Also, approaching a stall, you will have more elevator effectiveness with the T-tail, as the wing wash is below the horizontal stabilizer. Make sure to give it a thumbs up if you learned something! 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. T-tails also have a larger cross section. 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 vertical tail fin (with the airline logo on it) is technically called the vertical stabilizer. 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. If You Go-Around On A Visual Approach Under IFR, Do You Need To Contact ATC Immediately? or Seaplanes and amphibian aircraft (e.g. The t-tail is a popular design in aircraft with aft fuselage mounted engines (e.g. 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 stabilizer in undisturbed airflow will produce better L/D than in turbulent flow, as well. Become a better pilot.Subscribe to get the latest videos, articles, and quizzes that make you a smarter, safer pilot. Typical values are in the range of 8% to 10%. 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. Takeoff: The airplane has none of that "ready to fly" feeling as you accelerate. a lot of guys want the straight tail for the look of a 180 imo. The arrangement looks like the capital letter T, hence the name. The tail provides stability and control for the aircraft in flight. [2], T-tail aircraft can have better short-field performance,[2] such as on the Avro RJ-85. What do labyrinthulids do? BERIEV A-40 Albatross) often have T-tails in order to keep the horizontal surfaces as far from the water as possible. And on the landing roll the tail can seem to lose authority all at once with the nose coming down. What airframe design is best for stormy weather? Discussion in 'Flight Following' started by kontiki, Aug 5, 2012. Either way it makes more sense to have a pitch up tendency when appying more thrust. Upon approaching the ground, the increase in wing lift causes an auto-flare: the aircraft lands itself. Already a member? The empennage, also referred to as tail or tail assembly, gives stability to the aircraft. Tailplane more difficult to clear snow off and access for maintenance and checking. Here's how they're different than conventional tail configurations. [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. The resulting drag is what counts. Disadvantages: Very messy loading and structural design. Pictures of great freighter aircraft, Government Aircraft Inadequate maintenance of t-tail may lead to loss of control of the aircraft on air. Why do big modern airplanes not use a T-tail configuration for the horizontal stabilizer? 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. Seaplanes and amphibian aircraft (e.g. Asking for help, clarification, or responding to other answers. 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). 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. Tell us in the comments below. It also helps to reduce wave drag, especially when using a well designed Kchemann body (the round, long, spiky thing on the tail junction of a Tu-154) by stretching the structure lengthwise. Why are the Antonov An-124 horizontal stabilisers directly behind the wings? 3 7 comments Add a Comment Why do modern aircraft tend to have angular tails? ). position if empty. Airliners.net is the leading community for discovering and sharing high-quality aviation photography. Combining both the elevator and the rudder will, as with a conventional empennage, cause the plane to rotate around the yaw and pitch axes. Create An Account Here. BERIEV A-40 Albatross) often have T-tails in order to keep the horizontal surfaces as far from the water as possible. Not sure that's a T tail thing, you can hold the nose wheel off for ever in the PC12. Press question mark to learn the rest of the keyboard shortcuts. Yes the T tail requires a bit more speed for elevator authority to rotate on takeoff. I could imagine that the HTP is moved up to the T-configuration to ensure that the direction of air movement over the stabilizer is horizontal and not vertical. The simple answer is that they can be more efficient than a conventional tail. Boldmethod 4) Control Forces Lighter: V-tail-designed aircraft is lighter compared to the conventional tail configuration of other aircraft designs. 1. Many of the regional jets have T tails. You might see V-Tails used on high-performance models, such as slope soaring or discuss launch gliders. Rear mounted engines would also be much closer to the centerline of the aircraft, reducing the controllability issues in an engine out scenario. 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 anti-torque system works by placing a multi-bladed fan within a duct in the tail of the helicopter. It is the conventional configuration for aircraft with the engines under the wings. This was necessary in early jet aircraft with less powerful engines. T-tails keep the stabilizers out of the engine wake, and give better pitch control. TMetzinger, Aug 5, 2012 #10 wabower Touchdown! uhmmm very interesting but now I can't understand why commercial airliner strictly prefer conventional tail instead of T-Tail. Can archive.org's Wayback Machine ignore some query terms? This is because there is generally less surface area needed for a V-Tail (you have two surfaces cutting through the air, not three). That additional weight means the fusel. Gliders with V-Tails can slice through the air just that little bit better when they have less draggy surface area. 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. 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. 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. By designing the junction with the vertical well, the T-tail has less interference drag. Kingdom Chromista (= Stramenopila or Heterokonta): - Hyphochytriomycota, the "tinsel-tailed water moulds" They regulate aquatic populations of freshwater planktonic algae, chytrids and oomycetes. 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. 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. Thanks for the photo of the model. [5][2] Smaller and lighter T-tails are often used on modern gliders. High mounted horizontal stabilizers remain out of the turbulence of the wings and jetwash at much greater angles of attack. Why would a stretch variant need a larger horizontal stabilizer? Is the compressive load from the stabilator that much more than the bending load of the rudder. For the elevator, when the stick is pulled back, both ruddervators deflect upwards much like on a normal elevator (just think of this one as having an upward bend in the middle of it). 8. The advantage for the upright V-tail in models is usually primarily structural. It depends on the airplane. During that time, I never experienced an unusual attitude or soiled pants. Maintenance issues: It will be difficult to climb up there and work on the T-tail if it has some problems. 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. On light airplanes, the primary reason that T-tails were used was aesthetics. What design considerations go into the decision between conventional tails and T-tails? 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. obtain an immediate elevator authority by increasing the aircraft power. How do I connect these two faces together? Here's how to use them so you can avoid uncomfortable and dangerous flight conditions on your next mountain crossing. This is to keep the hot engine exhaust away from the tail surfaces. Moderators: richierich, ua900, PanAm_DC10, hOMSaR, Military Aircraft 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. Elevator operation in undisturbed air allows control movements that are consistent throughout most flight regimes. Build cost: The cost of designing the T-tail aircraft is high compared to the cost of a convention tailplane aircraft. I have had several mechanics and old timers tell me my conversion is one of the best they have seen. T-tails must be stronger, and therefore heavier than conventional tails. Both military and civil versions, Blimps / Airships The T-tail design is popular with gliders and essential where high performance is required. Why did the F-104 Starfighter have a T-tail? 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. The Verdict: These machines are most useful for applications where space is confined . 10. 1. Tail and Winglet closeups with beautiful airline logos.