172-551: The Shuttle Carrier Aircraft ( SCA ) are two extensively modified Boeing 747 airliners that NASA used to transport Space Shuttle orbiters . One (N905NA) is a 747-100 model, while the other (N911NA) is a short-range 747-100SR. Both are now retired. The SCAs were used to ferry Space Shuttles from landing sites back to the Shuttle Landing Facility at the Kennedy Space Center . The orbiters were placed on top of
344-459: A freighter airplane by installing a front cargo door, as it was initially thought that it would eventually be superseded by supersonic transports . Boeing introduced the -200 in 1971, with uprated engines for a heavier maximum takeoff weight (MTOW) of 833,000 pounds (378 t) from the initial 735,000 pounds (333 t), increasing the maximum range from 4,620 to 6,560 nautical miles [nmi] (8,560 to 12,150 km; 5,320 to 7,550 mi). It
516-610: A $ 569 million post-tax charge against its fourth-quarter 2015 profits. At the end of 2015, the company had 20 orders outstanding. On January 29, 2016, Boeing announced that it had begun the preliminary work on the modifications to a commercial 747-8 for the next Air Force One presidential aircraft, then expected to be operational by 2020. On July 12, 2016, Boeing announced that it had finalized an order from Volga-Dnepr Group for 20 747-8 freighters, valued at $ 7.58 billion (~$ 9.44 billion in 2023) at list prices. Four aircraft were delivered beginning in 2012. Volga-Dnepr Group
688-459: A 5,000-nautical-mile (9,300 km; 5,800 mi) range with a typical 452-passenger payload, and an increased MTOW of 750,000 lb (340 t) was offered. The first -100B order, one aircraft for Iran Air , was announced on June 1, 1978. This version first flew on June 20, 1979, received FAA certification on August 1, 1979, and was delivered the next day. Nine -100Bs were built, one for Iran Air and eight for Saudi Arabian Airlines . Unlike
860-590: A 520,000-pound (240 t) MTOW and Pratt & Whitney JT9D -7A engines derated to 43,000 pounds-force (190 kN) of thrust. Following the -100SR, Boeing produced the -100BSR, a 747SR variant with increased takeoff weight capability. Debuting in 1978, the -100BSR also incorporated structural modifications for a high cycle-to-flying hour ratio; a related standard -100B model debuted in 1979. The -100BSR first flew on November 3, 1978, with first delivery to All Nippon Airways (ANA) on December 21, 1978. A total of 20 -100BSRs were produced for ANA and JAL. The -100BSR had
1032-544: A 600,000 pounds (270 t) MTOW and was powered by the same JT9D-7A or General Electric CF6 -45 engines used on the -100SR. ANA operated this variant on domestic Japanese routes with 455 or 456 seats until retiring its last aircraft in March 2006. In 1986, two -100BSR SUD models, featuring the stretched upper deck (SUD) of the -300, were produced for JAL. The type's maiden flight occurred on February 26, 1986, with FAA certification and first delivery on March 24, 1986. JAL operated
1204-586: A Shuttle Carrier Aircraft on December 11, 2010. The Approach and Landing Tests were a series of taxi and flight trials of the prototype Space Shuttle Enterprise , conducted at Edwards Air Force Base in 1977. They verified the shuttle's flight characteristics when mated to the Shuttle Carrier Aircraft and when flying on its own, prior to the Shuttle system becoming operational. There were 3 taxi tests, 8 captive flight tests and 5 free flight tests. During
1376-610: A better weapon than the Falcon: B models managed a 14% kill ratio, while the much longer-ranged D models managed 19%. Its performance and lower cost led the Air Force to adopt it as well. The first heat-seeker built outside the US was the UK's de Havilland Firestreak . Development began as OR.1056 Red Hawk , but this was considered too advanced, and in 1951 an amended concept was released as OR.1117 and given
1548-546: A decision was made to preserve N905NA and display it at Space Center Houston with the mockup Space Shuttle Independence mounted on its back. N905NA was flown to Ellington Field where it was carefully dismantled, ferried to the Johnson Space Center in seven major pieces (a process called The Big Move), reassembled, and finally mated with the replica shuttle in August 2014. The display, called Independence Plaza, opened to
1720-452: A fully occupied 747. Nonetheless, many flag-carriers purchased the 747 due to its prestige "even if it made no sense economically" to operate. During the 1970s and 1980s, over 30 regularly scheduled 747s could often be seen at John F. Kennedy International Airport . The recession of 1969–1970 , despite having been characterized as relatively mild, greatly affected Boeing. For the year and a half after September 1970, it only sold two 747s in
1892-428: A good spread of support on the ground and safety in case of tire blow-outs. The main gear are redundant so that landing can be performed on two opposing landing gears if the others are not functioning properly. The 747 also has split control surfaces and was designed with sophisticated triple-slotted flaps that minimize landing speeds and allow the 747 to use standard-length runways. For transportation of spare engines,
SECTION 10
#17328445862502064-405: A high-capacity airliner with enough range to cover Pan Am's New York–Middle Eastern routes and Iran Air's planned Tehran–New York route. The Tehran–New York route, when launched, was the longest non-stop commercial flight in the world. The 747SP is 48 feet 4 inches (14.73 m) shorter than the 747-100. Fuselage sections were eliminated fore and aft of the wing, and the center section of
2236-437: A higher maximum takeoff weight (MTOW) variant, and the -100SR (Short Range), with higher passenger capacity. Increased maximum takeoff weight allows aircraft to carry more fuel and have longer range. The -200 model followed in 1971, featuring more powerful engines and a higher MTOW. Passenger, freighter and combination passenger-freighter versions of the -200 were produced. The shortened 747SP (special performance) with
2408-603: A large searchlight fitted with a filter to limit the output to the IR range. This provided enough light to see the target at short range, and Spanner Anlage was fitted to a small number of Messerschmitt Bf 110 and Dornier Do 17 night fighters . These proved largely useless in practice and the pilots complained that the target often only became visible at 200 metres (660 ft), at which point they would have seen it anyway. Only 15 were built and were removed as German airborne radar systems improved though 1942. AEG had been working with
2580-403: A long "spine" running the length of the aircraft with the wing spar passing through it, while Boeing blended the two, with a longer pod that ran from just behind the nose to just behind the wing. In 1965, Lockheed's aircraft design and General Electric's engine design were selected for the new C-5 Galaxy transport, which was the largest military aircraft in the world at the time. Boeing carried
2752-739: A long-term loan to the city from NASA. Shuttle Carrier N905NA was used to ferry the retired Space Shuttles to their respective museums. After delivering Endeavour to the Los Angeles International Airport in September 2012, the aircraft was flown to the Dryden Flight Research Facility, where NASA intended it to join N911NA as a source of spare parts for NASA's SOFIA aircraft, but when NASA engineers surveyed N905NA they determined that it had few parts usable for SOFIA. In 2013,
2924-410: A longer range was also developed, and entered service in 1976. The 747 line was further developed with the launch of the 747-300 on June 11, 1980, followed by interest from Swissair a month later and the go-ahead for the project. The 300 series resulted from Boeing studies to increase the seating capacity of the 747, during which modifications such as fuselage plugs and extending the upper deck over
3096-535: A maximum cruise speed of Mach 0.6 with the orbiter attached. A crew of 170 took a week to prepare the shuttle and SCA for flight. Studies were conducted to equip the SCA with aerial refueling equipment, a modification already made to the U.S. Air Force E-4 (modified 747-200s) and 747 tanker transports for the IIAF . However, during formation flying with a tanker aircraft to test refueling approaches, minor cracks were spotted on
3268-462: A missile airframe and considerable effort remained before an actual weapon would be ready for use. Nevertheless, a summer 1944 report to the German Air Ministry stated that these devices were far better developed than competing systems based on radar or acoustic methods. Aware of the advantages of passive IR homing, the research program started with a number of theoretical studies considering
3440-462: A more conventional hemispherical dome. The first test firing took place in 1955 and it entered service with the Royal Air Force in August 1958. The French R.510 project began later than Firestreak and entered experimental service in 1957, but was quickly replaced by a radar-homing version, the R.511. Neither was very effective and had short range on the order of 3 km. Both were replaced by
3612-421: A new jet airliner 2 + 1 ⁄ 2 times size of the 707, with a 30% lower cost per unit of passenger-distance and the capability to offer mass air travel on international routes. Trippe also thought that airport congestion could be addressed by a larger new aircraft. In 1965, Joe Sutter was transferred from Boeing's 737 development team to manage the design studies for the new airliner, already assigned
SECTION 20
