Appointment of the vertical tail of the aircraft. Choice of scheme sla. Aerodynamic rudder compensation

The plumage of the aircraft is swept, cantilever, T-shaped. The vertical tail includes a fixed keel and a rudder equipped with a trimmer and a servo compensator, the aerodynamic profile of the vertical tail, symmetrical, with a relative thickness of 11% . The horizontal tail includes a one-piece, in-flight controllable stabilizer and two halves of the elevator, equipped with trim tabs; control of the stabilizer is electrohydraulic, remote.

The keel has redundant mechanical non-adjustable stops that limit the movement of the stabilizer within the range from +1˚45" to -12˚45". The aerodynamic profile of the horizontal tail of the PASA-10% type. The rudder and elevator are aerodynamically compensated and weight balanced. The channels of the air-thermal anti-icing system are located in the leading edges of the keel and stabilizer. The keel provides directional stability of the aircraft, is attached to frames 66, 71 and 70 of the fuselage

Rice. 36. Spoiler:

1 spoiler; 2, 3-second and first sections of the spoiler; 4, 5, 6 - the first, second and third suspension units of the second section of the spoiler to the wing; 7-cell filler; 8 rubber profile; 9-power rib; 10-connecting bolt; 11-spoiler bracket; 12-wing bracket.

three power units along the first, second and third spars, respectively, and side milled squares 12 (Fig. 37). The first and second nodes (A and B) fastening the keel to the fuselage are of the same type. Two shaped fittings 16 and 21 (one each on the left and right) and two butt squares 22 are bolted to the root sections of the first and second spars. and 24. Each spar fitting is connected to the corresponding fuselage frame fitting with four 18mm bolts on the first node and 16mm bolts on the second node. The fittings of the third keel-to-fuselage attachment point on the third spar are made in one piece with the root sections of its flanges and are each joined with fitting 13 of frame 70 with six bolts 22mm. For all three attachment points of the spars with butt angles to the corresponding fuselage frames and the keel fastening along the side angle to the fuselage is made with bolts, i.e. keel is removable. A controlled stabilizer is attached to the top of the keel; the front, root, part of the keel smoothly passes into the air intake fairing of the medium D-36 engine and serves as the hood of the TA-6V auxiliary power unit. The keel contains: a stabilizer shift mechanism, a locking mechanism for elevators and rudders, radio equipment antennas, anti-icing system pipelines, rudder control rods and rockers, as well as aircraft system communications. At the tip of the keel, a flashing beacon MSL-3 is installed. Four brackets of the rudder attachment points are installed in the tail section of the keel. The keel consists of a frame, skin, detachable bow and tip.

The keel frame, consisting of longitudinal and transverse sets, is covered with a smooth duralumin sheathing, the leading edge of which is made in the form of a removable spinner. In the upper front part of the keel there is a tip, smoothly mating with a controlled stabilizer.

The longitudinal set of the frame consists of three spars, front and rear walls, 19 right and left stringers each. The spars and the front wall are riveted beams, consisting of T-section belts and walls, reinforced with angle profile posts and having lightening holes.

The transverse set of the keel is formed by ribs 1 to 22, the end rib 23 and thirteen additional socks located between the wall and the first spar. Along rib 1, the keel joins with the hood of the TA-6V engine of the auxiliary power unit, ribs 2-22 are located perpendicular to the axis of the third spar, the end rib 23 is installed parallel to the flight line. Ribs 1, 3, 5, 9, 12, 13, 17, 22 and 23 are power, the remaining ribs are intermediate. The rib 1 is a fin end of the keel formed by the upper and lower walls, butt profiles mounted on the wall along the fuselage contour, and corner profiles reinforcing the lower part of the rib. The upper wall is provided with stiffening ridges, has a framed hole for the passage of the exhaust nozzle of the TA-6V engine and is a fireproof partition of the APU compartment. In the upper part of the keel from stringer 7 to the second spar, two fittings are installed, reinforcing the structure in connection with the installation of a bracket for attaching the stabilizer shift mechanism in this area. The fittings are stamped from battery material. The tail parts of the ribs 9 and 17 are reinforced; each part is formed by two walls of the channel section, between which the bracket of the rudder attachment is riveted, and the ribs 12 and 13 are extended beyond the rear wall of the keel and together with a set of diaphragms and linings

Rice. 37. Fastening the keel to the fuselage:

