Though the helicopter principle, as is shown by the Chinese top, has been known in China for centuries, the first true Chinese helicopter goes back only as far as 1945. It was produced by Major-General Chu.
G.J.Chu studied aviation technology in the U.S.A, returned to China and was for thirteen years director of an aircraft manufacturing plant at Yunnan, which built various American aircraft and also the Soviet I-15 under licence.
In 1945 C.J.Ghu turned his attention to rotorcraft and designed a co-axial helicopter, known as the Humming Bird Model A. During the tie-down test, the ground screw came off with the rope, the Humming Bird tipped over and both its rotors were broken.
A start was immediately made on building a second version, the Humming Bird Model B.
Chu Humming Bird B
But, as the general tells the story: “Just as it was finished, however, I was sent to Formosa and for a variety of reasons we had to leave the ship on the mainland …”
While in Formosa, Chu became interested in the tandem configuration and set to work again. After eighteen months’ work, the aircraft was ready.
Humming Bird Model B Engine: 1 x Kinner B-5, 125 hp Rotor diameter: 7.62m Width: 2.34m Height: 2.63m Gross weight: 725kg Empty weight: 590kg Maximum speed: 136km/h Cruising speed: 112km/h Inclining climb: 140m/min Hover ceiling: 910m Range: 219km
In 1959, the U.S. Army, through its Trans¬portation Research and Engineering Command, initiated the development of three types of VTOL research aircraft in a programme aimed at pro¬ducing a flying jeep. Fundamentally a cross between an Army jeep and a reconnaissance helicopter, this type was intended ultimately to operate at speeds of about 50 mph a few feet above the ground, carrying a payload of about 1000 lb. Contracts were placed with the Chrysler Corporation, Acrophysics Development Corp¬oration and Piasecki Aircraft Corp¬oration. The Chrysler VZ 6, like the Piasecki flying jeep, was of the ducted fan type, using two fans in tandem with the pilot and engine in between. Work on this configuration had been going on at the Chrysler Defense Engineering Company since 1955 and a unique feature of the design was the use of rigid fixed pitch three blade rotors or fans. Since the fans could not therefore contribute to control of the aircraft, Chrysler developed a system of control vanes. Pitch control came from lateral vanes across the duct intakes and yaw and roll control came from longitudinal vanes in the duct exit. The engine was located in the center of the rectangular-shaped vehicle, next to the off-set pilot’s position. Rubber skirts around the outside of the vehicle’s bottom edge helped sustain the fan-generated lift. A 373 kW (500 hp) Lycoming engine powered the VZ 6, which weighed about 2,300 lb. fully loaded and was 23 ft. long. The diameter of the ducted fans was 8 ft. 6 in. During 1959, the VZ 6 (58 5506) made some tethered hovering flights. On the first attempt at a free flight it got out of control and overturned. The prototype was not repaired and the second example (serial 58-5507) which had been ordered (58 5507) was not completed. Both prototypes were disposed of in 1960.
Chrysler VZ-6 Engine: 1 x Lycoming piston, 370kW Rotor diameter: 2.6m Length: 6.55m Height: 1.58m Take-off weight: 1080kg
The Hydro flying boat built by Christofferson Aviation flew in 1913, and was probably designed by Alan Loughead who worked for Christofferson at the time.
A two-bay biplane, of the three or four examples known to have been completed in 1914, two were sold to explorer Roald Amundsen for a proposed Arctic flight (that never happened), and one was used by Silas Christofferson’s San Francisco-Oakland Aerial ferry in 1914. This was the second scheduled airline to operate in the US.
Another Hydro is listed as having been sold to Japan.
The Jaguar began in 1969 as a biplane class racing aircraft Pete Tomalesky, was interested in racing and felt that, the recently evolved biplane class would be fertile ground to explore. The project was literally shelved in early 1970 as business matters took most of Tomalesky’s time. As often happens, interests change, and he abandoned the project to design and build a two-place, side-.by-side biplane he called the Tomcat. The aircraft bare bones were purchased by Stavros Chrysostomides, a South Carolina artist/homebuilder.
This aircraft was designed for an O-290 Lycoming of 125 hp, and the mount was welded directly to the airframe to save weight. A one-piece steel spring landing gear was formed and fitted with 500 x 5 wheels and tires, which were later sold to a fellow building a Knight Twister.
The negative staggerwing configuration was selected to provide the pilot maximum visibility in pylon turns, and since the top wing root was aft of the pilot’s head, the forward sweep of the top wings was needed to locate the wing properly in relation to the CC and the lower wing.
Chrysostomides discovered. the need to adjust the angle of a forward sweep since he was using a larger O-320 Lycoming. Also included was a statically balanced elevator to reduce chances of high-speed elevator flutter. The counterweight was attached to the elevator horn, and thereby completely concealed inside the Nselage. Calculations placed the top speed near 200 mph with a cruise near 150 mph.
