Two engines are more fuel efficient than four, especially when they are modern gas turbines that merely sip kerosine when compared to gas-guzzling older models.
With the oil price so low at the moment, fuel costs are not foremost in airline chiefs’ minds. However, once the price begins to rise, cents on the barrel can mean the difference between profit and loss. At that point, the issue of fuel-thirsty aircrafts will return to the top of the agenda.
Safety regulations have also driven change. As engines became much more reliable, authorities decided aircraft with just two engines were safe to fly long and remote routes that took them far away from airports.
The logic behind “extended range twin operations” – or ETOPs – was that the chances of double engine failure was so unlikely the risk was acceptable, and the safety factor of having four engines was no longer essential.
Finally, there are worries about filling aircraft that are routinely equipped to carry more than 450 passengers. Economies of scale do work in the airline business but they can be hard to achieve.
If carriers can fill a Jumbo, then they can easily make money. But when they can’t, that’s a problem.
Scheduled flights almost always have to operate, often to fulfil contracts with airports and governments to fill valuable take-off and landing slots, and when they have empty seats the airline can lose money on a flight.
With a 747-400 – the model British Airways uses – having a per hour running cost of about $27,000, the hit from flying aircraft that are not packed out with passengers quickly mounts up.
In the Covid-19 world where demand for air travel has collapsed, it does not make sense to keep huge aircraft when you have little hope of filling them.
This isn’t just a problem specific to the jumbo. Last year Airbus announced it was winding up production of its even larger A380 superjumbo, having won only 251 orders for the double-decker aircraft, a third of the number for which it had hoped.
Many airlines including BA quickly took their A380s out of service when coronavirus hit. Many have said they will not be flying them ever again, with an eye on the superjumbo’s $30,000 an hour operating costs.
One other reason for the demise of the jumbo, and superjumbo, is how we fly. Passengers don’t like the “hub and spoke” model where big aircraft transport large numbers of people on long flights between major airports, before changing to smaller airliners for shorter journeys to arrive at their final destinations.
No one wants to spend more time in the air than they have to with the associated hassle of transiting through extra airports.