History of the 146
Early design studies | The HS 146 | The BAe 146 | 146 Developments | The Avro RJ | The Avro RJX
Since the late 1950s, de Havilland at Hatfield had been looking at creating an aircraft that would replace the continued use of Douglas DC3s (Dakotas) which were still being used as "feederliners" for short haul flights. The first study was the DH 123, a twin Gnome-engined turboprop along similar lines as the Airspeed Ambassador, Airspeed being in fact owned by de Havilland. However, de Havilland became part of the Hawker Siddeley group in 1960 and the idea was dropped for two reasons, firstly because the aircraft conflicted to some extent with other HS products, including the HS (Avro) 748 and secondly because it was believed at Hatfield, that a turboprop was only and interim solution and that a turbojet or turbofan aircraft would be the preferred way to go.
The next study was the DH 126, resembling a scaled up DH 125 executive jet with the fuselage diameter and length closely matching that of the DC3 it was intended to replace. The intended engine was the de Havilland PS.92 (later changed to Rolls Royce RB.172 or General Electric CF700), none of which were ever actually available. Seating was for between 26 and 32 passengers and after several changes to the design study it was concluded in 1964.
|The DH 126|
The next study was the HS 131, using the fuselage of the HS 748 to reduce costs, but with new wings, tail, undercarriage and a pair of rear mounted RB.172s, CF700s or Bristol Siddeley BS.304s (none of which were available). The cost savings of using carried over 748 parts were not deemed great enough considering the 'compromise' of the design and it was not proceeded with.
|The HS 131|
Beginning in 1964 (at the same time DH 126 studies ended and concurrently with the HS 131), another configuration was designed. This was the HS 136, which initially had the engines rear-mounted, but switched to under-wing mounts with a general arrangement similar to that of the Embraer 170/190 family. Engines were to be RB.172 on the early version with subsequent revisions to the design using the small Trent turbofan (no relation to today's Trent) which again was not built. Foreign object ingestion was found to be a significant problem with the low mounted intakes.
|The HS 136|
The HS 136 was evaluated by the Hawker Siddeley board concurrently with the HS 860, a jet powered derivative of the HS 748 designed at HSA Woodford (formerly Avro). They decided work should continue on a new design with input from both groups. This became the HS 144, which reverted to rear mounted Trent engines and a T-tail, with the engine intakes just over the trailing edge of the wing for better weight distribution and a passenger behind the exhaust. Work on the Trent slowed and stopped altogether after the Rolls-Royce bankruptcy in 1970.
Also worthy of mention is the V/STOL HS 141 design. Although a separate project, there are elements of cross-over, in the size, arrangement, engine type and short-haul nature of the aircraft. The principal difference was the inclusion of 16 RB.202 lift engines!
|The HS 141 - Photo: T. Vickers|
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