Howard 500

Le bimoteur à piston Howard 500 de 1959 vu sur Wikipedia.en Merci

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The Howard 500 was an executive transport aircraft produced in the United States during the early 1960s.

Design and development

During the 1950s and 60s, Howard Aero Inc had been remanufacturing military surplus Lockheed Lodestars and Lockheed Venturas for the executive market, but while the Howard 500 bore a strong resemblance to these aircraft, it was a substantially new design, and all 500s had completely new fuselages.


The only major components taken directly from its Lockheed forebears were the outer wing panels (from surplus Venturas) and undercarriage (from Harpoons). Howard purchased wing and fuselage jigs from Lockheed to use as patterns for jigs for the new aircraft.

The fuselage differed from the Ventura's in being designed from the outset for pressurisation, and the wings were designed wet.

The pressurisation system maintained a differential of 6.75 lb per square inch which was greater than any other prop or turboprop executive aircraft on the market at the time and maintained a sea level cabin pressure at up to 16,000 ft.


The engine chosen was a new, higher-power and lighter-weight version of the Pratt & Whitney R-2800 that had been developed for the Douglas DC-6. Propeller hubs were taken from F4U Corsairs, four-blade propellers and spinners from DC-7s.

Production and marketing

The prototype flew in September 1959, and certification was achieved on February 20, 1963.

By this time, however, the executive market was already dominated by turboprop aircraft, and although its performance was comparable to (or even better than) these new machines, and its price substantially lower, the Howard 500 could not effectively penetrate the market.

Executive operations

The Howard 500 could accommodate ten to fourteen passengers with a large window for each.

Increased fuel tankage over the PV-2 Ventura gave a maximum range with full reserves of 2,600 miles.

Maximum cruising speed was 350 mph at 21,000 ft.

This exceptional performance for a piston engined executive aircraft unfortunately came just as the competing turbo prop designs were coming to the market, and this restricted sales of the type.


Commercial firms operating the aircraft included Republic Steel, Green Construction of Indiana, Pacific Petroleum of Canada, Northern Natural Gas Company and U.S. Metal Refining Company.

22 Howard 500s were produced initially, with a further eight being converted from earlier PV-2s to virtually the same standard.

Survivors

Of the 17 examples built to full Howard 500 standard, two restored aircraft remain flying. One in the United States in 2008 (construction number 500-105, registration N500HP) which was initially operated by the Natural Gas Pipeline Company of America, and later by the Phillippi Equipment Company. more pictures can be seen at [Vous devez être inscrit et connecté pour voir ce lien]
This is the only known airworthy Howard 500 in the USA.
It is based at Anoka County Airport in Minnesota, and was awarded Grand Champion at EAA AirVenture Oshkosh in 1997.

Note: Dee Howard is not related to Benny Howard, racing pilot and aircraft designer of the Howard DGA aircraft series of two decades earlier.

The second, N500LN was restored in the UK and left Exeter (EGTE) on the 18th May 2010 at 14:42 UTC. The aircraft departed to Coventry airport. The aircraft's last flight prior to this was on the 14th August 2000, since then it had been in storage / restoration at Exeter until its departure to Coventry. N500LN was originally registered N539N built in 1962, construction number 500-113.
This aircraft was purchased by the tpaero group in October 2009 and will be based at the Anoka County Airport in US state of Minnesota.

Specifications

Data from Jane's All The World's Aircraft 1965-66

General characteristics

Crew: Two (pilot and co-pilot)

Capacity: 19 passengers

Length: 58 ft 5½ in (17.82 m)

Wingspan: 72 ft 4 in (21.44 m)

Height: 13 ft 7 in (4.11 m)

Wing area: 592.2 ft2 (55.02 m2)

Empty weight: 23,000 lb (10,430 kg)

Gross weight: 35,000 lb (15,875 kg)

Powerplant: 2 × Pratt & Whitney R-2800-CB17, 2,500 hp (1,870 kW) each

Performance

Maximum speed: 410[5] mph (660 km/h)

Cruise speed: 350[6] mph (563 km/h)

Stall speed: 103 mph (166 km/h)

Range: 2,600 miles (4,185 km)

Service ceiling: 35,000 ft (10,670 m)

Rate of climb: 2,550 ft/min (13.0 m/s)