#17328445862503784-525: A number of simple countermeasures, most notably by dropping flares behind the target to provide false heat sources. That works only if the pilot is aware of the missile and deploys the countermeasures on time. The sophistication of modern seekers has rendered these countermeasures increasingly ineffective. The first IR devices were experimented with during World War II . During the war, German engineers were working on heat-seeking missiles and proximity fuses but did not have time to complete development before
3956-610: A number of victories in the middle east and Vietnam. A major upgrade program for the Redeye started in 1967, as the Redeye II. Testing did not begin until 1975 and the first deliveries of the now renamed FIM-92 Stinger began in 1978. An improved rosette seeker was added to the B model in 1983, and several additional upgrades followed. Sent to the Soviet–Afghan War , they claimed a 79% success rate against Soviet helicopters, although this
4128-494: A position where the missile would be able to continue tracking even after launch. This problem also led to efforts to make new missiles that would hit their targets even if launched under these less-than-ideal positions. In the UK this led to the SRAAM project, which was ultimately the victim of continually changing requirements. Two US programmes, AIM-82 and AIM-95 Agile , met similar fates. New seeker designs began to appear during
4300-498: A practical detector. Nevertheless, it was used for some time by the US Navy as a secure communications system. In 1930 the introduction of the Ag–O–Cs ( silver – oxygen – cesium ) photomultiplier provided the first practical solution to the detection of IR, combining it with a layer of galena as the photocathode . Amplifying the signal emitted by the galena, the photomultiplier produced
4472-462: A range of 4,620 nautical miles (8,556 km), was the original variant launched in 1966. The 747-200 soon followed, with its launch in 1968. The 747-300 was launched in 1980 and was followed by the 747-400 in 1985. Ultimately, the 747-8 was announced in 2005. Several versions of each variant have been produced, and many of the early variants were in production simultaneously. The International Civil Aviation Organization (ICAO) classifies variants using
4644-447: A shortened code formed by combining the model number and the variant designator (e.g. "B741" for all -100 models). The first 747-100s were built with six upper deck windows (three per side) to accommodate upstairs lounge areas. Later, as airlines began to use the upper deck for premium passenger seating instead of lounge space, Boeing offered an upper deck with ten windows on either side as an option. Some early -100s were retrofitted with
4816-496: A single airline before or since. Ultimately, the high-winged CX-HLS Boeing design was not used for the 747, although technologies developed for their bid had an influence. The original design included a full-length double-deck fuselage with eight-across seating and two aisles on the lower deck and seven-across seating and two aisles on the upper deck. However, concern over evacuation routes and limited cargo-carrying capability caused this idea to be scrapped in early 1966 in favor of
4988-614: A single blue cheatline. That year, after secretly being fitted with an infrared countermeasures system to protect it from heat-seeking missiles , it was also used to fly Enterprise on a tour in Europe, with refueling stops in Goose Bay , Canada; Keflavik, Iceland ; England; and West Germany. It then went to the Paris Air Show . In 1988, in the wake of the Challenger accident , NASA procured
5160-563: A supersonic version. At this stage the concept was for a defensive weapon fired rearward out of a long tube at the back end of bomber aircraft . In April 1949 the Firebird missile project was cancelled and MX-904 was redirected to be a forward-firing fighter weapon. The first test firings began in 1949, when it was given the designation AAM-A-2 (Air-to-air Missile, Air force, model 2) and the name Falcon. IR and semi-active radar homing (SARH) versions both entered service in 1956, and became known as
5332-899: A surplus 747SR-46 from Japan Airlines . Registered N911NA, it entered service with NASA in 1990 after undergoing modifications similar to N905NA. It was first used in 1991 to ferry the new shuttle Endeavour from the manufacturers in Palmdale, California to Kennedy Space Center . Based at the Dryden Flight Research Center within Edwards Air Force Base in California the two aircraft were functionally identical, although N911NA has five upper-deck windows on each side, while N905NA has only two. The rear mounting points on both aircraft were labeled with humorous instructions to "attach orbiter here" or "place orbiter here", clarified by
Shuttle Carrier Aircraft - Misplaced Pages Continue
5504-405: A test aircraft was flown to Renton to have test equipment removed and a cabin installed. Pilot Ralph C. Cokely undershot the airport's short runway and the 747's right, outer landing gear was torn off and two engine nacelles were damaged. However, these difficulties did not prevent Boeing from taking a test aircraft to the 28th Paris Air Show in mid-1969, where it was displayed to the public for
5676-526: A total of 3,746 people have died. In 1963, the United States Air Force started a series of study projects on a very large strategic transport aircraft. Although the C-141 Starlifter was being introduced, officials believed that a much larger and more capable aircraft was needed, especially to carry cargo that would not fit in any existing aircraft. These studies led to initial requirements for
5848-447: A transparent plate with a sequence of opaque segments painted on them that was placed in front of the IR detector. The plate spins at a fixed rate, which causes the image of the target to be periodically interrupted, or chopped . The Hamburg system developed during the war is the simplest system, and easiest to understand. Its chopper was painted black on one half with the other half left transparent. For this description we consider
6020-429: A useful output that could be used for detection of hot objects at long ranges. This sparked developments in a number of nations, notably the UK and Germany where it was seen as a potential solution to the problem of detecting night bombers . In the UK, research was plodding, with even the main research team at Cavendish Labs expressing their desire to work on other projects, especially after it became clear that radar
6192-568: A very desirable device. Kutzscher's team developed a system with the Eletroacustic Company of Kiel known as Hamburg , which was being readied for installation in the Blohm & Voss BV 143 glide bomb to produce an automated fire-and-forget anti-shipping missile. A more advanced version allowed the seeker to be directed off-axis by the bombardier in order to lock on to a target to the sides, without flying directly at it. However, this presented
6364-448: A wider single deck design. The cockpit was therefore placed on a shortened upper deck so that a freight-loading door could be included in the nose cone; this design feature produced the 747's distinctive "hump". In early models, what to do with the small space in the pod behind the cockpit was not clear, and this was initially specified as a "lounge" area with no permanent seating. (A different configuration that had been considered to keep
6536-435: Is a passive weapon guidance system which uses the infrared (IR) light emission from a target to track and follow it seamlessly. Missiles which use infrared seeking are often referred to as "heat-seekers" since infrared is radiated strongly by hot bodies. Many objects such as people, vehicle engines and aircraft generate and emit heat and so are especially visible in the infrared wavelengths of light compared to objects in
6708-622: Is debated. The Soviets likewise improved their own versions, introducing the 9K34 Strela-3 in 1974, and the greatly improved dual-frequency 9K38 Igla in 1983, and Igla-S in 2004. The three main materials used in the infrared sensor are lead(II) sulfide (PbS), indium antimonide (InSb) and mercury cadmium telluride (HgCdTe). Older sensors tend to use PbS, newer sensors tend to use InSb or HgCdTe. All perform better when cooled, as they are both more sensitive and able to detect cooler objects. Early infrared seekers were most effective in detecting infrared radiation with shorter wavelengths, such as
6880-436: Is not required, instead, both signals can be extracted from a single photocell with the use of electrical delays or a second reference signal 90 degrees out of phase with the first. This system produces a signal that is sensitive to the angle around the clock face, the bearing , but not the angle between the target and the missile centerline, the angle off (or angle error ). This was not required for anti-ship missiles where
7052-437: Is set too small the image from the target is too small to create a useful signal, while setting it too large makes it inaccurate. For this reason, linear scanners have inherent accuracy limitations. Additionally, the dual reciprocating motion is complex and mechanically unreliable, and generally two separate detectors have to be used. Most early seekers used so-called spin-scan , chopper or reticle seekers. These consisted of
Shuttle Carrier Aircraft - Misplaced Pages Continue