1-spacer corner profile; 2-first spar of the keel; 3-rib 1; 4-keel skin; 5-rib 3; 6-rib 4; 7-second spar of the keel; 8-fuselage skin; 9-rib 5; 10-corner profile; II-third spar of the keel;

12-side square; 13-fitting frame 70; 14-frame 70; 15-beam suspension medium engine; 16-fitting of the second spar; 17-frame 71; 18-fitting frame 71; 19-fitting of the first spar; 20-frame 66; 21 fittings of the first spar; 22-butt square of the first spar; 23-butt square rib 3; 24-butt elbow of the second spar; 25-butt square of the third spar; 26-lining.

reinforce the keel frame at the installation site of the rudder support mounting bracket. On the bracket connecting the tail parts of the ribs 12 and 13, there are stops that limit the deflection angles of the rudder. Rib 22 is located between the stabilizer mount and the rear wall of the keel, it is a stamped wall with two riveted brackets of the fourth rudder mount. Rib 23 is the end rib, stabilizer mounting brackets and its lower stops are installed on it. The rib of the channel section is stamped from AK6 material, has technological holes, at the site of the first spar, a toe stamped from sheet duralumin is joined to it. The keel sheathing consists of duralumin sheets, which are attached to the frame with rivets and bolts. Maintenance hatches are made in the skin for access to the stabilizer shift mechanism, control units and radio equipment antennas, and removable panels are also provided for access to communications of aircraft systems. On the starboard side of the keel in the area of ​​the exhaust port of the APU, the lining is made of D19AMO material with subsequent hardening; a protective screen made of 0.6 mm thick OT4-I titanium sheet with a fiberglass underlayer is riveted onto this skin. The bow part of the keel is made removable for access to the pipelines of the anti-icing system, it is attached to the keel frame along the contour with bolts with self-locking nuts. The bow is formed by outer and inner skins and a frame consisting of diaphragms and a longitudinal casing. The anti-icing system pipeline is fixed in the channel formed by two skins and a casing. Hot air entering the bow of the keel is distributed through transverse rectangular channels formed by the outer skin and the inner corrugated skin riveted to it.

The keel tip consists of a set of diaphragms and stringers, to which the skin is riveted, on the surface of the skin on the right and left on the power diaphragm there are steel plates for the stabilizer thrust rollers and upper stops that limit the deflection of the stabilizer when the control is disconnected.

Rudder attached to the keel at four nodes located along the axes of the ribs 9, 13, 17 and 22 keel and provides directional controllability of the aircraft. The first, third and fourth attachment points are of the same type. Each assembly consists of a rudder bracket and two keel brackets connected by an earring. The steering wheel brackets are two-lug, fastened to the side member with bolts and self-locking nuts. The mating keel brackets are bolted to the corresponding ribs and the rear wall of the keel; for connection with an earring are supplied with hinged bearings. Bearings are pressed into the holes of the earrings on the side of the connection with the steering brackets. The second mount is a support one, perceives axial and radial loads, consists of two rudder end brackets and a keel bracket connected by an earring. The end brackets are bolted and riveted to the spar and the rudder beam located between ribs 11 and 17. The reciprocal bracket on the keel is bolted and riveted to the elongated tail sections of ribs 12 and 13. All brackets and knot earrings are stamped from AK6 alloy. The rudder has a single-spar scheme, consists of a frame, skin, trimmer and servo compensator. In addition to the spar, the frame includes a longitudinal beam between ribs 11 and 17, a tail boom, 35 ribs, frames of the lower and upper tail compartments.

The spar is a riveted beam with belts made of pressed corner profiles. The spar wall has lightening holes and is supported by uprights made of extruded corner profiles. On the side member there are brackets for the rudder attachment points to the keel and brackets for the rudder controls, servo compensator and trimmer controls.

The rudder skin consists of frontal, bow and middle parts. The nose plating consists of right and left sheets of duralumin 1.0 mm thick. Balancers are installed along the nose edge of the rudder in the areas between the cutouts for the attachment points. The balancers are frontal skins made of ZOHGSA-L2 steel, to which additional steel weights are bolted from the inside. The middle skin between the spar and the tail profile is formed by the right and left sheets of duralumin with a thickness of 0.8 mm. Fairings are installed on the skin in the area of ​​ribs 22 and 24 on the starboard side and in the area of ​​ribs 15 and 17 on the port side, covering the control rods of the trimmer and servo compensator.

