t tail vs conventional tail

Answer (1 of 17): A T-tail increases manufacturing and operating costs. The duct is integrated into the tail boom and is usually made of a fiberglass skin. Another major difference between these two configurations concerns the stability. Why did the F-104 Starfighter have a T-tail? Note: This is really depending on the details, the. Is there a proper earth ground point in this switch box? The T-tail differs from the standard configuration in which the tailplane is mounted to the fuselage at the base of the fin. Guy Inchbald / Wikimedia Commons / CC-BY-SA-3.0. There are several things to consider in a T-tail design. Quiz: Do You Know What These 5 ATC Phrases Mean? Tailplane more difficult to clear snow off and access for maintenance and checking. The effect of this is that the tail will be pushed left. Quiz: 6 Questions To See How Much You Know About Stalls. A stick pusher prevents the aeroplane from entering the deep stall area. All rights reserved. For gliders with T-tails the additional structural complications/weight are offset by less interference drag and more clearance for those special outlandings (think a barley field). (before we beat them up). 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. 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. However, T-tails are more likely to enter a deep stall, and is more difficult to recover from a spin. position if empty. T-tails are often used on regional airliners and business jets. Press J to jump to the feed. This is because there is generally less surface area needed for a V-Tail (you have two surfaces cutting through the air, not three). Aviation Stack Exchange is a question and answer site for aircraft pilots, mechanics, and enthusiasts. If You Go-Around On A Visual Approach Under IFR, Do You Need To Contact ATC Immediately? He graduated as an aviation major from the University of North Dakota in 2018, holds a PIC Type Rating for Cessna Citation Jets (CE-525), is a former pilot for Mokulele Airlines, and flew Embraer 145s at the beginning of his airline career. What design considerations go into the decision between conventional tails and T-tails? We thank you for your support and hope you'll join the largest aviation community on the web. I am not so sure about your argument for added drag @yankeekilo But you do agree that the wake is wider? At the other end, the fuselage does this already, so moving the horizontal tail up does not hurt so much there. Designers were worried that an engine failure would otherwise damage the horizontal tail. 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. Learn more about Stack Overflow the company, and our products. This shape resembles a capital T, giving birth to the moniker of T-tail. Combining both the elevator and the rudder will, as with a conventional empennage, cause the plane to rotate around the yaw and pitch axes. The conventional cross tail is the easiest to design, modify during the development process and adjust during set up of a new model. Do I need a thermal expansion tank if I already have a pressure tank? Making statements based on opinion; back them up with references or personal experience. 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). In the 1980s it was used on the Fokker 100 and the British Aerospace 146. There can also be some slight negatives in terms of efficiently generating pure pitch or yaw moments without also generating unwanted roll moments. Why are the Antonov An-124 horizontal stabilisers directly behind the wings? Mostly, there is little or no difference in how they perform, certainly not at the level we would notice on our little models. T-tail designs have become popular on many light and large aircraft, especially those with aft fuselage-mounted engines because the T-tail configuration removes the tail from the exhaust blast of the engines. As I already explained in this answer, the tail is used to create some lift that is required to fulfil the trim relations. Helicopters & rotorcraft, airships, balloons, paragliders, winged suits and anything that sustains you in the air is acceptable to post here. Legal. The wings have such a large chord that there is already 'dirty' airflow coming off of them. This occurs because the stabilator sits up out of the . However, the downwash induced by the main wing on the flow is taken into account (for the cruise conditions) in the design of the tail in order to reduce some negative aspects of the interaction between the main wing and the tail. Why Aircraft Weight Affects Climb Performance, How To Correct A Late Or Rapid Flare During Landing, How Pitot-Static Failures Affect Your Indicated Airspeed And Altitude, Why Landing With A Tailwind Increases Your Risk Of An Accident, Ice-Covered Pitot Tube Results In Low-Altitude Alert From ATC, How To Calculate Your Own VDP When An Instrument Approach Doesn't Have One, Quiz: 6 Questions To See How Much You Know About Aerodynamics. Upon approaching the ground, the increase in wing lift causes an auto-flare: the aircraft lands itself. Aerodynamically, the V tail provides the same stabilizing forces in both the pitch and yaw axes that the conventional tail does. 