My preparation for this article included going into the garden and lying on my back to look at the planes on final approach to Heathrow. At this point they are flying at about 4,000 feet. You get to learn the distinctive noises the different types make as they negotiate their descent from the bright empyrean to the more mundane Middlesex. And the mighty Boeing 747 is the most distinctive of them all.
A 747 'appears' first as an inaudible distant rumble, its vast turbofans churning the air in an arrogant fashion that would surely anger the gods. This evolves as the plane gets nearer into a deep, low-pitched whistle and, suddenly, over my central London garden, the engines spool up. The mighty ship then twitchily adjusts its course for home. These are sights and sounds that always impress. You could call the 747's presence in the air noisy and 'lumbering' were it not also so thrillingly sublime and curiously elegant.
By contrast, the Airbus A380, the 747's sole successor as a wide-bodied, double-deck, long-range, four-engined jetliner, is nearly silent, looks stable and almost stationary, reflecting the digital calm of its more advanced technology. Indeed, as the 747 nears the end of its commercial life, critics started saying that it was a 60s design being sold at 21st-century prices. The plane that so audaciously changed the shape of the world is now on the wrong side of history. Airlines are retiring older 747s - JAL no longer flies them - and Boeing's attempt at catch-up, the latest 747-8 model, has had technical problems and is selling only very slowly. The air above my garden will not be troubled by 747s for very much longer.
The majestic Boeing 747 in the skies. Credit: Boeing
So it is pleasant to consider the wonder of it all. The stats still astonish, 45 years after the first flight. The wingspan of a 747 is twice the length of the Wright Brothers' first flight at Kitty Hawk. Its rear elevators are bigger than a 737's entire wing. A 747-400's radio altimeter is so accurate that its calculations account for the time electrons take to travel through the craft's 274km of wiring. A loaded 747-8 weighs about a million pounds. The factory built to assemble the 747 at Everett, Washington, is still, by volume, the largest building on earth. By contrast, the 'heading selector' on the flight deck, which controls the whole of your journey from London to Tokyo, is a knob the size of a 5p piece.
But now the 747 is a flying antique: people are astonished when they see the analogue instruments. And the flight controls are all defiantly dependent on old-fashioned mechanical linkages. A 747 captain once explained to me that, if hydraulic assistance on the control yoke is lost, you can still put your feet on the instrument panel, give a big tug and wrench the plane about the sky. You cannot do that on a solid-state Airbus.
The 747 belongs to the past for other reasons too. It was the product of extraordinary enterprise and risk, requiring extreme commitment, not to say foolhardy bravery, from the management of a public company. At one point in its development during the late 60s, costs were racking up at $5m a day. The first airline customers suffered confidence-sapping delays because of problems with delivery of the (in any case unreliable) Pratt & Whitney engines. There are archive photos showing completed, but engineless, 747s lined-up to the horizon in customer livery at Everett, which were cumulatively worth more than the company itself. A record of $1.2 billion bank debt was established.
But even as Boeing's William M Allen said, 'It was really too large a project for us,' a gung-ho and can-do spirit dominated the company. Its chief test pilot was Alvin 'Tex' Johnson, one of the original barnstormers in cowboy boots and Stetson. In June 1955, demonstrating the prototype 707 to potential customers, Johnson did an astonishing 360 degree barrel roll over Lake Washington. Twenty-five years later, another 747 captain, after cocktails at a party in Aspen, confided in me that you can loop-the-loop in a 747. That's a sign of pilot confidence and structural integrity, but most of the 747 aerobatics were performed by Boeing's designers and engineers, not to mention the managers whose accounting methods defied gravity, and gave us all one of the greatest machines of all time. Just over 1,500 examples have been made as production winds down.
Significantly, for those keen to explore the functional reality of seductive creation myths, the 747 did not arise from any very clear vision. Certainly, with the 707, Boeing had demonstrated the commercial viability of intercontinental jet travel. True, the British de Havilland Comet had been the pioneer, but its poor safety record and sub-optimal economics made ambitious Boeing the de facto leader in jet travel. But the 747 was, primarily, the improvised product of a failed military contract, not a visionary creative brief.