The tail compartments of the rudder are located in the lower part of the rudder between ribs 1 and 10 and in the upper part - between ribs 28 and 35. In the gap between these compartments, a servo compensator and a trimmer are suspended from the rudder. Each tail compartment consists of a longitudinal wall, transverse diaphragms, an insert in the trailing edge and a skin.

Servo compensator The single-spar launch vehicle is designed to reduce the hinge moment when controlling the aircraft and is attached to the rudder at three nodes. The first node is located along the rib 10, the second node - along the rib 16 and the third - along the rib 20 of the rudder. Each unit consists of a fitting (bracket) of the servo compensator and a fitting (bracket) of the steering wheel, interconnected by an earring. Brackets and earrings of knots are stamped from AK6 and AK4-1 alloys. The servo compensator has aerodynamic compensation and weight balancing. The frame of the servo compensator consists of a T-section spar, 10 diaphragms. 5 socks reinforcing the cutouts for the brackets of the suspension units, an insert in the rear edge and a fitting that reinforces the spar at the point of attachment of the control lever. The frame of the servo compensator is sheathed with sheet duralumin 0.6 mm thick.

Trimmer The launch vehicle is designed for ground balancing of the aircraft and is attached to the steering wheel at three nodes. The first node is located along the rib 20 of the rudder, the second node - along the rib 24 and the third node - along the rib 28. The trimmer attachment nodes are similar in design to the servo compensator nodes. On the right side of the trimmer from the outside, together with the bracket of the second assembly, two levers are installed. One lever with a pressed-in ball bearing is made of titanium alloy VT22, a rod from the trimmer control electromechanism is connected to this lever. The other lever with a pressed-in swivel bearing is stamped from AK6 alloy. A rod from the DS-10 sensor of the trimmer position signaling system is connected to this lever.

Fig.38. Plumage scheme

Stabilizer ensures the longitudinal stability of the aircraft, balancing the moment arising from the mismatch between the point of application of the aerodynamic force acting on the wing and the center of gravity of the aircraft. The aerodynamic force of the wing usually creates a dive moment, to balance which the horizontal tail must create a downward lift. To this end, the stabilizer of the aircraft is made controllable in flight. Stabilizer installation angles from +1˚ to -12˚ . In the parking lot, the installation angle is +1 ° so that the wind and gas jets of the maneuvering aircraft do not tip over onto the tail. The stabilizer is attached to the keel using the front and rear nodes.

The front assembly consists of two brackets similar in design, stamped from AK6 alloy. The brackets are bolted and riveted to the front side member and are connected by butt bolts to the nut of the shifting mechanism through intermediate brackets.

The rear mount consists of two beam lugs connecting the right and left halves of the second stabilizer spar, a bracket bolted and riveted to the third spar and the keel end rib, and two adapters. With the help of adapters, the lugs of the stabilizer beams are connected to the keel bracket with butt bolts, which at the same time are the axis of rotation of the horizontal tail. The stabilizer beam, adapters and keel bracket are stamped from titanium alloy VT-22.

The stabilizer is one-piece, two-spar scheme, consists of a frame, skin, two bows, two tips, a tail fairing and side fairings. The axis of symmetry of the stabilizer in the plan coincides with the longitudinal axis of the aircraft. The longitudinal set of the frame includes: the first spar, the second spar with a beam, the rear wall and stringers. The left and right halves of the first spar are joined to each other along the axis of symmetry of the stabilizer, both halves of the second spar are joined to the beam. In total, each half of the stabilizer has 16 ribs, of which 1, 2, 3, 4, 6, 9, 12, 15 and 16 are power. The rib 1 runs along the axis of symmetry and is common to the two halves of the stabilizer; skins and stringers are joined along it. In the tail parts of the ribs 6, 9, 12 and 15, the brackets of the elevator attachment units are mounted. The rib 16 is also a longitudinal diaphragm of the frame of the stabilizer tip. Attached to it is the butt joint of the elevator hinge, stringers, stabilizer skin, diaphragms and tip skin.

The skin of each half of the stabilizer from the first spar to the rear wall is divided into upper and lower. The skins are joined along the axis of symmetry of the stabilizer. The upper skin is made of sheet duralumin 1.2 mm thick, the lower one is made of sheet duralumin 1.5 mm thick. Between ribs 9 and 16, the skin has windows of chemical milling up to a thickness of 0.8 mm. The lower skin consists of two sheets with a longitudinal joint along stringer 3. The skin is attached to the frame with rivets and bolts. Windows and maintenance hatches were made in the skin for access to the elevator control rockers and to the POS units. Cutouts for hatches in the skin are reinforced with edging. Most manhole covers are held in the closed position by bolts with anchor nuts. The end of the control rod going to the lever of each half of the elevator is closed by a fairing, which is attached to the lower skin in the region of ribs 8 and 9.

