Anyone know the typical area for horizontal tails for fighter jets like the F-18. Cheers
1 Answer
In pre-design phase the so-called volume method is used.
Tail counteracts the moments created by the wing and it does it creating an aerodynamic moment proportional to its area and its leverarm (area times leverarm is a volume, that's why the name):
- vertical tail surface is proportional to $S_v=\frac{c_vbS}{L_v}$
- horizontal tail surface is proportional to $S_h=\frac{c_h \cdot mac\cdot S}{L_h}$
where $c_v$ and $c_h$ are historical coefficients, $L_v$ and $L_h$ are vertical and horizontal tail's leverarms respectively and $mac$ is the wing mean aerodynamic chord.
According to Raymer¹, $c_v$ is between 0.07 and 0.12 for jetfighters, $c_h$ is 0.4 and leverarms for rear-mounted engine aircrafts are both some 0.45 to 0.5 of fuselage's length.
Just as an example let's do the math for the vertical stabiliser of the F-18 using intermediate values of the just given coefficients:
$S_v=\frac{0.095\cdot11.4\cdot37.15}{17.1\cdot0.475}=4.95m²$
F-18's actual vertical stabiliser surface is 4.85m², a very good result.
¹ Daniel P. Raymer, Aircraft Design: A Conceptual Approach, AIAA Inc.
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$\begingroup$ Thank you for the response. I am using Raymer's method to size the tail for a concept design and wanted something to compare my values with! $\endgroup$ Nov 4, 2022 at 3:44