In 1963, restless US Army procurers had just taken delivery of the new Lockheed C-141 Starlifter transport and already were keen to define its replacement. This was a programme called CX-HLS (Cargo Experimental Heavy Logistics System). The specification required a swinging nose door, the better to accept tanks. In the two leading proposals for the Army contract, this demand gave rise to a distinctive hump caused by placing the flight deck above the nose. Lockheed won the contract and CX-HLS became known as the C5 Galaxy. Boeing lost the contract, but used its military design studies in what was to become the 747. American corporations were good at this: Raytheon commercialised experience in missile guidance systems by selling microwave ovens.
Analogue age: the flight deck of an early Boeing 747. Credit: Roger Viollet/Rex
The context for the 747 had been established by Juan Trippe, the charismatic CEO of Pan American, the airline then favoured by the jet set. Trippe was lobbying Boeing for something twice the size of the 707 and an engineer called Joe Sutter was assigned to the project in 1965. By April 1966, Pan Am had ordered 25 of the new Boeing 747-100s. Trippe said the new plane would be 'a great weapon for peace, competing with intercontinental ballistic missiles for mankind's destiny'. Using fault tree analysis, a powerful debugging process, the team designed the 747 in just 28 months.
US Patent Des.212,564 filed on 29 October 1968 shows a 'side perspective view of an airplane showing our new design'. The hump is obvious. And the design is attributed to Joseph F Sutter, Rowland E Brown, Donald W Finlay, Milton Heinemann, Kenneth C Plewes and Everett L Webb.
Dramatic swept wings are also obvious, state-of-the art structures inspired by unacknowledged Germans - Max Munk at NACA and Johanna Weber at RAE - who quietly did so much to make fast, modern jet travel possible.
The 747 was a step-change in commercial aerospace: its flight deck is three times higher off the ground than a 737's. To acclimatise pilots to this perch, early testing was carried out with a mock-up cabin mounted on a wobbly structure fixed to the load-bed of a pick-up truck. This was known as 'Waddell's Wagon', after Jack Waddell, the 747 test pilot.
The 747's first commercial flight was on 22 January 1970, a Pan Am service from New York to London, which was delayed six hours because of an engine overheating. There were other less well-publicised problems. The size of the plane meant evacuation drills were fraught. First attempts took two and a half minutes. It was only possible to get it down to the FAA mandated 90 seconds with the acceptance of more injuries during the evacuation. Early models suffered from flutter, a self-exciting oscillation that can lead to catastrophic destructive failure. It was fixed by the fantastical Cold War remedy of putting lumps of depleted uranium in the outer engine nacelles. The El Al cargo 747 that crashed in Amsterdam in 1992 was carrying 282 kg of depleted uranium in its tailplane for reasons of stability.
Passengers love the 747. For me, that unforgettable first youthful sight of the Manhattan skyline is lodged next door in memory to the equally unforgettable sight of the plane's cavernous interior. Milton Heinemann had said for the first time, passengers would be in a room, not a tube. The man with the challenge to design that room was Frank del Giudice, of Walter Dorwin Teague Associates, one of the pioneer US design consultants from the 30s. At first he had no clear idea of what to do with the hump: early proposals included a first-class lounge with a sunken well and a cocktail bar. That signature spiral staircase first appeared in the 377 Stratocruiser, a civilian development of the B-29 Superfortress. While early ads for the 747 expressed a sense of bafflement at this enormous flying hotel and verged on baroque fantasmagoria, with hostesses, fountains and palms, it was del Giudice who created the sedate, modernistic design language of the 747, perhaps, in terms of exposure, the most familiar interior design ever.
