Rotor blade, Mi-8 helicopter

Contents

CONTENTS

Maintaining

1 Understanding the Carrier System

1.1 Main data of the rotor

1.2 Components of the load-bearing system

1.2.1 Bearing core bushing

1.2.2 Mechanism of centrifugal restriction of overhang

1.2.3 Journal of axial hinge

1.2.4 Axial hinge housing

1.2.5 Hydraulic damper

1.2.6 Vibration damper

Rotor blade

2 Carrier System Maintenance

2.1 Removal of the rotor blade

2.2 Survey of eyes of Komlev of tips of blades of the bearing screw and their plates in installation sites of bolts

2.3 Inspection of the surface of spars, tail sections and

anti-abrasive adhesive of HV blades

2.4 Check of condition of rear stringers, attachment of end fairings of blades

2.5 Installation of blade on helicopter

3 Types of technical services

3.1 Operational services

3.2 Periodic services

3.3 Special Services

4 characteristic failures and malfunctions of LV, methods of their elimination and improvement of flight safety

5 Maintenance Safety

6 Conclusion

Annex A Rotor blade of the Mi- helicopter

General View Drawing

Specification A

List of literature

Introduction

The purpose of the diploma project is to get acquainted with the maintenance and operational repair of the Mi8T helicopter carrier system.

The main tasks of the thesis are:

- to consider general information;

- study the description of the structure;

- familiarize yourself with the maintenance of the Mi8T helicopter carrier system;

- consider repair of Mi8T helicopter carrier system.

In total, more than 8,000 Mi-8 helicopters were produced at the Kazan Helicopter Plant and the UlanUde Aviation Plant, of which more than 2,000 were exported to more than 40 countries, where half of them are still in operation. The helicopter has two TV2117A turboprop engines.

The Mi-8 helicopter is produced in two versions of the Mi8T transport and passenger Mi8P.

Helicopters were produced in more than 30 different civilian and military modifications, including the main ones:

Mi-8P - passenger helicopter with GTD TV2117A;

Mi-UPU "Salon" - passenger helicopter;

Mi-8T - transport helicopter with GTD TV3117MT ;

Mi-8TG - modification of the Mi8T helicopter with GTD TV2117TG;

Mi-8TV - airborne transport helicopter;

Mi-8MT - upgraded landing transport helicopter

from TB3117MT GTE;

Mi-8PP - an active jammer helicopter with a container and with cruciform dipole antennas on the sides of the fuselage;

Mi-9 - helicopter to provide communication with additional antennas on the tail beam;

Mi-18 - military transport helicopter;

Mi-8MTV-2 and 3 - the last military transport modifications;

Mi-8AMTSh - a variant of the Mi8AMT combat helicopter.

The helicopter is made according to a single-screw scheme with a tail screw, two GTE and three-support landing gear.

The Mi-8 helicopter consists of the fuselage and the following systems:

fuselage;

stabilizer;

bonnets;

take-off and landing devices;

bearing and tail screws;

power plants;

transmissions;

helicopter control and autopilot;

hydraulic system;

air system;

anti-icing system;

heating and ventilation systems of cabins;

devices for external suspension of cargo and aircraft boom;

electrical, radio and instrument equipment.

Helicopter fuselage consists of nose and center parts, tail and end beams. In the bow there is a three-seater cabin of the crew, consisting of their two pilots and a flight mechanic.

A stabilizer with a size of 2.7 m and an area of ​ ​ 2 × 2 with a NACA 0012 profile installed on the tail beam provides the necessary stability and controllability of the helicopter. Angle of stabilizer installation relative to construction horizontal is equal to 3 °.

The stabilizer has a symmetrical profile and consists of two cantilevers ,

flanges on spar are interconnected. Riveted console

structure consists of spar, set of ribs, diaphragms, frontal

duralumin skin, tail stringer, end fairing and

linen skin of tail part.

Helicopter air system provides supply of reduced air pressure to brakes of MLG wheels and recharging of wheels pneumatics from aircraft cylinder under non-aerodrome conditions. Compressed air under pressure of 50 + 4 kg/cm2is located in cylinders, which are the cavities of two LG main legs struts. Recharge of cylinders compressed air is made by the AK50T1 compressor installed on the main reducer. For ground charging of pneumatics with compressed air on RH rear strut there is a charging connector .

