The Avro Type 748 is a twin turboprop airliner, powered by two Rolls-Royce Dart engines, that was sold successfully world-wide for both airline and military transport service.
The first prototype (G-APZV) first flew on 24th June 1960.
Designed by AV Roe & Co Ltd, the type was later built by Hawker Siddeley Aviation Ltd, British Aerospace and Hindustan Aeronautics Ltd (HAL) and is most widely known as the HS748, the majority having been built under the aegis of Hawker Siddeley Aviation.
The aircraft continued in production until 1988, and is still in limited service today, more than fifty years after its first flight.
With the rationalisation of the aircraft industry in 1960, A.V. Roe Ltd were absorbed into Hawker Siddeley Aviation and with it the designation changed to the HS748.
Never glamorous, the HS748 was remarkably successful and has been an effective Douglas DC-3 replacement, in many inhospitable parts of the world. A total of 381 aircraft were built including 89 aircraft manufactured by HAL, the first Indian-built aircraft flying on 1st November 1961.
The type was designed from the outset for operation from short, unimproved airstrips and was aided by the fitment of large Fowler flaps and reverse thrust propellers with and effective braking system. The use of the Rolls-Royce Dart engine also ensured excellent reliability.
In 1983, and following the privatisation under the heading of British Aerospace advertising for the type was highlighting 'In-service with seventy-nine operators in fifty countries around the world', with more than 300 aircraft having been exported by that time.
Significant users included Indian Airlines (Hindustan Aeronautics-built); Aerolineas Argentinas; VARIG; Phillipine Airlines; Thai Airways; LAN-Chile; Bouraq Airlines; the Indian Air Force (Hindustan Aeronautics-built); Brazilian Air Force; and the Royal Australian Air Force.
The last British HS748 to be built made its maiden flight at Woodford on 1st December 1988.
Two aircraft were used by the Civil Aviation Authority (CAA) in the UK, mainly for radio navigation and landing aid calibration, with a further six being used for the same duties in West Germany.
24 HS748 Srs 1 were built before production switched to the 52-seat HS748 Srs 2 with its more powerful Rolls-Royce Dart RDa7 Mk.531 engines. This was then followed by the HS748 Srs 2A and HS748 Srs 2B, with further increases in power and maximum weight.
The prototype HS.748 Srs 2 (G-ARAY) flew at Woodford on 6th November 1961.
In India, two of the locally-built HS 748 Srs 2M aircraft were modified with a large, circular, pylon-mounted surveillance antenna carried above the fuselage as the HAL 748 ASP (Airborne Surveillance Platform).
One HS748 Srs 2A (G-BCDZ) was modified to carry a maritime search radar mounted under the forward fuselage. This aircraft was marketed as the 'Coastguarder' and was designed around a crew of five (two pilots, a navigator and two observers). A flight endurance of up to 11 hours was available, taking advantage of an increased fuel capacity. However, no sales were achieved and the aircraft subsequently reverted to a standard configuration.
The military freighter derivative, the HS748MF flew on 21st December 1963. The type could be distinguished by larger propeller blades. The HS748MF take-off weight was increased to 50,000 lb with the power being provided by two 2,970 hp Dart R.Da.12 engines.
The original Avro 748 prototype (G-APZV) was modified to become the aerodynamic prototype for the HS748 Andover (re-registered as G-ARRV).
Thirty-one HS748 Andover C. 1 were built, the first production aircraft (XS594) flying on 9th July 1965. This type is also referred to as the HS780.
The HS748 Andover C.1 could typically carry 48 troops or 40 paratroops whilst for casualty evacuation it carried 15 sitting and 18 stretcher cases. After the HS748 Andover C.1 was withdrawn from RAF service from 1975 (whilst being operated in the tactical transport role), ten were sold to the Royal New Zealand Air Force and others were disposed of to civil operators, mainly in Africa.
One HS748 Andover C.1 PR (XS596) remained in use with the RAF at least until 2008, being used as the nominated UK aircraft under the international Open Skies treaty. This treaty allowed the mutual inspection of sites in NATO and ex-Warsaw Pact nations as a confidence building measure.
A small number of aircraft were also converted for electronic calibration duties, these being designated as HS748 Andover E.3 or hs748 Andover E.3A.
The BAe ATP was effectively a stretched and re-engined development of the HS748, designed for commuter airline and freight use.
