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72-408: Multiple observations of solar eclipses were performed from 1920 to 1980. NASA created first specialised airborne observatory, Galileo, in 1965. SOFIA, the latest such observatory, was retired in 2022. First attempts to observe astronomical objects from planes were made in 1920 from a biplanes . Until 1960, the main objects of such observations were solar eclipses . In 1923, US Navy tried to observe

144-411: A monoplane is its ability to combine greater stiffness with lower weight. Stiffness requires structural depth and where early monoplanes had to have this provided with external bracing, the biplane naturally has a deep structure and is therefore easier to make both light and strong. Rigging wires on non-cantilevered monoplanes are at a much sharper angle, thus providing less tension to ensure stiffness of

216-426: A biplane has the wings positioned directly one above the other. Moving the upper wing forward relative to the lower one is called positive stagger or, more often, simply stagger. It can increase lift and reduce drag by reducing the aerodynamic interference effects between the two wings by a small degree, but more often was used to improve access to the cockpit. Many biplanes have staggered wings. Common examples include

288-483: A case of bad weather. Two B-29s , stationed on the Aleutian Islands , successfully observed and photographed the eclipse. For the solar eclipse of June 30, 1954 , observations were made "from the open door of a special Lincoln aircraft". Photographs helped "to derive coronal brightness and polarization, along with sky brightness and polarization". Several missions were made in 1960s. Three NC-135 planes of

360-624: A documented jet-kill, as one Lockheed F-94 Starfire was lost while slowing down to 161 km/h (100 mph) – below its stall speed – during an intercept in order to engage the low flying Po-2. Later biplane trainers included the de Havilland Tiger Moth in the Royal Air Force (RAF), Royal Canadian Air Force (RCAF) and others and the Stampe SV.4 , which saw service postwar in the French and Belgian Air Forces. The Stearman PT-13

432-513: A faster and more comfortable successor to the Dragon. As the available engine power and speed increased, the drag penalty of external bracing increasingly limited aircraft performance. To fly faster, it would be necessary to reduce external bracing to create an aerodynamically clean design; however, early cantilever designs were either too weak or too heavy. The 1917 Junkers J.I sesquiplane utilized corrugated aluminum for all flying surfaces, with

504-601: A group of astronomers to observe a total solar eclipse from the USS Los Angeles airship over the New York City, with Captain Edwin Taylor Pollock as a head of the group. They used "two pairs of telescopic cameras", to capture inner and outer portions of Sun's corona, and a spectrograph. The expedition achieved good publicity, but it was not very successful in its observations - the dirigible

576-432: A low wing loading , combining both large wing area with light weight. Obtaining a large enough wing area without the wings being long, and thus dangerously flexible was more readily accomplished with a biplane. The smaller biplane wing allows greater maneuverability . Following World War I, this helped extend the era of the biplane and, despite the performance disadvantages, most fighter aircraft were biplanes as late as

648-496: A mass of 200,000 pounds (91 t). In contrast, a modern Boeing 737 MAX 8 typically carries 162 passengers and burns 4,460 lb (2.02 t) per hour at Mach 0.78 (450 kn; 833 km/h) at sub-optimal parameters. Swissair bought eight 990As beginning in 1962, operating them on long-distance routes to South America, West Africa, the Middle and Far East, as well as on European routes with heavy traffic. Their fleet

720-507: A minimum of struts; however, it was relatively easy to damage the thin metal skin and required careful handling by ground crews. The 1918 Zeppelin-Lindau D.I fighter was an all-metal stressed-skin monocoque fully cantilevered biplane, but its arrival had come too late to see combat use in the conflict. By the 1930s, biplanes had reached their performance limits, and monoplanes become increasingly predominant, particularly in continental Europe where monoplanes had been increasingly common from

