Friction welding fuses metals without melting them and is used in aerospace to join engine disks (rotational welding) or fabricate aircraft and spacecraft structures (friction-stir welding). Now hybrid components produced by linear friction welding of dissimilar metals promise to overcome a key disadvantage of composites: carbon fiber cannot be attached directly to aluminum because of galvanic corrosion, forcing use of higher-cost titanium. But friction welding can allow titanium to be incorporated into the join between aluminum and composite structures.

Isogrids are among the lightest and strongest of structures, the lattice pattern of integral stiffening ribs providing extremely high strength-to-weight ratios. Lightweight isogrid panels machined from aluminum plate to produce thin-walled, self-stiffened and damage-tolerant structures are used in launch vehicles and aircraft doors. Advanced grid structures made from composites have been used for components such as payload shrouds, but require time-consuming and costly manual layup. Isogrid Composites Canada Inc.

Composites may be replacing metals in aircraft structures, but the use of titanium is increasing both to reduce weight and because of the incompatibility of aluminum and carbon fiber. Boeing's 787 is 50% composite by structural weight, whereas its earlier 777 is only 12%, but a 787 contains almost 90 tons of titanium compared with 55 tons in a larger 777. And titanium can be around 10 times as expensive as aluminum, so pressure is on to reduce costs.

With ground to make up in the marketing battle with Airbus and the A320NEO, Boeing is going to new lengths to eke out improved aerodynamic efficiency on the competing 737 MAX.

As a former Darpa scientist and one of the world's foremost authorities on materials, Leo Christodoulou is accustomed to thinking out of the proverbial box when it comes to problem-solving. At the Defense Advanced Research Projects Agency, he applied his research expertise to developing revolutionary, new materials for the U.S. military.

Let's face facts: It has become nearly impossible to monitor Ryanair's economic model or to predict what's going to happen to Europe's lowest-fare airline in the next few years. The key question is how to determine whether the Ireland-based carrier can remain profitable in the face of declining traffic growth. In March, the airline carried 5.5 million passengers, a surprising 4% decrease. And, in the last 12 months, its traffic increased a relatively weak 5%. Clearly, this is no longer the two-digit growth to which the airline is accustomed.

Rarely in aerospace do the hopes of a company pivot almost entirely on the successful outcome of a single technology, but this is the gamble Pratt & Whitney faces as it embarks on flight tests of its second geared turbofan model and takes another key step toward revitalizing its civil engine fortunes.

When Chinese engineers began full-scale development of the ARJ21 regional jet in 2002, they must have doubted that they would meet the remarkably tight schedule to deliver the first unit in 2006. But it is unlikely that they imagined they would still be developing the aircraft 11 years later.