Avro 748 Specification
|HS 748 Series 2A|
|Powerplant||Two 2,280 eshp Rolls-Royce R.Da.7 Dart Mk 534-2 or Mk 532-2L|
|Span||98 ft 6 in|
|Maximum Weight||46,500 lb|
|Capacity||Two flight crew, 40 – 48 passengers, or mixed passenger / freight layout|
|Cruise Speed||280 mph (244 kt)|
|Range||1,066 miles with full payload and reserves; 1,796 miles with full fuel, 7,800 lb payload and reserves|
Variants & Number built
|Avro 748 Srs 1||Initial 44 passenger production version with two 1600 shp Rolls-Royce R.Da.6 Dart Mk 514 engines. 24 built, 4 by HAL|
|HS748 Srs 1A||Srs 1 modified with engines and undercarriage as the Srs 2A aircraft. (Four conversions from Srs 1)|
|HS748 Srs 2||Increased gross weight. Two 1910 shp Rolls-Royce R.Da.7 Dart Mk 531 engines. 148 built, 54 by HAL.|
|HS748 Srs 2A||Further increase in gross weight. As Srs 2 with two 2,290 eshp Rolls-Royce R.Da.7 Dart Mk 534-2 or Mk 535-2 engines. 107 built plus 43 converted to this standard.|
|HS748 Srs 2B||Main production model under British Aerospace, the 2B featured a 4-foot increase in wingspan, a further increase in weights, Mk 536 engines, and a modernised cabin. Rolls-Royce Dart R.Da.7 Mk 536-2 engines. 26 built plus two conversions to this standard.|
|HS748 Srs 2B Super||As Srs 2B featuring a modernised flight deck, improved efficiency and Rolls-Royce Dart R.Da.7 Mk 552-2 engines fitted with hush-kits. Eight built.|
|HS748 Srs 2M||Srs 2 with fuselage freight door and reinforced floor produced by HAL. Rolls-Royce Dart R.Da.7 Mk 536-2T engines. 31 built by HAL.|
|HS748 Andover CC.Mk.2||VIP transport version of the Srs 2 for RAF service. 6 built.|
|HS748MF||Initial designation of Type 780 Andover C.1. Prototype only G-ARRV, converted from 748 Srs 1 G-APZV.|
|HS748 Coastguarder||Maritime patrol variant of the Srs 2B. One conversion only G-BCDZ.|
|HS748 Multi Role||Multi role development of the Coastguarder. Two conversions only.|
|HS748 ASP||HAL produced aircraft fitted with rotodomes as prototype Airborne Surveillance Platforms. First flew in November 1990, Two Rolls-Royce Dart RDa.7 Mk 536-2 engines. Two conversions from 748 Srs 2M.|
|HS780 Andover C.1||Military variant with a rear loading ramp and a "kneeling" undercarriage. Two 2,970 eshp Rolls-Royce R.Da.12 Dart Mk.201C engines. 31 built|
|HS780 Andover C.1(PR)||HS748 Andover C.1 converted for Photographic Reconnaissance duties. Two conversions.|
|HS780 Andover E.3||HS748 Andover C.1 converted for radio and airport aids calibration. Four conversions.|
|HS780 Andover E.3A||Modified Andover E.3. Three conversions.|
|Total Built||381 aircraft: 262 UK-built Avro 748; 31 UK-built Avro 780 Andover C.1; 89 Avro 748 built by HAL in India.|
The HAL-built Avro 748 remains in service in India. Small numbers are thought to remain in airline service, for example with Air North in Canada. The following examples are preserved elsewhere.
Avro 748 Srs 1
|Speke Aerodrome Heritage Group at Liverpool Airport, United Kingdom|
HS748 Srs 2
|RAAF Museum at Point Cook, VIC.|
HS748 Srs 2
|Australian Aviation Museum at Bankstown.|
HS748 Srs 2A
|Museu Aeroespacial, Rio de Janeiro, Brazil|
HS748 Srs 2A
|Museo Aeronáutico de la FAE, Mariscal Sucre International Airport, Quito|
Avro 748 Srs 1
|Sri Lanka Air Force Museum, Ratmalana Airport, Colombo www.airforcemuseum.lk|
HS748 Srs 2A
|Sri Lankan Air Force, Koggala, Galle|
HS748 Srs 2A
|Sri Lankan Air Force Weerawilla|
HS748 Srs 2A
|Siam Country Club, Pattaya, Thailand|
|HS 748 Andover C.1 (NZ7621)||RNZAF Museum in Christchurch, New Zealand|
RAF Museum, Cosford