FlightGlobal.com
Home
Premium
Archive
Video
Images
Forum
Atlas
Blogs
Jobs
Shop
RSS
Email Newsletters
You are in:
Home
Aviation History
1958
1958-1- - 0130.PDF
132 FLIGHT Dart Herald Handley Page, Ltd., Cticklewood, London THE aircraft which originated as a four-piston-enginedbranchliner has now evolved—largely through the air trans-port industry's widespread acceptance of the Rolls-Royce Dart propeller turbine—into a twin-turboprop branchliner. It isthe Dart version of the Herald to which Handley Page are now applying their technical and commercial effort, and it is with thisvariant that the present description is concerned. The Dart Herald market is potentially a very large one, andfurthermore it is not likely to be influenced by the rapid pace of technological development which at present afflicts the finances ofthe trunk-route operators. This means that the Herald could be a marketable product for perhaps a decade hence, which puts intoperspective the fact that the aircraft is off to a later start than its chief competitor, the Fokker/Fairchild Friendship. Some minorchanges have been made since our previous description of this aircraft (Flight, May 2, 1958) and a dorsal fin has recently beenadded. Handley Page sum up the case for the Dart Herald as follows:"While effort has always been expended on the design and con- struction of aircraft for the world's better-known routes, there hasbeen no airliner which has brought the same high standards of flight comfort to the branchlines where low purchase cost andeconomic operation are even more important than on the 'prestige' services."Until recently those wishing to fly or send goods on the multitude of lesser—but equally important—airways have had tobe content with obsolete mainliners designed for different con- ditions or with small aircraft offering little passenger appeal."Increasing importance is being attached to flying as an every- day means of transport, particularly in territories where surfacetravel is formidable. This, combined with the specialization of current aircraft design, had made imperative a modern air trans-port built specifically for local services and operation in un- developed areas. "Handley Page realized that only those who used civil aircrafton routes of this type knew with certainty the qualities which such a transport must possess. Representatives of the company investi-gated operators' requirements by on-the-spot study of their needs. Their enquiries took them to almost every airline in the worldwith short- and medium-length routes. "The Dart Herald is a development of the aircraft which wasbuilt to the specification thus evolved. A pressurized, high-wing monoplane of all-metal, stressed-skin construction, its two turbo-prop engines give it a cruising speed of 275 m.p.h. "Branchline operators today show a marked preference forturboprop transports. The success and world-wide operation of the Rolls-Royce Dart engine in the Vickers Viscount has madethat engine pre-eminent in its field. Since its introduction the Dart has been developed continuously to give increased power and alower fuel consumption. The engines used on the Dart Herald give the equivalent of 2,100 h.p. each for take-off; their specificfuel consumption, when cruising at 15,000ft in I.S.A. conditions, is 0.66 lb per hour per shaft horse-power."More than four million engine hours have been flown by Darts. The popularity of this engine among its many operators arisesfrom its reliability, the small number of propeller featherings that have been necessary owing to engine trouble, the long periodbetween overhauls, and the small amount of routine maintenance necessary." COMMERCIAL HISTORY The Herald project was firstannounced in October 1954 and the first Alvis-engined Herald, G-AODE, flew on August 25, 1955, the second machine takingto the air just over a year later. Early interest in the Herald was Strong (options on 35 aircraft were placed by four operators) butairlines subsequently became more and more influenced by world acceptance of the Rolls-Royce Dart. This led Handley Page, inMay 1957, to concentrate on the twin-Dart version. First flight of the converted Herald took place in March 1958 and certifica-tion is planned by the year end. No firm orders have yet been announced for the Dart Herald. STRUCTURE The Herald airframe has been extensivelyre-stressed for Dart power. As a result of structural tests, the fuselage has been granted an infinite fatigue life by the A.R.B.and tests are now in hand for similar clearance of the wing. The structure has been designed according to the fail-safe multipleload-path philosophy. The new Dart installation has involved the complete redesign of the existing wing, which carries an additional30 per cent bending load (due to the higher speed and lack of bending moment relief from the outboard engines). This has CREW ENTRY AMI FORWARD FREIGh DOOR HANDLEY PAGE DART HERALD Two Rolls-Royce Dart RDa.7/2 Mark S27 turboprop* of 2,100 e.h.p., each driving Rotol four-bladed, Iljft propeller* Dimensions: Span, 94ft 9±in; length, 71ft 11in; height, 22ft 4in; wing area 886 sq ft; flaps, 81 sq ft each side; ailerons, 29.7 sq ft each; tailplane, 252 sq ft; elevator, 71.13 sq ft; fin and rudder (total), 193 sq ft; track, 22ft; wheelbase 25ft 10in. Weight*: Basic operating weight, 36-seater, 22,269 Ib; max. payload, 10,160 Ib;zero fuel weight, 32,968 Ib; max. take-off weight (also max. landing weight), 37,000 Ib. Performance: Take-off, balanced field length, sea level standard conditions, 3,700ft; tropical conditions (I.S.A.+ 15 deg C conditions), 3,950ft; sea level rate of climb, 1,580ft/min; rate of climb at 10,000ft, 1,030ft/min; cruising speed at 35,000 Ib, standard conditions, at 17,400ft, 241 kt; stalling speed, max. weight, sea level standard conditions, 69 kt; landing distance from 50ft, 2,260ft; corre- sponding distance in I.S.A.+ 15 deg C conditions, 2,350ft.
Sign up to
Flight Digital Magazine
Flight Print Magazine
Airline Business Magazine
E-newsletters
RSS
Events