7224-507: Is the parent of three major Russian air-freight carriers – Volga-Dnepr Airlines , AirBridgeCargo Airlines and Atran Airlines . The new 747-8 freighters would replace AirBridgeCargo's current 747-400 aircraft and expand the airline's fleet and will be acquired through a mix of direct purchases and leasing over the next six years, Boeing said. On July 27, 2016, in its quarterly report to the Securities and Exchange Commission , Boeing discussed
7396-463: The 767 and Airbus A300 / A310 twinjets ). Having tried replacing coach seats on its 747s with piano bars in an attempt to attract more customers, American Airlines eventually relegated its 747s to cargo service and in 1983 exchanged them with Pan Am for smaller aircraft; Delta Air Lines also removed its 747s from service after several years. Later, Delta acquired 747s again in 2008 as part of its merger with Northwest Airlines , although it retired
7568-545: The AIM-4 Falcon after 1962. The Falcon was a complex system offering limited performance, especially due to its lack of a proximity fuse, and managed only a 9% kill ratio in 54 firings during Operation Rolling Thunder in the Vietnam War . However, this relatively low success rate must be appreciated in the context of all these kills representing direct hits, something that was not true of every kill by other American AAMs. In
7740-554: The AIM-9M Sidewinder and Stinger use compressed gas like argon to cool their sensors in order to lock onto the target at longer ranges and all aspects. (Some such as the AIM-9J and early-model R-60 used a peltier thermoelectric cooler ). The detector in early seekers was barely directional, accepting light from a very wide field of view (FOV), perhaps 100 degrees across or more. A target located anywhere within that FOV produces
7912-508: The Boeing 747-400 fleet in December 2017. International flights bypassing traditional hub airports and landing at smaller cities became more common throughout the 1980s, thus eroding the 747's original market. Many international carriers continued to use the 747 on Pacific routes. In Japan, 747s on domestic routes were configured to carry nearly the maximum passenger capacity. The 747-100 with
8084-464: The Hamburg , an AC signal was generated that matched the rotational frequency of the disk. However, in this case the signal does not turn on and off with angle, but is constantly being triggered very rapidly. This creates a series of pulses that are smoothed out to produce a second AC signal at the same frequency as the test signal, but whose phase is controlled by the actual position of the target relative to
8256-401: The tailplane (horizontal stabilizer); detailed investigations showed, however, that the best estimate of the exposure to depleted uranium was ".. several orders of magnitude less than the workers' limit for chronic exposure." The flight test program was hampered by problems with the 747's JT9D engines. Difficulties included engine stalls caused by rapid throttle movements and distortion of
8428-426: The "Sun Tracker", was being developed as a possible guidance system for an intercontinental ballistic missile . Testing this system led to the 1948 Lake Mead Boeing B-29 crash . USAAF project MX-798 was awarded to Hughes Aircraft in 1946 for an infrared tracking missile. The design used a simple reticle seeker and an active system to control roll during flight. This was replaced the next year by MX-904, calling for
8600-503: The -100BSR SUD with 563 seats on domestic routes until their retirement in the third quarter of 2006. While only two -100BSR SUDs were produced, in theory, standard -100Bs can be modified to the SUD certification. Overall, 29 Boeing 747SRs were built. The 747-100B model was developed from the -100SR, using its stronger airframe and landing gear design. The type had an increased fuel capacity of 48,070 US gal (182,000 L), allowing for
8772-410: The 1960s. A new generation developed in the 1970s and the 1980s made great strides and significantly improved their lethality. The latest examples from the 1990s and on have the ability to attack targets out of their field of view (FOV) behind them and even to pick out vehicles on the ground. IR seekers are also the basis for many semi-automatic command to line of sight (SACLOS) weapons. In this use,
SECTION 50
#17328445862508944-474: The 1970s and led to a series of more advanced missiles. A major upgrade to the Sidewinder began, providing it with a seeker that was sensitive enough to track from any angle, giving the missile all aspect capability for the first time. This was combined with a new scanning pattern that helped reject confusing sources (like the sun reflecting off clouds) and improve the guidance towards the target. A small number of
9116-487: The 300 series were produced. In 1985, development of the longer range 747-400 began. The variant had a new glass cockpit , which allowed for a cockpit crew of two instead of three, new engines, lighter construction materials, and a redesigned interior. Development costs soared, and production delays occurred as new technologies were incorporated at the request of airlines. Insufficient workforce experience and reliance on overtime contributed to early production problems on
9288-436: The 4.2 micrometre emissions of the carbon dioxide efflux of a jet engine . This made them useful primarily in tail-chase scenarios, where the exhaust was visible and the missile's approach was carrying it toward the aircraft as well. In combat these proved extremely ineffective as pilots attempted to make shots as soon as the seeker saw the target, launching at angles where the target's engines were quickly obscured or flew out of
9460-513: The 747 Advanced that were eventually adopted. Similar in nature to the 747-X, the stretched 747 Advanced used technology from the 787 to modernize the design and its systems. The 747 remained the largest passenger airliner in service until the Airbus A380 began airline service in 2007. On November 14, 2005, Boeing announced it was launching the 747 Advanced as the Boeing 747-8 . The last 747-400s were completed in 2009. As of 2011 , most orders of
9632-545: The 747 can accommodate a non-functioning fifth-pod engine under the aircraft's port wing between the inner functioning engine and the fuselage. The fifth engine mount point was also used by Virgin Orbit 's LauncherOne program to carry an orbital-class rocket to cruise altitude where it was deployed. After the aircraft's introduction with Pan Am in 1970, other airlines that had bought the 747 to stay competitive began to put their own 747s into service. Boeing estimated that half of
9804-463: The 747 had been a major challenge, and building its assembly plant was also a huge undertaking. Boeing president William M. Allen asked Malcolm T. Stamper, then head of the company's turbine division, to oversee construction of the Everett factory and to start production of the 747. To level the site, more than four million cubic yards (three million cubic meters) of earth had to be moved. Time
9976-466: The 747-400, several stretching schemes for the 747 were proposed. Boeing announced the larger 747-500X and -600X preliminary designs in 1996. The new variants would have cost more than US$ 5 billion to develop, and interest was not sufficient to launch the program. In 2000, Boeing offered the more modest 747X and 747X stretch derivatives as alternatives to the Airbus A38X . However, the 747X family
10148-463: The 747-400. The -400 entered service in 1989. In 1991, a record-breaking 1,087 passengers were flown in a 747 during a covert operation to airlift Ethiopian Jews to Israel . Generally, the 747-400 held between 416 and 524 passengers. The 747 remained the heaviest commercial aircraft in regular service until the debut of the Antonov An-124 Ruslan in 1982; variants of the 747-400 surpassed
10320-501: The 747-8 were for the freighter variant. On February 8, 2010, the 747-8 Freighter made its maiden flight . The first delivery of the 747-8 went to Cargolux in 2011. The first 747-8 Intercontinental passenger variant was delivered to Lufthansa on May 5, 2012. The 1,500th Boeing 747 was delivered in June 2014 to Lufthansa. In January 2016, Boeing stated it was reducing 747-8 production to six per year beginning in September 2016, incurring
10492-455: The An-124's weight in 2000. The Antonov An-225 Mriya cargo transport , which debuted in 1988, remains the world's largest aircraft by several measures (including the most accepted measures of maximum takeoff weight and length); one aircraft has been completed and was in service until 2022. The Scaled Composites Stratolaunch is currently the largest aircraft by wingspan . After the arrival of
SECTION 60
#173284458625010664-490: The Block III version was put into production. The Soviets started development of two almost identical weapons in 1964, Strela-1 and Strela-2. Development of these proceeded much more smoothly, as the 9K32 Strela-2 entered service in 1968 after fewer years of development than the Redeye. Originally a competing design, the 9K31 Strela-1 was instead greatly increased in size for vehicle applications and entered service at around
10836-515: The CX-Heavy Logistics System (CX-HLS) in March 1964 for an aircraft with a load capacity of 180,000 pounds (81.6 t) and a speed of Mach 0.75 (430 kn; 800 km/h), and an unrefueled range of 5,000 nautical miles (9,300 km; 5,800 mi) with a payload of 115,000 pounds (52.2 t). The payload bay had to be 17 feet (5.18 m) wide by 13.5 feet (4.11 m) high and 100 feet (30 m) long with access through doors at
11008-576: The R-73 problem was initially going to be the ASRAAM , a pan-European design that combined the performance of the R-73 with an imaging seeker. In a wide-ranging agreement, the US agreed to adopt ASRAAM for their new short-range missile, while the Europeans would adopt AMRAAM as their medium-range weapon. However, ASRAAM soon ran into intractable delays as each of the member countries decided a different performance metric
