t tail vs conventional tail

What airframe design is best for stormy weather? 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. Discussion in 'Flight Following' started by kontiki, Aug 5, 2012. Quiz: Can You Identify These 7 Cloud Formations? some extra effort in hinging and hooking up. [citation needed], The T-tail configuration can also cause maintenance problems. 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. This will be a problem. 5. 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. By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. Anything related to aircraft, airplanes, aviation and flying. 4. I guess I'd like to know what makes a T-tail advantageous as opposed to a conventional tail. 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. However, once in the stall, the wings wash can blanket the elevators, making them much less effective. Pros: 1. YouTube Channel: www.youtube.com/projectairaviation, - Find this article & others like it at www.FliteTest.com -, By joining our mailing list via the home page or during checkout, you agree to The main hazard with this design is the possibility of entering aDeep Stall. 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. Sponsorships. Making statements based on opinion; back them up with references or personal experience. Aircraft flying government officials, Helicopters This causes an up and left force from the right tail surface and a down and left force from the left surface. Rudder authority: T-tail design gives you a better rudder authority when flying at a very high AOA and stalls thus preventing a spin. When I sell my Archer, I'm buying a lance. 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. Not so noticeable on landing as power is reduced, but still a consideration. 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. Loss of Control). The horizontal tail location can be easily adapted to an all moving horizontal tail which facilitates control link View the full answer The most noticeable difference is that V tail aircraft are much more sensitive to being loaded tail-heavy. . Provide plane leverage: T-Tail surfaces makes it easy to increase the distance between the wing and the tailplane without affecting the weight of the aircraft. Effective rotation: It is effective for aircraft flying at low speeds because having a responsive pitch control enables the aircraft to effectively rotate on landing. 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. This is to keep the hot engine exhaust away from the tail surfaces. 1. T-tails can cause flutter, such as with the Lockheed C-141 Starlifter. What do labyrinthulids do? 3 7 comments Add a Comment Already a member? Many large aircraft can have the fin and rudder fold to reduce height in hangars, however this generally isn't feasible or useful if there is a T-tail. The tail of an airplane won't drag behind it if the airplane uses tricycle landing gear. If you look at the Rafale planform you see that it has a small LERX on the wing and another on the canard (this one is really thick and rounded, but it will still have similar function aerodynamically). Started, Advertising & receive periodic yet meaningful email contacts from us and us alone. Create an account to follow your favorite communities and start taking part in conversations. There can be practical considerations, like them being less likely to drag in the grass. A stick pusher prevents the aeroplane from entering the deep stall area. Guy Inchbald / Wikimedia Commons / CC-BY-SA-3.0. What you get is the horizontal stab up out of the prop wash, which reduces inflight vibration -- the reason, I believe, which Piper did it. Rear-mounted engines pretty much force a T-tail, but allow to keep the wings clean. Why are the Antonov An-124 horizontal stabilisers directly behind the wings? Tail sweep may be necessary at high Mach numbers. At the other end, the fuselage does this already, so moving the horizontal tail up does not hurt so much there. T-tails. ..The T-tail Lances have the same issue. Takeoff: The airplane has none of that "ready to fly" feeling as you accelerate. Seaplanes and amphibian aircraft (e.g. There are several things to consider in a T-tail design. [5][2] Smaller and lighter T-tails are often used on modern gliders. What, if any, would be the most correct term for the aerodynamic flight control surfaces of SpaceX's Starship? 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. 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 suppose depending on the aircraft and the weight and balance situation though maybe it is possible. 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). Why is this the case? T-tails may be used to increase clearance at the rear of a cargo aircraft such as the Boeing C-17 Globemaster, to provide extra clearance when loading the aircraft. Popular in fighter jets: Twin Tail, aka Double Vertical Stabilizer. In a normal tailed engine aircraft, when the pilot increases power, he gets wind over the tail and has control authority of the aircraft. Rotate at 75 knots. BERIEV A-40 Albatross) often have T-tails in order to keep the horizontal surfaces as far from the water as possible. The Boeing 737 was initially planned with rear-mounted engines, like the Sud-Aviation Caravelle, which it was meant to replace. 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. Now, I'm not entirely sure about this, but the lift from the Wings generates what is approximated as a so called Horseshoe-Vortex. Not so! It is the conventional configuration for aircraft with the engines under the wings. 