Hello everyone, I’m an aviation student and i’m trying to find why different tail configurations are used, and why companies like to stay with those configurations. This is more specific with commercial aviation, because military tail configurations change all the time. For instance, T-Tail designs are not the best for Stall/spin characteristics because the tail doesn’t see as much airflow. But T-tails are good for avoiding engine exhaust and good for loading of the aircraft. I was wondering if anyone has information like this for other tail configurations. Thank you, Dan
By: mike currill - 25th October 2003 at 19:23
Originally posted by Kenneth
How about Fouga Magisters… 😀How about the Northrop flying wings of the late Forties… 😀 😀
plus the Robin Alpha and a few varieties of microlight
By: Distiller - 25th October 2003 at 09:02
Ja, richtig. Der Magister. Vergaß den. There was also a very early Yak and some swedish sportsplane I can’t remember the name right now.
On the Northrop bomber: I didn’t mention it because it had control problems since Northrop hadn’t figured out the bell shaped lift curve “Glockenkurvenverteilung” that makes it possible for a flying wing to be fully controllable. The Horten brothers found that out in the mid 30s and used it for their record breaking gliders in the Wasserkuppe competitions and later on their fighter and bomber designs. Northrop only copied the Horten shape w/o knowing about the lift curve.
Anyway, doesn’t fit GA.
By: Kenneth - 24th October 2003 at 18:59
“V” tail: less weight, less drag, but problems in coupled roll/slip situations. Only on old Beeches and gliders.
How about Fouga Magisters… 😀
no tail, “Nurfluegler”, flying wing: no drag, no weight, restrictions in crosswind, complex input. With manual input successfully done only by the Horten brothers in WW2 and a glider from Akaflieg Darmstadt around 1990. B-2 does it with computers.
How about the Northrop flying wings of the late Forties… 😀 😀
By: Distiller - 24th October 2003 at 17:40
“conventional” tail: since this is the general aviation forum I assume you mean low subsonic speeds (a conventional low tail is used on supersonic planes to avoid the main wing’s shockwave). Easy to build and rather straightforward in input response. Usually it doesn’t matter if the tail plane gets some turbulence flow, which it by the way hardly ever gets since it is spaced to avoid, and if if it does it only shakes a little, won’t loose control because of that. Jetairliners don’t enter AoAs that would put the tailplane in the wings turbulences. Behaviour depends on the locaton relative to the center of gravity/it’s axes and the center of lift.
“H”-tail: Isn’t done any more except A-10 (here for reasons of survivability). Only for really low mach numbers and military applications (if you want to shoot a gun straight back w/o putting a gun in the tail). The An-225 has it to increase stability and also to be able to put a space-glider on top.
“+” tail: don’t know why these are built. on old MiGs because they wanted to be able to take off the engine and exhaust, so they put they tailplane a little higher. same problems as a “T”
“T” tail: structurally heavier since the vertical part needs to take all the load from the horizontal stabiliser, but has less drag due to the increased geometrical lenght. can get into superstall. On biz-jets because of area ruling and the engines taking up the space down below.
“V” tail: less weight, less drag, but problems in coupled roll/slip situations. Only on old Beeches and gliders.
no tail, “Nurfluegler”, flying wing: no drag, no weight, restrictions in crosswind, complex input. With manual input successfully done only by the Horten brothers in WW2 and a glider from Akaflieg Darmstadt around 1990. B-2 does it with computers.
“Delta” configuration: not in GA, only good for supersonic drag
“Canard” and trebble flying planes = decoupled surfaces: Good for drag and weight, but complex input and restricts overall airframe design. Lóok at the Piaggo or Starship.
By: Marco - 23rd October 2003 at 14:58
I am a student myself but I can add a couple of tentative details about the differences between a traditional tail configuration and a traditional tail that I know about:
1 – with a normal tail, when you go full power the plane noses up by itself. That comes from the fact that the airflow of the prop is lined up with the elevator and the increased airflow on the elevator will increase the negative lift on it (elevators have negative lift in normal conditions). This makes it easy to climb and descent with engine power because all you have to do is increase throttle and the nose will stay up or will go down on its own without you having to work too much for it (at least initially, you will have to trim later as the airspeed changes though). A T-tail is generally immune by the prop speed (which has the advantage of making it more “predictable” and consistent, so to speak).
2 – with a normal tail you can’t slip with full flaps down (usually) if your plane is also a high wing (not too sure about low wings). If you slip with flaps down, the airflow over the elevator will be disrupted by the lowered flaps and you risk an elevator stall (which at low altitude probably ain’t gonna be pretty). A T-tail should be immune to that (with the added note that usually T-tails are low wings. Have not seen a high-wing T-tail … yet).
Of course all this refers to the small, prop planes, trainers for the most part.
Jets … well, if they have underwing engines they are usually normal tail, if they have rear engines … they are usually T-tails …
… and this is the extent of my VERY limited knowledge.
🙂
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October 23, 2003 at 11:19 am