The potential limitations include: (1) lower efficiency than existing propulsors due to inherent loss regions within the fan; (2) limited cruise speed due to flow contraction and acceleration within the through-flow region of the fan, producing high relative Mach number and choking; (3) pitching moment caused by fan rotation along the wing axis and unconventional aerodynamic loading distribution; (4) mechanical complexity due to coupling and drive systems needed to power the fan; (5) structures, materials, dynamics, and noise may present basic limitations for some applications.