Blocking of the wind: Aircraft with T-tail design can lose elevator authority because the wings block the wind. Aircraft painted in beautiful and original liveries, Airport Overviews What are the advantages of the Cri-Cri's tail and fuselage design? 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. This is because the V tail has projected area in both directions. I have about 200 hours in a T tail Lance and do some instructing in it. With heavy attachments or loads the zero swing is likely to pitch more than a conventional machine. A T-tail is an empennage configuration in which the tailplane is mounted to the top of the fin. At the other end, the fuselage does this already, so moving the horizontal tail up does not hurt so much there. 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). I guess I'd like to know what makes a T-tail advantageous as opposed to a conventional tail. Obviously MD-80s aren't shedding their tails in flight but. 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. This is a good description of the tail section, as like the feathers on an . Which T-tail airplanes have you flown? If "all flying rudders" for LSA aircraft need up to 40% less area, what about "all flying elevators (stabilators)"? 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? 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. High mounted horizontal stabilizers remain out of the turbulence of the wings and jetwash at much greater angles of attack. Yes the T tail requires a bit more speed for elevator authority to rotate on takeoff. 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. Learn more about Stack Overflow the company, and our products. [citation needed] T-tails can be harder to inspect or maintain, due to their height.[3]. Now, a T-tail would place the tail out of the wash during normal flight conditions, which maybe provides additional efficiency/effectiveness? [2][7], For propeller aircraft, a T-tail configuration may reduce pitch control effectiveness if the elevators are outside the propeller slipstream. 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. A T-tail may have less interference drag, such as on the Tupolev Tu-154. Pros: 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. Dunno. one thing I noticed was on preflight. The swept tail vs. straight tail i think is overrated. Beautiful shots taken while the sun is below the horizon, Accidents Already a member? Stabilizers on first Douglas DC-4 model: 5 (three above, two below) With the rudder, a right rudder input in the V-tail will lower the right ruddervator and raise the left one. uhmmm very interesting but now I can't understand why commercial airliner strictly prefer conventional tail instead of T-Tail. Tell us in the comments below. 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. normally I really get into the tail and look at every nut, bolt, rivet, piano hinge and control connection I can see. A T-tail has structural and aerodynamic design consequences. or As we all know, a standard tail uses the rudder for yaw and the elevator for pitch - so how do V-Tail arrangements achieve these two functions? 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. A V tail generates pitch authority as a vector with a horizontal and vertical component. Discussion in 'Flight Following' started by kontiki, Aug 5, 2012. Conventional-tail-swing excavators are most often operated in excavating, grading and site development where space constraints are not a concern. [1] Rear-mounting the engines keeps the wings clean and improves short-field performance. The t-tail is a popular design in aircraft with aft fuselage mounted engines (e.g. hmmm "wake size" is quite undefined. However, T-tails are more likely to enter a deep stall, and is more difficult to recover from a spin. Thanks. Quiz: Do You Know What These 5 ATC Phrases Mean? The simple answer is that they can be more efficient than a conventional tail. Page 1 of 3 1 2 3 Next > ror76a Well-Known Member. However, T-tails are more likely to enter a deep stall, and is more difficult to recover from a spin. All rights reserved. T-tails. The wings have such a large chord that there is already 'dirty' airflow coming off of them. By selecting the final version with wing-mounted engines in the underslung design. 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. Note: This is really depending on the details, the. Thanks for the photo of the model. 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. What design considerations go into the decision between conventional tails and T-tails? Rear-mounted engines pretty much force a T-tail, but allow to keep the wings clean. 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. Get 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 a thermonuclear weapon, often called a hydrogen bomb, the fission process is only the beginning. The most noticeable difference is that V tail aircraft are much more sensitive to being loaded tail-heavy. I've never met a T-tail that I thought was attractive. This ensures no dead air zone above the elevator. Tailplane more difficult to clear snow off and access for maintenance and checking. 2. Does a tandem ultralight need flaps on the rear wing if the front wing has flaps? T-tails must be stronger, and therefore heavier than conventional tails. 3. I really don't care either way except to be ready for the different feel on takeoff and the flare. Joined: Sep 1, 2008 Messages: This is because the conventional-tail aircraft has the downwash from the propeller pushing down on the tail to assist in raising the nose. 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What do labyrinthulids do? Our large helicopter section. Maintenance issues: It will be difficult to climb up there and work on the T-tail if it has some problems. 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. But when you got authority, you got it RIGHT NOW. The placement on top of the vertical gives it more leverage, Depending on wing location, it stays in undisturbed flow in a stall. Copyright 2023 Flite Test. What are the aerodynamic consequences a pilot needs to be aware of with a T-tail (e.g. 1. 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. A T-tail produces a strong nose-down pitching moment in sideslip. Aviation Stack Exchange is a question and answer site for aircraft pilots, mechanics, and enthusiasts. Swayne is an author of articles, quizzes and lists on Boldmethod every week. 