[2], T-tail aircraft can have better short-field performance,[2] such as on the Avro RJ-85. A stick-pusher can be fitted to deal with this problem. Why is this sentence from The Great Gatsby grammatical? The loss of Alaska Airlines Flight 261 was attributed to improper maintenance of the T-tail. 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. Every type from fighters to helicopters from air forces around the globe, Classic Airliners Why did the F-104 Starfighter have a T-tail? This article highlights the pros and cons of using a V-tail configuration. Making statements based on opinion; back them up with references or personal experience. Let me repeat that, just in case you missed it . 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. Learn how and when to remove this template message, "T-time? 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. 1. Tail Design and Sizing - Stanford University I have about 200 hours in a T tail Lance and do some instructing in it. There can be practical considerations, like them being less likely to drag in the grass. Quiz: Do You Know What These 5 ATC Phrases Mean? Source: I study aeronautical engineering and we had to do an exercise involving finding the correct posistion for the HTP to minimize downdraft. 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. As a consequence, the tail can be built lower. 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. The T-tail can be found often found on military transport aircraft, such as the Airbus A400M and the Boeing C-17 Globemaster III. Stabilizers on first Douglas DC-4 model: 5 (three above, two below) The T-tail differs from the standard configuration in which the tailplane is mounted to the fuselage at the base . Guy Inchbald / Wikimedia Commons / CC-BY-SA-3.0. 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. This ensures smooth flow and better pitch control of the aircraft. Greaser! 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. Press question mark to learn the rest of the keyboard shortcuts. As I already explained in this answer, the tail is used to create some lift that is required to fulfil the trim relations. In the 1980s it was used on the Fokker 100 and the British Aerospace 146. Observed form behind, this looks like the capital letter T. Sometimes the term is used to refer to an aircraft with such empennage. A T-tail is a form of empennage where the horizontal stabilizer is mounted to the top of the fin. 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. I have had several mechanics and old timers tell me my conversion is one of the best they have seen. 7. 2. Confused by the V-Tail? Rudder authority: T-tail design gives you a better rudder authority when flying at a very high AOA and stalls thus preventing a spin. The arrangement looks like the capital letter T, hence the name. We thank you for your support and hope you'll join the largest aviation community on the web. Which T-tail airplanes have you flown? Reduced and zero tailswing models have become popular due to their easy maneuverability in urban and residential areas where space is limited. Seaplanes and amphibian aircraft (e.g. Create An Account Here. 3. In this condition, the wake of the wing blankets the tail surface and can render it almost ineffective. Why do modern aircraft tend to have angular tails? Ascended Master. In addition to this, there is a horizontal stabilizer. 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. Pro's and Con's for a T-Tail - PPRuNe Forums The wings have such a large chord that there is already 'dirty' airflow coming off of them. It is the conventional configuration for aircraft with the engines under the wings. 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. 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. (https://www.airliners.net/discussions/tech_ops/read.main/138372/). 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. ARv is about 1.2 to 1.8 with lower values for T-Tails. Not so! The uninitiated pilot can overcontrol a bit at this point, but one soon gets used to it. Provides smooth flow: A T-tail ensures the tailplane surfaces behind the wings are out of the airflow. { "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. The swept tail vs. straight tail i think is overrated. All of the Boeings except the 717 have conventional tails. I am not so sure about your argument for added drag @yankeekilo But you do agree that the wake is wider? Use MathJax to format equations. Charles River Radio Controllers - A V-Tail Design Discussion A T-tail is a type of empennage where the tailplane (horizontal stabilizer) is mounted to the top of the fin. To give the perfect example let's have a look at the EC145 C2 and compare it to the H145 / EC145D2. Swayne is an editor at Boldmethod, certified flight instructor, and a First Officer on the Boeing 757/767 for a Major US Carrier. For smaller aircraft though it is very difficult to hold nose high enough to overshadow a T-tail. 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. This is the small wing-like protrusions from the main tail, or rear of the fuselage. Views from inside the cockpit, Aircraft Cabins 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. Swayne is an author of articles, quizzes and lists on Boldmethod every week. This is a lot lower compared to the Fenestron RPM of roughly 3150 RPM (about 50% higher RPM! (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. I would be keeping that in mind if I ever had an emergency in the plane. Get Boldmethod flying tips and videos direct to your inbox. Register Now. Are there other reasons for having a T-tail? There's a lot to this, and I'm no aircraft engineer, so if there are any other answers, I'll happily delete this. BillTIZ, Oct 4, 2015 #4 frfly172 Touchdown! List price for the PT is a little cheaper than conventional, but you have to buy a plug tail separately. position if empty. This may result in loss of elevator authority and consequently, inability to recover from the stall (i.e. somewhat difficult to align.. lots of ground clearance when landing. Discussion in 'Hangar Talk' started by SixPapaCharlie, Oct 4, 2015. an aft CG, T-tail aircraft may be more susceptible to a deep stall. [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. Many of the regional jets have T tails. 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). High mounted horizontal stabilizers remain out of the turbulence of the wings and jetwash at much greater angles of attack. Legal. Press J to jump to the feed. On the positive side you have a less noisy cabin (lets say in front of the by design clean wing). Moderators: richierich, ua900, PanAm_DC10, hOMSaR, Military Aircraft Note: This is really depending on the details, the. 