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. The placement on top of the vertical gives it more leverage, Depending on wing location, it stays in undisturbed flow in a stall. Legal. The stall speed must be demonstrated during certification, and safe recovery from a stall is a requirement. rev2023.3.3.43278. Doubling the cube, field extensions and minimal polynoms, A limit involving the quotient of two sums. Quiz: Do You Know What These 5 ATC Phrases Mean? Very interesting, Starlionblue. It has been used by the Gulfstream family since the Grumman Gulfstream II. Blocking of the wind: Aircraft with T-tail design can lose elevator authority because the wings block the wind. Photos taken by airborne photographers of airborne aircraft, Special Paint Schemes [1] Rear-mounting the engines keeps the wings clean and improves short-field performance. We hope you found this article helpful. The wings have such a large chord that there is already 'dirty' airflow coming off of them. Designers were worried that an engine failure would otherwise damage the horizontal tail. On the positive side you have a less noisy cabin (lets say in front of the by design clean wing). This is the small wing-like protrusions from the main tail, or rear of the fuselage. Airport overviews from the air or ground, Tails and Winglets T-tails must be stronger, and therefore heavier than conventional tails. By designing the junction with the vertical well, the T-tail has less interference drag. Stabilizers on first Douglas DC-4 model: 5 (three above, two below) Why do big modern airplanes not use a T-tail configuration for the horizontal stabilizer? 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. For pushing forward on the stick, as you might imagine, the ruddervators both deflect downwards to make the airplane pitch down. a lot of guys want the straight tail for the look of a 180 imo. Quiz: Do You Know What These 6 ATC Phrases Mean? [citation needed] T-tails can be harder to inspect or maintain, due to their height.[3]. The horizontal stabilizer acts like a winglet, reducing induced drag of the rudder. 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. The most popular conventionally V-tailed aircraft that has been mass-produced is the Beechcraft Bonanza Model 35, often known as the V-tail Bonanza or simply V-Tail. Now, a T-tail would place the tail out of the wash during normal flight conditions, which maybe provides additional efficiency/effectiveness? It can help to increase the effectiveness of the vertical tail by keeping the air on both sides of it separated. 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. 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. The C2 has a conventional tail rotor: The RPM of the tail rotor on the C2 is roughly 2150 RPM. The "top view" of the tail represents the equivalent area of a flat horizontal tail, and the "side view" of the tail represents half the equivalent . They are also commonly used on infrastructure commercial building site projects to load material into trucks. Pilots must be aware that the required control forces are greater at slow speeds during takeoffs, landings, or stalls than for similar size aircraft equipped with conventional tails. 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. Some people just think they look cool. All rights reserved. A given T, V, or conventional tail will all have essentially the same control authority if they have the same total area. Helicopters & rotorcraft, airships, balloons, paragliders, winged suits and anything that sustains you in the air is acceptable to post here. Greaser! MCDONNELL DOUGLAS MD-82) because it removes the tail from the exhaust blast. I wonder if full scale requires additional considerations on those tails. It has been used by the Learjet family since their first aircraft, the Learjet 23. [1], The aircraft may be prone to deep stall at high angles of attack, when airflow over the tailplane and elevators is blanked by the wings. MCDONNELL DOUGLAS MD-82) because it removes the tail from the exhaust blast. As a consequence of the smaller vertical tail, a T-tail can be lighter. Page 1 of 3 1 2 3 Next > ror76a Well-Known Member. However, now the fuselage must become stiffer in order to avoid flutter. Forecasts are excellent tools for being able to pinpoint mountain wave activity. 7. A T-tail is a type of empennage where the tailplane (horizontal stabilizer) is mounted to the top of the fin. Incorrect Traffic Pattern Entry Leads To Mid-Air Conflict, How To Correct A High Flare During Landing. It depends on the airplane. You might see V-Tails used on high-performance models, such as slope soaring or discuss launch gliders. All of the Boeings except the 717 have conventional tails. The t-tail is a popular design in aircraft with aft fuselage mounted engines (e.g. This ensures smooth flow and better pitch control of the aircraft. One advantage of the T-tail arrangement is that the horizontal tail acts as an end-plate for the vertical tail. This was necessary in early jet aircraft with less powerful engines. Together they are referred to as the empennage, which has French origins and translates to "feather an arrow". As I already explained in this answer, the tail is used to create some lift that is required to fulfil the trim relations. The conventional cross tail is the easiest to design, modify during the development process and adjust during set up of a new model. Are there other reasons for having a T-tail? uhmmm very interesting but now I can't understand why commercial airliner strictly prefer conventional tail instead of T-Tail. Joined: Sep 1, 2008 Messages: By selecting the final version with wing-mounted engines in the underslung design. On light airplanes, the primary reason that T-tails were used was aesthetics. Has 90% of ice around Antarctica disappeared in less than a decade? Raising the nosewheel also lowers the tail (duh! I've never met a T-tail that I thought was attractive. Thanks. Advantages Of A T-tail Vs. A Conventional Tail, RE: Advantages Of A T-tail Vs. A Conventional Tail. Mostly, there is little or no difference in how they perform, certainly not at the level we would notice on our little models. easiest to do. 8. Thanks for contributing an answer to Aviation Stack Exchange! BERIEV A-40 Albatross) often have T-tails in order to keep the horizontal surfaces as far from the water as possible. Reduced and zero tailswing models have become popular due to their easy maneuverability in urban and residential areas where space is limited. 