December 10, 2012
Credit: Photo Credit: Boeing
Fred George Seattle
Pilots who strap into Boeing's new 787 most likely will conclude that it is the easiest to fly and most intuitive jetliner ever built by the Seattle-based manufacturer, based upon our findings during a demo flight in mid-November. Five large-format LCD screens have 40% more display area than those in the Boeing 777, making room for better graphics that improve situational awareness. Standard left- and right-side head-up displays, plus left- and right-side electronic flight bags, (EFB), among other features, provide both pilots an equal access to all technology features. Enhancements to the digital fly-by-wire (FBW) flight-control system, adapted from the system used on 777s, make the new aircraft even more docile to handle, resulting in broader safety margins.
While the 777 and 787 share a common pilot type rating because of similar cockpit layouts, systems designs and handling qualities, there are substantive differences between the two aircraft. The 787 is the first commercial jetliner to have a primarily composite airframe. It has a higher aspect ratio wing with a 5% better lift-to-drag ratio than the 777.
The 787's higher bypass-ratio engines do not suffer efficiency losses from constant extraction of bleed air. The aircraft has a nearly all-electric systems architecture, except for high-pressure hydraulics to power some heavy loads and engine bleed air that is used occasionally for nacelle inlet anti-ice protection. Cabin pressurization is higher, so both crews and passengers will experience less fatigue on long flights. And the aircraft's more aerodynamic nose and windscreens means there is less ambient noise in the cockpit.
Boeing 787 engineers took on large-scale technology risks in designing this aircraft. Their goals included a 20% reduction in fuel burn, a lighter weight airframe and 30% lower maintenance costs than the 767, the aircraft that the 787, aka the “Dreamliner,” will replace in the model lineup. Increased range, a boost of cruise speed by nearly 30 kt., and an overall more comfortable passenger cabin were also key goals.
Overcoming some of the major risks was part of what led to a three-year delay in the aircraft's initial entry into service. The joints between the center wing carry-through box and main wing structures proved to be too weak, thus requiring modifications. An electrical fire in one of the aft-mounted large motor controllers, caused by metal foreign object debris, grounded flight-test aircraft until those boxes could be redesigned and hardened against moisture and metal-shaving intrusion. Myriad problems with outside suppliers also caused program delays.
After the aircraft went into service in October 2011, other snags emerged. One General Electric GEnx turbofan developed cracks in its fan mid-shaft. A manufacturing flaw in the aft fuselage section caused delamination of the carbon-fiber plies, resulting in extensive rework of several aircraft.
Boeing claims those woes now are history. At present, dispatch reliability exceeds 99%. Having delivered 38 aircraft and satisfied that they had matured sufficiently, Boeing invited Aviation Week to fly the 787 for an evaluation in mid-November.