11180-606: The SCA with Endeavour performed low level flyovers above various landmarks across California, from Sacramento to the San Francisco Bay Area, before finally being delivered to Los Angeles International Airport (LAX). From there the orbiter was transported through the streets of Los Angeles and Inglewood to its final destination, the California Science Center in Exposition Park . Shuttle Carrier N911NA
11352-453: The SCAs by Mate-Demate Devices , large gantry -like structures that hoisted the orbiters off the ground for post-flight servicing then mated them with the SCAs for ferry flights. In approach and landing test flights conducted in 1977, the test shuttle Enterprise was released from an SCA during flight and glided to a landing under its own control. The Lockheed C-5 Galaxy was considered for
11524-646: The Smithsonian was transported to the Intrepid Sea, Air & Space Museum in New York City on April 27, 2012, making low-level passes over the city's landmarks, before landing at John F. Kennedy International Airport , where it was transferred by barge to the museum. The last ferry flight took Endeavour from Kennedy Space Center to Los Angeles between September 19 and 21, 2012 with refueling stops at Ellington Field and Edwards Air Force Base. After leaving Edwards
11696-464: The ability to be fired at targets completely out of view of the seeker; after firing the missile would orient itself in the direction indicated by the launcher and then attempt to lock on. When combined with a helmet mounted sight , the missile could be cued and targeted without the launch aircraft first having to point itself at the target. This proved to offer significant advantages in combat, and caused great concern for Western forces. The solution to
11868-542: The additional drag and weight of the Orbiter imposed significant fuel and altitude penalties. The range was reduced to 1,000 nautical miles (1,900 km; 1,200 mi), compared to an unladen range of 5,500 nautical miles (10,200 km; 6,300 mi), requiring an SCA to stop several times to refuel on a transcontinental flight. Without the Orbiter, the SCA needed to carry ballast to balance its center of gravity. The SCA had an altitude ceiling of 15,000 feet (4,600 m) and
12040-477: The aircraft and thus produce an ever-increasing signal while the aircraft is providing little or none. Additionally, as the missile approaches the target, smaller changes in relative angle are enough to move it out of this center null area and start causing control inputs again. With a bang-bang controller, such designs tend to begin to overreact during the last moments of the approach, causing large miss distances and demanding large warheads. A great improvement on
12212-408: The aircraft's upper deck; instead of using a conventional slide, volunteer passengers escaped by using a harness attached to a reel. Tests also involved taxiing such a large aircraft. Boeing built an unusual training device known as "Waddell's Wagon" (named for a 747 test pilot, Jack Waddell) that consisted of a mock-up cockpit mounted on the roof of a truck. While the first 747s were still being built,
12384-458: The airframe, along with General Electric and Pratt & Whitney for the engines. The airframe proposals shared several features. As the CX-HLS needed to be able to be loaded from the front, a door had to be included where the cockpit usually was. All of the companies solved this problem by moving the cockpit above the cargo area; Douglas had a small "pod" just forward and above the wing, Lockheed used
12556-410: The angle-off and feed that into the controls as well. This can be accomplished with the same disk and some work on the physical arrangement of the optics. Since the physical distance between the radial bars is larger at the outer position of the disk, the image of the target on the photocell is also larger, and thus has greater output. By arranging the optics so the signal is increasingly cut off closer to
12728-479: The background. Infrared seekers are passive devices, which, unlike radar , provide no indication that they are tracking a target. That makes them suitable for sneak attacks during visual encounters or over longer ranges when they are used with a forward looking infrared or similar cueing system. Heat-seekers are extremely effective: 90% of all United States air combat losses between 1984 and 2009 were caused by infrared-homing missiles. They are, however, subject to
12900-451: The basic spin-scan concept is the conical scanner or con-scan . In this arrangement, a fixed reticle is placed in front of the detector and both are positioned at the focus point of a small Cassegrain reflector telescope. The secondary mirror of the telescope is pointed slightly off-axis, and spins. This causes the image of the target to be spun around the reticle , instead of the reticle itself spinning. Consider an example system where
13072-409: The center of the disk, the resulting output signal varies in amplitude with the angle-off. However, it will also vary in amplitude as the missile approaches the target, so this is not a complete system by itself and some form of automatic gain control is often desired. Spin-scan systems can eliminate the signal from extended sources like sunlight reflecting from clouds or hot desert sand. To do this,
13244-478: The center of the operator's telescope. SACLOS systems of this sort have been used both for anti-tank missiles and surface-to-air missiles , as well as other roles. The infrared sensor package on the tip or head of a heat-seeking missile is known as the seeker head . The NATO brevity code for an air-to-air infrared-guided missile launch is Fox Two . The ability of certain substances to give off electrons when struck by infrared light had been discovered by
13416-401: The centerline it was. Other systems used a second scanning disk with radial slits to provide the same result but from a second output circuit. AEG developed a much more advanced system during the war, and this formed the basis of most post-war experiments. In this case, the disk was pattered with a series of opaque regions, often in a series of radial stripes forming a pizza-slice pattern. Like
13588-457: The ceremonial 747 contract-signing banquet in Seattle on Boeing's 50th Anniversary, Juan Trippe predicted that the 747 would be "…a great weapon for peace, competing with intercontinental missiles for mankind's destiny". As launch customer, and because of its early involvement before placing a formal order, Pan Am was able to influence the design and development of the 747 to an extent unmatched by
13760-472: The code name Blue Jay . Designed as an anti-bomber weapon, the Blue Jay was larger, much heavier and flew faster than its US counterparts, but had about the same range. It had a more advanced seeker, using PbTe and cooled to −180 °C (−292.0 °F) by anhydrous ammonia to improve its performance. One distinguishing feature was its faceted nose cone, which was selected after it was found ice would build up on
13932-511: The concept but was committed to developing the engine for the C-5 Galaxy and did not enter the commercial market until later. Pratt & Whitney was also working on the same principle and, by late 1966, Boeing, Pan Am and Pratt & Whitney agreed to develop a new engine, designated the JT9D to power the 747. The project was designed with a new methodology called fault tree analysis , which allowed
14104-401: The control system and commands the missile to turn up. A second cell placed at the 3 o'clock position completes the system. In this case, the switching takes place not at the 9 and 3 o'clock positions, but 12 and 6 o'clock. Considering the same target, in this case, the waveform has just reached its maximum positive point at 12 o'clock when it is switched negative. Following this process around
14276-436: The decades of Shuttle operations, the SCAs were most often used to transport the orbiters from Edwards Air Force Base , the shuttle's secondary landing site, to the Shuttle Landing Facility (SLF) at the Kennedy Space Center where the orbiter was processed for another launch. The SCAs were also used to transport the orbiters between manufacturer Rockwell International and NASA during initial delivery and mid-life refits. At
14448-401: The detector, or in the case of Madrid , two metal vanes were tilted to block off more or less of the signal. By comparing the time the flash was received to the location of the scanner at that time, the vertical and horizontal angle-off can be determined. However, these seekers also have the major disadvantage that their FOV is determined by the physical size of the slit (or opaque bar). If this
14620-470: The device allowed pilots to practice taxi maneuvers from a high upper-deck position. In 1968, the program cost was US$ 1 billion (equivalent to $ 6.7 billion in 2023 dollars). On September 30, 1968, the first 747 was rolled out of the Everett assembly building before the world's press and representatives of the 26 airlines that had ordered the airliner. Over the following months, preparations were made for
14792-410: The disk spinning clockwise as seen from the sensor; we will call the point in the rotation when the line between the dark and light halves is horizontal and the transparent side is on the top to be the 12 o'clock position. A photocell is positioned behind the disk at the 12 o'clock position. A target is located just above the missile. The sensor begins to see the target when the disk is at 9 o'clock, as
