t tail vs conventional tail

Why are the Antonov An-124 horizontal stabilisers directly behind the wings? Quiz: What Should You Do When ATC Says '______'? And on the landing roll the tail can seem to lose authority all at once with the nose coming down. 9. Why was the skid landing gear located so far aft on the X-15? TMetzinger, Aug 5, 2012 #10 wabower Touchdown! Rotate at 75 knots. Passenger cabin shots showing seat arrangements as well as cargo aircraft interior, Cargo Aircraft Tail sweep may be necessary at high Mach numbers. MathJax reference. [3], The design and structure of a T-tail can be simpler. High performance: It results in high performance of aerodynamics and also ensure there is an excellent glide ratio since the empennage is not affected by the wing slip steam. Advantages Of A T-tail Vs. A Conventional Tail, RE: Advantages Of A T-tail Vs. A Conventional Tail. This shape resembles a capital T, giving birth to the moniker of T-tail. It only takes a minute to sign up. Quiz: 7 Questions To See How Much You Know About VFR Sectional Charts, Quiz: 7 Questions To See If You Can Fly The LOC/DME-E Approach Into Aspen. The C2 has a conventional tail rotor: The RPM of the tail rotor on the C2 is roughly 2150 RPM. The Pilot Handbook of Aeronautical Knowledge has a whole section talking about T-tails. Do I need a thermal expansion tank if I already have a pressure tank? The swept tail vs. straight tail i think is overrated. Planes operating at low speeds need clean airflow for control. 6. I guess I'd like to know what makes a T-tail advantageous as opposed to a conventional tail. Learn more about Stack Overflow the company, and our products. There were a LOT of legit proposals out there. Register Now. Most of the (small aircraft) T-tails I have flown it takes a bit of extra effort to stall the aircraft hard because gently the disruption just lets the nose back down and then you aren't stalled anymore. The wings have such a large chord that there is already 'dirty' airflow coming off of them. Note that the increased leverage means that the horizontal tail can be smaller as well. easiest to do. The disadvantages ot the T-tail concept are the mentioned deep stalls, maybe a elevator stall during flare, unfavourable C.G. You might see V-Tails used on high-performance models, such as slope soaring or discuss launch gliders. 5. avoiding hard de-rotation on touchdown, issues at high AOA, etc)? 1Cause deep stall: T-Tail surface may cause deep stall where the elevator/stabilizer becomes stalled making the nose impossible to push over due to the stalled condition. Get Create An Account Here. Guy Inchbald / Wikimedia Commons / CC-BY-SA-3.0. with the high t-tail of the lance it makes that a bit more difficult. In a normal tailed engine aircraft, when the pilot increases power, he gets wind over the tail and has control authority of the aircraft. This may result in loss of elevator authority and consequently, inability to recover from the stall (i.e. A T-tail produces a strong nose-down pitching moment in sideslip. For the pilots its interesting to note that if you apply thrust it has a pitch down tendency (when engines mounted rear) because the engines are above the C.G. Advantage: Redundancy in case of battle damage. The under-sized surfaces used in designing the V-tail make it lighter and faster. Before CFD, mounting the engines on the wing created lots of problems, prompting the engineers to move to tail-mounted engines in their next design (DC-8 -> DC-9, B707 -> B727), The mass of the horizontal tail on a long lever arm (= the vertical tail) means that the torsional eigenfrequency of the fuselage will go down. The T-tail differs from the standard configuration in which the tailplane is mounted to the fuselage at the base of the fin. Seaplanes and amphibian aircraft (e.g. T-tail is especially popular on modern gliders because of the high performance, the safety it provides from accidental spins, and the safety it provides the stabilizer and elevator from foreign object damage on take-off and landing. What are the aerodynamic consequences a pilot needs to be aware of with a T-tail (e.g. If a law is new but its interpretation is vague, can the courts directly ask the drafters the intent and official interpretation of their law? Now, a T-tail would place the tail out of the wash during normal flight conditions, which maybe provides additional efficiency/effectiveness? Inadequate maintenance of t-tail may lead to loss of control of the aircraft on air. Due to the aft C.G. One advantage to a T-tail is that the engines can be put on the tail, making them less suceptible to FOD ingestion, except for ice from the wings. Gliders with V-Tails can slice through the air just that little bit