Designing an airplane from a stealth perspective would undermine its aerodynamic performance. We considered the X-47 B UCAV as a case study to demonstrate this point. We performed MDO for this airplane ignoring stealth requirements. The MDO problem was formulated to maximize the flutter speed and minimize the total drag, while trimming the airplane in a longitudinal statically stable cruise condition. The performance of the optimum planform, camber and twist distributions was compared to that of the original aircraft. This comparison provides an estimate for the aerodynamic loss due to the stealth constraint.