The tail provides stability and control for the aircraft in flight. In comparison with conventional-tail aircraft, the elevator on a T-tail aircraft must be moved a greater distance to raise the nose a given amount when traveling at slow speeds. This shape resembles a capital T, giving birth to the moniker of T-tail. The main hazard with this design is the possibility of entering aDeep Stall. This reduces friction drag and is the main reason why most modern gliders have T-tails. Manufacturing cost because the vertical stabilizer needs to be built that much stronger to handle additional mass and aerodynamic forces that are now on the end of a long, slender lever. The 200-HP Piper Arrow is an unremarkable performer; the 180-HP version is, well, doggy. 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. T-tails were common in early jet aircraft. Answer (1 of 17): A T-tail increases manufacturing and operating costs. 7. Boeing could reduce the empty weight of the 733-100 by 700 pounds, We've added a "Necessary cookies only" option to the cookie consent popup. 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. This anti-torque system works by placing a multi-bladed fan within a duct in the tail of the helicopter. 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. From a structural point of view, when flying transonic (or even supersonic) it is not good to have a T-tail configuration because it usually induces flutter on the tail. With the rudder, a right rudder input in the V-tail will lower the right ruddervator and raise the left one. V-Tail versus Conventional Tail 16 Jun 2010, 15:59 I am a former owner of a high-performance single (Cessna TR182) with about 3000 hours, 2800 hours (mostly IFR) in type. [1] Rear-mounting the engines keeps the wings clean and improves short-field performance. We also acknowledge previous National Science Foundation support under grant numbers 1246120, 1525057, and 1413739. Sounds good, but if you examine engine FOD statistics, the MD80 actually has a higher rate of engine FOD events than the 73Classic/NG. List price for the PT is a little cheaper than conventional, but you have to buy a plug tail separately. Santa Rosita State Park, under the big 'W', https://m.youtube.com/watch?v=svRIi_cgtJE, (You must log in or sign up to reply here. What are the aerodynamic consequences a pilot needs to be aware of with a T-tail (e.g. BERIEV A-40 Albatross) often have T-tails in order to keep the horizontal surfaces as far from the water as possible. Making statements based on opinion; back them up with references or personal experience. Advantages Of A T-tail Vs. A Conventional Tail, RE: Advantages Of A T-tail Vs. A Conventional Tail. Note: This is really depending on the details, the. I would say that the use of V tails has almost nothing to do with performance. Others have given you aerodynamic reasons (which are all very good), but a reason why most military cargo planes have t-tails is also because it allows for larger loading ramps at the tail. We hope you found this article helpful. Modern nuclear weapons, such as the United States' B83 bombs, use a similar fission process to . The simple answer is that they can be more efficient than a conventional tail. Tail t/c values are often lower than that of the wing since t/c of the tail has a less significant effect on weight. fhdesign, Aug 31, 2007 #8. The wings have such a large chord that there is already 'dirty' airflow coming off of them. And it weighs more, because the vertical stab has its original task (yaw stability and control) as well as now having to take the horizontal stab's pitch loads, and the torque loads that a horizontal stab can also generate due to spiralling propwash, turbulence, and so on. 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. A T-tail produces a strong nose-down pitching moment in sideslip. ), lowering the stabilator into the energized propwash, making pitch control suddenly more effective and sensitive. Figure 2.13: Aircrafts empennage types. One advantage to a T-tail is that the engines can be put on the tail, making them less susceptible to FOD ingestion, except for ice from the wings. Assuming that you have the same amount of lift generated by the both configurations (this is relevant due to the "vertical" force equilibrium), a quick sketch will convince you that both the angle and the lever arm are different. Already at the earliest time point (i.e., 0.75 hpf) and much more prominently later (i.e., 5.5 hpf), we detected a . On a quote, I am averaging 2.50 per device difference between conventional and PT. And on the landing roll the tail can seem to lose