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. The Boeing 737 was initially planned with rear-mounted engines, like the Sud-Aviation Caravelle, which it was meant to replace. 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. First, it is true that using conventional tail leads to the fact that the airflow over the tail might be disturbed by the main wing and/or the engines and/or the fuselage. Create space for the engine: Have the tail surface mounted away from rear fuselage creates space for mounting engines. . By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. Quiz: Could You Pass An Instrument Checkride Today? They are also commonly used on infrastructure commercial building site projects to load material into trucks. 10. Frequent air travellers would have noticed different aircraft for longer and shorter air routes. Functionally the horizontal stabilizer/stabilator are the same in both cases, providing negative lift, the elevator control and a method for pitch trim. 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. To learn more, see our tips on writing great answers. (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. This may result in loss of elevator authority and consequently, inability to recover from the stall (i.e. 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. The arrangement looks like the capital letter T, hence the name. Provides smooth flow: A T-tail ensures the tailplane surfaces behind the wings are out of the airflow. 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. 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. 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. Has 90% of ice around Antarctica disappeared in less than a decade? This reduces friction drag and is the main reason why most modern gliders have T-tails. T-tails were common in early jet aircraft. Create An Account Here. I really don't care either way except to be ready for the different feel on takeoff and the flare. A T-tail produces a strong nose-down pitching moment in sideslip. 5. During that time, I never experienced an unusual attitude or soiled pants. Copyright SKYbrary Aviation Safety, 2021-2023. Accident, incident and crash related photos, Air to Air On the positive side you have a less noisy cabin (lets say in front of the by design clean wing). On light airplanes, the primary reason that T-tails were used was aesthetics. T-tails also have a larger cross section. Why do big modern airplanes not use a T-tail configuration for the horizontal stabilizer? The control runs to the elevators are more complex,[1] and the surfaces are more difficult to inspect from the ground. 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. The non-turbo d Arrows consume nine to 12 gallons per hour, with the blown versions using around 14 GPH when pushed. My code is GPL licensed, can I issue a license to have my code be distributed in a specific MIT licensed project? We hope you found this article helpful. 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? There's a lot to this, and I'm no aircraft engineer, so if there are any other answers, I'll happily delete this. Views from inside the cockpit, Aircraft Cabins 6. This article is for you. The horizontal tail location can be easily adapted to an all moving horizontal tail which facilitates control link View the full answer This causes an up and left force from the right tail surface and a down and left force from the left surface. Zero tail swing vs normal tail swing. It ensures clean airflow, at least on gulfstream aircraft. 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. Many of the regional jets have T tails. Blocking of the wind: Aircraft with T-tail design can lose elevator authority because the wings block the wind. BillTIZ, Oct 4, 2015 #4 frfly172 Touchdown! For pushing forward on the stick, as you might imagine, the ruddervators both deflect downwards to make the airplane pitch down. This is a good description of the tail section, as like the feathers on an . What is (theoretically) the most efficient shape for an aircraft, assuming you don't have to carry any cargo? Disadvantages: Very messy loading and structural design. The biggest thing I noticed was that soft field landings were a LOT harder (read almost impossible to keep the nose up) in the T-tail Arrow I flew on my CFI checkride vs. the low tail Arrow. MCDONNELL DOUGLAS MD-82) because it removes the tail from the exhaust blast. The most noticeable difference is that V tail aircraft are much more sensitive to being loaded tail-heavy. It was used in the 1950s by combat aircraft such as the Gloster Javelin, McDonnell F-101 Voodoo, and Lockheed F-104 Starfighter interceptors, and on the Blackburn Buccaneer attack aircraft. Are there tables of wastage rates for different fruit and veg? 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. The arrangement looks like the capital letter T, hence the name. The T-tail design is popular with gliders and essential where high performance is required. Beechcraft 1900 D of the Swiss Air Force. Typical values are in the range of 8% to 10%. 