Dornier Do-28 / Do-128

Professor Claude Dornier started his first aircraft company in 1922 as the successor to the “Do” division of the Zeppelin Werke, GmbH. When aircraft manufacturing became forbidden in Germany after World War II, Dornier continued his design work in Spain. There he developed the Do 25, a general-purpose airplane that later evolved into the Do 27.

 

The Do 28, a twin-engine version of the Do 27, first flown on 23 February 1966, was produced until 1971. The light utility transport Do 28 Skyservant was built starting in 1971. The Skyservant was a completely new design, retaining only the basic configuration of the earlier aircraft and featuring STOL capabilities. The high-wing airplane is adaptable to a variety of uses including ambulance and military surveys. For photographic missions, the Skyservant can be equipped with a darkroom and camera doors in the under fuselage. The Skyservant’s twin Lycomings and landing gear are mounted on stub wings that protrude from the lower fuselage directly underneath the main wings.

While the original Do 28 series had an advantage over the Do 27 by providing twin-engine safety and enhanced performance, it did not have any more internal space, the cabin dimensions being identical to those of its predecessor. Financial assistance provided by the German Ministry of Economics helped Dornier to develop the layout into a bulkier, higher-powered STOL transport which could carry up to 13 passengers and this redesigned version was designated Dornier Do 28D, later being named Skyservant. The redesign was so drastic that, apart from the layout and designation, the Do 28D bore little resemblance to the Do 28B. The prototype flew on 23 February 1966, receiving type approval a year later.

Developed as the Do 28D-1, the type won FAA certification on 19 April 1968 and military type approval in January 1970. Orders for 125 were placed for the German Luftwaffe and Bundesmarine, and other military deliveries have been made to Ethiopia, Morocco, Nigeria, Turkey and Zambia. More than 220 Skyservants are in operation world-wide.

A Do 28D-1 set several class records for piston-engined business aircraft in 1972, including an altitude of 8624m with a 1000kg payload, as well as several time-to-height records. It was followed by the Do 28D-2, which introduced a number of refinements. In 1980, a Luftwaffe Do 28D-2 was re-engined with Avco Lycoming TIGO-540 turbocharged engines under a contract from the German Federal Ministry of Defence prior to upgrading that country's military Skyservants; the new designation was Do 28D-2T.

Further development of the basic Do 28D design continued under a new designation: Do 128 Skyservant. Two basic designs were offered, the Do 128-2 and Do 128-6. Both 10-passenger models, the main difference was in powerplant, the Do 128-2 having two Avco Lycoming IGSO-540 piston engines and the Do 128-6 two 298kW Pratt & Whitney PT6A-110 turboprops. The latter had first been seen in prototype form as the Do 28D-5X, known then as the TurboSky and powered by two 447kW Avco Lycoming LTP 101-600-1A turboprops flat-rated to 298kW. The Do 128-6 had, in addition, a new fuel tank, reinforcements to the underwing engine supports and other modifications. Orders and options for 30 Do 128-6s from African customers were announced, the first going to Lesotho Airways. A variant of the Do 128-6 was also delivered to Cameroun for maritime patrol work, equipped with a 360 deg MEL Marec surveillance radar. Production ceased in the mid-1980s.

Dornier Do 28 D Skyservant
Length : 37.402 ft / 11.4 m
Height : 12.795 ft / 3.9 m
Wingspan : 50.853 ft / 15.5 m
Max take off weight : 8048.3 lb / 3650.0 kg
Max. speed : 173 kt / 320 km/h
Service ceiling : 24278 ft / 7400 m
Range : 992 nm / 1837 km
Engine : 2 x Lycoming IGSO-540-A1E, 375 hp
Crew : 2+12

Do-28D-1
Engines two 380 hp Lycoming O-540.
Gross wt. 8,470 lb
Empty wt. 5,066 lb
Top speed 202 mph.
Cruise 170 mph.
Stall 65 mph.
Vmca: 42 kts.
Initial climb rate 1,180 fpm.
Range 1,255 minle.
Ceiling 25,200 ft
Takeoff distance (50') 1,020 ft
Landing distance (50') 1,000 ft
Seats 12-13.

Do 128-2
Engine: 2 x Avco Lycoming IGSO-540-A1E, 283kW
Max take-off weight: 3842 kg / 8470 lb
Empty weight: 2346 kg / 5172 lb
Wingspan: 15.55 m / 51 ft 0 in
Length: 11.41 m / 37 ft 5 in
Height: 3.9 m / 12 ft 10 in
Wing area: 29 sq.m / 312.15 sq ft
Max. speed: 325 km/h / 202 mph
Cruise speed: 211 km/h / 131 mph
Ceiling: 7680 m / 25200 ft
Range: 642 km / 399 miles

Do-128-6
Engine: 2 x P&WAC PT6A.
Installed pwr: 600 kW.
Span: 15.9 m.
Length: 11.4 m.
Wing area: 29 sq.m.
Empty wt: 2540 kg.
MTOW: 4350 kg.
Payload: 1275 kg.
Cruise speed: 340 kph.
Initial ROC: 385 m / min.
Ceiling: 8580 m.
T/O run (to 15m): 555 m.
Ldg run (from 15m): 435 m.
Fuel internal: 895 (+475) lt.
Range/payload: 1460 km with 805 kg.
Capacity: 12 pax.

Dornier Do 128