Self-taught 31-year-old amateur builder Chris Christiansen designed and flew his third homebuilt airplane, the high-wing Savor, in just 15 months. The Savor, which is intended as a cross-country flying machine.
The Savor has a wingspan of 23.5 feet, and has aluminum control services and a fiberglass empennage and wings similar to a GlaStar.
The landing gear is aluminum rod. The cage frame goes all the way back to the tail. The most challenging aspect of the construction was the molds for the skins. The frame had the shape. The shells are one piece. Because of the angles and curves, the shells didn’t want to come out of the molds.
The shells are held in place by metal fasteners. The wings are removable. The wings are designed to have fuel tanks, 10 gallons on each side, and an additional fuel tank in the rear passenger compartment.
The front seat is 36 inches wide, while the backseat measures about 27 inches. The frame can accommodate someone who is 6 feet tall. The seat is 12 inches off the floor.
The interior is finished with textured semi-plastic foam. The texture can hide a lot of flaws and it is good for soundproofing. That’s 2 inches of insulation. The airplane also has carpet to help take the sound down.
Empty weight is 1,110 pounds, while gross weight is 1,550 pounds for the airplane, which cruises at 165 mph and lands at 60.
Patented biplane configuration as invented by William Whitney Christmas (U.S. Patent 957,744 Flying machine, patented May 10, 1910), constructed by the Christmas Aeroplane Co. of Washington, DC. This version was fitted with a 6-cylinder 75 hp Roberts motor, photographed after making practice flights in the hands of Clinton O. Hadley at a height of 500 feet.
Co-designed with aviation pioneer, Vincent Burnelli (who only admitted to designing the fuselage), the Christmas Bullet was intended to meet a requirement for a military scout plane. The single-engine biplane was fitted with unbraced cantilevered wings designed to flex during flight. This gross lack of wing strength led to in-flight structural failures of both aircraft on 30 December 1918 and 1 May 1919.
This failure aside, the Bullet was noteworthy for being the first or one of the first aircraft to introduce a veneer-clad fuselage to reduce skin-friction drag and interconnected movable ailerons on the wing trailing edge. Christmas received a patent for the Bullet design in 1914, a fact which he used to make the claim that he had invented the aileron. Dr. Christmas even claimed that the US government bought the rights to his movable ailerons in 1923 for $100,000 to avoid a copyright infringement suit, but there appears to be no evidence to support this claim. In fact, Christmas is only one of many early pioneers who claim to have invented the aileron, including the Wrights and Glenn Curtis.
Christmas seemed to have persuaded his backers to finance him based on two previous aircraft, for which no evidence ever existed.
Christmas managed to find funding to build two ‘proof of concept’ aircraft to demonstrate his ‘ideas’ of a deliberately flexible wing inspired by those of birds, and tepid support from the US Army, which loaned an engine for ground-testing and the services of a test-pilot, Cuthbert Mills. A flight was attempted in the first aircraft, whereupon the wings peeled off during take-off, and the aircraft crashed, killing Mills. Christmas claimed that the aircraft had reached a speed of 197mph.
A second aircraft was built, and a propeller issued by the Army, despite the loaned engine having been destroyed during the unauthorised flight as Christmas had kept this secret. The second aircraft also crashed, also fatally. Christmas was still trying to sue people for claiming the aircraft had killed its pilots as late as 1930 and insisted the aircraft had reached a speed of 222mph.
Christmas did patent, build, and fly a biplane of his own design in 1909. This aircraft, known as the Red Bird, was representative of many of his later designs and can be distinguished by its anhedral (down-sloping) upper wings and dihedral (up-sloping) lower wings. Another noteworthy tidbit about this design is that it appears to be a virtual copy of a plane built by a company named AEA that was, interestingly enough, also known as the Red Bird. In the words of one historian, “the eccentric Dr. Christmas was not above employing the ideas of others” and may well have patented another company’s design!
September 1910
Nonetheless, the success of the first of three iterations of Red Bird and a modified Red Bird II led to the founding of the Christmas Aeroplane Company based in Washington, DC, in 1910. The company became the Durham Christmas Aeroplane Sales & Exhibition Company around 1912 and later the Cantilever Aero Company after moving to Copiague, NY, in 1918.
The Red Bird II was flown at College Park, Maryland, in 1910.
Frank Christensen says he once tried to buy the Pitts Special type certificate but was turned away by the price. That apparently bothered him, because he went out and designed his own family of kit built sport biplanes, and the results were on view for the first time at Oshkosh 1977.