14964-401: The disk. By comparing the phase of the two signals, both the vertical and horizontal correction can be determined from a single signal. A great improvement was made as part of the Sidewinder program, feeding the output to the pilot's headset where it creates a sort of growling sound known as the missile tone that indicates that the target is visible to the seeker. In early systems this signal
15136-412: The early 747 sales were to airlines desiring the aircraft's long range rather than its payload capacity. While the 747 had the lowest potential operating cost per seat, this could only be achieved when the aircraft was fully loaded; costs per seat increased rapidly as occupancy declined. A moderately loaded 747, one with only 70 percent of its seats occupied, used more than 95 percent of the fuel needed by
15308-490: The effects of a failure of a single part to be studied to determine its impact on other systems. To address concerns about safety and flyability, the 747's design included structural redundancy, redundant hydraulic systems, quadruple main landing gear and dual control surfaces. Additionally, some of the most advanced high-lift devices used in the industry were included in the new design, to allow it to operate from existing airports. These included Krueger flaps running almost
15480-438: The emissions from the targets. This led to the practical discovery that the vast majority of the IR output from a piston-engine aircraft was between 3 and 4.5 micrometers. The exhaust was also a strong emitter, but cooled rapidly in the air so that it did not present a false tracking target. Studies were also made on atmospheric attenuation, which demonstrated that air is generally more transparent to IR than visible light, although
15652-425: The empennage. As Boeing did not have a plant large enough to assemble the giant airliner, they chose to build a new plant. The company considered locations in about 50 cities, and eventually decided to build the new plant some 30 miles (50 km) north of Seattle on a site adjoining a military base at Paine Field near Everett , Washington. It bought the 780-acre (320 ha) site in June 1966. Developing
15824-736: The end of the Space Shuttle program the SCA was used to deliver the retired orbiters from the Kennedy Space Center to their museums. Discovery was flown to the Udvar-Hazy Center of the Smithsonian Institution 's National Air and Space Museum at the Dulles International Airport on April 17, 2012, making low-level passes over Washington, D.C. landmarks before landing. Enterprise , which had been on display at
15996-403: The entire length of the fuselage were rejected. The first 747-300, completed in 1983, included a stretched upper deck, increased cruise speed, and increased seating capacity. The -300 variant was previously designated 747SUD for stretched upper deck, then 747-200 SUD, followed by 747EUD, before the 747-300 designation was used. Passenger, short range and combination freighter-passenger versions of
16168-409: The entire length of the wing's leading edge, as well as complex three-part slotted flaps along the trailing edge of the wing. The wing's complex three-part flaps increase wing area by 21% and lift by 90% when fully deployed compared to their non-deployed configuration. Boeing agreed to deliver the first 747 to Pan Am by the end of 1969. The delivery date left 28 months to design the aircraft, which
16340-433: The entire seeker assembly is mounted on a gimbal system that allows it to track the target through wide angles, and the angle between the seeker and the missile aircraft is used to produce guidance corrections. This gives rise the concepts of instantaneous field of view (IFOV) which is the angle the detector sees, and the overall field of view, also known as the tacking angle or off-boresight capability , which includes
16512-473: The evacuation of 560 volunteers from a cabin mock-up via the aircraft's emergency chutes. The first full-scale evacuation took two and a half minutes instead of the maximum of 90 seconds mandated by the Federal Aviation Administration (FAA), and several volunteers were injured. Subsequent test evacuations achieved the 90-second goal but caused more injuries. Most problematic was evacuation from
16684-504: The events of an emergency if they cannot do so through the cabin. The 747's maximum takeoff weight ranges from 735,000 pounds (333 t) for the -100 to 970,000 pounds (440 t) for the -8. Its range has increased from 5,300 nautical miles (9,800 km; 6,100 mi) on the -100 to 8,000 nautical miles (15,000 km; 9,200 mi) on the -8I. The 747 has redundant structures along with four redundant hydraulic systems and four main landing gears each with four wheels; these provide
16856-494: The famous Indian polymath Jagadish Chandra Bose in 1901, who saw the effect in galena , known today as lead sulfide, PbS. There was little application at the time, and he allowed his 1904 patent to lapse. In 1917, Theodore Case , as part of his work on what became the Movietone sound system , discovered that a mix of thallium and sulfur was much more sensitive, but was highly unstable electrically and proved to be of little use as
17028-529: The first 747 was rolled out of the custom-built Everett Plant , the world's largest building by volume . The 747's first flight took place on February 9, 1969, and the 747 was certified in December of that year. It entered service with Pan Am on January 22, 1970. The 747 was the first airplane called a " Jumbo Jet " as the first wide-body airliner. The 747 is a four-engined jet aircraft , initially powered by Pratt & Whitney JT9D turbofan engines, then General Electric CF6 and Rolls-Royce RB211 engines for
17200-583: The first effective French design, the R.530 , in 1962. The Soviets introduced their first infrared homing missile, the Vympel K-13 in 1961, after reverse engineering a Sidewinder that stuck in the wing of a Chinese MiG-17 in 1958 during the Second Taiwan Strait Crisis . The K-13 was widely exported, and faced its cousin over Vietnam throughout the war. It proved even less reliable than the AIM-9B it
17372-433: The first flight, which took place on February 9, 1969, with test pilots Jack Waddell and Brien Wygle at the controls and Jess Wallick at the flight engineer's station. Despite a minor problem with one of the flaps, the flight confirmed that the 747 handled extremely well. The 747 was found to be largely immune to " Dutch roll ", a phenomenon that had been a major hazard to the early swept-wing jets. During later stages of
17544-410: The first time. Finally, in December 1969, the 747 received its FAA airworthiness certificate , clearing it for introduction into service. The huge cost of developing the 747 and building the Everett factory meant that Boeing had to borrow heavily from a banking syndicate. During the final months before delivery of the first aircraft, the company had to repeatedly request additional funding to complete
17716-402: The fixed signal is filtered out. A significant problem with the spin-scan system is that the signal when the target is near the center drops to zero. This is because even its small image covers several segments as they narrow at the center, producing a signal similar enough to an extended source that it is filtered out. This makes such seekers extremely sensitive to flares, which move away from
17888-411: The flight by more than six hours to the following day when Clipper Victor (registration N736PA) was used. The 747 enjoyed a fairly smooth introduction into service, overcoming concerns that some airports would not be able to accommodate an aircraft that large. Although technical problems occurred, they were relatively minor and quickly solved. After the initial 747-100, Boeing developed the -100B ,
18060-431: The flight deck out of the way for freight loading had the pilots below the passengers, and was dubbed the "anteater".) One of the principal technologies that enabled an aircraft as large as the 747 to be drawn up was the high-bypass turbofan engine . This engine technology was thought to be capable of delivering double the power of the earlier turbojets while consuming one-third less fuel. General Electric had pioneered
18232-541: The flight test program, flutter testing showed that the wings suffered oscillation under certain conditions. This difficulty was partly solved by reducing the stiffness of some wing components. However, a particularly severe high-speed flutter problem was solved only by inserting depleted uranium counterweights as ballast in the outboard engine nacelles of the early 747s. This measure caused some concern when these aircraft crashed, for example El Al Flight 1862 at Amsterdam in 1992 with 622 pounds (282 kg) of uranium in
18404-495: The front and rear. The desire to keep the number of engines to four required new engine designs with greatly increased power and better fuel economy. In May 1964, airframe proposals arrived from Boeing, Douglas , General Dynamics , Lockheed , and Martin Marietta ; engine proposals were submitted by General Electric , Curtiss-Wright , and Pratt & Whitney . Boeing, Douglas, and Lockheed were given additional study contracts for
18576-445: The fuselage was redesigned to fit mating fuselage sections. The SP's flaps used a simplified single-slotted configuration. The 747SP, compared to earlier variants, had a tapering of the aft upper fuselage into the empennage , a double-hinged rudder, and longer vertical and horizontal stabilizers. Power was provided by Pratt & Whitney JT9D-7(A/F/J/FW) or Rolls-Royce RB211-524 engines. Heat-seeking missile Infrared homing
