Boeing 747-400
The Boeing 747-400 is a wide-body airliner produced by Boeing Commercial Airplanes, an advanced variant of the initial Boeing 747. The "Advanced Series 300" was announced at the September 1984 Farnborough Airshow, targeting a 10% cost reduction with more efficient engines and more range. Northwest Airlines (NWA) became the first customer with an order for 10 aircraft on October 22, 1985. The first 747-400 was rolled out on January 26, 1988, and made its maiden flight on April 29, 1988. Type certification was received on January 9, 1989, and it entered service with NWA  on February 9, 1989. It retains the 747 airframe, including the 747-300 stretched upper deck, with winglets. The 747-400 offers a choice of improved turbofans: the Pratt & Whitney PW4000, General Electric CF6-80C2 or Rolls-Royce RB211-524G/H. Its two-crew glass cockpit dispenses with the need for a flight engineer. It typically accommodates 416 passengers in a three-class layout over a 7,285 nmi (13,490) km range with its MTOW. The first -400M combi was rolled out in June 1989. The -400D Domestic for the Japanese market, without winglets, entered service on October 22, 1991 . The -400F cargo variant, without the stretched upper deck, was first delivered in May 1993. With an increased MTOW of , the extended range version entered service in October 2002 as the -400ERF freighter and the -400ER passenger version the following month. Several 747-400 aircraft have undergone freighter conversion or other modifications to serve as transports of heads of state, YAL-1 laser testbed, engine testbed or the "Cosmic Girl" air launcher. The Dreamlifter is an outsize cargo conversion designed to move Dreamliner components. With 694 delivered over the course of 20 years from 1989 to 2009, it was the best -selling 747 variant. Its closest competitors were the smaller McDonnell Douglas MD-11 trijet and Airbus A340 quadjet. It has been superseded by the stretched and improved Boeing 747-8, introduced in October 2011. In the late 2010s, older 747-400 passenger aircraft were being phased out by airlines in favor of long-range, wide-body twin engine aircraft, such as the Boeing 777 and Airbus A350. In 2021, China Airlines celebrated the retirement of its final passenger 747-400, which was also amongst the last delivered aircraft sixteen years earlier. Development. Background. Following its introduction in 1969, the Boeing 747  became a major success with airlines and the flying public. As the world's first wide-body jetliner, the 747 had revolutionized air travel, and cemented its manufacturer's dominance in the passenger aircraft market. In 1980, Boeing announced the 747-300, its latest 747 variant featuring greater passenger capacity. This was made possible by making a stretched upper deck (SUD), previously an option on the 747-200, a standard feature. The SUD was almost twice as long as the original 747 upper deck. Besides increased capacity, the 747-300 did not offer any increase in range, nor did it  include improvements in flight deck technology or construction materials. At the same time, 747s were becoming more costly to operate due to a number of factors, notably conventional flight control systems, three-person flight crews, and fuel costs. In 1982, Boeing introduced a two-crew glass cockpit, new engines, and advanced materials on its 757 and 767 twinjets. At the same time, combined sales of the 747-100, −200, −300, and 747SP models (collectively referred to as the 747 "Classics") exceeded 700, but new orders slowed precipitously. The introduction of the 747-300 did little to stem the decline, and  itself faced potential competition from more modern designs. As a result, Boeing began considering a more significant upgrade for its largest passenger jet. By early 1984, company officials had identified five development objectives for the latest 747 upgrade: new technologies, an enhanced interior, a range increase, more efficient engines, and a 10 percent reduction in operating cost. In September 1984, Boeing announced development of the newest 747 derivative, the "Advanced Series 300", at the Farnborough Airshow. On October 22, 1985, the type was officially launched when Northwest Airlines became the first 747-400 customer, with an order for 10 aircraft . Cathay Pacific, KLM, Lufthansa, Singapore Airlines, and British Airways also announced orders several months later, followed by United Airlines, Air France, and Japan Airlines. Design effort. Seven early customers, namely British Airways, Cathay Pacific, KLM, Lufthansa, Northwest, Qantas and