When Etihad Airways received its first Airbus SE A380 jets a good decade ago, the airline furnished the front of the giant double decker with a veritable luxury playground it called the Residence, a three-room layout featuring a double bed, living area and shower cubicle - all with a personal butler on hand.

Now, the Abu Dhabi-based carrier wants to squeeze its premium offering into far more constrained quarters: the narrow confines of an Airbus SE A321 long-range aircraft that joins its fleet in the next few months. While Etihad has dispensed with its Residence servant in tailcoats and white cotton gloves, the airline promises amenities like sliding privacy doors, lie-flat seats, and large screens, all packed into an aircraft no wider than a city bus.

Etihad's ambitious cabin layout highlights how the workhorse aircraft in the industry - the Airbus A320 family and the Boeing Co 737 - are increasingly pushing into spheres that were once the reserve of large planes. The A321LR and its longer-range sibling, the A321XLR, are built for long-distance routes like Europe to India or across the Atlantic, meaning passengers expect amenities they'd typically enjoy when flying on much bigger aircraft.

While budget carrier Wizz Air Holdings Plc has chosen to go the no-frills approach with its narrobody long-range jets, other airlines are using the planes to expand premium service on longer routes without needing to fill the more fuel-guzzling and sometimes too-large widebody jets.