Boeing 747

• 1. Introduction

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  On the 22nd of January 1970, a Pan Am 747 lifted off from New York bound for London, and air travel changed forever. The plane had been six hours late. The original aircraft, Clipper Young America, had developed engine overheating on the tarmac, forcing ground crews to scramble for a substitute. When Clipper Victor finally departed, it carried more passengers in a single flight than most airliners of the day could manage in several. The machine had a hump behind the cockpit, four massive engines, and a swept wing that gave it a cruise speed close to Mach 0.85. It was called, almost immediately, the Jumbo Jet. What made it possible for one airplane to carry hundreds of people across oceans at speed, with a budget ticket in reach of ordinary travelers? And why did Boeing, in building it, take a gamble so large that the firm's president later admitted it was "really too large a project for us"?

• 2. The Military Seed

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  In 1963, the United States Air Force launched a set of studies on an extremely large strategic transport. The C-141 Starlifter had just entered service, but military planners wanted something capable of carrying cargo no existing aircraft could handle. By March 1964, formal requirements had taken shape for the CX-Heavy Logistics System, calling for a payload capacity of 180,000 lb, a speed of Mach 0.75, and an unrefueled range of 5,000 nautical miles. The payload bay had to be 17 feet wide, 13.5 feet high, and 100 feet long, with doors at both ends. Proposals arrived from Boeing, Douglas, General Dynamics, Lockheed, and Martin Marietta. All of them faced the same puzzle: a nose cargo door was required, which meant the cockpit had to move. Douglas placed a small pod just forward and above the wing; Lockheed ran a long spine the full length of the fuselage; Boeing blended both ideas, using a longer pod stretching from just behind the nose to just behind the wing. In 1965, Lockheed won the contract with its design, which became the C-5 Galaxy. Boeing lost the bid, but the raised cockpit and nose door concept did not disappear. Joe Sutter and his team carried both features directly into the 747's design, where the raised cockpit produced the airplane's signature hump and left room for a front cargo door on freighter variants.

• 3. Pan Am and the Bet

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  Juan Trippe, president of Pan American Airways, pressed Boeing for a jet roughly twice the size of the 707, with a 30% reduction in cost per passenger-mile. Trippe also argued that a larger aircraft could relieve airport congestion. In 1965, Boeing transferred Joe Sutter from the 737 development team to lead design work on the new airliner, already assigned the model number 747. Sutter began consulting directly with Pan Am and other carriers to understand what they actually needed. The formal order arrived in April 1966: 25 Boeing 747-100 aircraft for $525 million. At the contract-signing banquet in Seattle, on Boeing's 50th anniversary, Trippe predicted the 747 would be "a great weapon for peace, competing with intercontinental missiles for mankind's destiny." Japan Airlines and Lufthansa followed with orders, and production approval came in July 1966. The schedule Boeing accepted was crushing. The company had 28 months to design the aircraft and deliver the first one to Pan Am by the end of 1969 - roughly two-thirds of the normal development time. Workers on the program were nicknamed "The Incredibles." The factory did not yet exist when the contract was signed. Boeing bought a 780-acre site near Everett, Washington, in June 1966, some 30 miles north of Seattle, adjacent to Paine Field. More than four million cubic yards of earth had to be moved to level the ground. At one point the 747's full-scale mock-up was built before the roof above it was finished. By 1968, the program cost had reached $1 billion. The firm's total debt exceeded $2 billion, with $1.2 billion owed to banks - a record for any American company at the time.

• 4. Engineering the Hump

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  The original 747 design called for a full-length double-deck fuselage, with eight-across seating on the lower deck and seven-across on the upper. Designers scrapped that plan in early 1966, troubled by evacuation routes and limited cargo capacity. The wider single-deck layout that replaced it required moving the cockpit to a shortened upper deck, producing the distinctive hump. The small space behind the cockpit had no obvious purpose in early designs; it was initially listed simply as a "lounge" area. One configuration that never made it off the drawing board placed the pilots below the passengers and was known internally as the "anteater." The wing was swept at 37.5 degrees, enabling a cruise speed between Mach 0.84 and 0.88. To allow the aircraft to operate from existing runways despite its enormous weight, engineers added Krueger flaps along almost the entire leading edge and complex triple-slotted flaps at the trailing edge; when fully deployed, those trailing-edge flaps increased wing area by 21% and lift by 90%. The entire project was designed using a new methodology called fault tree analysis, which mapped the effect of any single component failure on all connected systems. Structural redundancy was built in throughout: four redundant hydraulic systems, four main landing gear legs each with a four-wheel bogie, and split control surfaces. The wing's 37.5-degree sweep also had a secondary benefit: it reduced the overall wingspan enough that the 747 could fit existing airport hangars. A single 747 Classic airframe contained approximately 135 miles of electrical wiring and 1 mile of hydraulics.

• 5. First Flight and Early Troubles

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  On the 30th of September 1968, the first 747 was rolled out of the Everett assembly building before representatives of the 26 airlines that had placed orders. The first flight took place on the 9th of February 1969, with test pilots Jack Waddell and Brien Wygle at the controls and Jess Wallick at the flight engineer's station. Despite a minor flap problem, the aircraft handled well. It was found largely immune to Dutch roll, a dangerous oscillation that had troubled the early swept-wing jets. Flutter testing later in the program revealed wing oscillation under certain conditions; the most severe high-speed flutter problem required inserting depleted uranium counterweights as ballast in the outboard engine nacelles. When El Al Flight 1862 crashed at Amsterdam in 1992 carrying 282 kilograms of uranium in the tailplane, investigators looked closely at those weights; detailed analysis concluded that radiation exposure was several orders of magnitude below the limit set for chronic occupational exposure. The JT9D engines caused more immediate headaches. Engine stalls from rapid throttle movements and distortion of turbine casings after short periods of service stranded up to 20 completed aircraft at Everett while they waited for engine fixes. One test aircraft was damaged on the 13th of December 1969 when a pilot undershot the short runway at Renton Municipal Airport, tearing off the right outer landing gear and damaging two engine nacelles. Despite that incident, Boeing still managed to take a test aircraft to the 28th Paris Air Show in mid-1969 for the aircraft's first public appearance. The 747 received its FAA airworthiness certificate in December 1969, less than four years after Sutter's team began design work.