The cabin glazing provides good visibility, the right and left sliding blisters are equipped with emergency release mechanisms. The cargo cabin is designed to carry goods weighing up to 4 tons and is equipped with hinged seats for 24 passengers, as well as units for fixing 12 stretchers. In the passenger version, the cabin has dimensions of 6.36 × 2.05 × 1, 7 m and 28 seats, installed two on each side with a pitch of 0, 74m and a passage of 0, 3m; in the rear part of the cabin on the right there is a wardrobe, and in the rear part of the flaps there is an opening for the rear front door, consisting of a flap and a ramp.

Tail beam of riveted structure of beam-stringer type with working skin is provided with units for fixation of stabilizer and

tail support.

The chassis is three-support, non-retractable, front support self-orienting, with two wheels measuring 535 × 185mm, the main supports of the truss type with liquid-gas two-chamber shock absorbers with brake wheels measuring 865 × 280mm. The tail support consists of two braces, a shock absorber and a support heel; LG track 4.5m, LG base 4.26m.

Bearing screw with hinged attachment of blades, hydraulic

dampers and pendulum vibration dampers are installed with forward inclination of 4 ° 30. All-metal blades consist of pressed spar

made of aluminium alloy AVT1 hardened with an inclination by steel balls on the vibration stand, tail compartment, steel tip and tip.

The blades have a rectangular plan shape with a chord of 0.52m and profiles NACA 230 with a relative thickness of 12% to 11.38% and a geometric twist of 5%, the circumferential speed of the ends of the blades 217m/s, the blades are equipped with a visual warning system for damage to the spar and an electric thermal anti-icing device.

The steering screw with a diameter of 3.9m is three-blade, pushing, with a cardan bushing and all-metal blades of rectangular shape in plan, with a chord of 0.26 m and a profile of NACA 230M.

The power plant consists of two turboprop gas turbine engines with a free turbine TV2117AT, installed on top of the fuselage and closed with a common hood with opening doors. Engine has nine-stage axial compressor, annular combustion chamber and two-stage turbine. Engine length 2.835m, width 0.547m, height 0.745m, mass 330kg. Motors are equipped with dust protection devices. Free turbine RPM 12000 RPM

Fuel system consists of service fuel tank with capacity

445 litres, LH suspended tank 745 or 1154 litres, RH suspended tank 680 or 1044 litres of additional tanks 915 litres each in the cargo cabin.

Transmission consists of main, intermediate and tail reduction gears, transmission shafts, brake, and rotor. The main reduction gear BP8A is three-stage, provides summation of the engine power and transfer of this power to the rotor having a rotor speed of 192 rpm, steering screw - 1124 rpm and fan - 6021 rpm for cooling, engine oil radiators and the main reduction gear; two sensors of D1 tachometers, SGO30U DC generator, BP8A oil unit. The total capacity of the oil system is 38liters. Control with rigid and cable wiring and hydraulic amplifiers, with supply of liquid under pressure of main and backup hydraulic systems. AP34B four-channel autopilot stabilizes the helicopter in flight by roll, heading, pitch.

The main and backup hydraulic systems of the system are provided by operating pressure of 4.5MPa provides power supply to all hydraulic units.

The heating and ventilation system provides heated or cold air to the cabin of the crew and passengers. Anti-icing systems protect the blades of the carrier and steering screws, front windows of the crew cabin and engine air intakes from icing.

LPG300 aircraft boom is used for loading of small loads weighing up to 200 kg into the cockpit both on ground and in application mode. The boom is attached outside on the LH side, near the upper front corner of the sliding door opening, and is equipped with a retainer that allows locking the boom in working and retracted positions. Lifting and lowering of the load is performed by means of LPG300 electric pedestal, which is attached on the cargo floor to the right in the front part of the cockpit. Rope from winch passes through system of rollers and has carbine at its end for lifting of loads. Electric drive control - remote, electric from PUL-1 control panel by means of buttons. With the help of an on-board boom, it is possible to lift people during rescue operations in hanging mode.

Understanding the Carrier System

The bearing screw is designed to generate lifting and driving forces in all flight modes, as well as to create longitudinal and transverse moments of helicopter control. The bearing screw is five-blade, consists of a bushing and blades. Bearing screw consists of bushing and five blades.

The rotor bushing has spaced horizontal, vertical and axial hinges.

Horizontal hinges are intended for elimination of overturning moment, unloading of blade root part from bending moment of thrust, reduction of fatigue stresses in blades and reduction of vibrations caused by changes of blade thrust moment along azimuth. Horizontal hinges are 220 mm apart from rotor rotation axis. Axis of horizontal hinge is turned by angle of 5 ° 419 "relative to perpendicular to straight line passing through axis of rotation of screw and axis of vertical hinge. Displacement of bushing body eyes along axis of horizontal hinge in direction of rotation by 45 mm is achieved. The amount of displacement is selected so that at the main flight modes of the helicopter the equal aerodynamic force of drag and centrifugal force of the blade is directed perpendicular to the axis of the horizontal hinge and provides uniform distribution of load between needle bearings of the horizontal hinge.

