Since a V-tail is lighter and generates less drag than a conventional empennage, why has this solution been put away from production?

  • 1
    $\begingroup$ V-tail design is in production. One of most recent addition is SF50. $\endgroup$
    – Farhan
    Oct 27, 2017 at 19:01
  • 1
    $\begingroup$ Related explanation of V-tail effectiveness in damping. $\endgroup$
    – mins
    Oct 27, 2017 at 19:24

1 Answer 1


Controllability and redundancy. Airliners are certified according CFR 14 Part 25, which specifies that upon engine fail the aircraft must still be able to fly and climb: it must have more than one engine.

After an engine has failed, the rudder must be deflected in order to compensate for the asymmetric thrust of the remaining engine. With a V-tail, this means that after engine fail, there is less pitch authority: pitch and yaw surface deflections are coupled. A V-tail has two control surfaces that combine aircraft yaw control and pitch control, which goes well until one of the surfaces hits a stop.


Reduced pitch control due to an engine failure would be unacceptable for an airliner. For a single engine plane with the engine in the centreline, this yaw trim condition would not happen.

  • 1
    $\begingroup$ isn't it roll/yaw coupling? $\endgroup$ Oct 27, 2017 at 22:50
  • $\begingroup$ @user3528438 roll can be compensated with ailerons, in a v-tail there is not another control surface for compensating for pitch when the yaw control has to compensate for asymmetric thrust. $\endgroup$
    – Owen
    Oct 27, 2017 at 23:39
  • 2
    $\begingroup$ @user3528438 What is meant is that on a V-tail, the control surfaces placed there substitute the conventional rudder and elevator and are thus effecting yaw and pitch control combined. On an (asymmetric) engine failure, some - often significant enough to actually dimension the rudder in the first place - yaw control surface deflection is required which would then reduce available pitch deflection due to the same control surfaces being used for both. $\endgroup$ Oct 27, 2017 at 23:43
  • 1
    $\begingroup$ But arent the surfaces enlarged to compensate for double duty? Ref be33/36 vs v35. $\endgroup$
    – acpilot
    Oct 28, 2017 at 5:11
  • $\begingroup$ @acpilot Yes they can be, however there are practical limits: enlarge them enough and the advantage of smaller tail surfaces is gone. Engine fail means lower speed, higher required elevator & rudder deflections etc. All works out OK for centreline single engines - except for the fishtailing that is reported. $\endgroup$
    – Koyovis
    Oct 28, 2017 at 5:38

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.