t tail vs conventional tail

Very interesting, Starlionblue. Most of the entries in the NAME column of the output from lsof +D /tmp do not begin with /tmp. I have had several mechanics and old timers tell me my conversion is one of the best they have seen. Anything related to aircraft, airplanes, aviation and flying. I have heard a conventional tail has better stall recovery characteristics than a T-tail. This is one reason you'll find T-tail aircraft equipped with elevator down-springs or stick pushers for stall recovery. The t-tail is a popular design in aircraft with aft fuselage mounted engines (e.g. (Picture from the linked Wikipedia article). 5. The cruciform tail, in which the horizontal stabilizers are placed midway up the vertical stabilizer, giving the appearance of a cross when viewed from the front. 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. 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. Moreover, the T tail is the most advantageous on straightening from spin, as the stabilizer will act as an endplate for the rudder. somewhat susceptible to damage in rough field landings. 7. Are there other reasons for having a T-tail? There can also be some slight negatives in terms of efficiently generating pure pitch or yaw moments without also generating unwanted roll moments. Let me repeat that, just in case you missed it . 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. If "all flying rudders" for LSA aircraft need up to 40% less area, what about "all flying elevators (stabilators)"? This is because there is generally less surface area needed for a V-Tail (you have two surfaces cutting through the air, not three). On a quote, I am averaging 2.50 per device difference between conventional and PT. T-Tails are sometimes higher (5-5.5), especially to avoid aft-engine/pylon wake effects. Joined: Sep 1, 2008 Messages: It depends on the airplane. Tailplane forces: The vertical stabilizer should be made stronger and stiffer in order to support all the forces generated by the tailplane. Conventional. 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. Quiz: Do You Know These 6 Common Enroute Chart Symbols? Making statements based on opinion; back them up with references or personal experience. This causes an up and left force from the right tail surface and a down and left force from the left surface. Not so noticeable on landing as power is reduced, but still a consideration. 4. obtain an immediate elevator authority by increasing the aircraft power. The single-engine turboprop Pilatus PC-12 also sports a T-tail. Why was the skid landing gear located so far aft on the X-15? They are marine pathogens. The T-tail differs from the standard configuration in which the tailplane is mounted to the fuselage at the base of the fin. Planes operating at low speeds need clean airflow for control. Discussion in 'Excavators' started by ror76a, Aug 30, 2007. The fuselage must be made stiffer to counteract this. Some people just think they look cool. [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. 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. Name as many disadvantages and advantages of each that come to mind. Incorrect Traffic Pattern Entry Leads To Mid-Air Conflict, How To Correct A High Flare During Landing. Make sure to give it a thumbs up if you learned something! The T-tail raises the tailplane out of the fuselage drag-hole which can reduce your tailplane effective aspect ratio by 20% or more. A T-tail is an empennage configuration in which the tailplane is mounted to the top of the fin. Accident, incident and crash related photos, Air to Air 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. 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). 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. 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. Swayne is an author of articles, quizzes and lists on Boldmethod every week. A stick-pusher can be fitted to deal with this problem. 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. ). The duct is integrated into the tail boom and is usually made of a fiberglass skin. There is no prop wash over the elevator. Quiz: Do You Know What These 6 ATC Phrases Mean? In addition to this, there is a horizontal stabilizer. The under-sized surfaces used in designing the V-tail make it lighter and faster. 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. 10. Connect and share knowledge within a single location that is structured and easy to search. 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. 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. The Pilot Handbook of Aeronautical Knowledge has a whole section talking about T-tails. Aviation Stack Exchange is a question and answer site for aircraft pilots, mechanics, and enthusiasts. Tell us in the comments below. Reduced and zero tailswing models have become popular due to their easy maneuverability in urban and residential areas where space is limited. You use your radio for every flight, but did you know this? The simple answer is that they can be more efficient than a conventional tail. 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. Asking for help, clarification, or responding to other answers. We hope you found this article helpful. T-tails were common in early jet aircraft. All rights reserved. Build cost: The cost of designing the T-tail aircraft is high compared to the cost of a convention tailplane aircraft. 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. 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). A smaller elevator and stabilizer results in less drag. Quiz: 6 Questions To See How Much You Know About Stalls. Here are some habits that VFR pilots can pick up even before they become IFR certified. And on the landing roll the tail can seem to lose authority all at once with the nose coming down. Also, approaching a stall, you will have more elevator effectiveness with the T-tail, as the wing wash is below the horizontal stabilizer. 4. Provides smooth flow: A T-tail ensures the tailplane surfaces behind the wings are out of the airflow. 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. The T-tail can be found often found on military transport aircraft, such as the Airbus A400M and the Boeing C-17 Globemaster III. Everything from the Goodyear blimp to the Zeppelin, Night Photos The AC isn't prescriptive. The stall speed must be demonstrated during certification, and safe recovery from a stall is a requirement. 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. Quiz: What Should You Do When ATC Says '______'? Designers were worried that an engine failure would otherwise damage the horizontal tail. A T-tail produces a strong nose-down pitching moment in sideslip. So I make it a point to "fly" the nose more deliberately with t-tail airplanes. With heavy attachments or loads the zero swing is likely to pitch more than a conventional machine. Beautiful shots taken while the sun is below the horizon, Accidents The optimal treatment strategy for acute exacerbation of COPD in the ICU next to the well-known benefits of noninvasive ventilation (NIPPV) is unknown [5][2] Smaller and lighter T-tails are often used on modern gliders. The effect of this is that the tail will be pushed left. 