Singapore Airlines, formed a consultative group to advise Boeing on the 747-400's design process. While the aircraft was planned as a new-technology upgrade, Boeing originally proposed minimal design changes in order to reduce development cost and retain commonality with existing models. The airline consultative group sought more advanced changes, including a two-crew glass cockpit. As a result  of airline input, the 747-400's new digital cockpit design featured cathode-ray tube (CRT) display technologies first employed on the 757 and 767. The autopilot was also changed to that of the 757 and 767; on the 747-400 a software update was added to allow an 'altitude intervention' mode. The 747-400's wingspan was stretched by over the Classic 747 through wingtip extensions. For reduced aerodynamic drag, the wings were fitted with -tall winglets. Despite the added length, the wings were lighter as a result of new aluminum alloys. The horizontal tail was also redesigned to  fit a fuel tank, resulting in a range increase, and the rudder travel was increased to 30 degrees. The landing gear was redesigned with larger wheels and carbon brakes. Internal changes further included a restyled cabin with new materials and updated fittings. New engines offered on the 747-400 included the Pratt & Whitney PW4056, the General Electric CF6-80C2B1F, and the Rolls-Royce RB211-524G/H. The engines offered lower fuel consumption and greater thrust, along with a full-authority digital engine control (FADEC) which adjusted engine performance for improved efficiency compared with the Classic 747s. A new auxiliary power  unit (APU) manufactured by Pratt & Whitney Canada was also selected to provide on-ground power for the 747-400, with a 40 percent reduction in fuel consumption compared to previous APU designs. Production and testing. Final assembly of the first 747-400 began at Boeing's Everett factory, the longtime site of 747 production, in September 1987. More than fifty percent of the aircraft was produced by subcontractors, with major structures, engine nacelles, and sub-assemblies supplied by Northrop, and upper deck fuselage frames from Daewoo. All components were integrated during the final assembly process at the Everett factory. The  first aircraft, equipped with PW4056 engines, was completed over the winter months of late 1987. On January 26, 1988, the first 747-400 rolled out at the Everett factory, while the first 737-400 rolled out at Boeing's Renton factory on the same day, marking the first double jetliner rollout in the manufacturer's history. By the time of the rollout, the 747-400 program had amassed more than 100 orders. The 747-400 flew for the first time on April 29, 1988, under the command of test pilot James Loesch and co-pilot Kenneth Higgins. The first flight  was six weeks behind schedule, owing to subcontractor delays in supplying components, and extra troubleshooting on the aircraft's electronics systems. The maiden flight took off from Paine Field, site of the Everett factory, and landed at Boeing Field, south of Seattle, after an uneventful 2 hours and 26 minutes. The 747-400's flight test program utilized the first four aircraft built, one more than the minimum number necessary to certify the aircraft's three engine options. One test aircraft each was fitted with the CF6-80C2B1F and RB211-524G/H engines, while the other two featured PW4056 engines , with the fourth aircraft serving as a backup. Federal Aviation Administration (FAA) certification was received on January 9, 1989, with Pratt & Whitney PW4000 engines, May 18, 1989, with General Electric CF6-80C2s and June 8, 1989, with Rolls-Royce RB211-524Gs. As the flight test program proceeded, Boeing encountered problems in the 747-400's production process, leading it to disclose delivery delays of up to one month for the first 20 aircraft built. A primary reason for the delays was the unprecedented complexity of interior configurations offered to airlines, which ranged from lavatory and galley locations to the color  shades of cabin warning labels. Coupled with new, relatively inexperienced workers, a lack of veteran technicians, interior configurations needing costly re-work, and teething problems with electronics integration on the advanced flight deck, 747-400 production fell behind schedule. The company managed to resolve early production issues by mid-1989, with the first example airframes of all three engine variants delivered within four months of each other, and overall delays not exceeding several weeks. Service entry and operations. The first 747-400 (N661US) was delivered to launch customer Northwest Airlines. This jet became known for an incident on Northwest Flight 85  caused by a rudder hardover. N661US was later sold to Delta Airlines when Northwest merged with it. N661US later became preserved at the Delta Flight Museum. This was the twentieth anniversary of the 747-100's first flight. On May 31, 1989, Singapore Airlines operated the first international service using a 747-400, on a flight from Singapore to London. In May 1989, one week before the initial delivery to the 747-400's first European customer, KLM, the Joint Aviation Authorities (JAA) shocked Boeing by refusing to grant regulatory certification for the aircraft, citing the upper deck cabin floor 's resistance to collapse in the event of a sudden decompression. While the manufacturer asserted that the 747-400's cabin floor was no different from the already-certified and in-service 747-300, the JAA maintained that the newer model would have a service life into 2020 and beyond and was thus subject to a newer, more stringent standard which had been updated to reflect the risk of explosive devices. In the days leading up to the first delivery to KLM, negotiations between Boeing, the FAA, and the JAA resulted in a compromise: a temporary operating certificate would be  issued for the 747-400, provided that the manufacturer develop a structural retrofit for the aircraft within two years. The last-minute deal allowed KLM and Lufthansa to take delivery of their 747-400s without further delays. After the first 747-400 deliveries, Boeing began production on more variants of the aircraft. The first 747-400 Combi, able to carry both passengers and freight, was rolled out in June 1989. The 747-400 Domestic, a short-range variant of the aircraft designed for Japanese intra-island services, first flew on March 18, 1991, and entered service with Japan Airlines on  October 22, 1991. A cargo variant, the 747-400F, was first delivered in May 1993 to Cargolux. By the end of the 1990s, Boeing was producing four versions of the 747-400. Further developments. The extended range freighter (ERF) entered service in October 2002. The next month, the extended range (ER) passenger version entered service with Qantas, the only airline ever to order the passenger version of the 747-400ER. Qantas initially used the 747-400ER for the Melbourne to Los Angeles and Dallas to Sydney route allowing the completion of the flight with full passenger load and cargo. Prior  to the 747-400ER, Qantas would complete such flights by blocking out 'E' zone of the cabin and limiting passenger numbers and cargo. The 747-400ER featured the "Boeing Signature Interior", which was later made available on the 747-400 (either as a retrofit on existing 747-400s or factory installation on new frames). The 747-400ER also introduced some flight deck enhancements, including liquid-crystal displays (LCDs), which replaced the six cathode ray tube (CRT) displays found on the Boeing 747-400. LCDs later became standard on the 747-400 as well, and could be retrofitted to earlier aircraft . The three standby flight displays found on the 747-400 were also replaced by a single combined LCD, the integrated standby flight display (ISFD), which also became standard on the 747-400 in late 2003. In the 2000s, as part of an effort to promote sustainable and alternative fuel development, as well as lower emissions, several 747-400 operators studied the use of oil extracted from the jatropha plant. Air New Zealand carried out the first commercial flight using jatropha oil for fuel; the airline's 747-400 had one engine burning a mix of 50% jatropha oil and 50 % jet fuel for two hours during the flight while engineers collected data. Continental Airlines tested jatropha oil in one of its airliners on January 7, 2009. Jatropha is easy to grow, needs little fertilizer or water, and produces an oil-rich plant. In 2007, unit cost for the 747-400/-400ER was US$234 or 266.5 million, and for the 747-400F/-400ERF US$238 or 268 million. Production of the 747-400 passenger version officially ceased on March 15, 2007. The last four -400s on order were cancelled by Philippine Airlines (which switched to the 777-300ER). The last to order  the -400 was China Airlines in November 2002, with the last passenger 747-400 constructed in 2005 and delivered in April of that year. It was the 1358th 747 (MSN33737/B-18215). The last 747-400 was a -400ERF delivered on December 22, 2009, to Kalitta Air. Retirement and economic value. The 747-400's leasing, resale and salvage value has dropped