How the veteran 747 fell out of fashion as ‘big twins’ took off

When the end came for Boeing’s 747, it arrived not with a reverential fanfare but a brief mention – virtually a footnote – in the airframer’s second-quarter corporate filing for 2020.

“We are currently producing [747s] at a rate of 0.5 aircraft per month,” it stated, matter-of-factly. “We will complete production of the 747 in 2022.”

Boeing is handing the last 747, a -8 freighter, to cargo operator Atlas Air on 31 January.

The company had previously telegraphed the possibility of closing the line, after more than half a century, by referring to its continuing evaluation of the programme and the fact that such a decision would not have a material impact on its finances.

With the introduction of the 747, Boeing changed the economics of passenger transport at a time when attention in Europe was focusing both on high speed and the potential for twin-engined widebody operations.

When the UK government was assessing whether to withdraw from the supersonic BAC-Aerospatiale Concorde project, towards the end of 1969, it noted that Concorde’s seat-mile cost was 90% higher than the 747’s.

“Any improvements to the 747 would make the cost comparison even more unfavourable to Concorde, and it is quite possible that a 747 in stretched form will be an offer to the airlines by the time Concorde is entering service,” a government memorandum lamented.

Concorde’s appeal dramatically dwindled, particularly during the 1970s energy crisis, and the 747 emerged as the pre-eminent long-haul aircraft. Its characteristic twin-deck, raised-cockpit design, which had originated from a military requirement for a nose-loading outsize cargo lifter, meant it would have built-in longevity as a freighter.

But the seeds of the 747’s eventual demise were being sown in Toulouse even during Concorde’s protracted development.

After entering service with Pan Am in January 1970, the 747 had barely reigned for 1,000 days before the first Airbus A300 carried out its maiden flight. Powered by two General Electric CF6 engines, which would become an option on the 747, the A300 demonstrated the feasibility of widebody twinjet operations.

The A300 had limited range and, initially, limited appeal – the stout-looking aircraft hardly seemed to convey the same sense of futuristic advancement as Concorde’s sleek lines – but its fuel-consumption figures were undeniable, and famously became critical to securing a breakthrough US agreement with Eastern Airlines.

Twin-engined efficiency also had the potential to inflict damage on trijet rivals. The Lockheed L-1011 and McDonnell Douglas DC-10 were already engaged in a war of attrition for a limited market.

But the most critical aspect of the twinjet’s competitiveness was engine reliability and whether, in the event of failure, a single engine could power all the systems necessary to maintain safe flight.

Although former US Federal Aviation Administration (FAA) administrator Lynn Helms reportedly said it would be a “cold day in hell” before he allowed twinjets to fly overwater services, he faced pressure in the early 1980s to update 1950s-era rules preventing aircraft from flying more than 60min from a suitable landing site.

Boeing had flown its own widebody twinjet, the 767, in 1981 and the increasing range of such aircraft demanded a regulatory rethink. The advent of ETOPS – extended twin-engined operations – changed the dynamics, and opened new route potential by giving aircraft a wider flying-time margin to alternate airports.

While the 747 had range as a strength, technological advances meant twinjets were rapidly becoming capable of operating longer distances. Boeing did not produce another four-engined airliner after the 747.

Airbus faltered with its decision to build the long-haul A340, opting for a four-engined sister to its twin-engined medium-range A330 and saddling itself with a disadvantage when Boeing unveiled the ‘big twin’ 777.

The disparity between the two became more evident when Airbus doubled-down with the A340-500 and -600 while Boeing was developing the long-range 777-300ER. Virgin Atlantic’s attempt to promote the A340-600, for which it was a customer, with a Helms-esque ‘4 engines 4 long-haul’ slogan of reassurance came across as anachronistic in the age of ETOPS.

Higher seating capacity, increasing range, and inherent efficiency meant large twinjets gave carriers not only the opportunity to serve profitably routes too thin for the 747 but also to encroach on the 747’s own territory. Long-haul twinjets enabled fragmentation of networks, allowing airlines to bypass hubs, or offer more frequent service on intercontinental trunk routes with aircraft that were easier to fill.

Boeing, which had explored several proposals to stretch and update the 747, unveiled its final derivative, the 747-8, in 2005 – but notably prioritising the freighter sector. The airframer had delivered its last passenger 747-400 earlier that year, in April, the same month in which Airbus conducted the first flight of its A380.

While Airbus believed it was finally inheriting a much-coveted crown from its US rival, the A380 instead became a four-engined solution looking in vain for a problem that twin-engined passenger aircraft could not answer.

If Airbus believed that, someday, airlines would need high-capacity transport to overcome airport congestion, it was unable to convince customers. Operators of the largest 747 fleets, among them British Airways, Lufthansa, Singapore Airlines and Japan Airlines, proved reluctant to order the A380 in similar numbers – if at all.

Nor could the 747-8 offer much resistance to the twin-engined trend. The abortive attempt to create an A380 freighter left the 747-8F free to pursue the cargo market unfettered, but parallel pressures – particularly fuel price – that had pushed out four-engined passenger aircraft inevitably rippled through the freighter sector.

Twins with high-volume bays, able to lift over 100t, are emerging as the preferred platform for new-build, and converted, large cargo jets. The multitude of 777 modification programmes and orders for the 777-8F and A350F are testimony.

With the final 747 handover, Boeing’s long-haul industrial attention is concentrated on the 787 and 777, including the 777X programme, while Airbus – having axed the A380 in 2019 – has built its widebody future on the A350 and A330neo. Twins are the new quads.

But the 747, like other classic designs, is likely to remain a presence in air transport long after the roll-out doors from the production line are shut.

“Our customer commitment does not end at delivery,” says Boeing. “We’ll continue to support 747 operations and sustainment well into the future.”