Boeing is to flight test a full scale wing modification for the proposed 747X based on aerodynamic changes originally developed by McDonnell Douglas for the MD-11.

The company has completed initial windtunnel tests of the change, dubbed the trailing edge wedge, and plans to refine the modification before flight tests take place. Boeing director product marketing Joe Ozimek says: "It is giving us everything we wanted in terms of better performance. We have confirmed it in the windtunnel here and were pretty sure it would work because it has already been done on the MD-11."

The trailing edge wedge basically "-blunts the edge of the wing" explains Ozimek. who says the change is being evaluated as part of a series of modifications for the 747X. "The plan is to spend up to the end of the year working out what is the right way to serve the marketplace. We have got to talk to with the airlines and conduct technical studies internally to work out the business case before we decide whether to offer it."

Options being discussed for the 747X range from a simple stretch to a wing root insert to provide more fuel capacity, extra lift and longer range. The further growth step marries the two to provide Boeing with an immediate competitor to Airbus' proposed A3XX-100. The stretch would seat around 500 and probably exceed 13,900km (7,500nm) in range. Other wing optimisations under study include a 0.38m raked wingtip devices similar to those used on the MD-11.

The trailing edge wedge extends over 2.5% of the wing local chord and provides an improvement in lift over drag "in the order of 3% to 4%" says Ozimek.

Source: Flight International