792-531: A request from American Airlines : the 990 was lengthened by 10 ft (3.0 m), which increased the number of passengers from between 88 and 110 in the 880 to between 96 and 121. This was still fewer passengers than the contemporary Boeing 707 (110 to 189) or Douglas DC-8 (105 to 173), although the 990 was 25–35 mph (40–56 km/h) faster than either in cruise. American Airlines asked Convair to design an aircraft for coast-to-coast flights, able to fly nonstop from New York City to Los Angeles against

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864-511: A series of Venus observations in near infrared and Mars opposition. Galileo II, also a Convair 990, was used for a very short time. To avoid atmospheric absorption of infrared radiation, Frank J. Low developed devices that could be placed aboard aircraft, first using a Douglas A-3 Skywarrior from the United States Navy that carried a 2-inch telescope in 1965 and 1966. The Learjet Observatory with an open-port 12-inch telescope

936-473: A somewhat unusual sesquiplane arrangement, possessing a more substantial lower wing with two spars that eliminated the flutter problems encountered by single-spar sesquiplanes. The stacking of wing planes was suggested by Sir George Cayley in 1843. Hiram Maxim adopted the idea for his steam-powered test rig, which lifted off but was held down by safety rails, in 1894. Otto Lilienthal designed and flew two different biplane hang gliders in 1895, though he

1008-408: A spectrosopy. The Kuiper Airborne Observatory (KAO), first flown in 1974, consisted of a 36 in (91 cm) aperture Cassegrain reflector carried aloft on a Lockheed C-141 Starlifter jet transport to perform infrared observations. It was named after Gerard P. Kuiper . KAO was operational from 1974 to 1995, and usually flew about 70 flights per year. Among its discoveries are: discovery of

1080-492: Is a fixed-wing aircraft with two main wings stacked one above the other. The first powered, controlled aeroplane to fly, the Wright Flyer , used a biplane wing arrangement, as did many aircraft in the early years of aviation . While a biplane wing structure has a structural advantage over a monoplane , it produces more drag than a monoplane wing. Improved structural techniques, better materials and higher speeds made

1152-411: Is a two bay biplane , the extra bay being necessary as overlong bays are prone to flexing and can fail. The SPAD S.XIII fighter, while appearing to be a two bay biplane, has only one bay, but has the midpoints of the rigging braced with additional struts; however, these are not structurally contiguous from top to bottom wing. The Sopwith 1½ Strutter has a W shape cabane, however as it does not connect

1224-581: Is a 2.7 m (110 in) reflector telescope carried by a modified Boeing 747 for the Stratospheric Observatory for Infrared Astronomy (SOFIA) project. This instrument was put into use for astronomical observation in 2010. On 29 June 2015, the dwarf planet Pluto passed between a distant star and the Earth producing a shadow on the Earth near New Zealand that allowed SOFIA to study

1296-560: Is better known for his monoplanes. By 1896 a group of young men in the United States, led by Octave Chanute , were flying hang gliders including biplanes and concluded that the externally braced biplane offered better prospects for powered flight than the monoplane. In 1903, the Wright Flyer biplane became the first successful powered aeroplane. Throughout the pioneer years, both biplanes and monoplanes were common, but by

1368-624: Is much more common. The space enclosed by a set of interplane struts is called a bay (much as the architectural form is used), hence a biplane or triplane with one set of such struts connecting the wings on each side of the aircraft is a single-bay biplane . This provided sufficient strength for smaller aircraft such as the First World War -era Fokker D.VII fighter and the Second World War de Havilland Tiger Moth basic trainer. The larger two-seat Curtiss JN-4 Jenny

1440-608: The Army Air Corps , Stevens took the first photograph of the Moon's shadow projected onto the Earth during a solar eclipse . Royal Canadian Air Force observed the solar eclipse of July 9, 1945 from four planes: "a Spitfire, a Mitchell, and two Ansons"; three planes used seven standard aerial photography cameras, "adjusted to automatically take exposures". For the solar eclipse of May 8, 1948 , National Geographic society organized several ground stations and two backup planes for

