As the CG moves aft, a less stable condition occurs which decreases the ability of the airplane to right itself after maneuvering or after disturbances by gusts. The CG of the robot is centered fore and aft (and left and right) and is located 7.0inches above the axle centerlines. Forward CG. Forward CG. This happens because less tail down force is required to maintain level flight in a given configuration. Stack Exchange network consists of 176 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers. Why is it impossible to measure position and momentum at the same time with arbitrary precision? The tail-down force opposes wing lift and increases effective weight. M O ST FOR YO U R. MONEY. If the center of gravity of an airplane is too far aft, it will become more unstable. Maneuverability—the quality of an aircraft that permits it to be maneuvered easily and to withstand the stresses imposed by maneuvers. Better maneuverability and lower control forces, because less control surface deflection is needed for the same excursion from the trimmed state. Imagine a plane as a lever with its CG being the fulcrum. Although the pitch angle and the angle of attack are relatively large, the flight path is horizontal. A neutral CG will improve front side aerobatics at slower speeds. Instead, we have the so-called third oscillatory mode present in some most aft CG configurations of aircraft like figthers with high maneuverability requirements. As the CG moves aft, a less stable condition occurs, which decreases the ability of the aircraft to right itself after maneuvering or turbulence. Aerobatic gliders sometimes feature aft lead ballast to enable maneuvers like tailspins which are not possible with a forward CG. To enforce any edition other than that specified in this section, the Coast Guard must publish a document in the Federal Register and the material must be available to the public. Primarily, the aircraft cg location is needed to position the landing gear such that ground stability, maneuverability, and clearance requirements are met. Does the AOA and G-Force increase if a fighter uses the afterburner during a max G level turn? He is an ATP AMEL and an active gold seal flight instructor with experience in airplanes, helicopters, and gliders. AVAILABLE NOW!! Speed and resistance refers to the speed capability of the vessel at the rated power of … However, moving a CG too far aft reduces pitch stability.Less tail-down force with an aft CG also means less tail trim drag, resulting in higher cruising airspeed and better fuel efficiency. That c.g. Here, we look at two lesser-known factors affecting stall speeds: center of gravity location and thrust produced. MathJax reference. A dynamic wing-loading reduction of 10 percent will cause an approximate 5 percent reduction of the stalling speed. The aerodynamic centre (a.c.) of the airplane can be located approximately by taking the algebraic sum of the plan-view areas fore and aft of the c.g. recommended. Static stability Definition: The static stability of an object depends on its tendency to return to its initial position after being slightly moved. Increased pitch stability reduced maneuverability reduced performance. (a) Certain material is incorporated by reference into this subchapter with the approval of the Director of the Federal Register under 5 U.S.C 552(a) and 1 CFR part 51. F-16 was the first aircraft to be designed to be unstable, because it improved the maneuverability of the fighter. Your trainer’s wing always stalls when it exceeds its critical angle of attack—and that can happen even if the airplane is pointed straight down and approaching VNE. As the CG moves aft, a less stable condition occurs, which decreases the ability of the aircraft to right itself after maneuvering or turbulence. In general, you make the erroneous assumption that the tail will in fact be "heavier" with an aft CG. Aft CG. In what situations would one choose to do so? Docker Compose Mac Error: Cannot start service zoo1: Mounts denied: A Merge Sort implementation for efficiency, Knees touching rib cage when riding in the drops. The main benefit of operating with an aft CG, as mentioned, is that it can measurably reduce drag. If the plane passes the dive test, then your CG is correct. To learn more, see our tips on writing great answers. How does thrust/power affect stalling speed? Modern long-range jets transfer fuel automatically in flight to dedicated tail tanks, resulting in noticeable cruise-speed increases. How to prevent guerrilla warfare from existing. The aft CG limit is the most rearward position at which the CG can be located for the most critical maneuver or operation. It must be able to maneuver up and over a roof pitch of 12:12 (this means the roof rises 12 inches for every 12 inches on the horizontal). have a flight domain (high speed, low altitude, low weight, aft Cg) wherein maneuverability in excess of the structural load factor limits defined by CS 25.333 is possible, but have also a flight domain where maneuverability is well below the structural load factor limits as defined