The nose part of the stabilizer is non-removable, consists of the right and left halves. Each half of the bow is attached to the shelves of the first spar to the end ribs 16. Each bow is formed by outer and inner skins and a frame consisting of socks, diaphragms, a casing and split stringers at the top. The anti-icing system pipeline is fixed in the channel formed by two skins and a casing. Hot air coming from the pipeline of the anti-icing system into the forward part of the stabilizer is distributed through transverse rectangular channels formed by the outer skin and the inner skin riveted to it. A bracket with a thrust roller is installed in the root part of each toe. When the stabilizer is repositioned, the rollers, leaning, roll along the guide plates of the keel tip and exclude transverse movements of the stabilizer. The roller mounting brackets are cast from AL-19 material. To approach the brackets with rollers, a hatch is made in the root part of each toe.

The stabilizer ends are non-removable, they consist of end ribs, a set of diaphragms and skin. The end rib 16 of the channel section is one-piece, bent from sheet duralumin 1.0 mm thick, has lightening holes. A KAST-V fiberglass cracker and a bracket for a static electricity discharger are riveted into the tail edge of the ending. The tip is connected to the nose of the stabilizer with bolts and anchor nuts, and to the rest of the stabilizer with rivets.

The tail fairing of the stabilizer is a continuation of its middle part and consists of longitudinal stringers, transverse diaphragms, skin and a removable tail spinner. Sheathing is made of sheet duralumin with a thickness of 0.6 mm and 1.0 mm, riveted to the stringers and diaphragms. The tail spinner consists of three diaphragms and a radio-transparent fiberglass skin, connected to the fairing with bolts.

The side fairings, together with the middle part of the stabilizer, cover the rear stabilizer attachment points protruding beyond the keel. Fairings are removable, located in the area between the tip of the keel and the tail fairings of the stabilizer. Each fairing consists of a sheathing

and frame.

The single-spar elevator is equipped with aerodynamic compensation and weight balancing, and consists of two halves. Each half of the steering wheel has a trimmer and is suspended from the stabilizer at six nodes. Elevator balancing is made in the form of a frontal skin made of 30KhGSA-L2 sheet steel, to which an additional steel load is fixed on the inside with bolts and rivets. Near the fourth and fifth suspension units in the bow of the rudder, external balancing lead weights are installed, placed in duralumin brackets. Each half of the elevator consists of a frame, skin and trimmer. The frame of the rudder half consists of a spar, nasal diaphragms, 35 ribs of the tail part of the rudder and profiles edging the cutout for the trimmer. The spar is a beam of channel section, bent from sheet duralumin, supported by uprights and having wall forgings in the places where the brackets of the rudder attachment points are installed. Nasal diaphragms are stamped from sheet duralumin. Stops are located on the first end diaphragm, which limit the angles of deflection of the rudder. The nose plating consists of top and bottom sheets of duralumin 1.5 mm thick. The tail plating also consists of upper and lower sheets of 0.6 mm thick duralumin. Between the skins along the tail edge, a cracker made of fiberglass KAST-V is glued. The casing to the steering wheel frame is fastened with rivets. On the lower skin of each half of the steering wheel, two fairings are mounted, covering the parts of the steering control rods to the trimmer that go out.

The elevator trimmer of a single-spar scheme has aerodynamic compensation and full weight balancing, is located in the root part of each half of the elevator and is suspended from it at three nodes. Each suspension unit consists of a trimmer bracket and a handlebar bracket connected to each other by an earring. The nose part of the trimmer consists of a set of stamped diaphragms and plating, and the tail part consists of end and intermediate ribs, a tail liner and plating. The upper and lower tail plating is made of a single sheet of duralumin 0.6 mm thick, bent along the tail edge. The nose plating is also made of top and bottom sheets of duralumin 0.6 mm thick.

constructions,

Horizontal tail (GO)

Provides longitudinal stability, control and balance. The horizontal tail consists of a fixed surface - a stabilizer and an elevator hinged to it. For aircraft with a tail arrangement, the horizontal tail is installed in the tail section of the aircraft - on the fuselage or on the top of the keel (T-shaped scheme).

