It hasn’t surprised anyone in the industry to hear rumours – via the pages of the Wall Street Journal – that Boeing is working on the design of a new narrowbody jet, because it’s what everyone – including Boeing – knows the manufacturer should have done instead of launching the 737 Max.

The confidence in that statement is completely un-influenced by hindsight.

Now the Max has been purged of the ghastly design mistake that was MCAS (manoeuvring characteristics augmentation system), and Boeing has radically overhauled its corporate safety culture under a new leader – former Rockwell Collins engineer CEO Kelly Ortberg – the 737 series can once again trade on the lazy confidence that comes from the fact that – with all its faults and its antique technology – it’s a known quantity.

As a result the 737 is selling well, but nothing like as well as its competitor the Airbus A320 series.

The first 737-100 entered service in 1968, initially to fly the routes that the larger 727 series trijet was too big for. Its basic control technology was – and still is – just-post-war, except that in the latest versions the power-assisted cranks and pulleys are overlaid with electronic flight instrument systems and flight management computers to the extent that the pilots could almost believe the aircraft is fly-by-wire. They know, however, that they themselves are the flight envelope protection.

The industry needs a new-technology narrowbody competitor to the A320, and if Boeing doesn’t supply it, perhaps a development of China’s Comac C919, Russia’s Sukhoi Superjet 100, or a new product from Brazil’s Embraer will fill the gap.

Boeing’s first fly-by-wire airliner was its highly successful 777 widebody, which entered service in 1995 with virtually no birthing pains.

In 2011 it launched the 787 Dreamliner series, also highly commercially successful, but suffering from multiple early problems, some of them still being worked on.

Right now Boeing is struggling to re-launch the 777 as the 777X. The fact that it had a planned 2019 in-service date, but now its launch customer – Lufthansa – will not receive it until 2026, suggests how difficult a task bringing an entirely new narrowbody (the 797?) to service readiness may yet be.

The challenge is always to deliver a safe, trouble-free product, but the staggeringly advanced, fully-integrated electronic technology by which the aircraft and all its systems will be managed and controlled, plus the fact that there must be fallback systems that the pilots can access easily if it all goes wrong, mean its service entry will not be quick.

Look beyond this to the fact that the new systems will inevitably employ artificial intelligence, which makes passengers – and even engineers – nervous when it comes to managing safety-critical systems, and the size of the challenge becomes clear.

So the venerable 737 series will be with us for many years yet.