Handley Page Herald

Handley Page Dart Herald vu Wikipedia. de langue anglaise :

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The Handley Page Dart Herald was a 1950s British turboprop passenger aircraft.

Design and development

In the mid 1950s, the Handley Page Aircraft Company developed a new fast short-range regional airliner, intended to replace the venerable Douglas DC-3, particularly in third-world countries.

The design, originally known as the HPR-3 Herald, emanated from the drawing office at Handley Page (Reading) Limited - the former Miles Aircraft factory site, which developed an earlier airliner design, the Miles Marathon.

HPR. 3

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The Herald was an extensive re-development of the original concept of the Marathon; notable for its high mounted wing.

The HP Reading division succeeded in producing a modern design, which had excellent flight and performance characteristics.

However, the company made a serious misjudgement, which was, in the end, to cost the company dearly, and the Herald missed its chance, like some other classic British aircraft of the time.

Le HPR 1 Marathon

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As with the Marathon, the HPR-3 Herald was originally configured with four piston engines. In the case of the Herald they were 870 hp (650 kW) Alvis Leonides Major piston engines, driving three-bladed propellers.

By now, however, the Rolls-Royce Dart turboprop engine had shown proven success in the Vickers Viscount. HP failed to take early account of this in the Herald design phase; particularly the market desire for the new turboprops.

This misjudgement and the ensuing delay was to prove a costly mistake for the company.

However, the Herald was advanced in many ways for the time. Its pressurised cabin up to 30,000 ft (9,140 m), could seat up to 47 passengers in the series 100 (up from 44 originally) and could easily exceed 300 mph (480 km/h) in level flight. Initial climb rate was over 1,800 ft/min.

The first "Herald" prototype, G-AODE, first flew on 25 August 1955 and was demonstrated at the Farnborough Air Show two weeks later.

Although Queensland Airlines, Australian National Airways, and Lloyd Aéreo Colombiano had initially placed 29 orders, these were later cancelled with only the first prototype completed.

As a result Handley Page belatedly realised it had to make a major change to the engine configuration, if the Herald was to have any chance in the market.

There had already been a very substantial investment in the Herald project, such that the Management held a meeting to discuss continuation.

Handley Page decided to press ahead with the Herald project, in an effort to recover the investment; announcing a new uprated version, reworking the wing to use Rolls-Royce Dart turboprops fitted with 12.5 ft (3.81 m) variable pitch four-blade Dowty Rotol props, and lengthening the fuselage by 20 in (51 cm).

The first prototype series 100 first flew in 1958.

Now designated the HPR.7 Dart Herald, the new aircraft entered production in 1959. The first order was placed by BEA.

Operational history

The Herald attracted much early interest around the world because of its astonishing short field performance and excellent flight characteristics, but Handley Page failed to close many of the deals, as the F-27 and the HS.748 had become rival offerings, both of which were significantly cheaper.

There has been some speculation about the origin of the F-27 design, which first flew earlier than the Herald in turboprop configuration.

A key design feature of the Herald was the high mounted wing but notably with an upswept dihedral.

In addition, the Herald's vertical fin is covered in miniature aerofoils, adding further to the Herald's excellent stability.

Pilots reported the Herald flew like a dream; very stable in the air, yet highly maneuverable even at slow speed.

Ground handling was said to be the Herald's only vice due to an overlarge tail fin.

Credit for the Herald's useful wing and aerofoil features was due to the company's wing design office, which had garnered an unrivalled reputation for advanced wing design, including the crescent wing of the Victor bomber.

Handley Page invented the Slot, later referred to as the Handley Page Slot, without which most modern aircraft would not be nearly so easy to manage at slow speeds.

Despite the rework, that transformed the HPR.3 to the HPR.7 Herald, only four of the original 47 seat Series 100 HPR.7s were built.

Believing a yet larger version was needed, HP turned to Series 200 production, which featured a further 3 ft 4 in (1.07 m) stretch of the fuselage, seating up from 47 to 56 and corresponding increased weights.

Series 200 production began in 1961.

Herald 211

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The first production model was delivered to Jersey Airlines in January 1962.

However, by this point all sales momentum had been lost, and only 36 examples of this major production model were eventually built during the six years of production.

206

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The Herald Series 400 was specially developed in 1964 as a "tactical transport" built for the Royal Malaysian Air Force, with a strengthened cabin floor.

HP suspected that the Herald was still too small and so a 60-seater Series 700, powered by Dart 532s and having increased fuel and weights was designed.

A late attempt was made to revive sales when speculative production commenced on eight Series 700 airframes.

The project was cancelled as several of the airframes were approaching completion. The partially completed airframes were scrapped.

The 50th, and last, Herald (a series 200 for Israel's Arkia) was flown and delivered in August 1968, after which Herald production ceased and attention turned to the HP.137 Jetstream.

The Herald's last ever passenger flight was operated by British Air Ferries in 1987 doing subcharters for Ryanair on the Waterford-Luton route.

A durable and reliable aircraft, capable of being heavily worked, many continued on as freighters, plying the night sky across Britain and the near continent, for several operators including Royal Mail, BAF, Channel Express, DHL, Elan, Securicor and others; transporting papers, milk, parcels, post, tomatoes, flowers, and other goods round the clock.