Vought-sekorsky vs-300

The world's first successful single-main-rotor helicopter, the VS-300 is the progenitor of today's most prolific rotorcraft family. Igor Sikorsky had first experimented with helicopters in Russia in 1910, but it was not until the late 1920s, when he was engineering manager of Vought-Sikorsky in the USA, that he returned to the problem. In 1939 he designed and built the VS-300, and on September 14 he made his first tentative flights. The structure was kept simple for ease of modification, and the machine underwent more than 200 alterations, including several complete rebuilds. Over the following two years it became known as 'Igor's Nightmare'.

Originally it featured a basic airframe with the pilot seated in front of the 90 hp Lycoming engine, which drove a single three-bladed main ro­tor and a tail-rotor on a rear boom which also carried a large vertical surface for yaw control.

The boom was then replaced by a longer steel-tube structure which carried three tail-rotors, on one horizontal and two vertical shafts, counteracting the torque of the main rotor. This arrangement gave way to a single rotor on a vertical shaft and one working in the horizontal plane, and, finally, to the single anti-torque tail-rotor.

Two-minute tethered flights were being made by November 1939, and the ropes were abandoned on 13 May 1940, by which time a 100 hp Franklin engine was fitted. The VS-300 was also equipped with pon­toons and flown from water. Flight duration steadily increased until, on 6 May, 1941 Sikorsky set a world helicopter endurance record of 1 hour 32 minutes 26.1 seconds. This historic machine is now a prized exhibit in the Henry Ford Museum at Dearborn, Michigan, USA.

NORTH AMERICAN P-51 MUSTANG

After a speedy, but less than dramatic, start to life in response to an ; urgent UK requirement for an advanced fighter, the North American Mustang developed into what was arguably the most versatile single-seat fighter of World War II.

In April 1940, the British Purchasing Commission gave North American just 120 days to deliver their proposal in prototype form, which they did with three days to spare. Unfortunately, the lack of a suitable engine delayed the programme and the first aircraft did not fly until 26 October 1940.

While early models were put into service as fighter-reconnaissance machines because of their poor engine performance at higher altitudes, the installation of the American-built Packard Merlin put the Mustang in a class of its own. In their re-engined form, some 1,800 Mustang III and IV were delivered to the RAF for fighter duties, while the USAAF used its ultra-long-range P-51C and P-51D machines as escorts for its daylight bomber formations.

The RAF's Mustangs were withdrawn by the end of 1946, coinciding with the end of a production run of 15,576 aircraft. However, proving that you can't keep a good one down, the P-51 was re-engined with a Rolls-Royce Dart turbo-prop by Cavalier Aircraft Corp in 1967 as a low-budget performance aircraft, supplying to third-world nations under the United State's Mutual Aid Program.

The fourth prototype XP-51A was seconded to become the first in service with the USAAF for evaluation purposes. Later stored by the jsJational Air and Space Museum, it was acquired by the EAA Foundation with whom it was restored and regularly flown until August, 1982. It now has pride of place in the Warbirds section of their Oshkosh museum.