The Boeing 787 and Airbus A350 are the first of a new breed of planes that greatly enhance the passenger experience.
They are the biggest advance in commercial aviation in the jet era.
The key is the use of carbon fibre-reinforced polymer composite construction that is lighter and stronger than the usual aluminium frame and is corrosion-free.
This means that the pressurisation altitude can be reduced from 9000ft to 6000ft, eliminating altitude sickness.
The humidity can be raised from 5 per cent to 14 per cent, cutting dehydration.
Added to these features are very quiet engines that cut noise fatigue and a new cabin filtration system that removes alcohol and perfume vapours, delivering the biggest gain in making long-haul passengers feel much better on arrival.
Both planes burn up to 25 per cent less fuel than the planes they replace, helping to keep fare rises well below the inflation rate.
But there are some differences between the two planes.
The 787 has a gust suppression system and bigger windows to combat claustrophobia.
Built into the wings, the suppression system makes the ride 70 per cent smoother, Boeing said.
However, the A350 is slightly wider, giving airlines more seating options.
Because of their passenger features and fuel economy both are hot sellers.
Boeing is building 787s at the rate of 10 a month to support sales of 1057 and has delivered 170.
It plans to lift that production rate to 14 a month.
The A350 has sales of 748 with the first delivery at the end of the year to Qatar Airways.