Follow along with the video below to see how to install our site as a web app on your home screen.
Note: This feature may not be available in some browsers.
avbug said:Minitour,
The placement of the engines below the wings or on the wings really makes little difference, especially when considering a T-tail configuration. One reason, a big one, that the T-tail came about is sex appeal; it looked classier, and that's why you see it on a lot of smaller airplanes.
Placing the tail high above the airframe puts it in relatively undisturbed air from the powerplants and airframe. It also provides a greater aerodynamic range, with a greater moment potential against the center of lift, and center of gravity. It tends to permit, generally speaking, a wider CG range for a given design than a tail placed lower, and it means that the inboard sections of the horizontal stab are less affected by the aerodynamic influence of the empennage.
A t-tail puts the horizontal stab, spar,and associated mechanisms away from the engines, and allows for a thinner back end, with a reduced cross section. This is frequently reduced adjacent to the engine pods with aft mounted engines in an area rule configuration (empennage gets thinner, or concave, adjacent to the engine nacelles) to reduce interference drag.
A horizontal stabilizer that's out of the prop wash and out of the jet blast means less potential for damage to the stab, and less drastic changes in pitch trim with changes in power.
Think about Falcon's...they have a mid-tail. Maybe they had all of the employees vote. Then they tallied the votes for the T-tail and the votes for the low-tail and it came out even. So they held a recount and it was still dead even. The lawyers from both sides finally agreed to a compromise and that is how the mid-tail was born.When I was an engineer 99.99% of what you do is just a compromise between cost/perf or cost/manufacturing or some other combo.