steeply because it is relatively expensive to operate. As most 747-400s are now more than 20 years old, airlines are beginning to replace them. Airlines using the 747-400 have been retiring the model, replacing it with more  fuel efficient aircraft. The main appeal of the 747-400 like its predecessors was its range rather than its capacity, and in most cases it has been replaced by wide-body twin-engine aircraft of similar range, such as the Boeing 777 and Boeing 787 Dreamliner. The change in emphasis from hub and spoke operations to point-to-point flights has also reduced the need for jumbo jets. Airlines such as British Airways and Qantas that plan to maintain the same capacity on routes currently served by 747-400s ordered the Airbus A380 rather than the updated 747-8. For  example, Delta Air Lines reduced the number of flights it operated from the United States to Narita International Airport that were intended to transfer passengers to other destinations in Asia, switching to twin-engine widebody aircraft operating from an expanded hub at Seattle-Tacoma International Airport. Total capacity was cut, but load factors improved. In April 2015, Delta announced it would accelerate the retirement of its 747-400s and replace them either with Airbus A330 or Airbus A350 aircraft (both of which are twinjets). Delta could not keep the 747s full without deeply discounting ticket prices; the discounts and increased  maintenance required of a four-engine aircraft led to a drag on profits. Since the cost of replacing a 747-400 is high (an airline must purchase or lease another wide-body), some operators choose to fly the 747-400 to the conclusion of its accepted useful life and then scrap it. The current parts resale value for this aircraft has been reduced to its engines. When a 26-year-old 747-400 owned by Delta flew through a violent hailstorm, the company indicated it was likely the aircraft would be scrapped. George Dimitroff, head of valuations for FlightGlobal, estimated  the aircraft's value before the incident at about $8 million. He noted that this was not the same as its insured value. As discussed in the section on 747-400 converted freighters, there is no longer a viable economic model for converting retired passenger 747-400 aircraft into dedicated freighters, so most retired passenger aircraft will likely be scrapped. Several airlines have retired their 747-400s from the trans-pacific market. Remaining operators in 2014 included EVA Air, Qantas, Virgin Atlantic, British Airways and United. United's deployment of them also reflected a change in emphasis from Asian  hubs to domestic hubs. On January 11, 2017, United announced it would begin phasing out its 747-400s and made its last 747 flight on November 7 that year. Delta Airlines was the last US airline to operate the Boeing 747, retiring the last of the 747-400 fleet it inherited from Northwest Airlines in December 2017. British Airways, the largest passenger 747-400 operator, announced that they will be phasing out their 747-400 fleet in February 2024, British Airways will replace its Boeing 747-400s with the Airbus A350-1000. Lufthansa will be retiring their 747-400 fleet  in 2025 as they are being replaced by the Boeing 777x and the Boeing 747-8i. KLM will be retiring their 747-400 Combi and Passenger fleet in 2020 as they are being replaced by the Boeing 777-300ER, the Boeing 787-10 Dreamliner, and the Airbus A350-900. However, KLM announced it plans to retire its last Boeing 747-400 by January 1, 2021, instead of 2020 due to delivery delays for the new wide-body twin jets. The global COVID-19 pandemic hastened the retirement of many remaining passenger Boeing 747-400s due to a sharp decline in passenger  traffic. For instance, KLM retired its Boeing 747-400 Combi and Passenger fleets in March 2020. Qantas announced the retirement of its 747-400 and 747-400ER fleet by the end of 2020, with the Boeing 787-9 Dreamliner taking its place. China Airlines also announced that they will be retiring their remaining four passenger Boeing 747-400s by the end of 2020 due to the COVID-19 pandemic (which were delivered between 2004 and 2005, operating on flights within Asia) with the Airbus A350-900 and Boeing 777-300ER taking over all high-volume routes and all Asian International routes . However, China Airlines didn't retire its last passenger Boeing 747-400 until February 2021. British Airways retired its remaining 31 Boeing 747-400s 4 years ahead of the original February 2024 deadline. Virgin Atlantic also retired their remaining leisure fleet 747-400s in