From The Archives: A Timeline Of The 747

By late 1964, Boeing was already weighing the potential benefits of applying new high-bypass engine technology under development for the U.S. Air Force’s heavy logistics system (CX-HLS), later the C-5, to a new, high-capacity airliner. Boeing lost the CX-HLS contest to Lockheed in 1965 and turned its attention to the new 747 project.

Early strands of the 747’s DNA can be traced to the single-deck mockup of the CX-HLS airlifter.

Boeing’s initial 747-family concept—dubbed the 747-3, -4 and -5—was a double-decker based on a scaled-down version of the finalized CX-HLS double-bubble fuselage configuration proposed to the Air Force. Passenger capacities varied from 311 to 433, with a highest maximum takeoff gross weight of almost 600,000 lb. In the highest-capacity variant, the upper deck had 263 seats, while the lower deck, truncated by the mid-fuselage wingbox, seated around 170.

Once defined, the enormous cabin area of the 747 sparked some imaginative and fanciful interior concepts. This 1966 vision from Boeing depicts a movie theater showing “first-run films” along with “a TV or conversation area and a library.” Other ideas proposed included a bar, a stage and live entertainment.

With 737 fuselage sections in the background, the first cockpit section for the 747 prototype, RA001, is pictured under assembly in 1968 at what was then Boeing’s Wichita Division.

Another key component of the C-IV was the control and display unit, which could indicate a digital readout of the aircraft’s precise latitude and longitude and the distance and direction to the destination. The novel layout, now so familiar, included a keyboard with push-buttons that enabled pilots to program in up to eight navigational waypoints enroute.

The 747 was the first commercial airliner to be designed from the start with an inertial navigation system (INS) as part of the baseline avionics. The units, which had been recently developed for the Apollo space program as well as strategic missile guidance by the Charles Stark Draper Laboratory at the Massachusetts Institute of Technology (MIT), were built by the Milwaukee-based AC Electronics Division of General Motors. Known as the Carousel IV (C-IV) navigator, the main components of the 747 system included a digital computer and power supply and an inner turret, containing two vertical gyros and two accelerometers, which rotated continuously to offset gyro drift rates. Three C-IVs were on each aircraft and, because of their accuracy, meant that specialist navigators were no longer required for long-range overseas flights.

Designed to handle the 747’s weight and provide extra redundancy, the packaging of the aircraft’s complex main landing gear was one of the configuration’s most ingenious aspects. Illustrated here in mockup form, the wing-mounted gear bogie retracted inward while the body gear bogie retracted directly into the fuselage. A massive body bulkhead divided the bays and formed the main landing gear beam carry-through structure. A large keel member, which connected the forward and aft fuselage sections, formed the inboard walls of the unpressurized undercarriage bays.

Having earlier considered a blown-flap arrangement, the finalized 747 featured a complex, articulating triple-slotted trailing-edge flap system. When fully extended, together with the leading-edge flaps, total wing area increased by 21% and lift by up to 90%. In flight tests, stall speed at light weights of around 400,000 lb. and flaps at 30 deg. was only 92 kt. Even at the early aircraft’s maximum landing weight of 564,000 lb., stall speed with the same flap setting was a stately 110 kt.

Towering 63 ft. 5 in. above the assembly-line floor at Everett, Washington, the 747 vertical tail fin supported a two-piece rudder for multiple redundancy. The lower half, yet to be fitted in this image and measuring 9 ft. 3 in. in height, was moved with dual hydraulic actuators, while the upper half was moved with three actuators. Maximum rudder travel was 24 deg. on either side.

The full fuselage of RA001 begins to come together for the first time as the combined wings and center fuselage Section 44 is maneuvered on air bearings into position for mating with the newly joined forward Sections 41/42. Although the parts fitted together smoothly, the process did not go without incident. At one point, a jack failed and punched a hole in the left lower wing skin, but no stringers or other structure sustained damage and the area was quickly repaired.

The complete 747 airframe was depicted for the first time on the cover of Aviation Week & Space Technology’s July 15, 1968, edition. Major assembly was completed in just six days, although key elements such as the trailing-edge flaps and Pratt & Whitney JT9D engines still remained to be fitted.

Crew for the first flight were (from left) Flight Engineer Jess Wallick, Project Pilot Jack Waddell and Co-pilot Brien Wygle. Waddell, a former U.S. Navy aviator, would later become Boeing’s chief test pilot, and together with Wygle, helped with the 747 flight deck design. Wygle, who was lead project pilot for the B-52, also commanded the first flight of the 737 in April 1967 with Lew Wallick, brother of Jess, as co-pilot.

With pressure mounting to get the giant airliner into the air, the crew cleared the 747 ready for flight in early February 1968 after achieving 165 mph and, at one point, a 9-deg. nose-high attitude during fast taxi tests. “A few more knots and we’d have been airborne prematurely,” recalled Waddell at the time.

The era of the widebody airliner began at 11:34 a.m. on Feb. 9, 1969, when the first 747, RA001, took off from Runway 16R at Snohomish County Paine Field in Washington. With the four JT9Ds each generating around 39,000 lb. thrust, the huge aircraft weighing around 467,500 lb. became airborne after a ground roll of 4,300 ft.