Vertical hinges are designed to unload blade assembly from bending moments arising from action of aerodynamic and inertial forces in plane of rotor rotation. Vertical hinges are spaced 507 mm from rotor rotation axis.

The axial hinge allows changing the setting angle of the blade,

allows it to rotate about its axis.

Vertical hinges of the rotor bushing have hydraulic dampers that not only dampen the vibrations of the blades in the plane of rotation of the screw, but also prevent the occurrence of oscillation of the helicopter of the "earth resonance" type.

The rotor bushing has a swing compensator, which increases stability of the blade flyover motion by changing the setting angle oscillating around the blade horizontal hinge axis depending on the swing angle.

To prevent impact of blades against tail beam at non-rotating bearing screw or at its rotation at low speed, bushing is equipped with centrifugal limiters of blade overhang.

To reduce vibration level of a number of helicopter units and increase their operational reliability, a pendulum vibration damper is installed on the rotor bushing.

Rotor blades operate at significant amount of load from centrifugal force and variable loads - from aerodynamic and inertial forces. These loads are perceived by blade spars, which have a damage alarm system with a visual indicator, for protection against icing, the blades are equipped with an anti-icing system of electric heat action.

Main data of the rotor:

- LV diameter, m 21.3;

- direction of rotation, from above clockwise;

- marked LV area, m2 355.7;

- filling factor....... 0.0777;

- spacing of vertical hinges, mm...... . 507;

- horizontal........ 220;

- specific load on the marked area, kgf/cm2.......... 31 - 33.8;

- expansion compensator coefficient value........ . 0.5;

- maximum corner of a wave of the blade........ 25о±30";

blade overhang angle:

- at an emphasis on a bracket......... 4o +10 "20";

- at an emphasis on a doggie of the centrifugal limiter......1o40 "+20";

- a tilt angle of an axis of the bearing screw forward......... 4o30";

blade rotation angle around vertical hinge axis:

- forward in the direction of rotation......... 13o ±15";

- back against rotation......... 11o ±10";

- bushings, mm......... 1744;

- bushing weight (dry), kg......... 610;

- set of blades, kg......... 700.

Carrier System Maintenance

The rotor is one of the most important units of the helicopter, the reliability of which largely depends on flight safety. Therefore, the technical condition of the bushing and screw blades is monitored during all types of maintenance of the helicopter.

2.2 Survey of eyes of Komlev of tips of blades of the bearing screw and their plates in installation sites of bolts

Not allowed:

- cracks;

- in places of interface of eyes of Komlev of tips;

- in the area of connection of the tip plates with the spar ;

- at places of bolts installation (especially at places of tip conical neck transition to plates along plate ends and surfaces)

(If cracks are detected, replace the blade);

- corrosion and mechanical damages ↓ > 0.2 mm on lap tips (replace the blade);

(corrosion and mechanical damages ↓≤ 0.2 mm - grind);

- Frétingcorrosion at the points of joint of comer tips with HV bushing (frétingcorrosion is characterized by brown deposit in the joint zone is the result of friction of articulated parts);

- failure of locking (in case of violation of locking of through bolts - call the supplier representative);

(replace the broken locking, check Tightening = 8 + 2 kgs⋅m.);

- loosening of bolts for attachment of lap tips to spar

(detected by LCC violation at the point of contact with the spar);

(if loosening and turning of bolts is detected, call the supplier representative).

2.3 Inspection of the surface of spars, tail sections and

anti-abrasive adhesive of LV blades

To determine the nature of mechanical damage:

- remove paint coating;

- rub the places with ink rubber. to examine

area with magnifying glass;

- before measurement - remove nicks, scratches, hairlines

using shaver, skin and polishing with GOI paste

movements along the axis of the spar

(there should be no traces of hairlines after polishing.);

̶ measure;

- determine defect depth by indicator

(If the risk or face across the spar is measured several times by moving the indicator along the spar axis to determine the maximum depth.);

̶ inspect to:

a) in a 50 mm area in both directions on the same surface

there was no defect;

b) there were no traces in the 100 mm section on the reverse

elimination of defects;

̶ depth of grinding after defect removal;

– <0.1 mm. for zone B;

– <0.2 mm. for zone B.