10. Popular in fighter jets: Twin Tail, aka Double Vertical Stabilizer. I suppose depending on the aircraft and the weight and balance situation though maybe it is possible. Lighter: V-tail-designed aircraft is lighter compared to the conventional tail configuration of other aircraft designs. Note that the increased leverage means that the horizontal tail can be smaller as well. Moreover, the T tail is the most advantageous on straightening from spin, as the stabilizer will act as an endplate for the rudder. So unless you have some sources for that argument, I would not buy into it. Lets take a look at the pros and cons of this arrangement. Seaplanes and amphibian aircraft (e.g. Discussion in 'Excavators' started by ror76a, Aug 30, 2007. Gliders with V-Tails can slice through the air just that little bit better when they have less draggy surface area. For smaller aircraft though it is very difficult to hold nose high enough to overshadow a T-tail. From my reading, they take a longer take off roll and higher speed on approach. Here are some habits that VFR pilots can pick up even before they become IFR certified. The main hazard with this design is the possibility of entering aDeep Stall. Quiz: Can You Identify These 7 Cloud Formations? When I sell my Archer, I'm buying a lance. 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. ", "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. If you wish to contribute or participate in the discussions about articles you are invited to join SKYbrary as a registered user. ERROR: CREATE MATERIALIZED VIEW WITH DATA cannot be executed from a function. Yes the T tail requires a bit more speed for elevator authority to rotate on takeoff. somewhat difficult to align.. lots of ground clearance when landing. Stack Exchange network consists of 181 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers. Name as many disadvantages and advantages of each that come to mind. Twin tail (also referred to as H-tail) or V-tail are other configuration of interest although much less common. Why is there a voltage on my HDMI and coaxial cables? Yeah, V-tails look cool, and in some modeling instances are easier to run control lines for. A T-tail is an empennage configuration in which the tailplane is mounted to the top of the fin. T-tails have a good glide ratio, and are more efficient on low speed aircraft. Figure 2.13: Aircrafts empennage types. 4. 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. List price for the PT is a little cheaper than conventional, but you have to buy a plug tail separately. I would be keeping that in mind if I ever had an emergency in the plane. Thanks for contributing an answer to Aviation Stack Exchange! I would say that the use of V tails has almost nothing to do with performance. T-tails can cause flutter, such as with the Lockheed C-141 Starlifter. 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. You might see V-Tails used on high-performance models, such as slope soaring or discuss launch gliders. 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. Why is this the case? 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. The horizontal force generated is "wasted" in essence as it does not contribute to the desired pitch outcome. With the rudder, a right rudder input in the V-tail will lower the right ruddervator and raise the left one. 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. Reduced and zero tailswing models have become popular due to their easy maneuverability in urban and residential areas where space is limited. What do labyrinthulids do? In these designs, you can see very peculiar and different ta. Also, approaching a stall, you will have more elevator effectiveness with the T-tail, as the wing wash is below the horizontal stabilizer. This is due to the fact that the stabilator sits up out of the propwash, and so is less effective at low airspeeds. This ensures no dead air zone above the elevator. What video game is Charlie playing in Poker Face S01E07? Anything related to aircraft, airplanes, aviation and flying. The best answers are voted up and rise to the top, Not the answer you're looking for? This article highlights the pros and cons of using a V-tail configuration. Already a member? There is no prop wash over the elevator. To give the perfect example let's have a look at the EC145 C2 and compare it to the H145 / EC145D2. (However, T-tail aircraft may be vulnerable to deep stall, see Disadvantages below. I wonder if full scale requires additional considerations on those tails. In an aircraft with wing mounted engines you get a pitch up moment when you apply thrust (but most of the time if you have to increase thrust its because you are on speed and below profil or on speed but below profil). It has been used by the Learjet family since their first aircraft, the Learjet 23. Why Britain fell in love with the T-tailed aeroplane", "What Are The Advantages And Disadvantages Of T-Tails? or Asking for help, clarification, or responding to other answers. 