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. 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). Don't have an account? 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. How do elevator servo and anti-servo (geared) tabs differ? Elevator operation in undisturbed air allows control movements that are consistent throughout most flight regimes. 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. some extra effort in hinging and hooking up. Cruciform tails are often used to keep the horizontal stabilizers out of the engine wake, while avoiding many of the disadvantages of a T-tail. its more stable in turbulent conditions and centerline thrust (in case of engine failure). 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. I suppose depending on the aircraft and the weight and balance situation though maybe it is possible. I am not so sure about your argument for added drag @yankeekilo But you do agree that the wake is wider? 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. You can reach Swayne at swayne@boldmethod.com, and follow his flying adventures on his YouTube Channel. Raising the nosewheel also lowers the tail (duh! There can be practical considerations, like them being less likely to drag in the grass. Forecasts are excellent tools for being able to pinpoint mountain wave activity. 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. However, T-tails are more likely to enter a deep stall, and is more difficult to recover from a spin. Pictures of great freighter aircraft, Government Aircraft 3. I would say that the use of V tails has almost nothing to do with performance. ", "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. Why are the Antonov An-124 horizontal stabilisers directly behind the wings? This article highlights the pros and cons of using a V-tail configuration. The disadvantages ot the T-tail concept are the mentioned deep stalls, maybe a elevator stall during flare, unfavourable C.G. Here's how to use them so you can avoid uncomfortable and dangerous flight conditions on your next mountain crossing. Aircraft flying government officials, Helicopters 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). Either way it makes more sense to have a pitch up tendency when appying more thrust. Started, Advertising & The swept tail vs. straight tail i think is overrated. The vertical tail fin (with the airline logo on it) is technically called the vertical stabilizer. When flying at a very high AOA with a low airspeed and 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. Apart from that it was fine. The T-tail raises the tailplane out of the fuselage drag-hole which can reduce your tailplane effective aspect ratio by 20% or more. Advantage: Redundancy in case of battle damage. 8. Doubling the cube, field extensions and minimal polynoms, A limit involving the quotient of two sums. I would be keeping that in mind if I ever had an emergency in the plane. 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. ..The T-tail Lances have the same issue. Swayne is an editor at Boldmethod, certified flight instructor, and a First Officer on the Boeing 757/767 for a Major US Carrier. To give the perfect example let's have a look at the EC145 C2 and compare it to the H145 / EC145D2. 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. Already at the earliest time point (i.e., 0.75 hpf) and much more prominently later (i.e., 5.5 hpf), we detected a . (before we beat them up). Quiz: Can You Identify These 7 Cloud Formations? The considerations in the roe's answer are entirely correct but there might be other factors to take into account. With all these advantages, why at least some of commercials does not consider this solution? 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. T-tails. I'd like to learn as much in this area as possible. A given T, V, or conventional tail will all have essentially the same control authority if they have the same total area. This is because there is generally less surface area needed for a V-Tail (you have two surfaces cutting through the air, not three). The reason for this is the reversal of the $C_M$ - $\alpha$ slope of T-tails, as depicted below. The advantage for the upright V-tail in models is usually primarily structural. This may result in loss of elevator authority and consequently, inability to recover from the stall (i.e. Aircraft painted in beautiful and original liveries, Airport Overviews (However, T-tail aircraft may be vulnerable to deep stall, see Disadvantages below. ARv is about 1.2 to 1.8 with lower values for T-Tails. Tail and Winglet closeups with beautiful airline logos. What design considerations go into the decision between conventional tails and T-tails? Every type from fighters to helicopters from air forces around the globe, Classic Airliners Now, a T-tail would place the tail out of the wash during normal flight conditions, which maybe provides additional efficiency/effectiveness? A T-tail is a type of empennage where the tailplane (horizontal stabilizer) is mounted to the top of the fin. a lot of guys want the straight tail for the look of a 180 imo. However, once in the stall, the wings wash can blanket the elevators, making them much less effective. In a normal tailed engine aircraft, when the pilot increases power, he gets wind over the tail and has control authority of the aircraft. The aeroplane is aerodynamically stable when the $C_M$ - $\alpha$ slope is negative, such as in cases B and C. For configuration A, the slope becomes positive after the stall point, meaning that the nose wants to increase upwards after reaching the stall - not a good situation. Views from inside the cockpit, Aircraft Cabins Have you ever flown a T-tail airplane? The non-turbo d Arrows consume nine to 12 gallons per hour, with the blown versions using around 14 GPH when pushed. Page 1 of 3 1 2 3 Next > ror76a Well-Known Member. 9. It is structurally more compact and aerodynamically more efficient. What is (theoretically) the most efficient shape for an aircraft, assuming you don't have to carry any cargo? [citation needed] T-tails can be harder to inspect or maintain, due to their height.[3]. The wings have such a large chord that there is already 'dirty' airflow coming off of them. Sounds good, but if you examine engine FOD statistics, the MD80 actually has a higher rate of engine FOD events than the 73Classic/NG. 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). By designing the junction with the vertical well, the T-tail has less interference drag. 3 7 comments Add a Comment It can help to increase the effectiveness of the vertical tail by keeping the air on both sides of it separated. Labyrinthulomycota, the "net slimes" - Labyrinthulida. 2. More susceptible to damaging the aft fuselage in rough landings. What are the advantages of the Cri-Cri's tail and fuselage design? Tinsel vs whiplash flagella.