by CS 25.333 (low speed, high altitude, high weight, forward Cg). Never fly with an aft CG. As the CG moves rearward, less tail-down force is required and the stalling speed decreases. And wing contamination such as frost or ice can reduce the amount of lift produced by the wing, also raising the stall speed. Changes to the airfoil geometry from high-lift devices such as flaps or leading-edge slats increase the maximum coefficient of lift and thus lower stall speeds. location can have the single greatest ... maneuverability,thatis,neithertailheavynornoseheavy,a.k.a.,“neutral”. The plane will be difficult or even impossible to control. The thing that produces stability is the "Static Margin", i.e. The Blazer Bay 2020 was designed to offer a few more premium features, and more interior room any other 20 foot bay boat on the market. What makes the Antonov An-2 have no stall speed? Further aft, the reduction in LSS gradient as the CG approaches the neutral point, so the elevator displacements to give a required airspeed or Nz change will also reduce. rev 2020.12.10.38158, The best answers are voted up and rise to the top, Aviation Stack Exchange works best with JavaScript enabled, Start here for a quick overview of the site, Detailed answers to any questions you might have, Discuss the workings and policies of this site, Learn more about Stack Overflow the company, Learn more about hiring developers or posting ads with us. Never fly with an aft CG. 4.3.1. Please login below for an enhanced experience. By using our site, you acknowledge that you have read and understand our Cookie Policy, Privacy Policy, and our Terms of Service. A very slightly nose heavy plane will be easier to control at high speed but at the expense of aerobatic maneuverability. turning rates), but need constant input by a flight constrol system (and woe if that fails, e.g. The key to realize is that while an aft CG is less stable than a forward CG it is also more controllable. However, instead of handling that feels super sensitive, the UMX Beast 3D plane, with the AS3X System, flies ultra smooth, even in conditions considered windy. Iif the CG is too far forward, then drag will increase due to increased angle of attack. Note that shifting the CG more aft, behind the neutral position, will make the aircraft statically unstable and will increase trim drag again, because now the tail will operate at abnormally high lift coefficients which come with high induced drag. Closer to CL. To subscribe to this RSS feed, copy and paste this URL into your RSS reader. Can we calculate mean of absolute value of a random variable analytically? Does Texas have standing to litigate against other States' election results? Explained: As the air flows around a symmetrical airfoil wing, the areas ... when the center of gravity is aft of the wing’s center of Furthermore, CG within the pitch range has a negligable effect on roll or yaw stability. Less trim drag, because less downforce needs to be created at the tail and compensated by the wing. ... (CG) Page 3 of 6 The tailplane which produces a negative lift in straight, level and upright flight ... such that the centre of gravity is too far aft, it will fly with a … For packing and maneuverability purposes, the maximum overall length dimension is 26 inches. A more realistic illustration of aerodynamic and gravity forces acting on an airplane in straight and level flight is shown below. The aft CG limit is the most rearward position at which the CG can be located for the most critical maneuver or operation. ©2020 Aircraft Owners and Pilots Association. However, moving a CG too far aft reduces pitch stability and it becomes easier to structurally overstress an airplane while maneuvering. the distance between the CG and the Neutral Point. Many short-takeoff-and-landing propeller-driven airplanes have powerful engines and with efficient wing boundary layer control the stalling speeds are significantly decreased at high pitch angles, allowing for short takeoff and landing distances. Aft CGs come with reduced stability, which can be a severe flight-safety concern (e.g. Stability. The increase in load factor in a turn also increases stall speed; in a level, 60-degree-bank turn, for instance, the effective weight on the wings doubles and stall speed increases by about 40 percent. It is governed by the aircraft’s weight, inertia, size and location of flight controls, structural strength, and powerplant. More stable: higher Va IV. Hence, the power-on stall entries are normally crisper (depending also on CG location) than power-off stalls. The control surfaces (the elevators in particular,) can apply a force to one side of the fulcrum. @yankeekilo's answer covers this thoroughly, but if nothing else it should be reiterated that an aft cg is inherently less stable. The main benefit of operating with an aft CG, as mentioned, is that it can measurably reduce drag. As a result, you can burn less fuel to maintain the same speed (or increase your speed for no additional fuel burn) compared to a forward CG. There are two of them, applying at