18748-416: The fuselage was strengthened. Mounting struts were added on top of the 747, located to match the fittings on the Shuttle that attach it to the external fuel tank for launch. With the Shuttle riding on top, the center of gravity was altered. Vertical stabilizers were added to the tail to improve stability when the Orbiter was being carried. The avionics and engines were also upgraded. An internal escape slide
18920-549: The heaviest versions of the A340 until surpassing the 747 in size with the A380 , delivered between 2007 and 2021. Freighter variants of the 747 remain popular with cargo airlines. The final 747 was delivered to Atlas Air in January 2023 after a 54-year production run, with 1,574 aircraft built. As of December 2023 , 64 Boeing 747s (4.1%) have been lost in accidents and incidents , in which
19092-403: The high degree of sensitivity required to lock onto the lower-level signals coming from the front and sides of an aircraft. Background heat from inside the sensor, or the aerodynamically heated sensor window, can overpower the weak signal entering the sensor from the target. ( CCDs in cameras have similar problems; they have much more "noise" at higher temperatures.) Modern all-aspect missiles like
19264-449: The introduction of the 707 in October 1958, Pan Am wanted a jet 2 + 1 ⁄ 2 times its size, to reduce its seat cost by 30%. In 1965, Joe Sutter left the 737 development program to design the 747. In April 1966, Pan Am ordered 25 Boeing 747-100 aircraft, and in late 1966, Pratt & Whitney agreed to develop the JT9D engine, a high-bypass turbofan . On September 30, 1968,
19436-413: The location of the target by timing when the image disappeared (AEG) or reappeared (Kepka). The Kepka Madrid system had an instantaneous field of view (IFOV) of about 1.8 degrees and scanned a full 20 degree pattern. Combined with the movement of the entire seeker within the missile, it could track at angles as great as 100 degrees. Rheinmetall-Borsig and another team at AEG produced different variations on
19608-466: The main deck, the cockpit creates a hump. This raised cockpit allows front loading of cargo on freight variants. The upper deck behind the cockpit provides space for a lounge and/or extra seating. The "stretched upper deck" became available as an alternative on the 747-100B variant and later as standard beginning on the 747-300. The upper deck was stretched more on the 747-8. The 747 cockpit roof section also has an escape hatch from which crew can exit during
19780-555: The missile's field of view. Such seekers, which are most sensitive to the 3 to 5 micrometre range, are now called single-color seekers. This led to new seekers sensitive to both the exhaust as well as the longer 8 to 13 micrometer wavelength range, which is less absorbed by the atmosphere and thus allows dimmer sources like the fuselage itself to be detected. Such designs are known as "all-aspect" missiles. Modern seekers combine several detectors and are called two-color systems. All-aspect seekers also tend to require cooling to give them
19952-549: The model number 747. Sutter began a design study with Pan Am and other airlines to better understand their requirements. At the time, many thought that long-range subsonic airliners would eventually be superseded by supersonic transport aircraft. Boeing responded by designing the 747 so it could be adapted easily to carry freight and remain in production even if sales of the passenger version declined. In April 1966, Pan Am ordered 25 Boeing 747-100 aircraft for US$ 525 million (equivalent to $ 3.8 billion in 2023 dollars). During
20124-456: The movement of the entire seeker assembly. Since the assembly cannot move instantly, a target moving rapidly across the missile's line of flight may be lost from the IFOV, which gives rise to the concept of a tracking rate , normally expressed in degrees per second. Some of the earliest German seekers used a linear-scan solution, where vertical and horizontal slits were moved back and forth in front of
20296-399: The negative voltage portion of its waveform, so the switch inverts this back to positive. When the disk reaches the 9 o'clock position the cell switches again, no longer inverting the signal, which is now entering its positive phase again. The resulting output from this cell is a series of half-sine waves, always positive. This signal is then smoothed out to produce a DC output, which is sent to
20468-417: The new configuration. The -100 was equipped with Pratt & Whitney JT9D -3A engines. No freighter version of this model was developed, but many 747-100s were converted into freighters as 747-100(SF). The first 747-100(SF) was delivered to Flying Tiger Line in 1974. A total of 168 747-100s were built; 167 were delivered to customers, while Boeing kept the prototype, City of Everett . In 1972, its unit cost
20640-469: The next year. Wally Schirra recalls visiting the lab and watching the seeker follow his cigarette. The missile was given the name Sidewinder after a local snake; the name had a second significance as the sidewinder is a pit viper and hunts by heat, and moves in an undulating pattern not unlike the missile. The Sidewinder entered service in 1957, and was widely used during the Vietnam war. It proved to be
20812-446: The nose door and raised cockpit concepts over to the design of the 747. The 747 was conceived while air travel was increasing in the 1960s. The era of commercial jet transportation, led by the enormous popularity of the Boeing 707 and Douglas DC-8 , had revolutionized long-distance travel. In this growing jet age, Juan Trippe , president of Pan American Airways (Pan Am), one of Boeing's most important airline customers, asked for
20984-446: The original -100, the -100B was offered with Pratt & Whitney JT9D-7A, CF6-50, or Rolls-Royce RB211-524 engines. However, only RB211-524 (Saudia) and JT9D-7A (Iran Air) engines were ordered. The last 747-100B, EP-IAM was retired by Iran Air in 2014, the last commercial operator of the 747-100 and -100B. The development of the 747SP stemmed from a joint request between Pan American World Airways and Iran Air , who were looking for
21156-433: The original variants. With a ten-abreast economy seating, it typically accommodates 366 passengers in three travel classes . It has a pronounced 37.5° wing sweep , allowing a Mach 0.85 (490 kn; 900 km/h) cruise speed , and its heavy weight is supported by four main landing gear legs, each with a four-wheel bogie . The partial double-deck aircraft was designed with a raised cockpit so it could be converted to
21328-469: The period the target is visible to the sensor, the AC waveform is in the positive voltage period, varying from zero to its maximum and back to zero. When the target disappears, the sensor triggers a switch that inverts the output of the AC signal. For instance, when the disk reaches the 3 o'clock position and the target disappears, the switch is triggered. This is the same instant that the original AC waveform begins
21500-605: The potential termination of 747 production due to insufficient demand and market for the aircraft. With a firm order backlog of 21 aircraft and a production rate of six per year, program accounting had been reduced to 1,555 aircraft. In October 2016, UPS Airlines ordered 14 -8Fs to add capacity, along with 14 options, which it took in February 2018 to increase the total to 28 -8Fs on order. The backlog then stood at 25 aircraft, though several of these were orders from airlines that no longer intended to take delivery. On July 2, 2020, it
21672-562: The precautionary note "black side down". Shuttle Carriers were capable of operating from alternative shuttle landing sites such as those in the United Kingdom, Spain, and France. Because Shuttle Carrier's range is reduced while mated to an orbiter, additional preparations such as removal of the payload from the orbiter may have been necessary to reduce its weight. Boeing transported its Phantom Ray unmanned combat aerial vehicle (UCAV) demonstrator from St. Louis, Missouri, to Edwards on
21844-487: The presence of water vapour and carbon dioxide produced several sharp drops in transitivity. Finally, they also considered the issue of background sources of IR, including reflections off clouds and similar effects, concluding this was an issue due to the way it changed very strongly across the sky. This research suggested that an IR seeker could home on a three-engine bomber at 5 kilometres (3.1 mi) with an accuracy of about 1 ⁄ 10 degree, making an IR seeker
22016-401: The presence of Pan Am chairman Najeeb Halaby . Instead of champagne, red, white, and blue water was sprayed on the aircraft. The 747 entered service on January 22, 1970, on Pan Am's New York–London route; the flight had been planned for the evening of January 21, but engine overheating made the original aircraft (Clipper Young America, registration N735PA) unusable. Finding a substitute delayed
22188-428: The problem that when the bomb was first released it was traveling too slowly for the aerodynamic surfaces to easily control it, and the target sometimes slipped out from the view of the seeker. A stabilized platform was being developed to address this problem. The company also developed a working IR proximity fuse by placing additional detectors pointing radially outward from the missile centerline. which triggered when