authority all at once with the nose coming down. ..The T-tail Lances have the same issue. Conventional-tail-swing excavators are most often operated in excavating, grading and site development where space constraints are not a concern. However, now the fuselage must become stiffer in order to avoid flutter. Depending on the lift characteristics and generall geometric shape of the wing, this vortex results in updraft and downdraft zones. Here's how they're different than conventional tail configurations. ), An aircraft with a T-tail may be easier to recover from a spin, as the elevator is not in a position to block airflow over the rudder, which would make it ineffective, as can happen if the horizontal tail is directly below the fin and rudder.[4]. with the high t-tail of the lance it makes that a bit more difficult. There can be practical considerations, like them being less likely to drag in the grass. Create An Account Here. Sponsorships. ). The T-tail differs from the standard configuration in which the tailplane is mounted to the fuselage at the base . Loss of Control). Apart from that it was fine. [citation needed], The T-tail configuration can also cause maintenance problems. During flight test of the C-141 it was found that the antimetric wing bending mode would nicely couple with the torsional Eigenmode of the the tail, resulting in. What airframe design is best for stormy weather? Why are the Antonov An-124 horizontal stabilisers directly behind the wings? As far as I am aware the T-tails I have flown have T-tails for avoiding propwash (PA-44) or aft engine placement (EMB-145). Human Error in Aviation and Legal Process, Stabilised Approach Awareness Toolkit for ATC, Flight Deck Procedures (A Guide for Controllers). Finally, at a lower level but still a difference, using a T-tail increases the wake (compared to a conventional configuration, where the tail is almost in the wake of the main wings and the fuselage) behind your aircraft and thus the drag you need to overcome is larger. Aside from the aforementioned lack of propwash, because a T-tail is usually further aft and has more lever arm, it can be made smaller, with less overall drag. 9 Things You Didn't Know About Your Airplane's VHF Radio, 3 Ways To Identify Mountain Waves From Forecasts, 10 Skills VFR Pilots Can Learn From IFR Pilots. Press question mark to learn the rest of the keyboard shortcuts. { "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. in large a/c deep stalls can get quite stable because of fuselage lift and (especially in case of airliners) sweptback wings that move center of pressure forward when stalling. It has been used by the Learjet family since their first aircraft, the Learjet 23. The horizontal force generated is "wasted" in essence as it does not contribute to the desired pitch outcome. The LibreTexts libraries arePowered by NICE CXone Expertand are supported by the Department of Education Open Textbook Pilot Project, the UC Davis Office of the Provost, the UC Davis Library, the California State University Affordable Learning Solutions Program, and Merlot. 4. I have heard a conventional tail has better stall recovery characteristics than a T-tail. 10. The T-tail raises the tailplane out of the fuselage drag-hole which can reduce your tailplane effective aspect ratio by 20% or more. It can help to increase the effectiveness of the vertical tail by keeping the air on both sides of it separated. Quiz: Can You Answer These 5 Aircraft Systems Questions? With a minimized counterweight radius, the excavator. [citation needed], The vertical stabilizer must be made stronger (and therefore heavier) to support the weight of the tailplane. Tailplane forces: The vertical stabilizer should be made stronger and stiffer in order to support all the forces generated by the tailplane. 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. ", "Summary of spin technology as related to light general-aviation airplanes", https://en.wikipedia.org/w/index.php?title=T-tail&oldid=1142624641, This page was last edited on 3 March 2023, at 13:31. Together they are referred to as the empennage, which has French origins and translates to "feather an arrow". What leaves me questioning is that almost all large commercial aircraft feature a conventional tail (B747, B777, A340, A380) while most military aircraft of a similar or larger size have a t-tail (C-17, C-5), and then if you get even larger (AN124, AN225) you're back to having a conventional tail again. Moderators: richierich, ua900, PanAm_DC10, hOMSaR, Military Aircraft T-tails have a good glide ratio, and are more efficient on low speed aircraft. Legal. somewhat susceptible to damage in rough field landings. 