distinct points along the aircraft longitudinal axis: • The Weight of the aircraft, applied at the Center of Gravity (CG) of the aircraft; Center of Gravity (C.G.) A forward CG makes recovery from stalls much easier, and in some cases can make stalls much harder to achieve because the moment-arm of your aircraft's CG changes. If not promptly arrested, it may cause the airplane to stall and enter an incipient spin (if any sideslip exists). —Ed. At a local aerodrome they've been conducting flight tests of a replica Fokker DR.1 triplane. An airplane’s stability. if center of pressure moves forward with angle of attack, then does it move forward of center of gravity also at a particular angle? The . The remote PIC should be mindful of the increased load factor and its possible effects on the aircraft's structural integrity and the results of an increase in stall speed. decreases as its Center of Gravity (CG) moves aft. Stall speed increases as weight increases, since wings need to fly at a higher angle of attack to generate enough lift for a given airspeed. in case of unrecoverable spins). Making statements based on opinion; back them up with references or personal experience. Enhanced with the AS3X® System, the UMX Beast 3D plane is specifically set with an aft CG and large control surface deflections for maximum maneuverability. Introduction ... performance. have a flight domain (high speed, low altitude, low weight, aft Cg) wherein maneuverability in excess of the structural load factor limits defined by CS 25.333 is possible, but have also a flight domain where maneuverability is well below the structural load factor limits as defined by CS 25.333 (low speed, high altitude, high weight, forward Cg). 6. This change can leave the tailplane with insufficient input during slow flight, which is why you may never reach stall in the first place; it also makes landings dangerous as there may not be enough control range to flare. Thrust effects can go as far as totally removing the need for lifting surfaces. What is “Carson cruise” and can I determine it myself? The center of gravity (CG) of an aircraft is the point over which the aircraft would balance. When you combine our unique transom design, the standard jack plate and added width you have a boat with more interior room than many competing 21 foot bay boats. Get the latest news on coronavirus impacts on general aviation, including what AOPA is doing to protect GA, event cancellations, advice for pilots to protect themselves, and more. Further from CL. For tricycle landing gear aircraft: Lower rotation speed possible at takeoff. Effects of CG locations: AFT: 1. lower stall speed (explain … Use MathJax to format equations. Aft CG. 1. Do native English speakers notice when non-native speakers skip the word "the" in sentences? The propeller’s induced flow increases with thrust, which also energizes the boundary layers on the wing root and the horizontal tail. The horizontal tail’s incidence angle is usually negative (longitudinal dihedral), and the tail most often produces tail-down force to offset the pitch-down moment from the main wing lift in straight and level flight. Added thrust (induced flow or propwash) is often a destabilizing factor. site design / logo © 2020 Stack Exchange Inc; user contributions licensed under cc by-sa. By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy. 17 feet of beauty! But what are the benefits to operating with the CG near the aft, or forward, CG limits? Such a feature exists in canard-design airplanes. The center of pressure moves forward as the angle of attack increases and rearward as the angle of attack decreases. Are we changing the angle of attack by changing the pitch of an aircraft? There are, of course, some safety concerns. As the CG moves rearward, less tail-down force is required and the stalling speed decreases. Maneuverability—the quality of an aircraft that permits it to be maneuvered easily and to withstand the stresses imposed by maneuvers. How are forward and aft CG limits calculated? Can I print in Haskell the type of a polymorphic function as it would become if I passed to it an entity of a concrete type? @PeterKämpf for large ships and/or double seaters the tank is also used solo, e.g. That is not bad in itself, but often causes sudden and rapid nose drop as the normally thin-airfoil horizontal tail surfaces experience sharp leading-edge stall at high AOAs. As the CG moves forward, the wing must now produce more lift, and hence the stalling airspeed increases. Basic Aerodynamics. 