Singapore Airlines (SIA) announced today it would be splashing out on 39 new Boeing aircraft in a deal worth US$13.8 billion.

These aircraft, comprising 20 B777-9s and 19 B787-10 Dreamliners, will be delivered in the years ahead. It must be noted that the B777X family (of which the B777-9 is a member) is still to be built.

That’s the good news from Boeing’s viewpoint. But from the passenger’s viewpoint you can say goodbye to SIA’s roomy economy class seating.

It is on the cards that economy passengers wanting SIA’s traditional comfort will have to upgrade to premium economy.

The 20 B777-9s that SIA is ordering are the latest variant. Boeing has engineered this model to allow customers to more easily install ten-across (3-4-3) seating in economy class.

SIA remains one of the few global airlines which, until now, has remained committed to the more spacious nine-across (3-3-3) layout on its large B777 fleet.

But this policy will almost certainly change.

Why? It is not just because this B777 variant is engineered to accommodate the tighter ten-across economy seating. It is because SIA’s main rivals have adopted, or are in the process of adopting this (unpopular with our readers) layout.

By “main rivals” I am not simply referring to the European carriers like Air France, KLM and Swiss. Or the Gulf carriers such as Emirates, Etihad and Qatar Airways.

I am also considering carriers like Hong Kong’s Cathay Pacific, US carrier United, Japan’s ANA, Taiwan’s Eva Air and CAL plus, last but not least, the expanding airlines of mainland China.

These latter carriers compete with SIA on the busy transpacific routes and their ten-abreast economy cabins provide them with superior operating costs.

And indeed a number of the above carriers have themselves ordered the B777X.

What about the B787-9s which SIA has ordered?

Well SIA’s original batch of B787s were transferred to budget subsidiary Scoot. This new order (assuming the B787s end up with SIA’s mainline division) marks a change of policy.

But SIA is already taking delivery of more than 50 A350s. Although configured nine-across (3-3-3) their economy cabin is a little wider than that of the B787 and this, in terms of space and comfort,  has met with readers’ approval.

“SIA has been a valued Boeing customer for more than 50 years and we are honoured they have selected the 777X and additional B787-10s to expand their widebody fleet. They are the most efficient, and capable and passenger preferred airplanes in their class,” says Boeing’s commercial airplanes president and CEO, Kevin McAllister.

Adds Boeing, “Advanced technology, including a new composite wing, all-new engines and superior aerodynamics will result in the incredible fuel efficiency promised by the 777X family. B777-9 will be the largest and most efficient twin-engine commercial jet in the world with the lowest operating cost per seat of any commercial airplane and no competitor in its market segment.”

The next question is what does the long-term future hold for SIA’s A380 fleet? The answer must wait for another day.