better when they have less draggy surface area. Not only for the aerodynamic loads, but for the elevator and elevator trim mechanisms. uhmmm very interesting but now I can't understand why commercial airliner strictly prefer conventional tail instead of T-Tail. But the only other T I've flown is a Skipper. Observed form behind, this looks like the capital letter T. Sometimes the term is used to refer to an aircraft with such empennage. Tailplane more difficult to clear snow off and access for maintenance and checking. This will be a problem. The T-tail, depending on airspeed, is either very effective or far less effective than a conventional tail, which isnt as prone to abrupt transitions between different flying regimes. The T-tail avoids this, but it places a large mass (the stabilizer) at the end of a long moment arm (the fin). 1. To assess transcriptional activity before and after the major wave of ZGA, we determined the number of T>C reads in 3 mRNA SLAMseq datasets (T>C reads; +4sU) relative to unlabeled samples (-4sU; Figure 2 A) or in-sample background conversions (i.e., T>A; Figure S2 A). Labyrinthulomycota, the "net slimes" - Labyrinthulida. To subscribe to this RSS feed, copy and paste this URL into your RSS reader. Quiz: 6 Questions To See How Much You Know About Stalls. Are there other reasons for having a T-tail? Rear mounted engines also require more fuselage structure. Aviation Stack Exchange is a question and answer site for aircraft pilots, mechanics, and enthusiasts. I can't really say I know the aerodynamics of it though, so I might be very mistaken. The simple answer is that they can be more efficient than a conventional tail. The optimal treatment strategy for acute exacerbation of COPD in the ICU next to the well-known benefits of noninvasive ventilation (NIPPV) is unknown Most of the entries in the NAME column of the output from lsof +D /tmp do not begin with /tmp. Answer (1 of 17): A T-tail increases manufacturing and operating costs. This is because there is generally less surface area needed for a V-Tail (you have two surfaces cutting through the air, not three). The T-tail is very common on aircraft with engines mounted in nacelles on a high-winged aircraft or on aircraft with the engines mounted on the rear of the fuselage, as it keeps the tail clear of the jet exhaust. Yes the T tail requires a bit more speed for elevator authority to rotate on takeoff. The structural considerations are of course the increased weight of the vertical tail due to now having to support the forces and moments on the horizontal tail, including strengthening for flutter. Compare this to unstable conventional tailed planes such as the Super Hornet, Raptor, and Lightning which are all 50+ AoA fighters. This ensures no dead air zone above the elevator. That doesn't make sense. Quiz: Can You Identify These 7 Cloud Formations? MCDONNELL DOUGLAS MD-82) because it removes the tail from the exhaust blast. Cruise speeds range from 130 (180-HP) to 143 knots (normally aspirated 200-HP T-tail) and as high as 170 knots for a turbocharged version flown in the teens. This gives them greater authority and consistency over a wider flight regime, but unfortunately also means you will have the authority to worsen a developing stall. A conventional tail tends to drag the stabilizer through the grass on landing, hooking tips and causing massive bending loads on the tailboom. { "2.2.01:_Fuselage" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "2.2.02:_Wing" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "2.2.03:_Empennage" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "2.2.04:_Main_control_surfaces" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "2.2.05:_Propulsion_plant" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()" }, { "2.01:_Classification_of_aerospace_vehicles" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "2.02:_Parts_of_the_aircraft" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "2.03:_Standard_atmosphere" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "2.04:_System_references" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "2.05:_Problems" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "2.06:_References" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()" }, [ "article:topic", "license:ccbysa", "showtoc:no", "licenseversion:30", "authorname:msarnedo", "source@http://www.aerospaceengineering.es" ], https://eng.libretexts.org/@app/auth/3/login?returnto=https%3A%2F%2Feng.libretexts.org%2FBookshelves%2FAerospace_Engineering%2FFundamentals_of_Aerospace_Engineering_(Arnedo)%2F02%253A_Generalities%2F2.02%253A_Parts_of_the_aircraft%2F2.2.03%253A_Empennage, \( \newcommand{\vecs}[1]{\overset { \scriptstyle \rightharpoonup} {\mathbf{#1}}}\) \( \newcommand{\vecd}[1]{\overset{-\!