May 2020 citing the COVID-19 pandemic - the fleet was due to retire in 2021. As of September, 2021, there were just 42 passenger 747-400 in operation (10 actively flying, 32 in storage) across 10 carriers worldwide. Lufthansa and Air China had plans to resume flying some of their stored aircraft by October, 2021. Design. The  747-400's airframe features extended and lighter wings than the previous 747s, capped by winglets. The winglets result in a 3 percent increase in long-range cruise, improved takeoff performance, and higher cruise altitudes. The extended wingspan also gains an additional leading edge flap section. When unfurnished, the basic 747-400 fuselage is lighter than preceding models, but when fitted out it is heavier and stronger than previous models. The landing gear uses the same configuration as the previous 747s, but with carbon brakes replacing the previous steel ones, and overall weight savings of . The 747-400's glass  cockpit features CRT displays which show flight instrumentation along with engine indication and crew alerting system (EICAS) diagnostics. The flight engineer station on the previous 747s is no longer installed, and the new displays and simplified layout results in a two-thirds reduction of switches, lights, and gauges versus the Classic 747. Other new systems include an advanced Honeywell flight management computer (FMC) which assists pilots in calculating optimal altitudes and routes along with a Rockwell-Collins central maintenance computer (CMC) which automates troubleshooting tasks. The redesigned 747-400 interior features new cabin sidewalls, heat-resistant phenolic glass, carbon composite  paneling, and larger storage bins. An enhanced in-flight entertainment framework, called the Advanced Cabin Entertainment/Service System (ACESS), debuted on the 747-400, which integrates 18-channel audio capability, four-passenger intercom announcement zones, inter-cabin telephones, and passenger lighting into a central system. An eight-bunk overhead crew rest is installed above the aft cabin, while a second crew rest area is located on the upper deck behind the cockpit for flight crew use. The last few 747-400s delivered feature the Boeing Signature Interior, derived from the Boeing 777. Variants. 747-400. The original variant of the  redesigned 747, the 747-400 debuted an increased wingspan, winglets, revised engines, and a glass cockpit which removed the need for a flight engineer. The type also featured the stretched upper deck (SUD) introduced with the 747-300. The passenger model formed the bulk of 747-400s sold, and 442 were built. In 1989, the Qantas 747-400 VH-OJA flew non-stop from London Heathrow to Sydney, a distance of , in 20 hours and 9 minutes to set a commercial aircraft world distance record. , this is the fastest heavyweight flight between London and Sydney. This was a delivery flight  with no commercial passengers or freight on board. During testing, the first 747-400 built also set a world record for the heaviest airliner takeoff on June 27, 1988, on a flight to simulate heavy-weight stalls. The aircraft had a takeoff weight of , and in order to satisfy Fédération Aéronautique Internationale regulations, climbed to a height of . On February 9, 2020, a British Airways Boeing 747-400 broke the New York–London subsonic airliner speed record in 4 hours 56 minutes, pushed by the powerful Jetstream linked to Storm Ciara. 747-400F. The 747-400F (Freighter) is an all  freight version of the 747-400. While using the updated systems and wing design of the passenger versions, it features the original short upper deck found on the classic 747s to reduce weight. The 747-400F has a maximum takeoff weight of and a maximum payload of . The -400F can be easily distinguished from the passenger -400 by its shorter upper-deck hump and lack of windows along the main deck. The model's first flight was on May 4, 1993, and entered service with Cargolux on November 17, 1993. Major customers included Atlas Air, Cargolux, China Airlines, Korean Air , Nippon Cargo Airlines and Singapore Airlines. The 747-400F has a main deck nose door and a mechanized cargo handling system. The nose door swings up so that pallets or containers up to can be loaded straight in on motor-driven rollers. An optional main deck side cargo door (like the 747-400M Combi) allows loading of dimensionally taller cargo modules. A lower deck ("belly") side door allows loading of unit load devices (ULD) up to 163 cm in height. Boeing delivered 126 Boeing 747-400F aircraft with no unfilled orders . The last -400F was delivered to Nippon Cargo  Airlines on August 2, 2008. A 2008 747-400F value new was $253*0.4round0 million, a 2003 aircraft was leased $400,000 per month in 2019 for a $29 million value while a B747-400BCF was priced at around $10 million. 