1512-536: The Bristol M.1 , that caused even those with relatively high performance attributes to be overlooked in favour of 'orthodox' biplanes, and there was an allegedly widespread belief held at that time that monoplane aircraft were inherently unsafe during combat. Between the years of 1914 and 1925, a clear majority of new aircraft introduced were biplanes; however, during the latter years of the First World War,

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1584-703: The Grumman Ag Cat are available in upgraded versions with turboprop engines. The two most produced biplane designs were the 1913 British Avro 504 of which 11,303 were built, and the 1928 Soviet Polikarpov Po-2 of which over 20,000 were built, with the Po-2 being the direct replacement for the Soviet copy of the Avro 504. Both were widely used as trainers. The Antonov An-2 was very successful too, with more than 18,000 built. Although most ultralights are monoplanes,

1656-551: The J79 , used in supersonic military aircraft. Like most versions of the J79, the CJ805 and CJ805-23 were smoky, although secondary operator Spantax eventually had their engines refitted with low-smoke combustion chambers in the 1970s. Like the 880, 990s incorporated a dorsal "raceway" added to the top of the fuselage to house the two ADF antennas and one VHF antenna. The 990 did not meet

1728-617: The Lite Flyer Biplane, the Sherwood Ranger , and the Murphy Renegade . The feathered dinosaur Microraptor gui glided, and perhaps even flew, on four wings, which may have been configured in a staggered sesquiplane arrangement. This was made possible by the presence of flight feathers on both forelimbs and hindlimbs, with the feathers on the forelimbs opening to a greater span. It has been suggested that

1800-636: The Los Alamos Scientific Laboratory (LASL) were used for eclipses observations from 1965 to 1980. The planes were operated by the Atomic Energy Commission . In 1973, the French Concorde prototype, c/n 001, was modified with roof-top portholes for a solar eclipse observation mission of 30 June 1973 , at the end of the French testing programme. Observational instruments were installed on board, and

1872-556: The Nieuport-Delage NiD 42 / 52 / 62 series, Fokker C.Vd & e, and Potez 25 , all serving across a large number of air forces. In the general aviation sector, aircraft such as the Waco Custom Cabin series proved to be relatively popular. The Saro Windhover was a sesquiplane with the upper wing smaller than the lower, which was a much rarer configuration than the reverse. The Pfalz D.III also featured

1944-399: The atmosphere of Pluto . By carrying the telescope to a sufficiently high altitude, the telescope can avoid cloud cover , pollution , and carry out observations in the infrared spectrum, above water vapor in the atmosphere which absorbs infrared radiation. Airplane also allows to place telescope exactly to the needed position. Some drawbacks to this approach are the instability of

2016-497: The de Havilland Tiger Moth , Bücker Bü 131 Jungmann and Travel Air 2000 . Alternatively, the lower wing can instead be moved ahead of the upper wing, giving negative stagger, and similar benefits. This is usually done in a given design for structural reasons, or to improve visibility. Examples of negative stagger include the Sopwith Dolphin , Breguet 14 and Beechcraft Staggerwing . However, positive (forward) stagger

2088-514: The CR.42 was able to achieve success in the defensive night fighter role against RAF bombers that were striking industrial targets throughout northern Italy. The British Fleet Air Arm operated the Fairey Swordfish torpedo bomber from its aircraft carriers, and used the type in the anti-submarine warfare role until the end of the conflict, largely due to their ability to operate from

2160-528: The Caribou , performed the first non-stop flight between the Canadian mainland and Britain in 30 hours 55 minutes, although the intended target for this long distance flight had originally been Baghdad , Iraq . Despite its relative success, British production of the Dragon was quickly ended when in favour of the more powerful and elegant de Havilland Dragon Rapide , which had been specifically designed to be

2232-524: The Convair 880 and 990 led Convair's parent company, General Dynamics, to suffer one of the largest corporate losses in history. As a result, Convair exited the jet airliner business, although it later built fuselages for McDonnell Douglas , specifically for the DC-10 , KC-10 and MD-11 . When the major airlines retired their Convair 990s, they found a second life on charter airlines. Spantax of Spain had

