Boeing 747-8

The 747-8 is the last member of the 747 family and the largest aircraft Boeing has ever built. It came after almost two decades of failed attempts to enlarge the Jumbo. At the 1996 Farnborough Airshow the manufacturer announced the 747-500X and 747-600X, fuselage stretches that did not attract enough interest to enter development. In 2000 it offered the 747X and 747X Stretch as alternatives to Airbus's A3XX: the former widened the span to 229 ft (69.8 m) with a root insert to carry 430 passengers over 8,700 nautical miles; the latter stretched to 263 ft (80.2 m) and 500 seats with 7,800 nautical miles of range. Neither took hold, though some 747X ideas were reused on the 747-400ER. Next came the 747-400XQLR ("Quiet Long Range") study, with raked wingtips like the 767-400ER's and sawtooth nacelles to cut noise; it never reached production, but its features fed the following project, the 747 Advanced.

In early 2004 Boeing announced tentative plans for that 747 Advanced, and on November 14, 2005 it launched the aircraft as the 747-8, a designation chosen to underline its technological ties to the 787 Dreamliner: it would share the new twinjet's General Electric GEnx engines and cockpit technology, including fly-by-wire ailerons and spoilers. Boeing then forecast a market of 300 aircraft, split evenly between freighters and passenger versions. Cargolux and Nippon Cargo Airlines were the first customers, ordering the freighter in November 2005; an undisclosed VIP customer placed the first passenger order in May 2006 and Lufthansa became the first airline to order it, with 20 announced on December 6, 2006. The freighter's configuration was firmed in October 2006 and the Intercontinental's in November 2007.

It was the first lengthened 747 to go into production, and the second with a modified-length fuselage after the shortened 747SP. The fuselage grows by 18.3 ft (5.6 m) over the 747-400 to 250 ft 2 in (76.25 m), making it the longest passenger airliner in service, surpassing the Airbus A340-600 by 3.1 ft (0.95 m). With a maximum take-off weight of 975,000 lb (442 t) it is also the heaviest aircraft, commercial or military, built in the United States, and the heaviest Boeing airliner.

The wing was overhauled while keeping the sweep and basic structure to avoid extra cost, but with a thicker, deeper airfoil, single-slotted outboard and double-slotted inboard flaps, a carbon-fibre trailing edge and tip, and raked wingtips like those of the 777-200LR, 777-300ER and 787 in place of the 747-400's winglets. The greater span makes it a Category F airport aircraft, like the A380. The passenger version's wing holds 64,225 US gal (243 m³) of fuel and the freighter's 60,925 (231 m³), which spared Boeing from adding costly tail tanks. The engines are a smaller, more efficient version of the 787's GEnx, recognisable by the chevron edges on the nacelles. The result, Boeing says, is an aircraft 16% more fuel-efficient than the 747-400, with 13% lower seat-mile costs and a 30% smaller noise footprint; at London's three major airports it earned a Quota Count of 2 for take-off and 1 for landing.

The passenger version, the 747-8 Intercontinental, carries up to 467 passengers in three classes over 8,000 nautical miles (15,000 km) at Mach 0.855: 51 more passengers and two more pallets than the 747-400, with 26% more cargo volume. Its upper deck is longer than the -400's and the interior borrows from the 787 a curved stairway, curved overhead bins, windows 8% larger and LED mood lighting. The 747-8F freighter keeps the 747-400F's short upper deck, with a 975,000 lb maximum take-off weight, a 308,000 lb (140 t) payload and 4,390 nautical miles of range; it gains four pallet positions on the main deck and, according to the manufacturer, cuts ton-mile operating cost by 16% compared with the 747-400F.

Production of the first 747-8F began at Everett in August 2008, and the programme slipped from the outset: on November 14, 2008 Boeing announced the first delay, citing limited engineering resources, design changes and the factory strike. In February 2009, with Lufthansa as the only airline customer for the Intercontinental, the company admitted it was reassessing the project. In October 2009 the first flight was pushed to the first quarter of 2010, with a US$1-billion charge against earnings; Cargolux kept its thirteen freighters and Lufthansa its order. Korean Air became the second passenger customer on December 4, 2009 with five aircraft.