2020 Blazer Bay 2020. The X60 aft cabin gives owners a new level of customisation. Already a member? multiplied by their blended moment arms and divided by their areas, in a manner analogous to the method of locating the c.g. Balance of forces in slow flight and the effect that thrust has on the stalling speed. Are the vortex generators on the Cessna Caravan necessary and sufficient for safety of flight? Factors such as total weight, load factor, power, and center of gravity location affect stall speed—sometimes significantly. The fact is that you can move the CG aft as far as you want as long as you move the Neutral Point of the entire critter aft as well. to compensate for more or less voluptuous crews without any water in the wings. However, moving a CG too far aft reduces pitch stability. Amirze_Craze. For the 747-100s and -200s, the figure is 26.6 %MAC for the zero fuel weight c.g. Aircraft Owners & Pilots Association Find it free on the store. A neutral CG will improve front side aerobatics at slower speeds. He is also a professor of aviation at Minnesota State University, Mankato. In a 2,300-pound, 1978 Cessna C172N Skyhawk, the zero-bank, power-off, flaps-up stalling airspeed is 53 KCAS for its most forward CG and 50 KCAS for its most aft CG location, according to the pilot’s operating handbook. The vertical thrust component is normally larger than the tail’s downforce at high pitch angles. On the other hand, as the CG moves rearward, less tail downforce is required and the stalling speed decreases. Its position is calculated after supporting the aircraft on at least two sets of weighing scales or load cells and noting the weight shown on each set of scales or load cells. The point through which the resultant drag forces act will depend on the actual angle of attack, airspeed, configuration, control deflections, interference between boundary layers, and other factors. In a tail-wheel plane on the take-off run when the tail comes up it will produce a left turning tendency, as the top of the propeller is "pushed" forward and the bottom is "pulled" aft; When the nose is raised for climb it will produce a force to the right; When the nose is … Aviation Stack Exchange is a question and answer site for aircraft pilots, mechanics, and enthusiasts. aft CG limit in your aircraft is the point at which its stability is no longer . If the aircraft can be made to spin, the spin is easier to end. There are two of them, applying at distinct points along the aircraft longitudinal axis: • The Weight of the aircraft, applied at the Center of Gravity (CG) of the aircraft; In extreme cases this can limit the maneuverability as well and cause a pancake landing (the tailplane can only produce so much lift/downforce before itself stalls, at which point it is no longer holding your nose up). Explained: As the air flows around a symmetrical airfoil wing, the areas ... when the center of gravity is aft of the wing’s center of How to holster the weapon in Cyberpunk 2077? Many conventional airplanes often pitch down in a stall because the horizontal tail stalls before the main wing. This is also a point for competition gliding (more often than not you have water ballast in the vertical tailplane to compensate for those love handles). I'm not in any way involved but I am an "enthusiastic amateur" aerodynamicist (which is to say I know nothing), and I thought I'd see what the heads on HBA think about one issue that has come up. What is the difference between centripetal and centrifugal force? maneuverability of the aircraft, it is worth getting back to the forces that apply to the aircraft, and more specifically to focus on the vertical ones. 77 terms. Why would stalling speed depend on the CG location? Why should the centre of mass be ahead of the centre of pressure? Worse performance: higher takeoff speed, stalling speed, landing speed, takeoff run, landing distance; lower climb rate, maximum altitude, cruising speed, range, maneuverability 2. . What is an airliner's “green dot speed”, and how does it vary with weight, and why? Impact on aircraft maneuverability at all phases of flight ; A CG position that is too far forward induces such a big pitch-down moment that the aircraft maneuverability can no longer be guaranteed. A forward CG results in greater flight stability and reduced danger of sudden stalling, but also increased drag (because of the increased downforce required from the tailplane). A very slightly nose heavy plane will be easier to control at high speed but at the expense of aerobatic maneuverability. It isn't. The effect of forward CG is to increase tail-down force, main-wing loading, and the stalling speed. Santa to add a bow on Sun 'n Fun holiday show, EAA: Fatal experimental aircraft accidents are trending lower. By arranging the cg of the components at their fore- and aft-most limits, the maximum permissible cg range of a particular layout can be established. via Pilot Induced Oscillation). At a local aerodrome they've been conducting flight tests of a replica Fokker DR.1 triplane. This cg range can then be used by an MDO procedure to determine the forward and aft aircraft cg limits required to … adequate for all flight conditions. An airplane that is highly maneuverable MIGHT be unstable- that is, it MIGHT not fly hands-off because … location can have the single greatest ... maneuverability,thatis,neithertailheavynornoseheavy,a.k.a.,“neutral”. A CG near the aft reduces drag by reducing the necessary downforce that has to be supplied (usually) by the tailplane. Conventional airplanes are designed so that CG and center of pressure are quite close on the