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2304-515: The First World War, the British Royal Aircraft Factory developed airfoil section wire named RAFwire in an effort to both increase the strength and reduce the drag. Four types of wires are used in the biplane wing structure. Drag wires inside the wings prevent the wings from being folded back against the fuselage, running inside a wing bay from the forward inboard corner to the rear outboard corner. Anti-drag wires prevent

2376-577: The French Nieuport 17 and German Albatros D.III , offered lower drag than a conventional biplane while being stronger than a monoplane. During the Interwar period , numerous biplane airliners were introduced. The British de Havilland Dragon was a particularly successful aircraft, using straightforward design to could carry six passengers on busy routes, such as London-Paris services. During early August 1934, one such aircraft, named Trail of

2448-661: The Germans had been experimenting with a new generation of monoplanes, such as the Fokker D.VIII , that might have ended the biplane's advantages earlier had the conflict not ended when it had. The French were also introducing the Morane-Saulnier AI , a strut-braced parasol monoplane , although the type was quickly relegated to the advanced trainer role following the resolution of structural issues. Sesquiplane types, which were biplanes with abbreviated lower wings such as

2520-483: The aircraft flew across Africa for 74 minutes in the Moon's shadow. One of the scientists was Donald Liebenberg , who have previously flown on LASL's NC-135. The airplane is now at the Le Bourget Air and Space Museum on permanent display in eclipse livery, with the portholes displayed. NASA used two retrofitted WB-57F jet planes to chase the total solar eclipse of August 21, 2017 . Telescopes were mounted on

2592-483: The biplane configuration obsolete for most purposes by the late 1930s. Biplanes offer several advantages over conventional cantilever monoplane designs: they permit lighter wing structures, low wing loading and smaller span for a given wing area. However, interference between the airflow over each wing increases drag substantially, and biplanes generally need extensive bracing, which causes additional drag. Biplanes are distinguished from tandem wing arrangements, where

2664-608: The competition aerobatics role and format for such a biplane well-defined by the mid-1930s by the Udet U 12 Flamingo and Waco Taperwing . The Pitts Special dominated aerobatics for many years after World War II and is still in production. The vast majority of biplane designs have been fitted with reciprocating engines . Exceptions include the Antonov An-3 and WSK-Mielec M-15 Belphegor , fitted with turboprop and turbofan engines respectively. Some older biplane designs, such as

2736-499: The critical Mach by reducing transonic drag. The inboard shock bodies, which were larger, were also used for additional fuel tankage. Later during the design period, Convair modified the design to include fuel in the outboard pods as well, but during the initial test flights the extra weight caused the outboard engines to oscillate in certain conditions. The pods were redesigned once more and shortened by 28 inches (710 mm), causing increased drag. The inner set of pods were used to route

2808-549: The end of World War I . At the start of World War II , several air forces still had biplane combat aircraft in front line service but they were no longer competitive, and most were used in niche roles, such as training or shipboard operation, until shortly after the end of the war. The British Gloster Gladiator biplane, the Italian Fiat CR.42 Falco and Soviet I-153 sesquiplane fighters were all still operational after 1939. According to aviation author Gianni Cattaneo,

2880-473: The fuel-dump tubes from the fuel tanks, terminating in a prominent outlet. The engines were also changed to the uprated General Electric CJ-805-23s , which were unique in that they used a fan stage at the rear of the engines, compared to the fan stage at the front of the engine found on the Pratt & Whitney JT3D that powered the 990's competitors. The engine was a simplified, non-afterburning civil version of

2952-467: The hind limbs could not have opened out sideways but in flight would have hung below and slightly behind the fore limbs. Convair 990 The Convair 990 Coronado is a retired American narrow-body four-engined jet airliner produced between 1961 and 1963 by the Convair division of American company General Dynamics . It was a stretched version of its earlier Convair 880 produced in response to

