Paul Lewis/WASHINGTON DC
Embraer has unveiled further configuration changes to the ERJ-170's main wing to improve performance, as the Brazilian regional jet programme prepares to move to the next detailed design and certification phase and the start of fabrication in July.
With the completion of preliminary design review and the joint definition phase (JDP) drawing to a close, Embraer has extended the 72.5m² (780.4ft²) wing by adding blended winglets and opting for moving double slotted flaps. The locally designed 1m-high winglets are calculated to generate a 3-5% improvement in the standard ERJ-170's target 3,334km (1,800nm) range and fuel consumption.
The winglets draw on a similar modification made to the SIVAM airborne early warning version of the smaller EMB-145 jet. "The results from the simulation and flight test of the -145 were better than expected and led us to investigate the ERJ-170. Initial results were also good, though [the improvements are] not as big as SIVAM, and JDP is the time to make the change," says Luis Affonso, ERJ-170/190 programme director.
A decision now has to be made between Embraer or wing subassembly partner Kawasaki Heavy Industries on producing the new composite winglets. The Japanese manufacturer was to have produced the original wingtip. Embraer will wait until next year's JDP before deciding on fitting wingtips to the stretched ERJ-190-100/200, which will have a larger 90m² wing.
Launch customer Crossair required the 70-seater ERJ-170 to be designed to operate from runway-restricted Berne Lugano and London City airports. "Testing has shown that moveable double-slotted flaps will maximise lift co-efficient and produce better short field performance," says Affonso.
Embraer's on-going airline advisory board, numbering 25 carriers, suggests moving the front right hand side service door forward. This will create a larger space separation from the forward luggage hold door and the engine nacelles.
The follow-on critical design review runs from late July until September, after which the ERJ-170's design will be frozen. Embraer has ordered material for its first six pre-series ERJ-170 test aircraft and two static airframes. "Final assembly starts in April/May 2001 with a first flight before the end of the year," says Affonso.
Source: Flight International