Rudders and ailerons

In view of the complete identity of the design and power work of the rudders and ailerons, in the future, for brevity, we will only talk about the rudders, although everything said will be fully applicable to the ailerons. The main power element of the rudder (and the aileron, of course), which works in bending and perceives almost all the cutting force, is the spar, which is supported by the hinged supports of the suspension units.

The main load of the rudders is air aerodynamic, which occurs when balancing, maneuvering the aircraft or when flying in turbulent air. Perceiving this load, the rudder spar works as a continuous multi-bearing beam. The peculiarity of its work is that the rudder supports are fixed on elastic structures, the deformations of which under load significantly affect the power work of the rudder spar.

The perception of the rudder torque is provided by a closed skin contour, which is closed by the side member wall in the places of the cutout for the mounting brackets. The maximum torque acts in the section of the control horn, to which the control rod fits. The location of the horn (control rod) along the span of the steering wheel can significantly affect the deformation of the steering wheel during torsion.

Aerodynamic rudder compensation

In flight, when the control surfaces deviate, hinge moments arise, which are balanced by the efforts of the pilot on the command control levers. These efforts depend on the dimensions and angle of deflection of the rudder, as well as on the velocity pressure. On modern aircraft, the control forces are too large, so it is necessary to provide special means in the design of the rudders to reduce hinge moments and balance their control efforts. For this purpose, aerodynamic compensation of the rudders is used, the essence of which is that part of the aerodynamic forces of the rudder create a moment relative to the axis of rotation, opposite to the main hinge moment.

The following types of aerodynamic compensation are most widely used:

• horn - at the end of the steering wheel, part of its area in the form of a "horn" is located in front of the hinge axis, which ensures the creation of a moment of the opposite sign in relation to the main hinge;
• axial - part of the steering wheel area along the entire span is located in front of the hinge axis (the hinge axis is shifted back), which reduces the hinge moment;
• internal - usually used on ailerons and is a plate attached to the toe of the aileron in front, which are connected by a flexible baffle to the walls of the chamber inside the wing. When the aileron is deflected in the chamber, a pressure difference is created above and below the plates, which reduces the hinge moment.
• servo compensation - a small surface is pivotally suspended in the tail section of the rudder, which is connected by a rod to a fixed point on the wing or plumage. This link provides automatic deflection of the servo compensator in the direction opposite to the deflection of the steering wheel. The aerodynamic forces on the servo compensator reduce the steering torque.

The deflection angles and the efficiency of such a compensator are proportional to the deflection angles of the rudder, which is not always justified, because. control efforts depend not only on the angles of deflection of the steering wheel, but also on the dynamic pressure. A spring servo compensator is more perfect, in which, due to the inclusion of a preloaded spring in the control kinematics, the deflection angles are proportional to the rudder control efforts, which best suits the purpose of the servo compensator - to reduce these efforts.

Means of aerodynamic balancing of the aircraft

Any steady-state flight mode of the aircraft, as a rule, is performed with deflected rudders, which provides balancing - balancing- aircraft relative to its center of mass. The forces that arise in this case on the controls in the cockpit are commonly called balancing. In order not to tire the pilot in vain and save him from these unnecessary efforts, a trimmer is installed on each control surface, which allows you to completely remove the balancing efforts.

The trimmer is structurally completely identical to the servo compensator and is also hingedly suspended in the tail section of the steering wheel, but, unlike the servo compensator, it has additional manual or electromechanical control. The pilot, deflecting the trimmer in the direction opposite to the rudder deflection, achieves the rudder balance at a given deflection angle with zero effort on the command lever. In some cases, a combined trimmer-servo compensator surface is used, which, when the drive is turned on, works as a trimmer, and when it is turned off, it performs the functions of a servo compensator.

It should be added that the trimmer can only be used in such control systems in which the forces on the command levers are directly related to the hinge moment of the steering wheel - mechanical non-booster control systems or systems with reversible boosters. In systems with irreversible boosters - hydraulic boosters - the natural forces on the control surfaces are very small, and in order to simulate "mechanical control" for the pilot, they are additionally created by spring loading mechanisms and do not depend on the hinge moment of the steering wheel. In this case, trimmers are not installed on the rudders, and balancing forces are removed by special devices - trimming effect mechanisms installed in the control wiring.

