Pelikan Tail - Advantages and Disadvantages

Advantages and Disadvantages

The Pelikan design differs from the traditional elevator-and-rudder design in that it uses only two control surfaces in order to achieve control of pitch, yaw, and roll. When evaluated by Boeing engineers in October 1998, they found advantages of greater pitch control at high angles of attack and that two tails would have a lower radar signature than four. However, they also found that using two larger control surfaces instead of four, might actually make the aircraft heavier. The bigger hydraulic pumps and cylinders needed to operate the larger surfaces would add 800 to 900 pounds (360 to 410 kg) of weight to the design. This, and other factors made them use a four-post tail instead.