Flanked by Boeing’s Canadair-built Sabre chase aircraft, the 747 broke out of the overcast sky into brighter weather over Puget Sound on the first test flight that achieved a top speed of 280 mph and a maximum altitude of 15,000 ft. Originally set to last more than 2 hr., the flight was cut short when a flap misalignment, experienced as a "bump" on the flight deck, forced a precautionary early return.

Emphasizing the 747’s impressive 231-ft. overall length, the diminutive Boeing-owned Sabre chase aircraft keeps careful watch on the prototype during its maiden flight, which was featured on AW&ST’s March 10, 1969, cover. The aircraft’s 18-wheel landing gear was retracted in flight for the first time on the second test flight on Feb. 15, 1969.

Taken at Everett in 1969, this classic early Pan American publicity image of the airline’s first 747 was staged to illustrate the coming change in scale compared to one of the carrier’s 145-seat 707-321Bs. This 747, "Jet Clipper America" was refurbished after taking part in the certification program and, despite being involved in a serious takeoff accident at San Francisco in 1971, went on to serve the airline until it ceased operations in 1991. It later flew with a variety of operators before ending its days in South Korea, where it was converted into a restaurant and finally scrapped in 2010.

The final 747 cross-section configuration with the 20-ft.-wide main deck, lower hold and upper deck is clearly revealed in this April 1969 view of an early production aircraft Section 42 prior to mating with the cab Section 41 at one end and the overwing body section at the other.

Unlike today’s commercial airliner programs, in which engine development generally precedes that of the airframe by a significant margin, Pratt & Whitney’s pioneering JT9D high-bypass-ratio engine was developed virtually in parallel with the 747 and thus inevitably suffered reliability problems before and after entry into service. The challenge was exacerbated by the 747’s rapid weight growth, which forced a faster-than-expected increase in thrust requirement. Beginning with a rating of 41,000 lb., the JT9D was pushed quickly to 43,500 lb. and then 45,000 lb., a trajectory that resulted in turbine temperature problems. During the flight-test program, some 55 engines were changed, compared to just one on the JT8D-powered 737 test program.

To underline the impressive scale of the 747, the first few aircraft were frequently posed alongside other aircraft or everyday objects to emphasize the vast leap in sheer size. Here Pan American’s first 747 is pictured with the airline’s first Ford Trimotor, an aircraft flown in 1929 by Harold Gray, who had become the airline’s chairman of the board by the time of the 747.

Simply maintaining and servicing the 747 required development of a wide range of ground-service equipment capable of extending to the tip of the tail fin, which measured 63 ft. 5 in.

Pan American also saw an opportunity to brag about the 747’s size by comparing it to automobiles. Even by the standards of the large U.S. gas guzzlers of the 1960s and '70s, the 747 would come out on top. According to Pan Am’s publicity at the time, “four passengers in each of these Ford autos would little more than fill half the 747.”

To overcome problems with "ovalization"—or bowing of the engine during takeoff, which resulted in compressor blades rubbing excessively against the casing—Pratt developed several remedies to stiffen the attachments holding the engine to the strut. One of these, indicated with white arrows, was a Y-shaped frame that transferred thrust loads to the intermediate casing of the compressor. Eventually, all 747s were provided with retrofitted engines.

By mid-March 1970, completed 747s were emerging at the astonishing rate of one per three working days, the highest rate ever achieved in the program’s history. The late Robert Rosati, a Pratt veteran who led the formation of International Aero Engines, was JT9D deputy program manager during the crisis years and recalled: “We couldn’t supply upgraded engines fast enough, so Boeing was hanging concrete blocks off them. They were desperate days.”

The reliability and performance of the JT9D eventually improved, and the engine became a focus of attention for its unprecedented size at the time. Here, representing a very different world and time, three Iran Air cabin attendants pose inside the No. 2 inlet during an early 747 demonstration tour stop in Tehran. The airline eventually went on to operate more than 20 747s of different versions, including the 747SP, of which it was the last commercial operator.

TWA proudly installed wider screens for inflight movies in coach class. “TWA is offering two films (mature and general) on every flight. The passenger has his choice,” said the airline in 1970.

With its polished aluminum gleaming under the Everett factory lights, the first Lufthansa 747-200F was rolled out in a delivery ceremony in March 1972. Soon in service on the North Atlantic, the -200F could carry three times the load of the airlines’ 707 freighters and was occasionally loaded with up to 72 Volkswagen cars. Although cargo variants were slow to sell at first, business for the line and the associated conversion market would soon accelerate. The last -200F, which was also the very last -200 made, was delivered to Nippon Cargo in 1991, marking the end of a 21-year production run. In all, some 164 variants were produced, including combis and 73 dedicated freighters.

American Airlines eventually operated 19 747s, including two 747SPs, and installed Wurlitzer electric pianos in the coach-class main deck seating zone 5 area on its early 747-100s. The pianos had truncated keyboards and were bolted to the deck.

