FlightGlobal.com
Home
Premium
Archive
Video
Images
Forum
Atlas
Blogs
Jobs
Shop
RSS
Email Newsletters
You are in:
Home
Aviation History
2002
2002 - 3280.PDF
AIR TRANSPORT GUY NORRIS / LOS ANGELES Boeing wavers on Sonic Cruiser Possible change of direction away from transonic option to Super Efficient does not mean end of concept Boeing is offering airlines a choice between one of three Sonic Cruiser concepts and a "Super Efficient" conventional design amid signs that operators are pushing for the latter to enter service around 2008. Based on current talks with around 20 potential airline cus tomers, Boeing expects to make a final decision by January and get company board approval for authority to offer by the end of next year. Although declining to "indicate a leaning", Boeing now appears for the first time to be rein forcing earlier signs of a change in direction for its next generation transport away from Sonic Cruiser towards the conventional design, formerly dubbed Project Yellow stone. The change is believed to have been confirmed at a Sonic Cruiser airline meeting in Seattle in late October at which none of the potential operators gave a high rat ing to the faster aircraft's proposed Mach 0.96-0.98 cruise speed. BOEING SUPER EFFICIENT AIRCRAFT CONCEPT More electric environmental control system, ice protection and engine start systems 10:1 (or higher bypass ratio turbofans Advanced composite primary and secondary structure "Future" flightdeck LD3 compatible fuselage cross-section Sonic Cruiser vice-president and general manager Walt Gillette says a Super Efficient choice does not mean the end of the fast-jet con cept. "If we decide to do a Super Efficient aircraft first it does not Integrated vehicle health management system Advanced power system Common system architecture Simplified trailing edge flaps Simplified leading edge Distributed power system (using shaft-driven system rather than bleed air system) Length = 59m Span = 56.7m FLIGHT rule out a Sonic Cruiser," he says. Although Boeing "is not really thinking about launching two air craft simultaneously", the advanced processes being studied for the next step "will allow us to Super Efficient and Sonic specs revealed Boeing has revealed the first significant design details of the three alternative Sonic Cruiser studies and the con ventional Super Efficient aircraft that are among the final choices for its 250-seater development. The Super Efficient aircraft resembles a shortened hybrid of a 777-200 and 767-400. Configured with a cir cular fuselage cross-section wider than the 767, the aircraft will incorporate very high bypass ratio engines, raked wingtips and simplified wing trailing edges (see diagram). Many technologies considered for the Sonic Cruiser could be used, possibly including titanium- carbon structures and composite skin stringers. The three final Sonic Cruiser design studies comprise the baseline aft-wing, canard-configured aircraft which is Mach 2 capable, and two mid-wing designs. The aft- wing design is made mostly from advanced composites. The two mid-wing studies have conventional empen nages and feature area ruling. The faster M2 capable version has engines mounted on the wing trailing edge. The slower design, only capable of M1, is more pro foundly area-ruled with higher fineness-ratio engine nacelles mounted on pylons on the leading edge. do two fairly quickly", he says. Gillette also confirms two of the three final Sonic Cruiser designs are capable of supersonic speeds beyond M2, raising speculation that Boeing could be considering the development of a Supersonic Cruiser later this decade as a family adjunct to the Super Efficient and possibly nearer-term Sonic Cruiser. Baseline design goal for all the options is a 757/767-size aircraft with 200-250 seats, but with a 13,880km (7,500nm) range. "The airline's choice is either to go 15 to 20% faster at MO.96-0.98, or to fly at today's speed and altitude but burn quite a bit less fuel," says Gillette. The Super Efficient option burns around 10% less fuel than the Sonic Cruiser and 17-20% less per passenger than a 767-300. DEFENCE PAUL LEWIS / WILLIAMSBURG Interim solution found to V-22 gun turret expense The Rpll Rnpinc V.?.?. Osnrpv inint mnuntpd tn thp <;irlp and tail ramn pratpd with thp flicht rontrnl rnm-The Bell Boeing V-22 Osprey joint programme office has opted to equip the tiltrotor with a ramp- mounted machine gun as an interim alternative to an integrated weapon turret in a bid to cut costs. It is also answering Department of Defense criticism about the deci sion not to retrofit test tiltrotors with crashworthy fuel tanks. "We're looking at an interim gun mounted to the side and tail ramp for testing during Opeval [opera tional evaluation] as there are diffi culties with the nose gun," says Col Raymond Schwartz, head of avia tion weapons, Headquarters US Marine Corps. The programme office has shelved plans to integrate the General Dynamics GAU-19 gun turret under the chin due to cost. The gun would have been inte grated with the flight control com puter to ensure safe fields of fire, and slaved to the Raytheon AAQ- 27 forward-looking infrared imager and planned helmet mounted sight. The Osprey for now will be armed with manually operated 0.5in (13mm) machine guns. Meanwhile, the Pentagon's Office of Inspector General has crit icised the US Navy for not retro- concerns fitting the V-22 with new crashwor thy fuel tanks before resuming flight testing in May. But Col Dan Schultz, V-22 programme manager, says a risk analysis showed there was little value fitting the tanks to the engineering and manufactur ing development (EMD) machines given the type of flight testing. There are three EMD and one low rate initial production V-22s flying. 4 12-18 NOVEMBER 2002 FLIGHT INTERNATIONAL www.flightinternational.com
Sign up to
Flight Digital Magazine
Flight Print Magazine
Airline Business Magazine
E-newsletters
RSS
Events