Hotel in the sky: the first-class lounge of the Boeing 747-100, complete with spiral staircase, on Pan Am’s inaugural commercial flight on 22 January 1970 from New York to London. Credit: Pages Francois/Getty Images
Pilots love the 747. I know. I have flown one, or, at least, a 747-400 simulator that is so realistic, real pilots can do the transition from a smaller plane to a 747 without actually leaving the ground: 'Zero Flight Time Rated' is what it's called. The sensation is entirely convincing. Push thrust levers forward. Hear the four turbofans spool-up, ever so slowly picking-up speed. You sense a slight vibration followed by what is really a very big vibration. Seconds later, you have VR, the speed when you are committed. The 'R' stands for 'rotate', aerospeak for pulling-back. On rotation, nearly 400 tons of metal, glass, rubber, people and duty free are being hauled into the air. Suddenly, the shuddering and rattling stop, the engine note rises, wings take the load and we are flying. Take-off is what Alain de Botton calls the ecstasy of flight. You won't get a better yee-hah experience.
Even in the simulator, the vast floating gravity of a 747 amazes. You experience a sublime sense of concentrated, delicious terror that 18th-century poets enjoyed looking down black chasms in the Alps. But the cruise is a doddle. The simulator allows you to test the 747's safety margins. I hate turbulence, even the simulated sort, but from the pilot's seat, the big Boeing doesn't notice dirty air. The aerodynamics are so clean that until the A380, the front of a 747 was the quietest place in the sky. And the quietest place of all was, according to Joe Sutter, an aisle seat in row 3.
In his beautiful essay about the mysteries of flight, Skyfaring, Mark Vanhoenacker, a BA 747 pilot, explains some of the magic. 'More than a few colleagues have told me they decided to learn to fly only because they wished to fly the 747 ... I am never surprised when a colleague's email address contains some version of those famous numbers.'
The 747 was America at its proud and uncontaminated best. 'There's no substitute for cubic inches,' American race drivers used to say and the 747 expresses that truth in the air. There is still residual rivalry with the upstart European Airbus. Some Americans, referring to untested new technologies, call it Scarebus. There's an old saying: 'If it ain't Boeing, I ain't going.'
A comparison to the European Concorde is illuminating. The supersonic Anglo-French plane was an elite project created for elite passengers to travel in near space with the curvature of the Earth on one hand and a glass of first growth claret on the other. The 747 was mass-market, proletarianising the jet set. It was Coke, not grand cru and it was designed by a man named Joe.
Thus, the 747's active life was about twice that of Concorde and during that time, several attempts were made to realise extra potential. One was the 747SP, a truncated body on the standard wing offered greater range and superior economy, but the absurdity of building a wide body fuselage only to shorten its length was expressed in the plane's ludicrous aspect. The new 747-8 is only the third major variant in nearly half a century. It is the longest plane in production, but will not be long in production.
Airline economics have changed. International flights can now avoid the big hubs and go directly on long, thin routes between secondary cities. The first generation of high-bypass turbofans made the original 747-100 possible, but it was only ever economical when fully loaded, its efficiency tumbling disproportionately as seats were left empty. In the 45 years since its first flight, engine reliability has so dramatically improved there is no need for four thirsty engines. In any case, the fundamental appeal of the original 747 was its range rather than its capacity. Boeing's own efficient long-range modern twinjets, the 777 and 787 have made it redundant. And the A380 makes it look crude.
Still, the 747 remains an exemplar. It just looks so right. As a child, Joseph Sutter used to draw birds, and maybe natural life was some sort of inspiration for the plane's unique form. Certainly, it transcends all the limitations of its medium. Norman Foster devoted a 1991 BBC architectural documentary to the 747. Walking around a Qantas 747-400 on a runway, the designer of the HSBC building in Hong Kong, architecture's greatest hymn to the Machine Age, comments to camera of the 747's 'extraordinary presence' and says it is 'pure sculpture'. 'The fact that we call it an aeroplane, not a building,' Foster continued. 'Engineering, not architecture, is really a sort of historical hangover.'
And now this aerial architecture is becoming a monument. On my back, in my garden those lovely words of Exupéry’s about why he flew always come back: ‘car cela libère mon esprit de la tyrannie des choses insignificantes’ (because it releases my mind from the tyranny of petty things). It may soon be a thing of the past, but the Boeing 747 is surely one of the most significant things ever.