22360-426: The production line on December 6, 2022, and was delivered on January 31, 2023. Boeing hosted an event at the Everett factory for thousands of workers as well as industry executives to commemorate the delivery. The Boeing 747 is a large, wide-body (two-aisle) airliner with four wing-mounted engines. Its wings have a high sweep angle of 37.5° for a fast, efficient cruise speed of Mach 0.84 to 0.88, depending on
22532-496: The project. Had this been refused, Boeing's survival would have been threatened. The firm's debt exceeded $ 2 billion, with the $ 1.2 billion owed to the banks setting a record for all companies. Allen later said, "It was really too large a project for us." Ultimately, the gamble succeeded, and Boeing held a monopoly in very large passenger aircraft production for many years. On January 15, 1970, First Lady Pat Nixon christened Pan Am's first 747 at Dulles International Airport in
22704-474: The public for the first time on January 23, 2016. Data from Boeing 747-100 specifications Jenkins 2000 General characteristics Performance Aircraft of comparable role, configuration, and era Related lists Boeing 747 The Boeing 747 is a long-range wide-body airliner designed and manufactured by Boeing Commercial Airplanes in the United States between 1968 and 2023. After
22876-511: The resulting L models were rushed to the UK just prior to their engagement in the Falklands War , where they achieved an 82% kill ratio, and the misses were generally due to the target aircraft flying out of range. The Argentine aircraft, equipped with Sidewinder B and R.550 Magic , could only fire from the rear aspect, which the British pilots simply avoided by always flying directly at them. The L
23048-421: The reticle is modified by making one half of the plate be covered not with stripes but a 50% transmission color. The output from such a system is a sine wave for half of the rotation and a constant signal for the other half. The fixed output varies with the overall illumination of the sky. An extended target that spans several segments, like a cloud, will cause a fixed signal as well, and any signal that approximates
23220-410: The rotation causes a series of chopped-off positive and negative sine waves. When this is passed through the same smoothing system, the output is zero. This means the missile does not have to correct left or right. If the target were to move to the right, for instance, the signal would be increasingly positive from the smoother, indicating increasing corrections to the right. In practice a second photocell
23392-593: The same output signal. Since the goal of the seeker is to bring the target within the lethal radius of its warhead, the detector must be equipped with some system to narrow the FOV to a smaller angle. This is normally accomplished by placing the detector at the focal point of a telescope of some sort. This leads to a problem of conflicting performance requirements. As the FOV is reduced, the seeker becomes more accurate, and this also helps eliminate background sources which helps improve tracking. However, limiting it too much allows
23564-549: The same systems for use on tanks , and deployed a number of models through the war, with limited production of the FG 1250 beginning in 1943. This work culminated in the Zielgerät 1229 Vampir riflescope which was used with the StG 44 assault rifle for night use. The devices mentioned previously were all detectors, not seekers. They either produce a signal indicating the general direction of
23736-527: The same technologies have appeared in the Chinese PL-10 and Israeli Python-5 . Based on the same general principles as the original Sidewinder, in 1955 Convair began studies on a small man-portable missile ( MANPADS ) that would emerge as the FIM-43 Redeye . Entering testing in 1961, the preliminary design proved to have poor performance, and a number of major upgrades followed. It was not until 1968 that
23908-461: The same time. The UK began development of its Blowpipe in 1975, but placed the seeker on the launcher instead of the missile itself. The seeker sensed both the target and the missile and sent corrections to the missile via a radio link. These early weapons proved ineffective, with the Blowpipe failing in almost every combat use, while the Redeye fared somewhat better. The Strela-2 did better and claimed
24080-615: The same year as MX-798, 1946, William B. McLean began studies of a similar concept at the Naval Ordnance Test Station, today known as Naval Air Weapons Station China Lake . He spent three years simply considering various designs, which led to a considerably less complicated design than the Falcon. When his team had a design they believed would be workable, they began trying to fit it to the newly introduced Zuni 5-inch rocket . They presented it in 1951 and it became an official project
24252-403: The seeker is mounted on a trainable platform on the launcher and the operator keeps it pointed in the general direction of the target manually, often using a small telescope. The seeker does not track the target, but the missile, often aided by flares to provide a clean signal. The same guidance signals are generated and sent to the missile via thin wires or radio signals, guiding the missile into
24424-410: The seeker's mirror is tilted at 5 degrees, and the missile is tracking a target that is currently centered in front of the missile. As the mirror spins, it causes the image of the target to be reflected in the opposite direction, so in this case the image is moving in a circle 5 degrees away from the reticle's centerline. That means that even a centered target is creating a varying signal as it passes over
24596-541: The shuttle-carrier role by NASA but rejected in favor of the 747. This was due to the 747's low-wing design in comparison to the C-5's high-wing design, and also because the U.S. Air Force would have retained ownership of the C-5, while NASA could own the 747s outright. The first aircraft, a Boeing 747-123 registered N905NA, was originally manufactured for American Airlines . With a decline in air traffic and failure to fill their 747s, American Airlines sold it to NASA. It still wore
24768-405: The signal strength began to decrease, which it did when the missile passed the target. There was work on using a single sensor for both tasks instead of two separate ones. Other companies also picked up on the work by Eletroacustic and designed their own scanning methods. AEG and Kepka of Vienna used systems with two movable plates that continually scanned horizontally or vertically, and determined
24940-576: The spinning-disk system. In the post-war era, as the German developments became better known, a variety of research projects began to develop seekers based on the PbS sensor. These were combined with techniques developed during the war to improve accuracy of otherwise inherently inaccurate radar systems, especially the conical scanning system. One such system developed by the US Army Air Force (USAAF), known as
25112-430: The standard 747. The initial 747SR model, the -100SR, had a strengthened body structure and landing gear to accommodate the added stress accumulated from a greater number of takeoffs and landings. Extra structural support was built into the wings, fuselage, and the landing gear along with a 20% reduction in fuel capacity. The initial order for the -100SR – four aircraft for Japan Air Lines (JAL, later Japan Airlines ) –
25284-417: The tailfin of N905NA. While these were not likely to have been caused by the test flights, it was felt that there was no sense taking unnecessary risks. Since there was no urgent need to provide an aerial refueling capacity, the tests were suspended. By 1983, SCA N905NA no longer carried the distinct American Airlines tricolor cheatline . NASA replaced it with its own livery, consisting of a white fuselage and
25456-407: The target is moving very slowly relative to the missile and the missile quickly aligns itself to the target. It was not appropriate for air-to-air use where the velocities were greater and smoother control motion was desired. In this case, the system was changed only slightly so the modulating disk was patterned in a cardioid which blanked out the signal for more or less time depending on how far from
25628-483: The target to move out of the FOV and be lost to the seeker. To be effective for guidance to the lethal radius, tracking angles of perhaps one degree are ideal, but to be able to continually track the target safely, FOVs on the order of 10 degrees or more are desired. This situation leads to the use of a number of designs that use a relatively wide FOV to allow easy tracking, and then process the received signal in some way to gain additional accuracy for guidance. Generally,
25800-465: The target, or in the case of later devices, an image. Guidance was entirely manual by an operator looking at the image. There were a number of efforts in Germany during the war to produce a true automatic seeker system, both for anti-aircraft use as well as against ships. These devices were still in development when the war ended; although some were ready for use, there had been no work on integrating them with
25972-414: The transparent portion of the chopper is aligned vertically at the target at 12 o'clock becomes visible. The sensor continues to see the target until the chopper reaches 3 o'clock. A signal generator produces an AC waveform that had the same frequency as the rotational rate of the disk. It is timed so the waveform reaches its maximum possible positive voltage point at the 12 o'clock position. Thus, during