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). 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. 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. 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. Ground handling is pretty easy as well. The T-tail raises the tailplane out of the fuselage drag-hole which can reduce your tailplane effective aspect ratio by 20% or more. 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. Some people just think they look cool. Let me repeat that, just in case you missed it . A stabilizer in undisturbed airflow will produce better L/D than in turbulent flow, as well. Can archive.org's Wayback Machine ignore some query terms? Greaser! T-tails also have a larger cross section. The conventional tail Lance (or Six) benefits from having air pushed over it by the prop - which means that it is effective at much lower indicated airspeeds - hence allowing you to rotate the wing into a flying attitude (and fly off) at much lower ias than in the T Tail. ..The T-tail Lances have the same issue. This anti-torque system works by placing a multi-bladed fan within a duct in the tail of the helicopter. T-tail will give you better rudder authority at very high AOA and stalls so as to prevent a spin. The horizontal stabilizer acts like a winglet, reducing induced drag of the rudder. 1. All of the Boeings except the 717 have conventional tails. Modern nuclear weapons, such as the United States' B83 bombs, use a similar fission process to . Advantages Of A T-tail Vs. A Conventional Tail, RE: Advantages Of A T-tail Vs. A Conventional Tail. T-tails keep the stabilizers out of the engine wake, and give better pitch control. Forecasts are excellent tools for being able to pinpoint mountain wave activity. We thank you for your support and hope you'll join the largest aviation community on the web. Lets take a look at the pros and cons of this arrangement. The t-tail is a popular design in aircraft with aft fuselage mounted engines (e.g. Doubling the cube, field extensions and minimal polynoms, A limit involving the quotient of two sums. 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. The single-engine turboprop Pilatus PC-12 also sports a T-tail. Anything related to aircraft, airplanes, aviation and flying. 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. The T-tail differs from the standard configuration in which the tailplane is mounted to the fuselage at the base . (https://www.airliners.net/discussions/tech_ops/read.main/138372/). Conventional. 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. Pretty much mirrors my experience with T-Tailed Pipers. 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. The simple answer is that they can be more efficient than a conventional tail. I have heard a conventional tail has better stall recovery characteristics than a T-tail. Prevalence over the years While T-tails are a rarity in modern aviation, they were well spotted in the past. Get access to additional features and goodies. Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. This article is for you. The arrangement looks like the capital letter T, hence the name. [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. T-tails are also sometimes chosen to provide additional separation from non-sky (as in sea planes). Legal. Views from inside the cockpit, Aircraft Cabins [6][2] The American McDonnell F-101 Voodoo jet fighter suffered from this problem,[citation needed] as did the British Gloster Javelin, Hawker Siddeley Trident and BAC One-Eleven. 4. 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 aerodynamic consequences of a T-tail have most to do with stability and control in stall and post-stall behaviour, and can be grave. There are several things to consider in a T-tail design. Not only that, but on aircraft where the engines are mounted on the tail section, it puts the tail out of the way of the exhaust. Improve your pilot skills. 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. A stick pusher prevents the aeroplane from entering the deep stall area. A T-tail has structural and aerodynamic design consequences. However, now the fuselage must become stiffer in order to avoid flutter. The resulting drag is what counts. Every type from fighters to helicopters from air forces around the globe, Classic Airliners But the only other T I've flown is a Skipper. The under-sized surfaces used in designing the V-tail make it lighter and faster. I have no idea how those loads are calculated much less how they are combined in order to estimate total stress. MCDONNELL DOUGLAS MD-82) because it removes the tail from the exhaust blast. The horizontal force generated is "wasted" in essence as it does not contribute to the desired pitch outcome. There can also be some slight negatives in terms of efficiently generating pure pitch or yaw moments without also generating unwanted roll moments. The horizontal tail location can be easily adapted to an all moving horizontal tail which facilitates control link View the full answer I wonder if full scale requires additional considerations on those tails. The tail provides stability and control for the aircraft in flight. This will be a problem. Discussion in 'Hangar Talk' started by SixPapaCharlie, Oct 4, 2015. And on the landing roll the tail can seem to lose authority all at once with the nose coming down. an aft CG, T-tail aircraft may be more susceptible to a deep stall. 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. But, they handle turbulence much better and are very smooth fliers. Everything from the Goodyear blimp to the Zeppelin, Night Photos A stalled wing at high angles of attack may lead to blanking of the airflow over tailplane and the elevators may lead to loss of pitch control. Kingdom Chromista (= Stramenopila or Heterokonta): - Hyphochytriomycota, the "tinsel-tailed water moulds" They regulate aquatic populations of freshwater planktonic algae, chytrids and oomycetes. its more stable in turbulent conditions and centerline thrust (in case of engine failure). It got them more weight and less authority in the TO roll and flare. Nahhthe 90 and 100 were pretty good lookin' birds. 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. 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. [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.