Stall Recovery vs Tail/Fuselage design

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clanon

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Not a hijacker here but...

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Does ventral fins help on this cases ?

 

bmcj

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A ventral fin can help if the design experiences heavy blanketing of the airflow over the fin and rudder.
 

orion

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Ventral fins, like many other add-ons to established, production aircraft, are usually fixes for what was either a poorly conceived design in the first place or one where the organization wishes to expand the aircraft's capabilities or safety features. Depending on layout and configuration, ventral fins are generally used to aid deep stall recovery by providing assistance to the horizontal tail in generating a positive vertical force. The aid may be required either due to an initially unforeseen condition where the aircraft experiences an excessive amount of blanketing of the horizontal surface, or one where an undersized surface was used.
 

bmcj

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A ventral fin can help if the design experiences heavy blanketing of the airflow over the fin and rudder.
Sorry... meant to say blanketing of the elevator (by the wing in a deep stall). These are the fins you see on the bottom that are not vertical, but jut out on both sides of the tailcone (most often at an angle that is not vertical, nor horizontal.

A vertical ventral fin can be added to the tail to enhance yaw stability (same effect as enlarging the fin, but it can have a beneficial yawing effect from the prop's spiral slipstream). It may also affect spin recovery if the rudder is subject to heavy blanketing of the airflow by the horizontal tail surfaces.
 
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