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. 6. Quiz: Can You Identify These 6 Uncommon Airport Lighting Systems? Let me repeat that, just in case you missed it . I am not so sure about your argument for added drag @yankeekilo But you do agree that the wake is wider? Aircraft flying government officials, Helicopters It has been used by the Gulfstream family since the Grumman Gulfstream II. Either way it makes more sense to have a pitch up tendency when appying more thrust. If You Go-Around On A Visual Approach Under IFR, Do You Need To Contact ATC Immediately? It is structurally more compact and aerodynamically more efficient. Pictures of great freighter aircraft, Government Aircraft - I would guess that a T-tail necessitates a stronger, and thus heavier fin. BERIEV A-40 Albatross) often have T-tails in order to keep the horizontal surfaces as far from the water as possible. In addition to this, there is a horizontal stabilizer. Yes the T tail requires a bit more speed for elevator authority to rotate on takeoff. Provides smooth flow: A T-tail ensures the tailplane surfaces behind the wings are out of the airflow. 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. This is a lot lower compared to the Fenestron RPM of roughly 3150 RPM (about 50% higher RPM! With true ZTS you lose some stability and width, the undercarriages need to be longer and wider to gain back the stability that you would have with a conventional tail swing, the conventional tail swings can have a narrower undercarriage so getting through gate openings and posts is easier, but hitting something with the rear is an issue. 8. I have about 200 hours in a T tail Lance and do some instructing in it. MathJax reference. The reason for this is the reversal of the $C_M$ - $\alpha$ slope of T-tails, as depicted below. Popular in fighter jets: Twin Tail, aka Double Vertical Stabilizer. Aircraft painted in beautiful and original liveries, Airport Overviews Lighter: V-tail-designed aircraft is lighter compared to the conventional tail configuration of other aircraft designs. (https://www.airliners.net/discussions/tech_ops/read.main/138372/). We thank you for your support and hope you'll join the largest aviation community on the web. Copyright 2023 Flite Test. As your AOA increases the wash from the wings will come closer and closer to the tail, not further, and so your tail will become more and more inundated by the wash, rather than less in the case of a conventional tail. Here's how to use them so you can avoid uncomfortable and dangerous flight conditions on your next mountain crossing. Frequent air travellers would have noticed different aircraft for longer and shorter air routes. The duct is integrated into the tail boom and is usually made of a fiberglass skin. PoA Supporter Joined: Oct 22, 2008 Messages: 15,568 Location: mass fla Display name: T-tails are often used on regional airliners and business jets. You can reach Swayne at swayne@boldmethod.com, and follow his flying adventures on his YouTube Channel. an aft CG, T-tail aircraft may be more susceptible to a deep stall. By clicking Post Your Answer, you agree to our terms of service, privacy policy and cookie policy. Support group/articles: Places where you can find help and resources related to this article: Rcgroups fixed wing builder FPV/UAV discussion board: https://www . [1] (However other factors may make the T-tail smaller and lighter, see Advantages above.). A conventional aircraft tail consists of two lifting surfaces oriented at right angles to one-another: a horizontal stabilizer and a vertical stabilizer. The arrangement looks like the capital letter T, hence the name. There can also be some slight negatives in terms of efficiently generating pure pitch or yaw moments without also generating unwanted roll moments. The effect of this is that the tail will be pushed left. easiest to do. The cruciform tail, in which the horizontal stabilizers are placed midway up the vertical stabilizer, giving the appearance of a cross when viewed from the front. Regarding the "vertical" force equilibrium equation, there is no real difference between the two configurations but there is a big one for the moment equilibrium. 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. Greaser! 