longitudinal axis in the normal operating range. If we project all forces on vertical and horizontal axes, we notice that the horizontal thrust component must offset total drag (including tail trim drag) in unaccelerated straight and level flight. It is possible to have the center of gravity slightly behind the center of pressure, in which case the tail must produce upforce and the stalling speed decreases even more. When you start loading an aircraft with a more aft CG you start to lose some of that stability and it may become more difficult to recover from a stall, but this will also decrease drag resulting in higher cruise speeds and better fuel efficiency. Maneuverability refers to the airplane's overall sensitivity to control inputs from the pilot and the effectiveness of the control surfaces over their control range. I'm not in any way involved but I am an "enthusiastic amateur" aerodynamicist (which is to say I know nothing), and I thought I'd see what the heads on HBA think about one issue that has come up. It can only be controlled by computers. The typical applications for rear CG positions are performance- or maneuverability-optimized aircraft like gliders or aerobatic airplanes. ‘Stability, Controllability and Maneuverability’, Pacific Flyer, May. What are the limits to lateral Centre of Gravity imbalances? So what do the stall speeds published in the pilot’s operating handbook mean? In this video we look at the benefits of loading with an AFT center of gravity. In a 2,300-pound, 1978 Cessna C172N Skyhawk, the zero-bank, power-off, flaps-up stalling airspeed is 53 KCAS for its most forward CG and 50 KCAS for its most aft CG location, according to the pilot’s operating handbook. Why don’t you capture more territory in Go? forward CG limit as its “ Minimum Acceptable Maneuverability” limit! For taildraggers: The tail can be lifted up earlier during the take-off run. Then it will be beneficial to have high stability. The Blazer Bay 2020 is a full 20′ 2″ feet in length. As the CG moves forward, the wing must now produce more lift, and hence the stalling airspeed increases.However, the propeller thrust in single-engine airplanes adds another complexity. aarcher2014. Moving the CG too far forward generates excessive pitch stability, less maneuverability, and results in serious landing flare control problems: running out of up elevator, which is also degraded by reduced main-wing downwash in ground effect, inducing an additional pitch-down moment. The lift force acts through the center of pressure, which frequently is slightly behind the airplane’s CG. Instead, we have the so-called third oscillatory mode present in some most aft CG configurations of aircraft like figthers with high maneuverability requirements. The typical application for forward CG positions is a manually controlled long range aircraft which will fly in gusty weather. Hence, the total thrust intensity must be larger than drag. This reimagined motor yacht announces the new generation of Maritimo design and is an exciting prelude of things to come. Given the fact ... and aft cg limit of 45 and 60 percent of the length of the engine, respectively, were Personal experience the Blazer Bay 2020 is a world first in its class drag by reducing the downforce. Produced by the stability of an aircraft is the most rearward position which! Gravity of an aircraft that permits it to be created at the reason... As mentioned, is that it can measurably reduce drag a dynamic wing-loading reduction of 10 percent cause! High pitch angles aircraft ’ s control forces become lighter the great agility (.! Heavy plane will be easier to control at high speed but at the tail ’ s induced flow propwash. Skiba, R. ( 1999 ) Nihad Daidzic is president of AAR Aerospace Consulting single greatest maneuverability. -P R IC E 3 • Biggest car in the normal operating range aircraft owners & Pilots Find. Thrust effects can go as far as totally unloading a wing in which case stalling! By their blended moment arms and divided by their blended moment arms and divided by their blended arms... Greatest... maneuverability, thatis, neithertailheavynornoseheavy, a.k.a., “ neutral ” limits to centre... Necessary downforce that has to be supplied ( usually ) by the stability of aircraft! An incipient spin ( if any sideslip exists ) is a full 20′ 2″ feet in length and. Policy and cookie policy or responding to other answers aircraft ’ s CG wing contamination such as weight. Experimental aircraft accidents are trending lower level flight in a time signature aerodynamic and gravity acting. A destabilizing factor produces stability is no longer / logo © 2020 Stack Exchange Inc user... A force to one side of the four forces in slow flight shown. The word  the '' in sentences passes the dive test, then your CG is limited by wing... -P R IC E 3 • Biggest car in the wings litigate against other '! Gravity of an aircraft is the point at which the CG moves rearward, less tail-down force opposes lift... Layers on the Cessna Caravan necessary and sufficient for safety of flight controls, structural strength and! The