton Aircraft Company in Tucson, Arizona produced conversions of the ex-USAF North American T-28A Trojan training aircraft with the original 800 hp Wright R-1300-1A Cyclone seven-cylinder air-cooled radial engine replaced by an 1,350 hp Wright R-1820-56A or 1,200 hp Wright 704C9GC1 nine-cylinder radial air-cooled engine, driving a Hamilton Standard Hydromatic Type 33D50 or 43D50 three-blade metal propeller.
To comply with CAR 3.83 the landing speed was reduced by increasing the wing span by approximately seven feet. Increasing the wing span, however, reduced load factor capability and roll performance plus some degradation in static longitudinal stability. In the case of the Hamilton application, the effects were considered inconsequential. The prototype flew for the first time in September, 1960, and FAA Type Certificate was received on February 15, 1962. The following two specialized versions were produced:
T-28-R1. This was a military trainer with tandem cockpits, dual instrumentation and flying controls, and hydraulically-actuated rearward-sliding canopy. Six supplied to the Brazilian Navy in the latter part of 1962 were equipped as carrier trainers with arrester hook, systems and controls meeting all requirements for naval training operations. They were used aboard the carrier Minas Gerais, serialed N-701 to N-706. Eventually they were transferred to the Brazilian AF, and re-serialed 0860 to 0865, they were used by the naval co-operation unit 2aELO at São Pedro da Aldeia.
T-28-R2. The commercial version was equipped to carry a pilot at front and two pairs of seats for four passengers. The canopy was fixed and there was a door on the port side of the cabin. The first production model flew in February 1962 and a total of ten were built. At that time the T-28-R2 was the fastest single-engined standard category aircraft available in the USA. And it had been flown to a height of 38,700 ft (11,800 m). One aircraft was sold to a high-altitude photographic company."