747-400M. The 747-400M (a passenger/freight or "Combi" variant originally designated as 747-400BC) first flew on June 30, 1989, and entered service with KLM on September 12, 1989. Based on the successful Combi versions of the Classic 747s, the -400M has a large cargo door fitted to the rear of the  fuselage for freight loading to the aft main deck cargo hold. A locked partition separates the cargo area from the forward passenger cabin, and the -400M also features additional fire protection, a strengthened main deck floor, a roller-conveyor system, and passenger-to-cargo conversion equipment. The last 747-400M was delivered to KLM on April 10, 2002. Boeing sold 61 747-400M aircraft, which was similar to earlier 747 "Combi" versions (78 747-200M, 21 747-300M). KLM is the last 747-400M operator. The Boeing 747-400M was initially planned to  be retired by January 1, 2021, however the Boeing 747-400M was instead retired by March 27, 2020, as Air France-KLM announced in early March 2020 to retire all remaining passenger Boeing 747-400s of KLM (including all KLM Boeing 747-400M aircraft) immediately due to reduced air travel demand caused by the COVID-19 pandemic, although, due to a global shortage in air cargo capacity, three KLM 747-400Ms were temporarily reactivated after just a week to operate cargo-only flights to Asia. 747-400D. The 747-400D (Domestic) is a high-density seating model developed for  short-haul, high-volume domestic Japanese flights, serving the same role as the prior Boeing 747-100SR domestic model. This model is capable of seating a maximum of 568 passengers in a two-class configuration or 660 passengers in a single-class configuration. The -400D lacks the wingtip extensions and winglets included on other variants. Winglets would provide minimal benefits on short-haul routes while adding extra weight and cost. The -400D may be converted to the long-range version if needed. The 747-400D can be distinguished from the otherwise similar-looking 747-300 by the extra windows on  the upper deck. These allow for extra seating at the rear of the upper deck, where a galley would normally be situated on longer flights. In total, 19 of the type were built, with the last example delivered to All Nippon Airways on February 11, 1996. This variant was retired when ANA retired its last 747-400D on March 31, 2014. 747-400ER. The 747-400ER (Extended Range) was launched on November 28, 2000, following an order by Qantas for six aircraft. The model was commonly referred to as the '910k' signifying its maximum weight achieved via structural modifications and  modified landing gear. The 747-400ER included the option of one or two additional body fuel tanks in the forward cargo hold, however, Qantas was the only customer that ordered the single body tank configuration, and no airplanes were delivered with dual body fuel tanks. Manufactured by Marshall Aerospace, these tanks utilized metal to metal honeycomb-bonded technology to achieve a high fuel volume-to-dry weight ratio. The tanks feature a double wall, integrated venting system, and achieve fuel control via a modified Fuel System Management Card (FSMC) which optimizes fuel transfer into the Center Wing Tank (CWT) in  flight along with the fuel transfer from the Horizontal Stabiliser Tank (HST). The tank is removable using tooling that interfaces with the cargo loading system. Similar technology has been used by Marshall in the development of body fuel tanks for the Boeing 777-200LR and Boeing P-8A Poseidon. Other changes to the 747-400ER include the relocation of oxygen system components and the potable water system tanks and pumps, since the body fuel tanks prevent access to the standard locations. The first 747-400ER was used as a test flight airplane and painted in Boeing colors, registration N747ER. Qantas received  the first delivery of a 747-400ER registration VH-OEF on October 31, 2002; however, this was the second airplane built. The flight test airplane was later refurbished, repainted in standard QANTAS livery, and registered as VH-OEE. Qantas was the only customer for the passenger version of the 747-400ER, chosen by the airline to allow for full loads between Melbourne and Los Angeles, particularly in the western direction. The 747-400ER can fly farther, or carry more payload, than the -400. In May 2018 Qantas announced that it would retire its entire 747 fleet including all 747-400ERs  by 2020. 