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? Passenger cabin shots showing seat arrangements as well as cargo aircraft interior, Cargo Aircraft Less drag: In a T-tail design, the arm of the CG is made smaller. 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. In these designs, you can see very peculiar and different ta. Copyright SKYbrary Aviation Safety, 2021-2023. In the 1990s it was used on the Fokker 70, the McDonnell Douglas MD-90, the Boeing 717, the Embraer ERJ family, and the Bombardier CRJ700 series. T-tails have a good glide ratio, and are more efficient on low speed aircraft. What is (theoretically) the most efficient shape for an aircraft, assuming you don't have to carry any cargo? (https://www.airliners.net/discussions/tech_ops/read.main/138372/). 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). [citation needed], The vertical stabilizer must be made stronger (and therefore heavier) to support the weight of the tailplane. What video game is Charlie playing in Poker Face S01E07? Disadvantages: Very messy loading and structural design. 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. During that time, I never experienced an unusual attitude or soiled pants. This article is for you. My code is GPL licensed, can I issue a license to have my code be distributed in a specific MIT licensed project? Create space for the engine: Have the tail surface mounted away from rear fuselage creates space for mounting engines. Copyright 2023 Flite Test. 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. Many of the regional jets have T tails. A T-Tail design is an aircraft configuration in which the tail control surfaces with the horizontal surface are mounted on top of the aircraft fin forming a T look when viewed from the front. Functionally the horizontal stabilizer/stabilator are the same in both cases, providing negative lift, the elevator control and a method for pitch trim. This is due to the fact that the stabilator sits up out of the propwash, and so is less effective at low airspeeds. Dunno. List price for the PT is a little cheaper than conventional, but you have to buy a plug tail separately. With a minimized counterweight radius, the excavator. T-tails also have a larger cross section. 1. Cons: Due to their shorter tail radius, zero swings are likely to have lower rated operating capacities than reduced tail or conventional tail swings designs. Discussion in 'Hangar Talk' started by SixPapaCharlie, Oct 4, 2015. 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. 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. Zero tail swing vs normal tail swing. 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. 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. Rear mounted engines also require more fuselage structure. A V tail generates pitch authority as a vector with a horizontal and vertical component. Why is there a voltage on my HDMI and coaxial cables? 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. The reason for this is the reversal of the $C_M$ - $\alpha$ slope of T-tails, as depicted below. Yeah, V-tails look cool, and in some modeling instances are easier to run control lines for. Another major difference between these two configurations concerns the stability. The conclusion of this study cannot be drawn without a specific example but I hope it is clear for you that stability is really impacted by the choice of the tail. The empennage, also referred to as tail or tail assembly, gives stability to the aircraft. Human Error in Aviation and Legal Process, Stabilised Approach Awareness Toolkit for ATC, Flight Deck Procedures (A Guide for Controllers). The Pilot Handbook of Aeronautical Knowledge has a whole section talking about T-tails. Upon approaching the ground, the increase in wing lift causes an auto-flare: the aircraft lands itself. If they were better, they would be used everywhere, and mostly they are not. 5. T-tails have a good glide ratio, and are more efficient on low speed aircraft. Combining both the elevator and the rudder will, as with a conventional empennage, cause the plane to rotate around the yaw and pitch axes. 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. Do I need a thermal expansion tank if I already have a pressure tank? Connect and share knowledge within a single location that is structured and easy to search. A T-tail is an empennage configuration in which the tailplane is mounted to the top of the fin. A stabilizer in undisturbed airflow will produce better L/D than in turbulent flow, as well. I'd like to learn as much in this area as possible. Twin tail (also referred to as H-tail) or V-tail are other configuration of interest although much less common. Note that the increased leverage means that the horizontal tail can be smaller as well. And on the landing roll the tail can seem to lose authority all at once with the nose coming down. Which T-tail airplanes have you flown? The under-sized surfaces used in designing the V-tail make it lighter and faster. 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. Press question mark to learn the rest of the keyboard shortcuts. The arrangement looks like the capital letter T, hence the name. 