Is there a better solution than the U-shaped tailplane for this Airbus concept?

Question

Image source: airbus.com

This U-Shaped tail is from a concept aircraft from Airbus, I was wondering if there is an alternative but just as good solution to the U-shaped tail. Using a canard in the front for pitch and winglets on the wingtips?

Answer 1

In airplane empennage design, there is a thing called Tail Volume Coefficient. Mind you, there are no volumes here, but you are working with $m^3/m^3$. It is calculated as follows:

Horizontal tail volume:

$V_{HT} = \cfrac{ l_{HT} \cdot S_{HT} }{ c_{REF} \cdot S_{REF} }$

Vertical tail volume:

$V_{VT} = \cfrac{ l_{VT} \cdot S_{VT} }{ b_{REF} \cdot S_{REF} }$

here

• $c_{REF}$ - mean geometric chord (~MAC)
• $b_{REF}$ - wingspan
• $S_{REF}$ - reference wing area
• $l_{HT}$ - horizontal tail arm
• $l_{VT}$ - vertical tail arm
• $S_{HT}$ - horizontal tail area
• $S_{VT}$ - vertical tail area

Now, with that in mind, you can have a perfectly reasonable cruciform solution, U-tail, H-tail, or triple-tail solution, or whichever.

However, freely choosing empennage configuration is not the only condition in design. Engineers likely have other requirements. These two vertical stabilizers (VS) look relatively slender. Perhaps a single VS would be too slender and cause structural issues, perhaps flight dynamics department required better yaw or sideslip control, in which two VSs would maybe be proved better. I think Russians designed An-225 with an H-tail to carry extreme payloads (like Buran), whereas Americans didn't modify 747's empennage for Space Shuttle carrying. There are a number of considerations here. One of which, mind you, is also aesthetics, especially for a passenger airliner.

So, is there a better solution than the U-shaped tailplane for this Airbus concept? It depends. There is no single universally best solution in these things.

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Equations from S. Gudmundsson: General Aviation Aircraft Design