The criteria were: unlimited class aerobatic performance; a two place cockpit; all the creature comforts the Pitts lacked; attractive styling; and, last but in a way most essential, that the airplane should be amateur built. To certificate and sell the airplane in the normal market would be too confining and too expensive, Christensen felt. By selling it as a kit, he could channel his expenditures where they belonged into providing materials of the highest quality instead of into justifying everything to the FAA.
The Eagle is a biplane with a swept symmetrical wing structure of built up wooden ribs and spars. The Eagle’s bubble cano¬py, hinged oh the right side of the airplane, slides back to unlock and swings aside to ad¬mit the pilot and passenger to a long, wide tandem cockpit with a single instrument pan¬el in front and dual controls. The fuselage is built from welded steel tube and covered with metal back to the rear cockpit, then fabric the rest of the way aft. The fabric-covered wings are built with wood ribbing over spruce spars. The amateur builder has the option of buying 26 kits in sequence, starting with the ailerons, to test his dexterity.
Many parts are prefabricated or partially prefabricated, and the Ea¬gle’s steel tube structures are welded at the factory. Christen kits include everything you need to build them. Price in 1982: $41,000 (includes complete kit). Kit less engine and propeller, costs $26,000. Units delivered to June 1982: 450 started, 100 flying.
The Eagle I and I F will be the single-¬place unlimited competition version, pow¬ered by a 260 horsepower Lycoming aero¬batic engine; the F means fixed pitch. The I model will compete at 1,262 pounds and carry 1,478 pounds at gross with a wing loading of 11.82 pounds per square foot. Its empty weight power loading is 3.83 lbs. per hp. With a rate of climb of 2,640 fpm, it offers social climbers a verti¬cal penetration of 1,650 feet. The II, by comparison, is pure luxury, featuring a spacious forward cockpit with no intruding instructor’s feet and a huge bubble canopy molded of a single hunk of clear plastic. It rides behind 200 hp Lycoming AEIO 360 AlD and a second F version, except that this time, the F means the 260 hp en¬gine of the I model. Its gross weight is 1,578 pounds, and it provides for an elec¬trical system and a radio. Both models are stressed to +9and 6 Gs and have roll rates of 187 degrees per second and a power loading of 5.25 lbs/hp. For a second time, Christensen turned his attention toward the Pitts factory (locat¬ed at Afton, in the middle of nowhere in Wy¬oming). This time, he was successful: Pitts Aerobatics is now part of Christen Indus¬tries, and Christensen wants the Pitts and the Eagle, formerly arch rivals in the field of competition aerobatics, to live in harmony as stablemates. Christensen himself, of course, developed the Eagle as a refined Pitts after purchase negotiations with Curtis Pitts fell through in the mid 1970s. Although the very exis¬tence of the Eagle testifies to which airplane Christensen thinks is better, he is quick to assure the Pitts purists that their airplane has its own special place in the past and in the future. Christensen had no plans to axe the Pitts marque, but one model, the 200¬hp two seat S 2A, will mutate to become the factory built Eagle. This is a crucial reason behind Christen Industries’ acquisition of Pitts Aerobatics. It is the most direct route to a factory built, certificated Eagle. For the purposes of certification, the factory built Eagle will actually be a Pitts S 2A modified to Eagle standards. The Christen Eagle is very similar to the S 2A: both share the same airfoil, span, length, engine and propeller, but the Eagle has less lower wing dihedral, a further aft CG, different cowling and landing gear, modified ailerons and linkages and a more spacious and better designed interior. Christensen sees the Eagle as being almost imperceptibly different: “Like a washed car, it runs smoother.” At the time he was developing the Eagle, Christensen was convinced that an unusual¬ly complete kit would appeal to a larger market than would comparable homebuilts or factory built airplanes. With 550 kits sold by 1975, it seems he was right.
The Eagle II is a two-seat sporting biplane that can be used for unlimited-class aerobatics as well as for advanced training. The Eagle II and II-F have a full electrical system (starter-alternator-battery). The Eagle II uses a 200-hp engine with constant-speed propeller. The Eagle II-F uses a 260-hp engine with fixed-pitch propeller. Characterized by their startling paint scheme, the Eagles feature swept symmetrical wings, a strong fuselage, and a blown canopy that covers both cockpits. With a roll rate of 187 degrees/second and a power loading of 7.89 lbs./hp, the Eagle is a strong performer. The fuselage is finished in metal from the cowling back to the rear cockpit. The midsection, all the way to the empennage, is covered in fabric. The fabric-covered wings are built with aluminum ribbing over spruce spars. The amateur builder has the option of buying 25 kits in sequence, starting with the ailerons, to test his or her dexterity.
The Eagle II, first offered in kit form in 1977, was still available in 1998 at US$55,000.