Entered via the spiral stairway at the front of the cabin, United Airlines 747-100 upper-deck lounges seated up to 16 in first class. Five regional themes were used in their 1970s decor.

Despite being designed from the outset with the ability to load cargo directly through the nose, the first freighter variant—a 747-200F—was not produced until 1971. The 747C convertible passenger-cargo variant, which followed into initial production in 1972, retained windows in the upward-hinging nose section.

To satisfy the growing demand for much longer-range capability, Boeing developed the short-bodied 747SP special performance derivative, the first of which is was rolled out of the Everett facility alongside the prototype 747-100 in the summer of 1975 (pictured). The design reduced capacity to around 281 in three class and cut overall length to 176 ft. 9 in., or about the same as the 767-300, which would follow a decade later. However, it did enable ranges of 5,700 nm and more at higher cruise altitudes of 49,000 ft.

Rolls-Royce became the third engine-maker to power the 747 when Line No. 292 powered by RB.211-524s flew for the first time on Sept. 3, 1976. Ordered the previous year by British Airways, the RB211-powered variant could fly 700 nm farther than the airlines’ original JT9D-powered 747-136s and carry up to 15,000 lb. more payload from hot and high airports like Nairobi, Kenya. During flight tests to measure noise in November 1976, the Rolls-powered test aircraft set a new world record for mass lifted to 2,000 nm when it took off from Lemoore NAS, California, at a weight of 840,500 lb. A wind tunnel model of the RB211-524-configured 747 is pictured undergoing thrust-reverser flow analysis.

Taking to the air for the first time on July 4, 1975, with test pilot Jack Waddell in command, the 747SP certification program was completed in under seven months. Although issues were discovered such as an unexpected local shock around the wing-fuselage fillet (which was cured with a reprofiled fairing), the aircraft’s long-range cruise performance was 0.1% better than predicted and overall weight was 1% lower than forecast. Launch customer Pan American took delivery of the first aircraft, Clipper Freedom, on March 5, 1976. However, the SP market niche was short-lived. With the development of longer-range 747-200s and competing trijets, the orderbook was closed after the sale of the 45th aircraft, which was delivered to the United Arab Emirates in 1987.

In response to airline requests for greater capacity, Boeing developed the 747SUD (stretched upper deck), which later became the 747-300. Capable of seating 91 in an all-economy class on the upper deck, the development was a far cry from the luxurious exclusivity of the early lounge concepts of the original design. The upper deck included additional windows and two larger exits and was accessed by a straight stairway that led aft from the main deck. The stretch added about 10,000 lb. empty weight but unexpectedly had lower drag and higher speed and could typically cruise at Mach 0.85.

The difference in the stretched upper deck of the -300 against the baseline upper deck was clearly distinguished by additional windows and an upward-opening upper exit. First deliveries to UTA French Airlines/Swissair took place in 1983, and although overall sales amounted to a disappointing 81 including combi freight and passenger models, the stretched upper deck provided much of the structural foundation for the best-selling -400.

The 747-400 propelled the model into the 21st century with a radical redesign that included a new two-crew flight deck, new avionics, strengthened structure, updated engines and a bigger wingspan with winglets. Development proved more difficult than expected, partially due to the over-ambitious plan to attempt flight test and certification of three different engine-airframe combinations in as many months. The time table was also complicated by completion challenges with numerous different customer configurations, some of which were held up by supplier delays, and by an upper-deck floor redesign to meet European safety regulations. Despite the issues, the 747-400 proved to be the most popular variant ever developed, with 694 of all versions delivered. Making its first flight in April 1988, the final -400 variant, a 400ERF freighter, was delivered to Kalitta Air in December 2009.

After decades of studying a potential stretch of the 747 and facing the threat of the newly developed Airbus A380, Boeing launched the high-capacity, long-range 747-8 in 2005. The third-generation 747 design leveraged new-generation General Electric engines developed for the 787 and took advantage of improved aerodynamics for a new 224-ft. 7-in. wingspan. In common with past family members, passenger as well as freighter models were developed based on a fuselage stretch of 18.3 ft. over the 747-400, bringing the total length to 250 ft. 2 in. The 747-8F made it first flight in February 2010, followed by the initial 747-8 Intercontinental in March 2011. Sales of the 747-8 Intercontinental passenger version ended in 2018 with 47 deliveries, two of which are destined to become the future VC-25B ‘Air Force One’ U.S. Presidential transports from 2024 onward.

First delivered to Cargolux in 2011, the 747-8F is the ultimate derivative of the family and still based on the basic single main-deck concept of the original design. Distinguished by its shorter upper deck, the aircraft’s 18-ft. 4-in. fuselage stretch is just before and aft of the wing. Designed with a 975,000-lb. maximum takeoff weight and a payload capability of 308,000 lb., the 747-8F has a range of 4,390 nm. By late 2020 more than 90 747-8F freighters were in service. However with orders slowing down Boeing has signaled it will end 747 deliveries in 2022, bringing down the curtain on the longest-lived commercial aircraft production in aviation history.