, built in 1948 transport
ISR aircraft Twin tails in an H-tail configuration are outboard of the turbulence created by the wider fuselage, improving stability and control especially at high angles of attack when the wider fuselage can interfere with airflow over the vertical tail. Separating the control surfaces allows for additional
rudder area or vertical surface without requiring a massive single tail. On multi-engine,
propeller designs, twin fin and rudders operating in the propeller
slipstreams give greater rudder authority and improved control at low
airspeeds, and one-engine-out situations, and when
taxiing. H-tails may sometimes provide "end plate effect" that improves the effectiveness of the horizontal tail. It also affords a degree of
redundancy: if one tail is damaged, the other may remain functional. Further the dihedral angle may reduce radar-reflection by the vertical tail, reducing aircraft detectability (desirable for combat aircraft). and
Grumman F-14 Tomcat. H-tails can, in some cases, conceal hot jet exhausts from infrared-guided weapons, as in the design of the
Fairchild Republic A-10 Thunderbolt II attack jet. However, twin tails are more complex to design, and tend to weigh more, than single-tail designs. ==Variations==