-\!\rightharpoonup}{\vphantom{a}\smash{#1}}} \)\(\newcommand{\id}{\mathrm{id}}\) \( \newcommand{\Span}{\mathrm{span}}\) \( \newcommand{\kernel}{\mathrm{null}\,}\) \( \newcommand{\range}{\mathrm{range}\,}\) \( \newcommand{\RealPart}{\mathrm{Re}}\) \( \newcommand{\ImaginaryPart}{\mathrm{Im}}\) \( \newcommand{\Argument}{\mathrm{Arg}}\) \( \newcommand{\norm}[1]{\| #1 \|}\) \( \newcommand{\inner}[2]{\langle #1, #2 \rangle}\) \( \newcommand{\Span}{\mathrm{span}}\) \(\newcommand{\id}{\mathrm{id}}\) \( \newcommand{\Span}{\mathrm{span}}\) \( \newcommand{\kernel}{\mathrm{null}\,}\) \( \newcommand{\range}{\mathrm{range}\,}\) \( \newcommand{\RealPart}{\mathrm{Re}}\) \( \newcommand{\ImaginaryPart}{\mathrm{Im}}\) \( \newcommand{\Argument}{\mathrm{Arg}}\) \( \newcommand{\norm}[1]{\| #1 \|}\) \( \newcommand{\inner}[2]{\langle #1, #2 \rangle}\) \( \newcommand{\Span}{\mathrm{span}}\)\(\newcommand{\AA}{\unicode[.8,0]{x212B}}\), source@http://www.aerospaceengineering.es, status page at https://status.libretexts.org. From the wikipedia page of the Handley Page Victor: One unusual flight characteristic of the early Victor was its self-landing capability; once lined up with the runway, the aircraft would naturally flare as the wing entered into ground effect while the tail continued to sink, giving a cushioned landing without any command or intervention by the pilot. T-tail of aircraft ( Tu-154) A T-tail is an empennage configuration in which the tailplane is mounted to the top of the fin. Quiz: Can You Identify These 6 Uncommon Airport Lighting Systems? Source: I study aeronautical engineering and we had to do an exercise involving finding the correct posistion for the HTP to minimize downdraft. The stall speed must be demonstrated during certification, and safe recovery from a stall is a requirement. What, if any, would be the most correct term for the aerodynamic flight control surfaces of SpaceX's Starship? Rudder authority: T-tail design gives you a better rudder authority when flying at a very high AOA and stalls thus preventing a spin. How do I connect these two faces together? I have about 200 hours in a T tail Lance and do some instructing in it. Why is this the case? A T-tail is an empennage configuration in which the tailplane is mounted to the top of the fin. T-tails are also sometimes chosen to provide additional separation from non-sky (as in sea planes). A T-tail is a form of empennage where the horizontal stabilizer is mounted to the top of the fin. I have heard a conventional tail has better stall recovery characteristics than a T-tail. The Fokker 28 and F100 had stick pushers that acted upon detecting a high angle of attack, making it pretty much impossible to keep the columns at aft position. All of the Boeings except the 717 have conventional tails. With the rudder, a right rudder input in the V-tail will lower the right ruddervator and raise the left one. What is (theoretically) the most efficient shape for an aircraft, assuming you don't have to carry any cargo? Another major difference between these two configurations concerns the stability. Confused by the V-Tail? Quiz: Do You Know These 6 Common Enroute Chart Symbols? V-tails.. easy to assemble. Depending on the lift characteristics and generall geometric shape of the wing, this vortex results in updraft and downdraft zones. As I already explained in this answer, the tail is used to create some lift that is required to fulfil the trim relations. The most noticeable difference is that V tail aircraft are much more sensitive to being loaded tail-heavy. This ensures smooth flow and better pitch control of the aircraft. T-tail will give you better rudder authority at very high AOA and stalls so as to prevent a spin. The uninitiated pilot can overcontrol a bit at this point, but one soon gets used to it. In the 1970s it was used on the McDonnell Douglas MD-80, and the Russian freighter Ilyushin Il-76, as well as the twin turboprop Beechcraft Super King Air. I have no idea how those loads are calculated much less how they are combined in order to estimate total stress. I really don't care either way except to be ready for the different feel on takeoff and the flare. Not so! T-Tails are sometimes higher (5-5.5), especially to avoid aft-engine/pylon wake effects. Connect and share knowledge within a single location that is structured and easy to search. It got them more weight and less authority in the TO roll and flare. Nahhthe 90 and 100 were pretty good lookin' birds. It is the conventional configuration for aircraft with the engines under the wings. In the 1980s it was used on the Fokker 100 and the British Aerospace 146. When the vertical tail is swept, the horizontal tail can be