10. It got them more weight and less authority in the TO roll and flare. Nahhthe 90 and 100 were pretty good lookin' birds. I've never met a T-tail that I thought was attractive. Quiz: Can You Identify These 7 Cloud Formations? A T-tail is a type of empennage where the tailplane (horizontal stabilizer) is mounted to the top of the fin. My thoughts on 159 hours in rented T-tail Turbo Arrows One nice feature on my Sky Arrow is that the position of the CG means that if you lower the tail to the ground it stays there: I think the OP was asking about 'real' planes. Mostly, there is little or no difference in how they perform, certainly not at the level we would notice on our little models. A T-tail produces a strong nose-down pitching moment in sideslip. its more stable in turbulent conditions and centerline thrust (in case of engine failure). 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). Thanks. The Verdict: These machines are most useful for applications where space is confined . Tail sweep may be necessary at high Mach numbers. I would be keeping that in mind if I ever had an emergency in the plane. I think to have the engines underneath the wing and a conventional tail is the better concept (hence why most of the new airliners are like that). What do labyrinthulids do? Too many people still have the idea that you can give a V-tail the same projected area as the supposedly equivalent conventional tail, which results in an undersized V-tail. Seaplanes and amphibian aircraft (e.g. In a normal tailed engine aircraft, when the pilot increases power, he gets wind over the tail and has control authority of the aircraft. The control runs to the elevators are more complex,[1] and the surfaces are more difficult to inspect from the ground. Rear mounted engines also require more fuselage structure. The swept tail vs. straight tail i think is overrated. The t-tail is a popular design in aircraft with aft fuselage mounted engines (e.g. 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. A V tail generates pitch authority as a vector with a horizontal and vertical component. normally I really get into the tail and look at every nut, bolt, rivet, piano hinge and control connection I can see. Different configurations for the empennage can be identified (See Figure 2.13): The conventional tail (also referred to as low tail) configuration, in which the horizontal stabilizers are placed in the fuselage. A stabilizer in undisturbed airflow will produce better L/D than in turbulent flow, as well. The bending loads are the same..but when placed at the top of the tail the vertical structure must be capable of transmitting those loads and could require additional material (stiffening). As a consequence, the tail can be built lower. 1. Functionally the horizontal stabilizer/stabilator are the same in both cases, providing negative lift, the elevator control and a method for pitch trim. Can archive.org's Wayback Machine ignore some query terms? (apart some minor commercial airplanes, I saw it above all in military ones like C5 and C-17), @LucaDetomi: Airliners with their sweptback wings run the risk of. Get Boldmethod flying tips and videos direct to your inbox. This occurs because the stabilator sits up out of the . This may result in loss of elevator authority and consequently, inability to recover from the stall (i.e. Anything related to aircraft, airplanes, aviation and flying. The T-tail avoids this, but it places a large mass (the stabilizer) at the end of a long moment arm (the fin). The simple answer is that they can be more efficient than a conventional tail. The T-tail lifts the horizontal tail clear of the wing wake (downwash) and propwash, which make it more efficient and hence allow reducing its size and also allows high performance aerodynamics and excellent glide ratio as the horizontal tail empennage is less affected by wing slipstream. Build cost: The cost of designing the T-tail aircraft is high compared to the cost of a convention tailplane aircraft. 1. Why Britain fell in love with the T-tailed aeroplane", "What Are The Advantages And Disadvantages Of T-Tails? Why was the skid landing gear located so far aft on the X-15? The vertical tail can be shorter due to the end plate effect of the horizontal tail, and the moment arm to the CoG is longer - however for most higher subsonic speed aircraft these effects merely reduce the weight penalty. In the 1980s it was used on the Fokker 100 and the British Aerospace 146. With the conditions you said you operate in I would go with a conventional tail swing, talk to a cat road mechanic about servicing/repairing. Has 90% of ice around Antarctica disappeared in less than a decade? Tailplane more difficult to clear snow off and access for maintenance and checking. There were a LOT of legit proposals out there. V-tails.. easy to assemble. MCDONNELL DOUGLAS MD-82) because it removes the tail from the exhaust blast. (However, T-tail aircraft may be vulnerable to deep stall, see Disadvantages below. Some people just think they look cool. A T-tail has structural and aerodynamic design consequences. You might see V-Tails used on high-performance models, such as slope soaring or discuss launch gliders. Photos taken by airborne photographers of airborne aircraft, Special Paint Schemes In this condition, the wake of the wing blankets the tail surface and can render it almost ineffective. Observed form behind, this looks like the capital letter T. Sometimes the term is used to refer to an aircraft with such empennage. 