• 6. A World of Passengers

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  On the 15th of January 1970, First Lady Pat Nixon christened Pan Am's first 747 at Dulles International Airport, spraying red, white, and blue water on the fuselage in place of champagne. Lufthansa received its first 747-100 on the 10th of March 1970 and entered service on the Frankfurt-New York route the following month, becoming both the first European operator and the first carrier outside the United States to begin 747 service. Japan Airlines followed in June 1970 with routes between Tokyo, Hong Kong, and Los Angeles. Within the first year, Air France, Air India, and Sabena had joined the list of operators. The aircraft's economics were demanding. A fully occupied 747 offered the lowest seat cost in aviation; a 747 running at only 70% occupancy still consumed more than 95% of the fuel of a full one. Many flag carriers bought the aircraft for its prestige, even when the economics did not fully support it. When the recession of 1969-1970 struck, Boeing sold only two 747s in the year and a half following September 1970 - both to Irish flag carrier Aer Lingus. American Airlines tried replacing coach seats with piano bars to attract passengers before eventually retiring its 747-100s from passenger service in 1983 and exchanging them with Pan Am for smaller aircraft. The aircraft found its most durable commercial home in Asia and Europe. On one business trip to Japan, Joe Sutter counted 55 aircraft at Narita International Airport while waiting for his flight, and estimated that even at 75% occupancy they carried roughly 20,000 people in the two hours he spent watching. Japanese carriers operated the 747SR short-range variant on dense domestic routes with seating for up to 550 passengers, responding to a domestic load factor that had reached an average of 85% by 1970.

• 7. Variants and Reinventions

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  Boeing introduced the 747-200 in 1971 with more powerful engines and a maximum takeoff weight of 833,000 lb, up from the initial 735,000 lb on the -100. The range grew from 4,620 to 6,560 nautical miles. A prototype 747-200B reached a maximum takeoff weight of 820,700 lb in a test flight on the 12th of November 1970 at Edwards Air Force Base. On the 1st of November 1976, an RB211-powered -200 set a world record for maximum mass lifted during a trial flight at NAS Lemoore, reaching 840,500 lb. The shortened 747SP entered service in 1976. It was 48 feet 4 inches shorter than the -100, with a simplified single-slotted flap configuration, a double-hinged rudder, and longer stabilizers. Pan Am and Iran Air were its launch customers, and Iran Air launched what was at the time the longest non-stop commercial flight in the world on the Tehran-New York route. The 747-300, launched in 1980 and first delivered in 1983, added a stretched upper deck and increased seating to up to 400 in three classes. Throughout the early 1980s, customers complained publicly that Boeing was making only incremental improvements. An interview published in the 28th of May 1984 issue of Aviation Week and Space Technology quoted Lufthansa's then-deputy chairman warning against a "piecemeal approach" that would saddle airlines with 747 fleets having little remaining commonality. Boeing responded by launching the 747-400 in October 1985. It featured a two-crew glass cockpit, reducing the instrument count from nearly 690 dials and lights and 280 switches to 300 indicators and 200 switches. The 747-400 eliminated the flight engineer's position and entered service in 1989. The 747-8, announced on the 14th of November 2005 and powered by the General Electric GEnx engine developed first for the 787 Dreamliner, was first delivered in October 2011. The 1,500th Boeing 747 was handed over to Lufthansa in June 2014.

• 8. Freighters, Government, and Final Delivery

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  Lufthansa Cargo took delivery of the first dedicated 747 freighter, a -200F, on the 9th of March 1972. Air France, Japan Airlines, and Seaboard World Airlines followed in 1974. The first conversion from a passenger airframe was also carried out in 1974 at Boeing's Wichita plant, on an ex-American Airlines 747-100 acquired by Flying Tiger Line. Freighter variants featured an upward-opening hinged nose and a side cargo door; conversions on former passenger aircraft added only the side cargo door, reinforced the main deck floor, and stripped out seats and galleys. Military users put the aircraft to striking purposes. During Operation Solomon in 1991, an El Al 747-200C carried 1,087 passengers on a single flight evacuating Ethiopian Jews from Addis Ababa to Tel Aviv - exceeding the maximum capacity of the 747-400. Two other El Al 747s flew the same operation that day, each carrying 920 passengers. The United States Air Force operated the VC-25 as the presidential transport and the E-4B as an airborne command post; NASA used a 747-100 and a 747SR as Shuttle Carrier Aircraft and an ex-Pan Am 747SP as the SOFIA airborne observatory, which flew until its retirement in 2022. As twin-engined widebody jets grew capable of long oceanic routes under ETOPS rules, the economics that had once favored the 747 shifted. Production of the 747-8 was cut to six aircraft per year beginning in September 2016, incurring a $569 million post-tax charge against Boeing's fourth-quarter 2015 results. On the 6th of December 2022, the last 747 rolled off the production line at Everett. It was a 747-8F registered N863GT, destined for Atlas Air. Boeing held a ceremony at the factory for thousands of workers and industry executives. The aircraft was delivered on the 31st of January 2023, closing a production run of 54 years during which 1,574 aircraft were built.