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Aviation History
1962
1962 - 2119.PDF
482 FLIGHT International, 20 September 1962 AIR COM MERCE TURBOFAN HERALD FOR 1965 ANNOUNCEMENT of the H.P. 127 Jet Herald was one of the big surprises at the Farnborough Show. The reason for the interest was not so much the existence of the project as its un orthodox design arrangement, and the boldness of Handley Page's proposed commercial programme for the aircraft. For some time, civil engine manufacturers have been applying their large-turbofan expertise to the design of smaller-thrust units, and it is not sur prising that successful manufacturers of medium-sized, short-range turboprop transports, such as Fokker, Handley Page, and BAC, are being quick to present the advantages of turbofan power to their traditional markets. After a slow start to Herald sales, Handley Page can now be counted widely experienced builders in this category, no fewer than ten operators having signed contracts. In order to minimize that most important of operating-cost factors, first price, the Jet Herald will—say Handley Page—use a high proportion of components from its turboprop predecessor. The new Rolls-Royce powerplants of the Jet Herald are unofficially stated to be RB.183/ls, alias Spey Junior, with 8,8501b sea-level thrust for take-off. This engine has lower thrust, and is simpler, lighter and cheaper than the RB.163 Spey from which it is de veloped, although how this is achieved has yet to be explained. In the Jet Herald the engines are cantilevered from below and behind the existing wing at the same span-wise distance from the fuselage as the Darts in the Herald. The twin-wheel main undercarriage retracts forward into a fairing ahead of the engine, which necessi tates a bifurcated air intake. Greater power for take-off has allowed the wing span to be reduced by 15ft, without increasing the modest field-length requirements even at the greater maximum take-off weight. Landing distances at the higher approach speeds are also virtually the same, as a result of the incorporation of reverse thrust Clearly, some development will be necessary on the reverser instal lation, to avoid either heating the wheels or blasting against the windows. However, the ingenious location of the engines, apart from permitting maximum use of Herald components, also has its own significant advantages compared with the classic rear- fuselage mounting. With the exhaust nozzles aft of the passengers, cabin noise levels should be comparable, and the payload can be stowed aboard with the same freedom from e.g. worries. Fuel and wing de-icing connections are short and simple, whilst total struc ture weight is probably less. Landing torsion loads on the wing are partially alleviated, and a military beaver-tail rear door would not pose such a difficult structural design problem. The fuselage has been extended by over lift, in order to carry, entirely as passengers, the increased payload made possible by the Left, comparative payloadjrange in ISA still-air conditions. The payload is based on an APS weight calculated for a maximum economy-class seating layout 30 o o o. x 20 a 3 1,000 1,500 2,000 RANGE (it miles, no reserves) 3,000 Right, design cruising speed comparisons against altitude 10 This model of the Jet Herald was shown by Handley Page at Farnborough s.l BAC ONE-ELEVEN. JET HERALD VISCOUNT 8IO FRIENDSHIP 200 " HERALD / 200 "> H^h 200 500 400 500 TRUE AIR SPEED(kt) Effect of range on take-off distance to 35ft at ISA sea level 5 10 15 20 RANGE (it miles x 100, no reserves)
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