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. MathJax reference. I suppose depending on the aircraft and the weight and balance situation though maybe it is possible. [citation needed] T-tails can be harder to inspect or maintain, due to their height.[3]. 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). Why was the skid landing gear located so far aft on the X-15? Like many T-tail airplanes, the Arrow IV flies differently than Arrows with conventional tail feathers. (before we beat them up). Loss of Control). Copyright 2023 Flite Test. What Are The Advantages And Disadvantages Of T-Tails? - Simple Flying The advantage for the upright V-tail in models is usually primarily structural. easiest to do. 3. Connect and share knowledge within a single location that is structured and easy to search. 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. 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. 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. 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. [2], For a transsonic aircraft a T-tail configuration may improve pitch control effectiveness, because the elevator is not in disturbed air behind the fuselage, particularly at moderate angles of attack. How can this new ban on drag possibly be considered constitutional? This is because the conventional-tail aircraft has the downwash from the propeller pushing down on the tail to assist in raising the nose. Improve your pilot skills. Here's how to use them so you can avoid uncomfortable and dangerous flight conditions on your next mountain crossing. On a quote, I am averaging 2.50 per device difference between conventional and PT. 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. Quiz: 7 Questions To See How Much You Know About VFR Sectional Charts, Quiz: 7 Questions To See If You Can Fly The LOC/DME-E Approach Into Aspen. The 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. T-tails were common in early jet aircraft. So I make it a point to "fly" the nose more deliberately with t-tail airplanes. The tail provides stability and control for the aircraft in flight. [citation needed], The T-tail configuration can also cause maintenance problems. While this can occur on other aircraft as well, the risk is greater with T-tails as a highAOAwould likely place the wing separated airflow into the path of the horizontal surface of the tail. 2.2.3: Empennage - Engineering LibreTexts I guess I'd like to know what makes a T-tail advantageous as opposed to a conventional tail. Don't have an account? Advantages Of A T-tail Vs. A Conventional Tail - Airliners.net Accident, incident and crash related photos, Air to Air Inspection: It is difficult to inspect the evaluator surface from the ground since the controls running to the elevators are very complex. Advantages Of A T-tail Vs. A Conventional Tail, RE: Advantages Of A T-tail Vs. A Conventional Tail. Disadvantages: Very messy loading and structural design. 10. Are there specific advantages to a T-Tail vs. a conventional tail? The Fokker 28 and F100 had stick pushers that acted upon detecting a high angle of attack, making it pretty much impossible to keep the columns at aft position. Get below 95 kts on final (especially with just one or two people up front) and the wing will start to blank out the tail and things get squirrely. You just compared RC airplane design and quality to FAA certified airplane design and quality. What do labyrinthulids do? 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). ), lowering the stabilator into the energized propwash, making pitch control suddenly more effective and sensitive. It has been used by the Gulfstream family since the Grumman Gulfstream II. Elevator operation in undisturbed air allows control movements that are consistent throughout most flight regimes. The effect of this is that the tail will be pushed left. I suppose it is possible to disrupt the flow enough to where the controls are ineffective but not enough that it can still hold the nose pitched up to a stall although it seems like long shot and/or a poor design. Maintenance issues: It will be difficult to climb up there and work on the T-tail if it has some problems. ). receive periodic yet meaningful email contacts from us and us alone. 4. 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. How do conventional and T-tails differ? - Aviation Stack Exchange 72V Well-Known Member . ..The T-tail Lances have the same issue. Most of the (small aircraft) T-tails I have flown it takes a bit of extra effort to stall the aircraft hard because gently the disruption just lets the nose back down and then you aren't stalled anymore. If "all flying rudders" for LSA aircraft need up to 40% less area, what about "all flying elevators (stabilators)"? Used Aircraft Guide: Piper Arrow - Aviation Consumer 3 7 comments Add a Comment Typical aspect ratios are about 4 to 5. Twin tail (also referred to as H-tail) or V-tail are other configuration of interest although much less common. What's the difference between a power rail and a signal line? How do elevator servo and anti-servo (geared) tabs differ? The single-engine turboprop Pilatus PC-12 also sports a T-tail. In a normal tailed engine aircraft, when the pilot increases power, he gets wind over the tail and has control authority of the aircraft. 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. 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. In these designs, you can see very peculiar and different ta. You might see V-Tails used on high-performance models, such as slope soaring or discuss launch gliders. 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. Passenger cabin shots showing seat arrangements as well as cargo aircraft interior, Cargo Aircraft Tailplane more difficult to clear snow off and access for maintenance and checking. The under-sized surfaces used in designing the V-tail make it lighter and faster. 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. Functionally the horizontal stabilizer/stabilator are the same in both cases, providing negative lift, the elevator control and a method for pitch trim. avoiding hard de-rotation on touchdown, issues at high AOA, etc)? 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. Helicopter Tail Rotors - The Different Types Explained With tricycle landing gear, the secondary wheel is in front of the two primary wheels. For pushing forward on the stick, as you might imagine, the ruddervators both deflect downwards to make the airplane pitch down. 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. ), 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]. But the only other T I've flown is a Skipper. Log-In
Beautiful shots taken while the sun is below the horizon, Accidents Why don't large commercial aircraft use T-tail designs? - Quora