The 747-8F first flew on February 8, 2010 from Paine Field, after a 2.5-hour weather delay. Boeing estimated more than 1,600 flight hours would be needed for certification, and the campaign moved to Moses Lake and Palmdale so as not to interfere with 787 testing. Problems emerged: turbulence off the landing-gear doors interfering with the inboard flaps (fixed by redesigning the outboard doors), a possible defect in an upper longeron made by Vought, inboard-aileron oscillation and structural flutter, which used up almost all the schedule margin. By the end of June 2010 the three test aircraft had flown more than 500 hours, and on August 21, 2010 a 747-8F took off from Victorville weighing 1,005,000 lb (455,860 kg). The freighter received its amended type certificate from the FAA and EASA on August 19, 2011; Cargolux refused the first two deliveries scheduled for September 19 and 21 over "unresolved contractual issues", and finally took the first aircraft on October 12, 2011.

Major assembly of the first 747-8 Intercontinental began on May 8, 2010; it was unveiled at Everett on February 13, 2011 and flew on March 20, 2011. The FAA certified it on December 14, 2011. Aeroelastic flutter found in testing forced the horizontal-stabiliser fuel tanks to be closed off, cutting range by 300–500 nautical miles until a performance package allowed their reactivation in early 2014. The first Intercontinental went to a VIP customer on February 28, 2012; Lufthansa received its first on May 5, 2012 and put it into service on June 1, 2012 between Frankfurt and Washington. In 2014 Boeing launched the "Project Ozark" improvement programme: aircraft built from that year weigh 9,000 lb (4.1 t) less than the first off the line and burn 3.5% less fuel.

Demand fell well short of projections and concentrated on the freighter, which had no direct competitor after the A380F was cancelled. Emirates and British Airways considered the passenger version but chose the A380, and the 777-9X ended up outselling the Intercontinental. The production rate dropped from 2 to 1.75 aircraft a month in April 2013, to 1.5 in October 2013, to one in 2016 and to 0.5 from September 2016, with charges of $569 million (2015), $70 million and $814 million (2016). UPS's order for 14 freighters on October 27, 2016, extended by another 14 on February 1, 2018, kept the line alive. On July 2, 2020 it emerged that Boeing would end 747 production in 2022, and on January 12, 2021 Atlas Air ordered the final four. The last 747, a 747-8F for Atlas Air and the 1,574th of the family, rolled off the line on December 6, 2022 and was delivered on January 31, 2023, closing more than 50 years of production. A total of 155 were built: 107 freighters and 48 passenger aircraft.

In July 2018 there were 110 aircraft in airline service, with Lufthansa (19), Korean Air (17), Cargolux (14), Cathay Pacific Cargo (14), AirBridgeCargo (11), UPS (7), Polar Air Cargo (7), Air China (7), Silk Way West (5), Atlas Air (3), Nippon Cargo Airlines (1) and CargoLogicAir (1). VIP-configured Intercontinentals have been a niche of their own: the Qatar Amiri Flight received three, and Kuwait, Oman, Brunei, Morocco, Turkey, Saudi Arabia and Egypt (the last, in 2021, with an airframe built for Lufthansa as D-ABYE that the airline never accepted) operate one each. The first BBJ 747-8 with an AeroLoft sleeping area in the crown space was produced in 2012. In January 2015 the US Air Force selected the 747-8 to replace the VC-25A presidential aircraft, with delivery having slipped to 2029 by 2025; in April 2024 Sierra Nevada Corporation won the Survivable Airborne Operations Center contract, successor to the E-4, for which five 747-8Is were bought from Korean Air out of a planned nine.

Two incidents marked the freighter's entry into service: on September 11, 2012 an AirBridgeCargo 747-8F suffered a low-pressure turbine shaft separation in a GEnx, prompting the NTSB to recommend ultrasonic inspections, and on July 31, 2013 another of the airline's aircraft suffered core icing in three engines near Chengdu, addressed with software changes by Boeing and General Electric.

The 747-8 closed the Jumbo's story. Conceived to fill the niche between the A380 and the 777-300ER, it met a market that no longer bought range with four engines: wide-body twinjets offered similar range with lower fuel burn and a lower upfront cost. As a freighter, by contrast, it inherited the dominant position of the 747-400s, which carried around half of the world's air freight, and the 747-8F accounted for the great majority of orders right up to the end of the assembly line.