สุดยอดเครื่องบิน: Gossamer Ablatross เครื่องบินขับเคลื่อนด้วยกำลังคน

Gossamer Ablatross

From the earliest of times man has dreamed of flying by his own means, even Da Vinci had such dreams and made designs as early as 1490. By the 1920s man was able to make successful human powered flight, though never making any great
distances.

The Gerhardt Cycleplane looked like just about any other airplane of the early 1920s except it had seven wings. And then there was Gerhardt's method of propulsion: bicycle power. Since high-aspect ratio wings were the best way to get into the air with lower, bicycle speed drag, the wingspan would need to be longer than a battleship to get the Cycleplane airborne. So Gerhardt divided that wing and came up with seven. Of course he had to add the drag of all those struts and wires from all those wings. But he forgot all about that. It didn't matter anyway. Built lightly, the Cycleplane's top wings collapsed on its only take-off run.

All the way up to modern times we still have had such dreams, and in the late 70's the dream was truly achieved. The Gossamer Albatross, designed by Dr. Paul MacCready, on June 12, 1979 flew across the English Channel piloted and powered by Bryan Allen. MacCready had been designing sail planes since the mid 70s his first major success was the Gossammer Condor which set a distance record of a 1 mile flight in 1977. He took up construction of these planes in response to a challenge made by industrialist Henry Kremer. Two years later another challenge was offered and met with the crossing of the English Channel.

Unlike just about any other flying craft, the machines that emerged from MacCready's workshop were built with one aim in mind: to break records.

The first of these the Condor, had a wingspan of 96 feet and was a pusher design, with a large two-bladed propeller mounted at the back and an auxiliary aero foil placed well forward. The pilot sat in an enclosed cabin directly below the main wing. For the record breaking flight which took place at Shafter, California, championship cyclist Bryan Allen was chosen as the pilot. On the hot August day in 1977, he flew the strange-looking Condor between the two pylons in 7 minutes 2.5 seconds.

Two years later, with Henry Kremer's challenge to fly across the English Channel, MacCready and his team build an improved version of the Condor, the Albatross. In many respects it was identical to the Condor and once again Bryan Allen piloted it on the journey. He landed at Cap Gris-Nez, near Boulogne, after pedaling 23 miles over the water.

Overview:

The Albatross was powered using pedals to drive a large two-bladed propeller. Piloted by amateur cyclist Bryan Allen, it completed the 22.2 mi crossing in 2 hours and 49 minutes, achieving a top speed of 18 mph and an average altitude of 5 feet.

The Gossamer Albatross is of unusual "canard" configuration, using a large horizontal stabilizer forward of the wing in a manner similar to the Wright brothers' successful "Flyer" aircraft. The Gossamer Albatross was constructed using a carbon fiber frame, with the ribs of the wings made with expanded polystyrene; the entire structure was then wrapped in a thin, transparent plastic (mylar aka PET film). The empty mass of the structure was only 71 lb, although the gross mass for the Channel flight was almost 220 lb. To maintain the craft in the air it was designed with very long tapering wings (high aspect ratio), like those of a glider, allowing the flight to be undertaken with a minimum of power. In still air the required power was of the order of 300 W, though even mild turbulence made this figure rise rapidly.

History:

The Gossamer Albatross was designed and built by a team led by Paul B. MacCready, a noted US aeronautics engineer, designer, and world soaring champion. Gossamer Albatross was his second human-powered aircraft, the first being the Gossamer Condor, which won the first Kremer prize on August 23, 1977 by completing a specified figure-eight course.

A follow-up to the Albatross was the solar-powered Gossamer Penguin (above) in 1980.The Penguin was fragile and not very airworthy, but led to the Solar Challenger

MacCready's team built two Albatrosses; the back-up plane was jointly tested as part of the NASA Langley/Dryden flight research program in 1980 and was also flown inside the Houston Astrodome, the first ever controlled indoor flight by a human-powered aircraft. The Albatross II is currently on display at the Museum of Flight in Seattle, Washington. The aircraft used in the channel crossing is on display at the Smithsonian Institution's Udvar-Hazy Center.