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. I've tried to research this before, but about all I've been able to come up with is that T-tails can suffer from deep-stalls, while conventional tails do not. % of aircraft with conventional tails: ~75%. The single-engine turboprop Pilatus PC-12 also sports a T-tail. 4. 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. Pictures of great freighter aircraft, Government Aircraft Joined: Sep 1, 2008 Messages: I have no idea how those loads are calculated much less how they are combined in order to estimate total stress. ). 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. All rights reserved. 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. I'd like to learn as much in this area as possible. T-tails have a good glide ratio, and are more efficient on low speed aircraft. 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. However, once in the stall, the wings wash can blanket the elevators, making them much less effective. Airliners.net is the leading community for discovering and sharing high-quality aviation photography. The stabilator, which is 13% smaller in span and area than that of a Warrior/Archer/low-tail Arrow, is up out of the energized propwash, so it seems ineffective. Why would a stretch variant need a larger horizontal stabilizer? Notify me of follow-up comments by email. 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. Quiz: Can You Identify These 6 Uncommon Airport Lighting Systems? Anyway, from what I've been told: The T-tail sticks the elevators out of the disturbed air of the wings, prop, and (usually most of) the fuselage which gives you better elevator authority, and makes a tail stall less likely. Quiz: What Should You Do When ATC Says '______'? The tail of an airplane won't drag behind it if the airplane uses tricycle landing gear. Cons: 1. A conventional tail tends to drag the stabilizer through the grass on landing, hooking tips and causing massive bending loads on the tailboom. 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 configuration, in which the horizontal stabilizer is mounted on top of the fin, creating a "T" shape when viewed from the front. Results show that the V-tail configuration greatly affects the aerodynamic characteristics in directional stability as the side force and yaw moment tends to vary linearly with yaw angles up to. 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. PoA Supporter Joined: Oct 22, 2008 Messages: 15,568 Location: mass fla Display name: Advantage: Redundancy in case of battle damage. This edition of theFlite Test Aerodynamics Simplified series is all about that weird arrangement of tail feathers you see on some unusual looking airplanes. The T-tail differs from the standard configuration in which the tailplane is mounted to the fuselage at the base . The difference lies in the arrangement of their respective wheels. Dunno. 7. This anti-torque system works by placing a multi-bladed fan within a duct in the tail of the helicopter. Other common tail designs: V-Tail, T-Tail, Cruciform, Dual-Tail, Inverted Y. Make sure to give it a thumbs up if you learned something! Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. rev2023.3.3.43278. Raising the nosewheel also lowers the tail (duh! This is because the conventional-tail aircraft has the downwash from the propeller pushing down on the tail to assist in raising the nose. A T-tail is a type of empennage where the tailplane (horizontal stabilizer) is mounted to the top of the fin. 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. Have you ever flown a T-tail airplane? 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. What are the differences though? There were a LOT of legit proposals out there. Seaplanes and amphibian aircraft (e.g. What is a 'deep stall' and how can pilots recover from it? 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. The T-tail increases the effectiveness of the vertical tail because of "end plate" effect. When flying at a very high AOA with a low airspeed and Rudder authority: T-tail design gives you a better rudder authority when flying at a very high AOA and stalls thus preventing a spin. Sounds good, but if you examine engine FOD statistics, the MD80 actually has a higher rate of engine FOD events than the 73Classic/NG. Swayne is an editor at Boldmethod, certified flight instructor, and a First Officer on the Boeing 757/767 for a Major US Carrier. There can be practical considerations, like them being less likely to drag in the grass. Not only for the aerodynamic loads, but for the elevator and elevator trim mechanisms. MCDONNELL DOUGLAS MD-82) because it removes the tail from the exhaust blast. What are the aerodynamic consequences a pilot needs to be aware of with a T-tail (e.g. @p1l0t; you are correct; I was however under the impression that the condition is more or less stable, pushing the tail back into the vortex when it tries to leave (such as when the nose tips over due lack of rear downward pressure). 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.