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3024-520: The less the interference, but the spacing struts must be longer, and the gap must be extremely large to reduce it appreciably. As engine power and speeds rose late in World War I , thick cantilever wings with inherently lower drag and higher wing loading became practical, which in turn made monoplanes more attractive as it helped solve the structural problems associated with monoplanes, but offered little improvement for biplanes. The default design for

3096-487: The lifting platform, the weight restrictions on the instrument, the need to safely recover the gear afterward, and the cost compared to a comparable ground-based observatory. Airborne observatories are very expensive to operate, because they require a crew, a pilot, and fuel. The cost of running SOFIA observatory per year was nearly the same as of the Hubble Space Telescope . Biplane A biplane

3168-639: The low speeds and simple construction involved have inspired a small number of biplane ultralights, such as Larry Mauro's Easy Riser (1975–). Mauro also made a version powered with solar cells driving an electric motor called the Solar Riser . Mauro's Easy Riser was used by "Father Goose", Bill Lishman . Other biplane ultralights include the Belgian-designed Aviasud Mistral , the German FK12 Comet (1997–),

3240-412: The main wings can support ailerons , while flaps are more usually positioned on the lower wing. Bracing is nearly always added between the upper and lower wings, in the form of interplane struts positioned symmetrically on either side of the fuselage and bracing wires to keep the structure from flexing, where the wings are not themselves cantilever structures. The primary advantage of the biplane over

3312-411: The mid-1930s. Specialist sports aerobatic biplanes are still made in small numbers. Biplanes suffer aerodynamic interference between the two planes when the high pressure air under the top wing and the low pressure air above the lower wing cancel each other out. This means that a biplane does not in practice obtain twice the lift of the similarly-sized monoplane. The farther apart the wings are spaced

3384-573: The most famed copies was the Siemens-Schuckert D.I . The Albatros D.III and D.V , which had also copied the general layout from Nieuport, similarly provided the backbone of the German forces during the First World War. The Albatros sesquiplanes were widely acclaimed by their aircrews for their maneuverability and high rate of climb. During interwar period , the sesquiplane configuration continued to be popular, with numerous types such as

3456-609: The night ground attack role throughout the Second World War. In the case of the Po-2, production of the aircraft continued even after the end of the conflict, not ending until around 1952. A significant number of Po-2s were fielded by the Korean People's Air Force during the Korean War , inflicting serious damage during night raids on United Nations bases. The Po-2 is also the only biplane to be credited with

3528-505: The noses of the planes, that allowed to capture the clearest images to date of the Sun's corona and the first-ever thermal images of Mercury, revealing how temperature varies across the planet’s surface. The high-definition pictures, captured 30 times per second, will be analyzed for wave motion in the corona to see if waves move towards or away from the surface of the Sun, and with what strengths and sizes. First NASA airborne observatory, Galileo,

3600-486: The outbreak of the First World War biplanes had gained favour after several monoplane structural failures resulted in the RFC's "Monoplane Ban" when all monoplanes in military service were grounded, while the French also withdrew most monoplanes from combat roles and relegated them to training. Figures such as aviation author Bruce observed that there was an apparent prejudice held even against newly-designed monoplanes, such as

3672-406: The outer wing. On a biplane, since the angles are closer to the ideal of being in direct line with the forces being opposed, the overall structure can then be made stiffer. Because of the reduced stiffness, wire braced monoplanes often had multiple sets of flying and landing wires where a biplane could easily be built with one bay, with one set of landing and flying wires. The extra drag from the wires

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3744-404: The pre-production 990 aircraft, while demonstrating the margin between its operating speed and its capability during a dive at .97 Mach from 32,000 ft to 22,500 ft, reached 675 miles per hour (1,086 km/h) at an altitude of 22,000 feet (6.7 km): the fastest true airspeed ever attained by a commercial jet transport at that time. However, in level flight the maximum speed, 0.84 Mn,