747-400ERF. The 747-400ERF (Extended Range Freighter) is the freight version of the -400ER, launched on April 30, 2001. The 747-400ERF is similar to the 747-400F, except for increased gross weight capability which allows it to carry more payload. Unlike the 747-400ER, no customers ordered the optional body (cargo compartment) fuel tanks which reflects the desire to carry more cargo, not fuel, as the benefit of the improved payload rating. The 747-400ERF has a maximum takeoff weight of and a maximum payload of . It offers cargo airlines the choice of either adding more  payload than other 747-400 freighter variants, or adding to the maximum range. The -400ERF has a range of with maximum payload, about farther than the standard 747-400 freighter, and has a strengthened fuselage, landing gear, and parts of its wing, along with new, larger tires. The first -400ERF was delivered to Air France (via ILFC) on October 17, 2002. Boeing has delivered 40 Boeing 747-400ERFs with no outstanding orders. The new 747-8 Freighter has more payload capacity, but less range than the 747-400ERF when both are at MTOW. 747-400 Boeing Converted Freighter. The 747 -400BCF (Boeing Converted Freighter), formerly known as the 747-400SF (Special Freighter), is a conversion program for standard passenger 747-400s. The project was launched in 2004 with conversions by approved contractors such as HAECO, KAL Aerospace and SIA Engineering Company. The first Boeing 747-400BCF was redelivered to Cathay Pacific Cargo and entered service on December 20, 2005. Cathay retired the 747-400BCF in 2017 after 11 years of service. The 747-400BDSF (BeDek Special Freighter) is another passenger-to-freighter conversion, carried out by Israel Aerospace Industries (IAI). The first 747-400BDSF was redelivered to Air China Cargo  in August, 2006. Several Boeing 747-400Ms of EVA Air have been converted as BDSF model after retiring from passenger service. Neither the 747-400BCF nor the 747-400BDSF has a nose cargo door; freight can only be loaded through the side cargo door. The demand for converted 747-400 freighters declined in the early 2010s, due to the availability of belly cargo capacity on more efficient passenger wide-body twin jets, and new orders for Boeing 747-8F and 777F freighters. Approximately 79 747-400 aircraft were converted before the programs were terminated; 50 of these converted aircraft were  747-400BCF, with the remaining 29 being 747-400BDSF. Boeing announced the end of their conversion program in 2016, although conversions had ceased years earlier with no orders after 2012. Some converted freighters, that had been retired to desert storage, were returned to active service due to the increase in demand for air cargo capacity in the 2020-2021 COVID era. 747 Large Cargo Freighter. Boeing announced in October 2003 that, because of the amount of time involved with marine shipping, air transport would be the primary method of transporting parts for the Boeing 787 Dreamliner. Used passenger 747-400  aircraft have been converted into an outsize, "Large Cargo Freighter" (LCF) configuration to ferry sub-assemblies to Everett, Washington for final assembly. The LCF has a bulging fuselage similar to that of the Aero Spacelines Super Guppy or Airbus Beluga cargo aircraft. The conversion, designed by Boeing engineers from Puget Sound, Moscow and Canoga Park, Cal., and Gamesa Aeronáutica in Spain, was carried out in Taiwan by a subsidiary of the Evergreen Group. Boeing purchased four second-hand aircraft and had them all converted; the fourth and final LCF took its first flight in January 2010. Delivery times are as  low as one day using the 747 LCF, compared to up to 30 days for deliveries by ship. The LCF had the largest cargo hold of any aircraft until being surpassed by the Airbus Beluga XL, and can hold three times the volume of a 747-400F freighter. The LCF is not a Boeing production model and has not been offered for sale to any customers. The LCFs are intended for Boeing's exclusive use. Operators. As of March 2022, there are 41 passenger aircraft in service. The largest operator is Rossiya Airlines with nine. Additionally, there are 215 freighters  in service, operated primarily by Atlas Air (36), Kalitta Air (24) and China Airlines (18). Former operators. This list also includes carriers that used the aircraft temporarily, besides main operators. Incidents and accidents. The first hull loss of a 747-400 occurred on November 4, 1993, when China Airlines Flight 605, flying