Can the wings retract while in flight?
Three features act independently to prevent a wing retract while flying. The first is that the air pressure utilized to extend the wings initially is constantly pressurizing the wing spars, forcing the wings to remain extended. Secondly, should an engine failure lessen the air pressure, winglets act with an outward component of force to keep the wing extended. Finally, a series of pins lock the spars and wings in an extended configuration.