3816-657: The relatively compact decks of escort carriers . Its low stall speed and inherently tough design made it ideal for operations even in the often severe mid-Atlantic weather conditions. By the end of the conflict, the Swordfish held the distinction of having caused the destruction of a greater tonnage of Axis shipping than any other Allied aircraft. Both the German Heinkel He 50 and the Soviet Polikarpov Po-2 were used with relative success in

3888-469: The rings around the planet Uranus; detection of water vapor in comets; discovery of Pluto's atmosphere; the composition, structure, and dynamics of Supernova 1987a; luminosity, dust, and gas distributions in the Galactic Center; emission by shocked gas components of the interstellar medium; and the structure of star-forming clouds. In terms of aperture, the largest aircraft-borne instrument to date

3960-499: The same overall strength and is therefore lighter. A given area of wing also tends to be shorter, reducing bending moments on the spars, which then allow them to be more lightly built as well. The biplane does however need extra struts to maintain the gap between the wings, which add both weight and drag. The low power supplied by the engines available in the first years of aviation limited aeroplanes to fairly low speeds. This required an even lower stalling speed, which in turn required

4032-502: The same portion of the atmosphere and thus interfere with each other's behaviour. In a biplane configuration with no stagger from the upper wing to the lower wing, the lift coefficient is reduced by 10 to 15 percent compared to that of a monoplane using the same airfoil and aspect ratio . The lower wing is usually attached to the fuselage , while the upper wing is raised above the fuselage with an arrangement of cabane struts , although other arrangements have been used. Either or both of

4104-728: The series of Nieuport military aircraft—from the Nieuport 10 through to the Nieuport 27 which formed the backbone of the Allied air forces between 1915 and 1917. The performance of the Nieuport sesquiplanes was so impressive that the Idflieg (the German Inspectorate of flying troops) requested their aircraft manufacturers to produce copies, an effort which was aided by several captured aircraft and detailed drawings; one of

4176-491: The solar eclipse of September 10 from sixteen planes, including Felixstowe F5L biplane, "to determine the centerline of the eclipse from air." No photo recorded the eclipse. Officer and photographer Albert William Stevens was one of the pilots on this expedition, he is sometimes called "the father of airborne astronomy". There was another attempt to observe a solar eclipse, this time from a dirigible. On 24 January 1925, U.S. Naval Observatory and U.S. Bureau of Standards gathered

4248-539: The specifications promised, and American Airlines reduced its order as a result. The 990A was developed by adding fairings to the engine nacelles, among other changes. Despite the modifications from the basic 880 and those in response to drag problems in testing, the aircraft never lived up to its promise of coast-to-coast nonstop capability from JFK to LAX. American Airlines' timetables show little or no difference in scheduled time between 707 and 990A flights. AA began to dispose of its 990As in 1967. During May 1961, one of

4320-400: The upper and lower wings together. The sesquiplane is a type of biplane where one wing (usually the lower) is significantly smaller than the other. The word, from Latin, means "one-and-a-half wings". The arrangement can reduce drag and weight while retaining the biplane's structural advantages. The lower wing may have a significantly shorter span, or a reduced chord . Examples include

4392-418: The wind. They wanted a larger passenger capacity than the Convair 880 , which was the smallest of the first-generation U.S. jet airliners. The design was known as the Convair 600 and was redesignated the Convair 990 in the month of its first flight. The 990 began flight testing on January 24, 1961. One change from the 880 was the large anti-shock bodies on the upper trailing edge of the wings, to increase

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4464-419: The wings are placed forward and aft, instead of above and below. The term is also occasionally used in biology , to describe the wings of some flying animals . In a biplane aircraft, two wings are placed one above the other. Each provides part of the lift, although they are not able to produce twice as much lift as a single wing of similar size and shape because the upper and the lower are working on nearly