26144-434: The turbine casings after a short period of service. The problems delayed 747 deliveries for several months; up to 20 aircraft at the Everett plant were stranded while awaiting engine installation. The program was further delayed when one of the five test aircraft suffered serious damage during a landing attempt at Renton Municipal Airport , the site of Boeing's Renton factory . The incident happened on December 13, 1969, when
26316-422: The variant. The sweep also reduces the wingspan, allowing the 747 to use existing hangars . Its seating capacity is over 366 with a 3–4–3 seat arrangement (a cross section of three seats, an aisle, four seats, another aisle, and three seats) in economy class and a 2–3–2 layout in first class on the main deck. The upper deck has a 3–3 seat arrangement in economy class and a 2–2 layout in first class. Raised above
26488-479: The visible American cheatlines while testing Enterprise in the 1970s. It was acquired in 1974 and initially used for trailing wake vortex research as part of a broader study by NASA Dryden , as well as Shuttle tests involving an F-104 flying in close formation and simulating a release from the 747. The aircraft was extensively modified for NASA by Boeing in 1976. While first-class seats were kept for NASA passengers, its main cabin and insulation were stripped, and
26660-485: The war ended. Truly practical designs did not become possible until the introduction of conical scanning and miniaturized vacuum tubes during the war. Anti-aircraft IR systems began in earnest in the late 1940s, but the electronics and the entire field of rocketry were so new that they required considerable development before the first examples entered service in the mid-1950s. The early examples had significant limitations and achieved very low success rates in combat during
26832-476: The world, both to Irish flag carrier Aer Lingus . No 747s were sold to any American carrier for almost three years. When economic problems in the US and other countries after the 1973 oil crisis led to reduced passenger traffic, several airlines found they did not have enough passengers to fly the 747 economically, and they replaced them with the smaller and recently introduced McDonnell Douglas DC-10 and Lockheed L-1011 TriStar trijet wide bodies (and later
27004-540: Was US$ 24M (174.8M today). Responding to requests from Japanese airlines for a high-capacity aircraft to serve domestic routes between major cities, Boeing developed the 747SR as a short-range version of the 747-100 with lower fuel capacity and greater payload capability. With increased economy class seating, up to 498 passengers could be carried in early versions and up to 550 in later models. The 747SR had an economic design life objective of 52,000 flights during 20 years of operation, compared to 24,600 flights in 20 years for
27176-502: Was added behind the flight deck in case of catastrophic failure mid-flight. In the event of a bail-out, explosives would be detonated to make an opening in the fuselage at the bottom of the slide, allowing the crew to exit through the slide and parachute to the ground. The slide system was removed following the Approach and Landing Tests because of concerns over the possibility of escaping crew members being ingested into an engine. Flying with
27348-501: Was announced on October 30, 1972; rollout occurred on August 3, 1973, and the first flight took place on August 31, 1973. The type was certified by the FAA on September 26, 1973, with the first delivery on the same day. The -100SR entered service with JAL, the type's sole customer, on October 7, 1973, and typically operated flights within Japan. Seven -100SRs were built between 1973 and 1975, each with
27520-432: Was based on, with the guidance system and fuse suffering continual failure. As Vietnam revealed the terrible performance of existing missile designs, a number of efforts began to address them. In the US, minor upgrades to the Sidewinder were carried out as soon as possible, but more broadly pilots were taught proper engagement techniques so they would not fire as soon as they heard the missile tone, and would instead move to
27692-412: Was fed directly to the control surfaces, causing rapid flicking motions to bring the missile back into alignment, a control system known as "bang-bang". Bang-bang controls are extremely inefficient aerodynamically, especially as the target approaches the centerline and the controls continually flick back and forth with no real effect. This leads to the desire to either smooth out these outputs, or to measure
27864-661: Was first delivered in October 2011. The 747 is the basis for several government and military variants, such as the VC-25 ( Air Force One ), E-4 Emergency Airborne Command Post, Shuttle Carrier Aircraft , and some experimental test aircraft such as the YAL-1 and SOFIA airborne observatory. Initial competition came from the smaller trijet widebodies: the Lockheed L-1011 (introduced in 1972), McDonnell Douglas DC-10 (1971) and later MD-11 (1990). Airbus competed with later variants with
28036-582: Was going to be a better solution. Nevertheless, Frederick Lindemann , Winston Churchill 's favorite on the Tizard Committee , remained committed to IR and became increasingly obstructionist to the work of the Committee who were otherwise pressing for radar development. Eventually they dissolved the Committee and reformed, leaving Lindemann off the roster, and filling his position with well known radio expert Edward Victor Appleton . In Germany, radar research
28208-456: Was more important. The US eventually bowed out of the program, and instead adapted the new seekers developed for ASRAAM on yet another version of the Sidewinder, the AIM-9X. This so extends its lifetime that it will have been in service for almost a century when the current aircraft leave service. ASRAAM did, eventually, deliver a missile that has been adopted by a number of European forces and many of
28380-518: Was not given nearly the same level of support as in the UK, and competed with IR development throughout the 1930s. IR research was led primarily by Edgar Kutzscher at the University of Berlin working in concert with AEG . By 1940 they had successfully developed one solution; the Spanner Anlage (roughly "Peeping Tom system") consisting of a detector photomultiplier placed in front of the pilot, and
28552-550: Was reported that Boeing planned to end 747 production in 2022 upon delivery of the remaining jets on order to UPS and the Volga-Dnepr Group due to low demand. On July 29, 2020, Boeing confirmed that the final 747 would be delivered in 2022 as a result of "current market dynamics and outlook" stemming from the COVID-19 pandemic , according to CEO David Calhoun. The last aircraft, a 747-8F for Atlas Air registered N863GT, rolled off
28724-520: Was retired on February 8, 2012, after its final mission to the Dryden Flight Research Facility at Edwards Air Force Base in Palmdale, California, and was used as a source of parts for NASA's Stratospheric Observatory for Infrared Astronomy (SOFIA) aircraft, another modified Boeing 747. N911NA is now preserved and on display at the Joe Davies Heritage Airpark in Palmdale, California as part of
28896-517: Was shortened for the longer-range 747SP in 1976, and the 747-300 followed in 1983 with a stretched upper deck for up to 400 seats in three classes. The heavier 747-400 with improved RB211 and CF6 engines or the new PW4000 engine (the JT9D successor), and a two-crew glass cockpit , was introduced in 1989 and is the most common variant. After several studies, the stretched 747-8 was launched on November 14, 2005, with new General Electric GEnx engines, and
29068-564: Was so effective that aircraft hurried to add flare countermeasures, which led to another minor upgrade to the M model to better reject flares. The L and M models would go on to be the backbone of Western air forces through the end of the Cold War era. An even larger step was taken by the Soviets with their R-73 , which replaced the K-13 and others with a dramatically improved design. This missile introduced
29240-409: Was so short that the 747's full-scale mock-up was built before the factory roof above it was finished. The plant is the largest building by volume ever built, and has been substantially expanded several times to permit construction of other models of Boeing wide-body commercial jets. Before the first 747 was fully assembled, testing began on many components and systems. One important test involved
29412-606: Was two-thirds of the normal time. The schedule was so fast-paced that the people who worked on it were given the nickname "The Incredibles". Developing the aircraft was such a technical and financial challenge that management was said to have "bet the company" when it started the project. Due to its massive size, Boeing subcontracted the assembly of subcomponents to other manufacturers, most notably Northrop and Grumman (later merged into Northrop Grumman in 1994) for fuselage parts and trailing edge flaps respectively, Fairchild for tailplane ailerons, and Ling-Temco-Vought (LTV) for
29584-642: Was unable to attract enough interest to enter production. A year later, Boeing switched from the 747X studies to pursue the Sonic Cruiser , and after the Sonic Cruiser program was put on hold, the 787 Dreamliner . Some of the ideas developed for the 747X were used on the 747-400ER , a longer range variant of the 747-400. After several variants were proposed but later abandoned, some industry observers became skeptical of new aircraft proposals from Boeing. However, in early 2004, Boeing announced tentative plans for
#249750