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Like would for example the P-47 most likely have symmetric, normal or inverted airfoil as horz. tail?

Is my analysis correct?:

It has a CG at 25-32% MAC according to manual. Since AC on wings is usually located around 25% MAC it safe to assume the CG is aft of AC. Since the setup is that way, it would be normal to have horizontal tail producing positive lift.

Also; did typical WWII planes have inverted airfoils as horizontal stabilizers?

What about general aviation planes today?

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  • $\begingroup$ The P-51 used a NACA 6-Series airfoil which was not symmetric $\endgroup$ – Carlo Felicione Apr 7 '17 at 16:24
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From the Longitudinal Stability (Pitching) chapter in the FAA Pilot's Handbook, two things stand out to me:

One:

enter image description here

Regardless of the airfoil shape, nose-heavy airplanes like WWII fighters will almost always have downforce on the horizontal stabilizer.

Even if the airfoil is not inverted, it will be attached at a negative angle of attack.

Compensation for this nose heaviness is provided by setting the horizontal stabilizer at a slight negative angle of attack.

Cutaway drawings for the P-47 seem to suggest they're not inverted, example:

enter image description here
(Source)

Two:

Unless it's a T-tail, the propwash combined with the downwash results in downforce on the horizontal stabilizer.

enter image description here
(Source)


P.S. Do not rush to accept, wait for votes or wait for our resident aerodynamicists to answer.

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