AM Staff

Mitsubishi Heavy Industries Ltd. will use aluminum rather than carbon-fiber composites to form the wings of the series of regional jets it is planning to introduce in about five years. The manufacturer shifted its design plans because it concluded that composites would require more material to achieve the necessary structural strength, and thus would not achieve the expected savings in weight.

The change was revealed in a company newsletter, along with the decision to postpone the jets’ introduction from late 2013 to early 2014.

The Aluminum Association, the U.S.-based industry trade group that frequently promotes the light metal’s strength-to-weight advantages over ferrous materials, welcomed Mitsubishi’s decision. “Aluminum’s light weight and strength is an advantage in primary and secondary weight savings, structural performance, fuel savings and design flexibility. Aluminum is the material of choice for aerospace customers throughout the world and continues to grow as the sustainable option markets ranging from ground transportation to consumer electronics to defense applications,” it stated in a release.

MHI’s new jets will be offered in 78-, 92-, and 100-seat configurations, and will be targeted against regional jets available now from Bombardier Inc. and Embraer.

The new jets’ updated design involves “an aluminum wing box, which will make it easier to manufacture the optimal wing structure,” the newsletter reported. Wing boxes form the shape of the wings and attach them to the fuselage.

Mitsubishi manufactures the carbon-fiber wings for Boeing Co.’s 787 Dreamliner, and both Boeing and Airbus SAS use carbon-fiber composites for wing structures to reduce weight are their jumbo jets (the 787 and the A350, respectively.) The 787 design also features a composite fuselage.