Contamination on the elevator like ice from a dripping leaky hangar roof is easily detected on a normal tail, but I almost missed it one winter day preflighting my T-tail Grob 109B TMG. Generally low surfaces are good when preflighting. Ever wondered why Cessnas run out of fuel more often than Pipers? One likely reason is that visual inspection of the fuel takes a climb on the Cessna.
I regularly fly Piper Arrows with both tail configurations and do not think much about differences except during take-off. The t-tail is of course out of the slipstream and it is not possible to rotate until there is elevator authority from the airspeed alone. For this reason the t-tail Arrow is not suitable for soft-field take-offs – it is not possible to unload the nosewheel early or to lift off early to build up speed in ground effect.
The Arrow’s big brother, the PA-32R(T) Lance, has the same. It also comes with either normal or T-tail. Due to the long cabin and a larger CoG envelope, the effect of the t-tail is even more marked, and there is a note in the POH performance section to add 25% to the take-off run if the CoG is in the forward part of the envelope.
I find that the T-tail versions have more rudder authority in crosswind landings, especially on the PA-32R(T) Lance. Apart from that, and the elevator during take-off, I do not find much handling difference, not even in the stall.
HK-36R wrote:
Not really sure, if this is really true. Even for non T-tail gliders, the elevator is generally one piece: Libelle, Ka6, Ka8, Fox, Swift, …
Obviously, if we get into the details, it gets more complex. But generally yes: There have also been gliders where the elevator has been mounted in front of the vertical stabilizer (Ka8, Standard-Libelle) or behind them (esp. Aerobatics-gliders like Fox, Swift).
My impression is, that these are mainly 50ies and early 60ies designs and later on they moved away from it: The KA-6E had a two part elevator. The Club-Libelle a T-Tail (as far as I remember as I have flown the KA-6E but never a Libelle)…
And have to admit: Forgot about the Ka-8 – so long ago since last time I had to put it in a trailer…
However, one of the drawbacks of the T-tail is the possibility of getting into a deep stall with the tail shielded by the wing
This may be relevant on a swept wing design, not sure so applicable to straight wing GA.
A theoretical benefit of a T-tail in GA is there is less risk of rudder blanking in a spin, but I doubt this is why Piper introduced T-tails in the Lance and Arrow.
I heard it said once (sounds plausible, but really don’t know) that the T tail in something like an Arrow and others helps to reduce some of the aircraft internal noise because the T tail is lifted above most of the turbulent prop wash into smoother air. So less surface to collect the ‘drone/drumming’ of air spiralling around the fuselage.
(4. Easier assembly of the gilder out of the trailer?)
That has actually always been a big pro for T-Tails in gliders: With a T-Tail the horizontal stabilizer is one part that can be detached. For non-T-Tails it is two parts – so double the options to mount it wrongly, forget a splint, etc.
Not really sure, if this is really true. Even for non T-tail gliders, the elevator is generally one piece: Libelle, Ka6, Ka8, Fox, Swift, …
HK-36R wrote:
(4. Easier assembly of the gilder out of the trailer?)
That has actually always been a big pro for T-Tails in gliders: With a T-Tail the horizontal stabilizer is one part that can be detached. For non-T-Tails it is two parts – so double the options to mount it wrongly, forget a splint, etc.
The T tail on my plane is to keep it out of the water. It’s position has zero effect on handling. Other types have T tails for other reasons, and there are handling differences in some. Pilots new to a T tail plane should either get some type training, or approach with caution for the first few circuits.
The MCR01 Ban-Bi and Spacek SD1 would be examples of modern, diminutive designs that are built for efficiency and have T-tails.
T tails in piston GA were done AFAIK to look good on the ramp.
Mechanically they must be less strong, and more troublesome, because you have to reinforce the VS structure from base to halfway up, and have an extra joint in the control linkage.
Probably, all modern gliders have T-tails for the following reasons:
1. Ground clearance for off-airport (= field) landings.
2. Less interference drag as the upper surface is continuous.
3. Slightly better rudder authority (“elevator” works like a winglet).
(4. Easier assembly of the gilder out of the trailer?)
The only exception I am aware of as far as modern gliders are concerned applies for gliders specifically designed for aerobatics: the mass of an elevator at the top of the rudder leads to more torque load on the fuselage tube. Thus, the T-tail is not used for structural reasons.
