[GSlob]

I'd rather have titanium. Composites are not cheap, either.

[Paleo Conservative]

I'd rather have titanium. Composites are not cheap, either.

They may not be cheap, but they require less labor to fabricate, and they don't require as much maintenance.

[magellan]

Composites dramatically reduce assembly time (you just glue the thing together, fewer rivets, etc.), which reduces the cost, composites virtually eliminate corrosion (a BIG problem with older airplanes, just ask the Air Force), and composites have a longer fatigue life, which will allow the airplane to be used longer (assuming its fuel efficiency remains competitive). The latter is a real big deal for a 737 replacement (remember the "convertible" 737 over Hawaii?).

My only question is, with the cost of fuel through the roof, will GE dust off its old "propfan" concept it tested on an MD-80 in the late 1980s. A composite update to the Boeing 7J7 concept might be ideal for the next decade. Especially facing off against a slightly updated Airbus A320.

[skeptoid]

"....Composites are not cheap, either."

They ARE cheaper than anything else, because the fuselage sections and the wing box and the wing structures are composite. The fuselage is laid up on a rotating mandrel and then cured in a huge oven (AUTOCLAVE) and emerging in ONE PIECE. This saves about a gazillion parts (and associated rivets) and therefore LOTS AND LOTS AND LOTS of LABOR.

I agree; composites are not 'CHEAP', but they are RELATIVELY cheap.

And they are proven.

Boeing and Airbus have been using composites for years. Notably, in Boeing-built military aircraft and control surfaces in transport ships. The BIG DEAL now is the fuselage, because it is a 'pressure vessel'.

And I'm crossing my fingers with everyone else that this works.

See this Mulally report from Farnborough for more inspiring news.

[RayChuang88]

Unfortunately, up till now titanium metal has been very expensive to refine--something like 6-7 times the cost of refining aluminum metal. However, recent developments in titanium refining technology could drastically cut the cost of titanium refining, which could make it possible for airliners to use far more titanium structural parts. The switch to titanium structural parts could cut the weight of an airliner as much as 18%, since you don't need as much titanium alloy for the ssame structural strength as you need with aluminum alloy.