TCDS and T-tail
john_tullamarine, you being the person who showed me the TCDS online charts, I found one interesting problem with the Arrow IV there.
The TCDS in question lists that the CG envelope has a linear change after 2240 lbs of weight.
I found that strange since my POH specifies 2400 lbs, not 2240. I was confused, but then I found a scanned copy online of a Turbo Arrow IV original AFM, and to my surprise, it was also specifying the change after 2400 lbs.
So, do the online TCDS suffer from typing errors? 2400 to 2240 seems like one...
But my main question here is, for anyone that cares to help:
Why does an aircraft manufacturer decides to use a T-tail?
I can understand that in turboprops and jets in general, the exhaust gases heat would damage the empennage, but I really cannot see the benefit (instead of maybe, I don't know, visual appealing marketing?) of a T-tail in a conventional piston powered aircraft.
If my theory is correct, a T tail horizontal stabilizer (and elevator... or stabilator for that matter) is outside the propwash (specially in single engines).
Being outside the propwash means less energy on the tail surface's boundary layer, and less lift is produced.
Since posters here have told me that a T tail have less pitch authority (can anyone elaborate on that?), and our Turbo Arrow IV in question even has slots in its stabilator design (meaning it probably had control problems maybe?), why did the manufacturer choose to use the T tail?
Thank you once again!