A French engineer Morten Müller who has been urging airlines to fit twin aisles but fewer seats into existing single aisle jets has jumped into the debate over the Airbus proposal to make the aisle seats in an A320 wider at the expense of narrower middle and window seats.

He makes the point that no-one will pay a premium for a wider aisle seat if they are have a degree of certainty that after take off those that remain unsold can be occupied at no extra charge.

In fact it’s exactly the point critics are making of Air Asia’s policy of selling options to buy empty seats in the same row. After takeoff they are free game, and it would take more than the minimum complement of cabin attendants to save them being ‘liberated’ by others seeking more space, which is not unknown aboard Air Asia flights.

The two aisles into a single aisle jet concept, supplied image

The French designer has an incredibly detailed presentation of his ideas online, which he developed after being given a less than supportive hearing by reporters in Europe and North America.

The concepts involved are worth thinking about. In fact, they might even make readers wonder about how something at least a wide as a 777 could also be split by three aisles to provide four sets of double seats across the cabin in economy, compared to three sets of triple seats divided by two aisles.

Would Qantas or Virgin Australia ever contemplate replacing a single aisle jet cabin  providing six seats across with one that has a single seat, an aisle, a set triple seats, another aisle, and then a single seat? Let me guess. No? But we can dream.