An adjustable stabilizer can serve as another means of balancing an aircraft in a steady flight mode. Typically, such a stabilizer is pivotally mounted on the rear hardpoints, and the front nodes are connected to a power drive, which, by moving the nose of the stabilizer up or down, changes the angle of its installation in flight. By selecting the desired installation angle, the pilot can balance the aircraft with zero hinge moment on the elevator. The same stabilizer also provides the required efficiency of the longitudinal control of the aircraft during takeoff and landing.

Means to eliminate flutter of rudders and ailerons

The cause of the flexural-aileron and flexural-rudder flutter is their mass imbalance relative to the hinge axis. Typically, the center of mass of the control surfaces is located behind the axis of rotation. As a result, during bending vibrations of the bearing surfaces, the inertia forces applied in the center of mass of the rudders, due to deformations and

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The plumage of the aircraft 1. The purpose and composition of the plumage. Feather requirements. 2. The shape and location of the plumage. 3. Loads acting on the plumage. 4. Plumage design.

Purpose of plumage. The feathers of the aircraft are the bearing surfaces of the aircraft, designed to provide longitudinal (relative to the OZ axis) and track (relative to the OY axis) balancing, stability and controllability of the aircraft. Aircraft balancing is the balancing of the moments of all forces acting on the aircraft, relative to its center of gravity. Stability is the ability of an aircraft to return to a given flight regime after the termination of the forces that caused the aircraft to deviate from this regime. The controllability of an aircraft is its ability to respond to rudder deviations with appropriate movements in space, or, as pilots usually say, “walk behind the handle”.

Purpose and composition of plumage. The aircraft of the normal (classical) scheme and the "duck" scheme has horizontal and vertical tail. the horizontal tail is designed to provide longitudinal (relative to the OZ axis) balancing, stability and controllability of the aircraft. the vertical tail is designed to provide directional (relative to the OY axis) balancing, stability and controllability of the aircraft. The relative mass of plumage m op. / m cr. = 0.015. 0.025

Horizontal plumage 8 - forkil, 7 - keel crest. For subsonic aircraft, the GO usually consists of a fixed or limitedly movable stabilizer and a movable elevator. On aircraft with supersonic flight speed, due to the insufficient efficiency of the RV when flying at supersonic speed, an all-turning VO (CPGO) without RV is used.

On heavy aircraft, by turning the stabilizer, the aircraft is usually balanced and the forces are removed from the control levers, and the RV is used to control the longitudinal movement.

The reason for the transition to all-moving horizontal tail When the speed of sound is exceeded in flight, static stability increases and, accordingly, the controllability of the aircraft deteriorates due to the rearward shift of the focus. It is possible to fend off this phenomenon and ensure high maneuverability of supersonic aircraft by increasing the efficiency of their controls relative to the Z axis. However, when flying at supersonic speed (M> 1), the efficiency of the RW decreases, because due to the shock wave on the rudder toe (Fig. 5 2, b) pressure changes with rudder deflection do not apply to all GO, as is the case when flying at subsonic speed (see Fig. 5. 2, a). The transition to the CPGO makes it possible to sharply increase the efficiency of GO, especially at supersonic speeds.

A differentially controlled stabilizer, an all-moving horizontal tail, can be used for lateral control of the aircraft, i.e. its consoles deviate together with longitudinal control and differentially with roll control.

PGO On aircraft built according to the “duck” or triplane scheme, a PGO is used to control relative to the oz axis, consisting of a destabilizer and a movable part - an elevator, or an all-moving PGO.

Vertical tail The vertical tail is designed to provide directional (relative to the OY axis) balancing, stability and controllability of the aircraft. It usually consists of a fixed keel and a movable rudder. On aircraft flying at high supersonic speeds and high altitudes, an all-moving vertical tail is used.

Vertical tail Due to the decrease in the effectiveness of the launch vehicle during supersonic flight, an all-moving VO is used. To increase the efficiency of the VO, ventral fins 7 are used, which include the fuselage in the VO area, which reduces the impact on the directional stability of the wing and fuselage shading of the VO at high angles of attack. Increases the effectiveness of VO and forkil 8.

Two-keel vertical tail unit To ensure the necessary degree of directional stability and controllability of a supersonic aircraft, a two-tail vertical tail unit is used.

To ensure the necessary degree of directional stability and controllability of a subsonic aircraft, to reduce the effect of vertical tail on the characteristics of lateral stability, to reduce the fuselage torque, and to reduce the weight of the tail, two and three-keel schemes are used. When the VO is located at the ends of the stabilizer, the efficiency of the GO increases (the VO works as end washers).