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. Seaplanes and amphibian aircraft (e.g. T-tails must be stronger, and therefore heavier than conventional tails. [2], T-tail aircraft can have better short-field performance,[2] such as on the Avro RJ-85. Why did the F-104 Starfighter have a T-tail? On a quote, I am averaging 2.50 per device difference between conventional and PT. With all these advantages, why at least some of commercials does not consider this solution? 10. If OT and PD cost me 25 dollars and hour more than standard time, I have to do 50% more devices at trim out per hour to break even. 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. However both halves typically have to be larger in surface area to make up for only having two stabilizing surfaces, so the drag reduction is rendered null. Not sure that's a T tail thing, you can hold the nose wheel off for ever in the PC12. The AC isn't prescriptive. Discussion in 'Excavators' started by ror76a, Aug 30, 2007. Disadvantages: Very messy loading and structural design. A T-tail produces a strong nose-down pitching moment in sideslip. Depending on the lift characteristics and generall geometric shape of the wing, this vortex results in updraft and downdraft zones. But the only other T I've flown is a Skipper. A smaller elevator and stabilizer results in less drag. 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 . In addition to this, there is a horizontal stabilizer. T-tails keep the stabilizers out of the engine wake, and give better pitch control. The T-tail stays out of ground effect for longer than the main wing. 6. It ensures clean airflow, at least on gulfstream aircraft. In the 1960s, several passenger jets with rear-fuselage-mounted engines featured T-tails, such as the BAC One-Eleven, the Vickers VC10, the McDonnell Douglas DC-9, the Boeing 727, the Fokker F28 Fellowship, and the Russian Ilyushin Il-62 and Tupolev Tu-154. ARv is about 1.2 to 1.8 with lower values for T-Tails. The loss of Alaska Airlines Flight 261 was attributed to improper maintenance of the T-tail. Create An Account Here. (before we beat them up). Swayne is an editor at Boldmethod, certified flight instructor, and a First Officer on the Boeing 757/767 for a Major US Carrier. Have you ever flown a T-tail airplane? Quiz: 6 Questions To See How Much You Know About Stalls. The control runs to the elevators are more complex,[1] and the surfaces are more difficult to inspect from the ground. Other examples include the Lockheed F-117 Nighthawk stealth attack aircraft and the Fouga CM.170 Magister trainer. This occurs because the stabilator sits up out of the . [2][7], For propeller aircraft, a T-tail configuration may reduce pitch control effectiveness if the elevators are outside the propeller slipstream. 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. Though on most aircraft the horizontal stabilizer does indeed produce negative lift, for positive stability it is only required that the rear surface flies at lower angle of attack than the forward surface. The arrangement looks like the capital letter T, hence the name. 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. Our large helicopter section. Answer (1 of 17): A T-tail increases manufacturing and operating costs. position if empty. basically the best visual inspection I can do and I'll also hop on the wing and move the yoke back and forth so I can see on top of the elevators, basically looking for bird sht and whatnot. In a thermonuclear weapon, often called a hydrogen bomb, the fission process is only the beginning. The fan consists of between 8-18 blades, depending on the aircraft model, and is of a much smaller diameter than a conventional tail rotor system. 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. T-tail will give you better rudder authority at very high AOA and stalls so as to prevent a spin. Given the option, I preferred the conventional tail. 3. Views from inside the cockpit, Aircraft Cabins The aircraft was sold in 2006 with the thought that I was finished with flying. 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. [1], During normal flying conditions, the tailplane of a T-tail is out of the disturbed airflow behind the wing and fuselage,[2] which provides for more consistent elevator response. 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. Beechcraft 1900 D of the Swiss Air Force. Log-In Planes operating at low speeds need clean airflow for control. ), lowering the stabilator into the energized propwash, making pitch control suddenly more effective and sensitive. If You Go-Around On A Visual Approach Under IFR, Do You Need To Contact ATC Immediately? Apart from that it was fine. 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. avoiding hard de-rotation on touchdown, issues at high AOA, etc)? Why do T- tail airplanes have a shorter vertical stabilizer? High mounted horizontal stabilizers remain out of the turbulence of the wings and jetwash at much greater angles of attack. Boldmethod 4) Control Forces Name as many disadvantages and advantages of each that come to mind. 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. When flying at a very high AOA with a low airspeed and Quiz: Can You Answer These 7 IFR Checkride Questions? T-tails were common in early jet aircraft. Lighter: V-tail-designed aircraft is lighter compared to the conventional tail configuration of other aircraft designs. 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. Save my name, email, and website in this browser for the next time I comment. 4. Veterans such as Boeing's 717, 727, and 717 boasted this tail. Rear mounted engines would also be much closer to the centerline of the aircraft, reducing the controllability issues in an engine out scenario. For example, the T-tail Arrows have a small tendency to blanket the airflow to the tail in certain angles of attack. The vertical tail fin (with the airline logo on it) is technically called the vertical stabilizer.