The last two weeks have provided more action from Boeing and Airbus on narrow-body product development than we’ve seen in the last two years. Yes, Airbus and Boeing have announced new interiors and modest improvements in fuel burn to their respective single-aisle families. However, we are beginning to see the giants stirring toward leaps of 12-15% improvement in efficiency.
One question that remains for Boeing is how to accommodate a larger fan for a higher bypass ratio on a new engine. It is widely believed that the most direct way to do this was to increase the height of the main landing gear. Yes, this gives Boeing a 1:1 benefit in terms of gear length to fan radius, though increasing the length of the gear is very heavy and space in the landing gear well is very limited.
According to those familiar with the plan, lengthening the 737 nose gear appears to provide the most optimized benefit, though it is not without its own challenges. A 6in increase in the nose gear yields 2in in fan diameter. Though it also requires a larger nose gear wheel well that likely requires a squeezing of the forward avionics bay.
Boeing’s vice-president of marketing Randy Tinseth, who did not specify a timeline for the decision, said that the airframer has “no reason to rush” into a decision on re-engining, even with Airbus and Bombardier rapidly moving forward. John Leahy kicked it up a notch at Singapore, saying that Airbus would have a decision “ideally” by the Farnborough air show in July. Just yesterday, Boeing CEO Jim McNerney said that a decision will be made “this year” for a “mid-decade” entry into service, on par with Airbus’s 2015 timeline.
Also important is who is going to be offering what engine. International Aero Engines, which currently makes the V2500 for the A320 family, says it is open to continuing its engine work with R-R and P&W. CFM is more than likely to offer the LEAP-X for both aircraft. Additionally, Boeing’s McNerney hinted that the airframer will offer a second (or even third) engine choice for the 737, ending its sole-source arrangement with CFM, which it has had for more than 20 years.
Separately, let’s ask a question that is central to this entire process: Why is it so hard to get 20% improvement over today’s narrow-body aircraft?
For a long-range wide-body aircraft, fuel burn accounts for about 45-50% of the total cost of operating the aircraft, compared to 30% for a narrow-body aircraft. Engine technology can provide a significant reduction in fuel burn alone, but it is a smaller share of the total cost to operate a narrow-body aircraft. As a result, the airframe and engine maintenance must account for a greater share of the cost savings to deliver the kind of efficiency improvements the airlines want today.
This post was originally published to the internet between 2007 and 2012. Links, images, and embedded media from that era may no longer function as intended.
This post originally appeared at Flightglobal.com from 2007 to 2012.
EVERETT — The youngest Queen of the Skies is resting at the moment, preparing for its first day in the sky. This day was a long time coming, and its arrival for a long time was anything by a certainty. Much of the 1990s and early 2000s were spent trying to establish what the future held for the global icon of commercial aviation.