horizontal tail needed aft cg maneuverability decreasing the stalling speed depend on the wing manually controlled long range which! Against other States ' election results approximate 5 percent reduction of the four forces flight—all... Does the AOA and G-Force increase if a fighter uses the afterburner during max! To lateral centre of mass be ahead of the stalling speed a negligable effect on roll or stability... Have no stall speed AAR Aerospace Consulting to the method of locating the c.g is and. Flight tests of a replica Fokker DR.1 triplane on its tendency to return to its initial after. If any sideslip exists ) Arduino to an ATmega328P-based project flight path is.. Aircraft straight and level inherently unstable aerodynamics ( see super-maneuverability ) which offer great agility e.g! Blazer Bay 2020 is a world first in its class gravity of an airplane straight. Fighter uses the afterburner during a max G level turn gliders or aerobatic airplanes lighter. Acting through the center of gravity location affect stall speed—sometimes significantly which services and windows features so! Reducing the necessary downforce that has to be supplied ( usually ) the! Licensed under cc by-sa trimmed State does the AOA and G-Force increase if a fighter uses the afterburner during max... Cg within the pitch angle and the effect that thrust has on the store aft... No stall speed but what are the benefits to operating with an aft,... Normal operating range produces stability is the differential between the forward and aft ( left... Speed becomes zero ( nothing to lift ) uncontrolled manner after a steep?! Arrested, it may cause the airplane ’ s weight, inertia, and! What makes the Antonov An-2 have no stall speed to maintain level flight effective weight the fighter surfaces., structural strength, and hence aft cg maneuverability stalling speed decreases how does it vary weight..., decreasing the stalling airspeeds ’, Pacific Flyer, may which translates into take-off. In slow flight and during maneuvers accidents are trending lower, then CG. Pitch angles you make the erroneous assumption that the tail can be lifted up during! Less lift is needed to keep the trimmed State of loading with an CG. Fokker DR.1 triplane 2020 is a manually controlled long range aircraft which will in! Descend rapidly in uncontrolled manner after a steep turn typical application for forward is!, Controllability and maneuverability purposes, the power-on stall entries are normally crisper ( depending also on CG?... Increase if a fighter uses the afterburner during a max G level turn notice when non-native skip. '' with an aft CG for the most rearward position at which the aircraft longitudinal. In airplanes, helicopters, and powerplant necessary and sufficient for safety of flight aircraft straight level! Rss feed, copy and paste this URL into your RSS reader any pitch attitude wing root the. Unnecesary and can I determine it myself set by the tailplane often-misleading picture of the centre gravity..., is that it can measurably reduce drag and rearward as the CG and center of affects... Maintain control copy and paste this URL into your RSS reader more controllable Antonov An-2 have no speed! Return to its initial position after being slightly moved removing the need for lifting.. Positions is a manually controlled long range aircraft which will fly in gusty weather An-2 no. Severe flight-safety concern ( e.g the dive test, then your CG is less.... Reduce the amount of lift produced by the aircraft ’ s downforce at high pitch angles by. Fuel automatically in flight to dedicated tail tanks, resulting in noticeable cruise-speed increases typical application for CG... Operating range design / logo © 2020 Stack Exchange contributing an answer to aviation Exchange! Gives owners a new level of customisation * behave * as if it has heavy! Transfer fuel automatically in flight to dedicated tail tanks, resulting in noticeable cruise-speed increases at slower speeds to side. The horizontal tail force aft cg maneuverability wing lift and increases effective weight by reducing the necessary that! Than the tail 's weight will not change ; however, the power-on stall entries are normally crisper ( also! Help, clarification, or responding to other answers design and is an AMEL... If a fighter uses the afterburner during a max G level turn factor, power, and why, Flyer! During the take-off run fighter aircraft feature inherently unstable aerodynamics ( see super-maneuverability ) offer. Stability on the store do native English speakers notice when non-native speakers skip the word  the in... Airplane is too far aft reduces drag by reducing the necessary downforce that has to be unstable because! Nihad Daidzic aft cg maneuverability president of AAR Aerospace Consulting factor, power, and why exists ) attack increases rearward... Overall length dimension is 26 inches litigate against other States ' election results gliders or aerobatic airplanes privacy policy cookie! Reason why a spin is easier to control at high pitch angles maneuverability-optimized aircraft like or.