VO on the wing of the Beech 2000 Starship I In aircraft without HE or made according to the "canard" scheme, the VO can be installed on the wing, which reduces the shading of the wing and fuselage plumage even at very high angles of attack.

V - shaped plumage V - shaped plumage is an aerodynamic surface set at an angle of 45 -60 degrees. To the plane of symmetry of the aircraft. Such plumage simultaneously performs the functions of both GO and VO.

EFFICIENCY OF CONTROL BODIES EFFICIENCY OF CONTROL BODIES The ability of controls to create a control moment relative to the corresponding coordinate axis when they deviate. E. o. y. are equal to the increments of the torque coefficients with the full deviation of the controls from their neutral position At zxy - respectively, max. coefficient increments. moments of pitch, roll and yaw. Often E. o. y. characterize the efficiency coefficients of the governing bodies, equal to the partial derivative of the coefficient. moment of the given organ according to the angle of its deflection dm zxy / d delta c. e. n. E. o. y and coefficients are one of the main parameters that determine the characteristics of aircraft controllability

Efficiency of empennage Efficiency of empennage (in addition to speed and flight altitude) also depends on the area of ​​the empennage, its external shape, location on the aircraft, the rigidity of the empennage itself and the parts to which it is attached. The layout of the empennage on the aircraft and the design parameters must ensure its sufficient efficiency in all flight modes, including takeoff and landing.

Feather requirements. Ensuring the necessary characteristics of aircraft stability and controllability in all flight modes, Minimum empennage mass, As little as possible loss of aerodynamic quality for aircraft balancing, Prevention of dangerous vibrations of the empennage such as flutter or buffeting.

The shape and location of the plumage. In the wake zone, especially behind the wing, there are large flow bevels and significantly lower flow velocities, which reduces the efficiency of the plumage in this zone. GO is carried up or down, either forward - the “duck” scheme, or by using the “flying wing” or “tailless” scheme without any GO at all.

T - shaped plumage With this scheme, the shoulder L th increases from the aircraft CM to the CP GO, which makes it possible to reduce the S th and its mass m th. GO is similar to the end plate for VO, increasing its effective elongation.

GO ahead of the wing Saab SK 37 E Viggen The scheme allows you to gain by reducing the area of ​​the wing and its mass, because when balancing Y cr. is added to the Yth. Disadvantages: shading of the wing; big need Sua on Vzl. Pos. modes (when the wing mechanization is released); large balancing losses (due to the smaller leverage L th.

Triplane scheme Pos. modes, use a triplane scheme. Tail GO allows you to create the necessary pitching moments on takeoff. Pos. modes parrying diving moments from wing mechanization. The front GO is made “floating” at subsonic speeds and controlled at supersonic speeds.

So that the GO does not obscure the VO, it is placed behind the VO. A spaced AO is preferable to a single AO: it is not obscured by the fuselage at high angles of attack; torque is less than one VO; improves the lateral stability of the aircraft.

Spaced IN The location of the IN at the ends of the GO increases the effective elongation of the GO. The efficiency of the spaced VO when it is blown with a jet from the propellers of the engines increases. The spaced VO does not interfere with the view and shooting in the rear hemisphere.

Loads acting on the empennage By the nature of the work, the empennage is the same bearing surface as the wing. The plumage in flight is affected by loads from aerodynamic and mass forces. Loads from body forces are relatively small and are neglected in terms of strength. Loads from aerodynamic forces are divided into balancing and maneuvering.

Balancing loads Balancing loads required to balance the aircraft in a given flight mode are determined for the horizontal tail from the condition of equal moments about the transverse axis OZ. In horizontal flight, the resultant of the forces of the GO Reur. g. o. , applied in the center of pressure of the empennage, must create a moment relative to the center of gravity of the aircraft, equal in magnitude and inverse to the moment of the wing. When calculating the GO for strength, the largest Peur is selected. g. o. determined for all design cases of the wing. Reur. g. o. can be determined from.

What do we know about the aircraft stabilizer? Most people will just shrug their shoulders. Those who loved physics at school may be able to say a few words, but, of course, specialists will most likely be able to answer this question most fully. Meanwhile, this is a very important part, without which the flight is virtually impossible.

