T-Tail vs. Conventional Tails

[aviationluver]

Does anyone know the why some manufacturers choose T-Tails over conventional tails? What are the advantages and disadvantages of each? Thanks.

[DIBO]

Pending a more useful reply, in the meantime you can maybe spend some time reading https://www.pprune.org/flight-testing/503356-pro-s-con-s-t-tail-2.html

[tdracer]

You tend to see T-tails on aircraft with aft mounted engines - it simply makes it simpler to place the engines if you put the horizontal tail on-top. However T-tails are far more susceptible to the uncoverable 'deep stall' phenomena. That's were the separated flow from a stalled wing effectively blanks out the tail so you can't push the nose back down to recover from the stall. Low tails are not normally susceptible to that 'deep stall' since at high angles of attack the horizontal tail is below the separated flow from the wing.

[c52]

When I asked my gliding instructor, I was told that a T-tail required extra strength in the fin, and therefore extra weight, and that was a bad thing.

It also occurs to me that if the fin falls off, it is better for it not to take the horizontal stabiliser with it.

[NutLoose]

You tend to see T-tails on aircraft with aft mounted engines - it simply makes it simpler to place the engines if you put the horizontal tail on-top. However T-tails are far more susceptible to the uncoverable 'deep stall' phenomena. That's were the separated flow from a stalled wing effectively blanks out the tail so you can't push the nose back down to recover from the stall. Low tails are not normally susceptible to that 'deep stall' since at high angles of attack the horizontal tail is below the separated flow from the wing.

And as such on some aircraft the stalling airflow off the wing will give you buffet over the lower tailplane warning you of an impending stall. The wing is twisted slightly along its length or has other methods so the root stalls first and triggers the stall warning horn / gives you buffet on the controls ( Shake ) the reason you have the twist / other methods is you still need part of the wing not in stall to allow you to have aileron control.

A T-tail as said is mounted high and can get into a deep stall, these aircraft tend to have a stick shaker that warns of an approaching stall and if the pilot does not respond to it and lower the nose, the aircraft systems force the stick forward preventing the aircraft from entering the deep stall.
This will explain it

https://learjet35instruments.wixsite.com/learjet35instrument/aoa

other clever ways around the stall problems

https://www.v2aviation.org/post/30-september-1990