The Handley Page Dart Herald made its first flight on this day in aviation history in 1955.
The history of the Handley Page Dart Herald (aka Handley Page Herald) goes back to the HPR.3 Herald. The HPR.3 Herald was designed as a replacement aircraft for the venerable Douglas DC-3 and was based on the Miles Marathon. During the HPR.3 Herald design, the Handley Page had extensive contact with DC-3 operators about the requirements for the new aircraft. Based on the feedback from the DC-3 operators it was decided that the HPR.3 would be equipped with 4 radial engines, as there was no faith with the DC-3 operators in the turboprops being developed at the time. The engine chosen at the time was the Alvis Leonides Major 14-cylinder radial engine, driving three-bladed propellers This proved to be a huge error later in the development of the HPR.3
The HPR.3 Herald Prototype
While Handley Page went for piston engines, the Dutch aircraft manufacturer Fokker did go for the turboprop engines on its F.27 Friendship and choose the Rolls Royce Dart as the powerplant.
Although the F.27 Friendship would not make its first flight until late November 1955.
The HPR.3 had a pressurised cabin with seats for 44 passengers and could be quickly reconfigured to an all-cargo aircraft, loading and unloading was facilitated by the two large doors in the forward and aft fuselage. For short-field performance, the aircraft was equipped with large flaps it could land and take off at distances less than 1500 feet. Its cruise speed was a couple of knots shy of 200 knots (224 mph - 360 kph)
The Handley Page Herald flight deck
They hoped to reach 300 sales, well past the (estimated) break-even point of 75 aircraft. After hard work some orders for the aircraft started to materialise and when the prototype made its first flight. They had 29 orders in the order book on this day in 1955. But even before the second prototype of the HPR.3 would fly the Rolls Royce Dart engine had shown its reliability on the Vickers Viscount. And orders got cancelled in favour of the Dart powered Friendship and currency issues. And Handley Page had their order book wiped clean.
To not lose the substantial investment already made in the aircraft it was decided to upgrade the design of the HPR.3 and fit it with two Rolls Royce Dart 527 engines. Besides the turboprop engines, the fuselage was stretched by 20" (51 cm). The designation for the redesigned aircraft would be the Handley Page HPR.7 Dart Herald. This redesigned aircraft's first prototype was the modified prototype of the 1st HPR.3, getting air under its wings for the first time on the 11th of March 1958. The first production aircraft would be making its maiden flight on the 30th of October 1959, with certification by the CAA granted in of the initial series 100 aircraft in April 1958. A total of 15 versions of Handley Page HPR.7 Dart Herald would come out of the design department, only 3 made it to production besides the original prototype we described above. The other versions never made it to the production stage for several reasons.
The produced versions were;
HPR.7 Dart Herald Series 100, 4 built Initial production version
HPR.7 Dart Herald Series 200, 36 built A stretched version of the series 100 (4' 7" stretch) With a capacity for 56 passengers
HPR.7 Dart Herald Series 400, 8 built Military version of the Series 200, with a reinforced floor for freighter operations, is also capable of carrying 50 troops or 24 stretchers
Specifications for a Series 200 aircraft General characteristics
Crew: 2
Capacity: 50-56 passengers / 11,700 lb (5,307 kg) maximum payload
Length: 75 ft 6 in (23.01 m)
Wingspan: 94 ft 9.5 in (28.893 m)
Height: 24 ft 1 in (7.34 m)
Wing area: 886 sq ft (82.3 m2)
Empty weight: 25,800 lb (11,703 kg) equipped
Max takeoff weight: 43,700 lb (19,818 kg)
Maximum zero-fuel weight: 37,500 lb (17,010 kg)
Maximum landing weight: 39,500 lb (17,917 kg)
Fuel capacity: 1,080 imp gal (1,297 US gal; 4,910 l) 2x optional 600 imp gal (721 US gal; 2,728 l) under-wing tanks
Powerplant: 2 × Rolls-Royce RDa.7 Dart Mk.527 turboprop engines,
Propellers: 4-bladed Rotol, 12 ft 6 in (3.81 m) diameter constant-speed fully-feathering propellers
Performance
Cruise speed: 239 kn (275 mph, 443 km/h) at 15,000 ft (4,572 m) at 39,500 lb (17,917 kg) AUW
Stall speed: 65 kn (75 mph, 120 km/h) at 30,000 lb (13,608 kg) AUW
Vmo: 304 kn (350 mph, 563 km/h)
Range: 608 nmi (700 mi, 1,126 km) with max. payload, 87 nmi (100 mi; 161 km) diversion, 45 minutes holding 1,529 nmi (1,760 mi; 2,832 km) with max. standard fuel, no allowances
Service ceiling: 27,900 ft (8,500 m) at 35,000 lb (15,876 kg) AUW
Service ceiling on one engine: 13,000 ft (3,962 m) at 35,000 lb (15,876 kg) AUW
Rate of climb: 1,805 ft/min (9.17 m/s) at 41,000 lb (18,597 kg) AUW
Take-off distance to 35 ft (11 m): 2,700 ft (823 m) at 39,500 lb (17,917 kg) AUW
Landing distance from 50 ft (15 m): 1,900 ft (579 m) at 39,500 lb (17,917 kg) AUW
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