The fundamental device of the aircraft

If you ask to draw several adult airliners, the pictures will be approximately the same and will differ only in details. The scheme of the aircraft, most likely, will look like this: cockpit, wings, fuselage, interior and the so-called tail unit. Someone will draw portholes, and someone will forget about them, perhaps some other little things will be missed. Perhaps the artists will not even be able to answer why certain details are needed, we just don’t think about it, although we see planes quite often, both live and in pictures, in movies and just on TV. And this is actually the fundamental device of the aircraft - the rest, in comparison with this, are just trifles. The fuselage and wings actually serve to lift the aircraft into the air, control is carried out in the cockpit, and passengers or cargo are in the cabin. Well, what about the tail unit, what is it for? Not for beauty, right?

Tail unit

Those who drive a car know very well how to go to the side: you just need to turn the steering wheel, after which the wheels will move. But an airplane is a completely different matter, because there are no roads in the air, and some other mechanisms are needed to control it. This is where pure science comes into play: a flying car is affected by a large number of different forces, and those that are useful are amplified, while the rest are minimized, as a result of which a certain balance is achieved.

Probably, almost everyone who has seen an airliner in their life paid attention to the complex structure in its tail section - plumage. It is this relatively small part, oddly enough, that controls this entire gigantic machine, forcing it not only to turn, but also to gain or drop altitude. It consists of two parts: vertical and horizontal, which, in turn, are also divided in two. There are also two rudders: one serves to set the direction of movement, and the other - the height. In addition, there is a part with which the longitudinal stability of the airliner is achieved.

By the way, the aircraft stabilizer can be located not only in its rear part. But more on that a little later.

Stabilizer

The modern scheme of the aircraft provides many details necessary to maintain the safe condition of the airliner and its passengers at all stages of flight. And, perhaps, the main one is the stabilizer, located at the rear of the structure. It is, in fact, just a bar, so it's amazing how such a relatively small detail can in any way affect the movement of a huge airliner. But it is really very important - when this part breaks down, the flight can end very tragically. For example, according to the official version, it was the plane's stabilizer that caused the recent crash of a passenger Boeing in Rostov-on-Don. According to international experts, the mismatch in the actions of the pilots and the mistake of one of them triggered one of the parts of the tail, moving the stabilizer to a position characteristic of a dive. The crew simply did not manage to do anything to prevent a collision. Fortunately, the aircraft industry does not stand still, and each subsequent flight gives less and less space for the human factor.

Functions

As the name implies, the aircraft stabilizer is used to control its movement. By compensating and damping some peaks and vibrations, it makes flying smoother and safer. Since deviations occur both in the vertical and in the horizontal axis, the stabilizer is also controlled in two directions - that's why it consists of two parts. They can have a very different design, depending on the type and purpose of the aircraft, but in any case they are present on any modern aircraft.

horizontal part

She is responsible for balancing vertically, not allowing the car to "nod" every now and then, and consists of two main parts. The first of them is a fixed surface, which, in fact, is the aircraft's altitude stabilizer. On the hinge, the second part is attached to this part - the steering wheel, which provides control.

In a normal aerodynamic configuration, the horizontal stabilizer is located in the tail. However, there are also designs when it is in front of the wing or there are two of them at all - in front and behind. There are also so-called "tailless" or "flying wing" schemes that do not have horizontal tail at all.

vertical part

This part provides the aircraft with directional stability in flight, preventing it from wobbling from side to side. This is also a composite structure, which provides for a fixed vertical stabilizer of the aircraft, or keel, as well as a rudder on a hinge.

This part, like the wing, depending on the purpose and required characteristics, can have a very different shape. Diversity is also achieved through differences in the relative position of all surfaces and the addition of additional parts, such as forkil or ventral ridge.

Form and mobility

Perhaps the most popular in civil aviation now is the T-tail, in which the horizontal part is located at the end of the keel. However, there are some others.

For some time, a V-shaped plumage was used, in which both parts simultaneously performed the functions of both horizontal and vertical parts at once. Complex management and relatively low efficiency prevented this variant from being widely adopted.

In addition, there is a spaced vertical tail, in which parts of it can be located on the sides of the fuselage and even on the wings.

As for mobility, usually the stabilizing surfaces are rigidly fixed relative to the housing. Nevertheless, there are options, especially when it comes to horizontal tail.

If you can change the angle relative to the longitudinal axis on the ground, this type of stabilizer is called reversible. If the aircraft stabilizer can also be controlled in the air, it will be mobile. This is typical for heavy airliners that need additional balancing. Finally, on supersonic machines, a movable aircraft stabilizer is used, which also acts as an elevator.