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. I have no idea how those loads are calculated much less how they are combined in order to estimate total stress. Advantage: Redundancy in case of battle damage. Yeah, V-tails look cool, and in some modeling instances are easier to run control lines for. With tricycle landing gear, the secondary wheel is in front of the two primary wheels. Given the option, I preferred the conventional tail. 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). The placement on top of the vertical gives it more leverage, Depending on wing location, it stays in undisturbed flow in a stall. Ground handling is pretty easy as well. In a normal tailed engine aircraft, when the pilot increases power, he gets wind over the tail and has control authority of the aircraft. Why is there a voltage on my HDMI and coaxial cables? Does a tandem ultralight need flaps on the rear wing if the front wing has flaps? uhmmm very interesting but now I can't understand why commercial airliner strictly prefer conventional tail instead of T-Tail. This causes an up and left force from the right tail surface and a down and left force from the left surface. T-tails must be stronger, and therefore heavier than conventional tails. This is due to the fact that the stabilator sits up out of the propwash, and so is less effective at low airspeeds. Thanks for the photo of the model. Greaser! Accessibility StatementFor more information contact us atinfo@libretexts.orgor check out our status page at https://status.libretexts.org. The Boeing 737 was initially planned with rear-mounted engines, like the Sud-Aviation Caravelle, which it was meant to replace. I wonder if full scale requires additional considerations on those tails. Become a better pilot.Subscribe to get the latest videos, articles, and quizzes that make you a smarter, safer pilot. Don't have an account? Quiz: Do You Know What These 6 ATC Phrases Mean? T-Tails are sometimes higher (5-5.5), especially to avoid aft-engine/pylon wake effects. Other common tail designs: V-Tail, T-Tail, Cruciform, Dual-Tail, Inverted Y. A smaller elevator and stabilizer results in less drag. Quiz: 6 Questions To See How Much You Know About ILS Approaches, Final Video: Your Questions About Mountain Flying, Coffin Corner And Mach Tuck, Explained: Boldmethod Live, Why Fast Jets Have Swept Wings: Boldmethod Live, 6 Aerodynamic Facts About Ailerons Every Pilot Should Know, 5 Things You Learn In Your First 50 Hours Of Instructing, How Airline Pilots Manage Maximum Landing Weight, 8 Tips For Keeping Your Logbooks Clean, Professional, And Interview-Ready, 6 Questions You Should Be Prepared To Answer During Your CFI Interview. T-tails are also often used when engines are mounted to the rear of the fuselage as often seen on business jets. The main advantage of a T-tail is that during normal flight conditions the elevator is above most of the effects of downwash from the propeller (in case of a propeller-driven aircraft) and the airflow around the fuselage and wings. Others make/models don't. By designing the junction with the vertical well, the T-tail has less interference drag. [5][2] Smaller and lighter T-tails are often used on modern gliders. And on the landing roll the tail can seem to lose authority all at once with the nose coming down. It has some drawbacks though, by putting the elevators directly in the (turbulent) separated flow from the wings during a stall can put you in a (more or less) unrecoverable deep stall. Also, approaching a stall, you will have more elevator effectiveness with the T-tail, as the wing wash is below the horizontal stabilizer. The T-tail stays out of ground effect for longer than the main wing. The T-tail configuration, in which the horizontal stabilizer is mounted on top of the fin, creating a "T" shape when viewed from the front. 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. The T-tail design is popular with gliders and essential where high performance is required. (before we beat them up). Asking for help, clarification, or responding to other answers.