4536-434: The wings from folding up, and run from the underside of the outer wing to the lower wing root. Conversely, landing wires prevent the wings from sagging, and resist the forces when an aircraft is landing, and run from the upper wing centre section to outboard on the lower wings. Additional drag and anti-drag wires may be used to brace the cabane struts which connect the fuselage to the wings, and interplane struts, which connect

4608-421: The wings from moving forward when the aircraft stops and run the opposite direction to the drag wires. Both of these are usually hidden within the wings, and if the structure is sufficiently stiff otherwise, may be omitted in some designs. Indeed many early aircraft relied on the fabric covering of the wing to provide this rigidity, until higher speeds and forces made this inadequate. Externally, lift wires prevent

4680-604: The wings to each other, it does not add to the number of bays. Large transport and bombing biplanes often needed still more bays to provide sufficient strength. These are often referred to as multi-bay biplanes . A small number of biplanes, such as the Zeppelin-Lindau D.I have no interplane struts and are referred to as being strutless . Because most biplanes do not have cantilever structures, they require rigging wires to maintain their rigidity. Early aircraft used simple wire (either braided or plain), however during

4752-460: Was a modified Convair 990 . It first flew for the solar eclipse of May 30, 1965 . It was named Galileo because during the eclipse Guglielmo Righini  [ it ] spotted the moons of Jupiter from the plane. Galileo was used until 1973, when it was destroyed in a mid-air collision. It was used to observe eclipses, comet Ikeya-Seki , planetary IR observations, and Giacobinid meteor showers . Planetary scientist Gerard P. Kuiper performed

4824-461: Was less than that guaranteed to American Airlines, 0.89 Mn, because the drag levels with the anti-shock bodies were much higher than predicted. A drag reduction program was instituted during which streamlining of the engine pylon/wing interface and addition of nacelle fairings achieved 0.89 Mn. In 1963, the 990A was reported to burn 13,750 pounds (6.24 t) per hour of fuel at Mach 0.84 (484 kn; 897 km/h) at 35,000 feet (11 km) at

4896-423: Was not enough to offset the aerodynamic disadvantages from having two airfoils interfering with each other however. Strut braced monoplanes were tried but none of them were successful, not least due to the drag from the number of struts used. The structural forces acting on the spars of a biplane wing tend to be lower as they are divided between four spars rather than two, so the wing can use less material to obtain

4968-621: Was not very stable and the photos were blurred. The next attempt was successful: an expedition of the Naval Observatory to observe the solar eclipse of April 28, 1930 on Honey Lake , California, with Vought 02U-1 plane equipped with a camera, recorded "the approach of the shadow". Army Air Corps and the National Geographic Society organized another expedition in 1932, to observe the eclipse of August 31 . Accompanied by Lieutenant Charles D. McAllister of

5040-525: Was proposed in 1966 by Low, and made its first flight in 1968. It allowed to perform infrared astronomy; among other discoveries are "the first measurement of the internal energies of Jupiter and Saturn, far-infrared observations of the great nebula in Orion, studies of star formation regions and the bright IR sources at the center of the Milky Way galaxy", and also to determine the nature of Venus' clouds using

5112-777: Was widely used by the United States Army Air Force (USAAF) while the US Navy operated the Naval Aircraft Factory N3N . In later civilian use in the US, the Stearman became particularly associated with stunt flying such as wing-walking , and with crop dusting, where its compactness worked well at low levels, where it had to dodge obstacles. Modern biplane designs still exist in specialist roles such as aerobatics and agricultural aircraft with

5184-671: Was withdrawn from service in 1975. Scandinavian Airlines (SAS) also operated 990A Coronados on their long-haul schedules to Tokyo and other destinations in the Far East and also to South America and Africa. The 990's niche was soon captured by the Boeing 720 and Boeing 720B , derivatives of the Boeing 707 , and later by the Boeing 727 . By the time the assembly line shut down in 1963, only 37 990s had been produced, bringing General Dynamics' entire production of commercial jet airliners to 102 airframes. The failure of airlines to broadly accept

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