made smaller because it is further rearwards and therefore has a greater lever arm. This article highlights the pros and cons of using a V-tail configuration. The aircraft was sold in 2006 with the thought that I was finished with flying. Santa Rosita State Park, under the big 'W', (You must log in or sign up to reply here. In a T-tail configuration, the elevator is above most of the effects of downwash from the propeller, as well as airflow around the fuselage and/or wings. In fact, I was under the impression that a major disadvantage of a T-tail was that the wash during a stall could envelope the tail and remove the authority needed to correct the situation. But when you got authority, you got it RIGHT NOW. Upon approaching the ground, the increase in wing lift causes an auto-flare: the aircraft lands itself. Does a tandem ultralight need flaps on the rear wing if the front wing has flaps? The FAA has issued a draft of the AC on Flightpath Management and it includes a host of measures the agency wants operators to include in training and operations to ensure pilots can get from A to B safely. Twin tail (also referred to as H-tail) or V-tail are other configuration of interest although much less common. Now, I'm not entirely sure about this, but the lift from the Wings generates what is approximated as a so called Horseshoe-Vortex. On light airplanes, the primary reason that T-tails were used was aesthetics. There can be practical considerations, like them being less likely to drag in the grass. PoA Supporter Joined: Oct 22, 2008 Messages: 15,568 Location: mass fla Display name: It has been used by the Gulfstream family since the Grumman Gulfstream II. If "all flying rudders" for LSA aircraft need up to 40% less area, what about "all flying elevators (stabilators)"? Mostly, there is little or no difference in how they perform, certainly not at the level we would notice on our little models. Tailplane forces: The vertical stabilizer should be made stronger and stiffer in order to support all the forces generated by the tailplane. 2. At the other end, the fuselage does this already, so moving the horizontal tail up does not hurt so much there. Swayne is an author of articles, quizzes and lists on Boldmethod every week. 8. During that time, I never experienced an unusual attitude or soiled pants. MCDONNELL DOUGLAS MD-82) because it removes the tail from the exhaust blast. Helicopters & rotorcraft, airships, balloons, paragliders, winged suits and anything that sustains you in the air is acceptable to post here. The T-tail raises the tailplane out of the fuselage drag-hole which can reduce your tailplane effective aspect ratio by 20% or more. Control: T-tail design ensures the elevator and the aircraft stabilizer are out of the way of FOD kicked up by the engines and gears. % of aircraft with conventional tails: ~75%. Thanks. T-tails can cause flutter, such as with the Lockheed C-141 Starlifter. Making statements based on opinion; back them up with references or personal experience. its more stable in turbulent conditions and centerline thrust (in case of engine failure). 1. Veterans such as Boeing's 717, 727, and 717 boasted this tail. The T-tail raises the tailplane out of the fuselage drag-hole which can reduce your tailplane effective aspect ratio by 20% or more. Zero tail swing vs normal tail swing. I suppose depending on the aircraft and the weight and balance situation though maybe it is possible. . 1. The non-turbo d Arrows consume nine to 12 gallons per hour, with the blown versions using around 14 GPH when pushed. The conventional cross tail is the easiest to design, modify during the development process and adjust during set up of a new model. This is a good description of the tail section, as like the feathers on an . This page titled 2.2.3: Empennage is shared under a CC BY-SA 3.0 license and was authored, remixed, and/or curated by Manuel Soler Arnedo via source content that was edited to the style and standards of the LibreTexts platform; a detailed edit history is available upon request. Reduces stick lightening: The greater height of T-tail can help reduce stick lightning caused by the conventional tail after entering the wake while maneuvering. So unless you have some sources for that argument, I would not buy into it. The airplane lands in typical crosswind with no issues. They are marine pathogens. There can also be some slight negatives in terms of efficiently generating pure pitch or yaw moments without also generating unwanted roll moments. A T-tail may have less interference drag, such as on the Tupolev Tu-154. Cruciform tails are often used to keep the horizontal stabilizers out of the engine wake, while avoiding many of the disadvantages of a T-tail.