from Taipei to Hong Kong's Kai Tak Airport, touched down more than past the runway's displaced threshold during 20-knot (gusting to 38 knots) crosswinds. Combined with the disengagement of auto brakes and retracted speed brakes, manual braking and thrust reversal were not enough to prevent  the aircraft from sliding into Victoria Harbour. No one was seriously injured, but the aircraft was written off. The type's second hull loss occurred on October 31, 2000, when Singapore Airlines Flight 006, a 747-400 flying on a Singapore to Los Angeles route via Taipei, rammed into construction equipment while attempting to take off from a closed runway at Chiang Kai-shek International Airport. The aircraft caught fire and was destroyed, killing 79 passengers and four crew members. The cause was attributed to the flight crew navigating to the wrong runway. The 747-400F has recorded four hull -loss accidents. On September 3, 2010, UPS Airlines Flight 6 from Dubai International Airport to Cologne Bonn Airport, a 747-400F with two crew members on board, crashed roughly 25 minutes after departure. The crew declared an emergency, apparently due to an in-flight fire, and after abandoning one attempt at landing, are unable to see their instruments due to the smoke entering the cockpit and their oxygen masks did not have good filtering of the smoke from the pilot's vision and ran out of oxygen in the attempt to land. The aircraft impacted with the ground at high  speed, killing both crew members. The result after the accident was that the fire started with lithium-ion batteries and the FAA decided to limit how powerful can lithium batteries be transported by plane and the powerful ones, more than 160 watt-hours, which per person can carry two. On July 28, 2011, Asiana Airlines Flight 991, a Boeing 747-400F flying from Incheon Airport to Shanghai Pudong Airport, crashed into the Pacific Ocean off Jeju Island, South Korea, after reportedly suffering mechanical problems due to a possible on-board fire. Two crew members on board were killed. National Airlines  Flight 102, a 747-400BCF crashed on April 29, 2013 (the 25th anniversary of the type's first flight) at Bagram Air Base Afghanistan killing 7 crew members. The crash was attributed to a cargo shift of military vehicles to the back of the hold during take-off. On January 16, 2017, Turkish Airlines Flight 6491, a 747-400F operated by ACT Airlines, failed to reach the runway on landing in thick fog at Manas International Airport in Bishkek, Kyrgyzstan, crashed into a residential area, and caught fire. 39 people died, including all four crew members, and 35 people on  the ground. Other incidents involving the 747-400 did not result in irreparable aircraft damage. On December 15, 1989, KLM Flight 867, a 747-400M, en route to Tokyo's Narita International Airport from Amsterdam's Schiphol International Airport via Anchorage International Airport, flew through a thick cloud of volcanic ash, causing severe damage to the aircraft and replacement of all four engines. On July 23, 1999, a man killed the pilot of All Nippon Airways Flight 61, a 747-400D bound for New Chitose Airport near Sapporo, Hokkaidō from Tokyo International Airport (Haneda), during an attempted hijacking, and  was restrained by other crew members; the aircraft landed safely. On September 23, 1999, Qantas Flight 1, flying from Sydney to London via Bangkok, overran the runway after touching down more than from the threshold during a storm with heavy rain, resulting in aircraft damage and minor passenger injuries. On January 31, 2001, the pilot of Japan Airlines Flight 907, a 747-400D bound for Naha International Airport from Tokyo International Airport, made an emergency dive, narrowly avoiding a collision with a Japan Airlines DC-10-40 due to conflicting instructions from air traffic control; several people on the 747-400  suffered injuries during the evasive manoeuvres and some interior damage was sustained to the aircraft. On October 9, 2002, Northwest Airlines Flight 85, traveling from Detroit Metropolitan Wayne County Airport to Narita International Airport, made an emergency landing at Anchorage International Airport after a sudden lower rudder hardover. On July 25, 2008, Qantas Flight 30, traveling to Melbourne Airport from Hong Kong International Airport, made an emergency landing at Ninoy Aquino International Airport in Manila, Philippines with a gaping hole in its lower forward fuselage; no one was hurt, and authorities determined that an exploding emergency oxygen supply bottle was  the most likely cause.