A little more than a decade ago I was sweating out my final semester in Aeronautical and Astronautical Engineering, and the capstone class was Senior Design - Aircraft. We were placed in teams and tasked with fleshing out a design concept for a Super Short TakeOff and Landing cargo aircraft. My responsibilities were Aircraft Performance and Environmental Impact, though my effective responsibility was only Performance. There simply was no design manual for Environmental Impact; noise was a tangential factor that deserved just a bit of consideration, and Specific Fuel Consumption played into range and weight, but little more. The very thin section in our final design report admitted we could find no guide and little information on Environmental issues as related to aviation, and we were let off the hook.
December of 2002 marked a significant shift away from this attitude in the aviation world. In that month, Boeing was forced to admit defeat and abandon their sexy Sonic Cruiser concept due to lack of interest. As this followed shelving of the 747 stretch program a year prior, many industry watchers openly wondered if Boeing Commercial had lost its mojo. Those concerns were amplified when the 7E7 was announced, with the "dowdy" goal of using Sonic Cruiser developments to wring out ~20% efficiency gains from a basic tube and wing planform. Boeing was in effect claiming that the century of aviation focused on higher, bigger, and faster heroics was now giving way to those sniveling environmental concerns. Conventional wisdom said that it could be the company's last hand in the poker game of airliner manufacturing, and that it had unceremoniously checked.
Sixteen months of gut-check played out between the 7E7's announcement it's official program launch, when ANA first signed up for 50 of the aircraft in April of 2004. And it was almost another year before the narrative started to change and Boeing started to rack up more orders. Lingering overcapacity post 9/11 and an extreme rise in fuel prices in the wake of Hurricane Katrina made airlines vulnerable, and a 20% efficiency gain became a compelling sales point. By April of 2007, the renamed 787 Dreamliner had become the fastest selling commercial airliner ever, with 544 firm orders on the books. Even with numerous painful delays to the program, Boeing now holds 840 orders for the plane, when it only flew for the first time a couple of weeks ago.
In aviation, efficiency has gone from something of a tangential concern to the primary selling point for new aircraft in less than 10 years. Airbus's A350 had to undergo three major design iterations before a marketable product emerged, now largely embracing the 787 design direction of composite primary structures, highly efficient turbines, and more electric systems. Engine technology seems to be the pacing item for Boeing and Airbus narrowbody redesigns, with open rotor and Geared TurboFan engines competing with conventional high-bypass turbofans for the next step in efficiency. Bombardier is trying to move upmarket with the C-Series narrowbody design, using composites and the GTF engine as differentiators from Embraer and the smaller Boeing and Airbus planes.
It's typical for aviation to be in the vanguard of transportation development. And with the development of energy (and hence cost) efficient aircraft heating up over the past several years, aviation will continue to set the direction of transportation development for some time to come.