The Edmondson Blog

The Dreamliner was unveiled in Seattle last night. I read an interesting piece in last week's Economist on the aircraft:

The flight from Shanghai will be landing at Toronto in two hours' time and the cabin crew have switched on dawn. No more rude awakenings from a blast of sunlight as the plastic blinds are yanked up. Over the next 20 minutes light-emitting diodes slowly illuminate the ceiling with a soft blue hue. The large electronically darkened windows also start to brighten.

The passengers have probably slept fairly well too. There is less of that dry, wrung-out feeling often associated with long flights because the air in this plane is less arid and the pressure is higher. The carbon offsets for this trip are also lower because the aircraft is using 20% less fuel than other jets and emitting correspondingly less CO2. Welcome on board the new Boeing 787 Dreamliner.

With half its primary structure, including the fuselage and wings, made from composites, the 787 is much lighter than any metal aircraft of similar size. That not only saves fuel but allows other improvements. For example, the air is nicer to breathe. Airliners have to be pressurised when flying above 10,000 feet because oxygen levels drop dangerously low. At cruising height, usually around 35,000 feet, cabin pressure in most aircraft is kept at the equivalent of around 8,200 feet (about the same as Mexico City) because maintaining a higher pressure in a conventional aircraft might accelerate metal fatigue. To add to passengers' discomfort, the air is kept as dry as possible because moisture causes metal to corrode. But the 787 is pressurised at the equivalent of 6,000 feet and the air can be kept less dry because the composites are stronger than metal and unaffected by moisture.