Not allowed on rotor blades:

- snow (remove with hairbrush);

- ice and frost

(remove by blowing warm air of temperature t0 < 60 ° С from the ground heater);

- dust, dirt and oil stains

(remove in summer with 3% aqueous solution of technical soap)

(in winter, dust, dirt - with a dry napkin,

oil spots - with a napkin wetted with kerosene and squeezed out).

(Special attention to section from compartment 10 to blade end, at joints

tail compartments where LCP is broken.);

- damage of paint coating with metal bare;

- corrosion centers. (Call the representative of the supplying plant.)

Not allowed on anti-abrasive protection rubber of blades:

- cracks;

- abrasive wear;

- mechanical damages of rubber of anti-abrasive protection of blades

With bare belts of heating element and metal of spar.

Repair the rubber coating.

Not allowed: on steel anti-abrasive shackles:

- violation of gluing of the shackle;

- S > 8 cm2 on one lobe - extending to the edge of the lobe;

- S with total > 50 cm2 per one shackle;

- corrugation > 0.5 m (with violation of gluing of shackles;);

- dents without through breakdown of shackles > 1 mm.

If there are defects outside the tolerance, replace the shackles.

on blades having polyurethane protection on shackles, remove with knife.

It is allowed:

̶ uniform abrasive wear of the polyurethane coating.

Note: On the area with polyurethane protective tape is not applied.

Warning. It is strictly forbidden to determine the gluing violation by introducing metal probes under the skin.

- cracking and painting of sealant at joints of tail compartments under spar until its bare;

- scratches on the skin until metal is bare;

- skin swelling;

- dents ↓> 2 mm S> 100 cm2> 2 x on everyone

compartment side;

- dents with material rupture and LCC violation;

- holes;

(compartments with holes of 20 x 20 mm, and located closer:

a) 20 mm - from spar wall

b) 10 mm - from ribs and posterior stringer

c) > 2 - on compartments from the 2nd to the 10th

d)> on other compartments to replace the 1st)

2.4 Check of rear stringers condition,

attachment of end fairings of blades

On stringers it is not allowed:

- touching of rear stringers of adjacent compartments (make sure that there are no unacceptable curvatures of rear stringers and deformations of tail compartments)

(If there are no stringers deformations and curvatures, then touch

eliminate by spraying the ends of the contacting stringers with a filer);

- curvature of rear stringer > 5 mm (remove blade for repair)

(Allowed with deflection boom < 5 mm, if they do not cause disturbances in rotor operation).

On end fairings it is not allowed:

- cracks of contour light glass (replace glass);

- cracks, holes and dents of fairing (cracks are most likely around holes);

- dents ↓> 2 mm. (point dents are allowed without limitation);

- loosening of attachment screws of tail fairings of LV blades (Loosening is detected by absence of paint at the screw heads and by dark grey deposit around the screw heads (Loose screws tighten and paint).

2.5 Installation of the blade on the helicopter:

- rinse the lugs and lugs with Nefras

blades;

- to grease TsIATIM201 bolts and openings OSH and Komlev

blade tips;

- install the sling on the blade, raise it to the level of SHH;

- to combine the lower opening of a comb OSH and corresponding

a blade opening (using a cone pin);

- remove the pin, install the lower bolt, put under the head

washer;

- install the blade horizontally;

- install the upper bolt in the same order (Install bolts with thread forward to the side of HV rotation.);

- tighten the nuts of bolts. Tightening = 810 kgs⋅m;

- lock with cotter pins;

- connect wiring to anti-icing system

blades;

- flanged the electric submarine to the bracket on the SHH;

- install rubber covers in place.

Types of Technical Services

3.1 Operational services

In form A1:

1.06.01 Inspect LV bushing, automatic skew, units and units located on them. Make sure that there are no mechanical damages and violations of bolts and nuts locking of parts and units. Make sure that there is no oil leak from the bushing joints and from the hydraulic dampers compensating system.

Operation content as per Job Instruction No.1.06.01:

1) check if there are oil leaks from axial, vertical, horizontal hinges and hydraulic dampers of the rotor bushing. Oil leakage from hinges and hydraulic dampers is not allowed. It is allowed to insignificantly push the lubricant through the joints seals without drop formation;

2) clean the rotor bushing and the skew machine from dust, dirt and lubricant traces;

3) check on the parts of the bushing, the skew machine, if there are no centers of corrosion, nicks or cracks. Examine places with suspected cracks using magnifying glass, Corrosion centers, nicks and cracks;

4) inspect the earrings connecting the hydraulic damper with the horizontal hinge, make sure that there are no cracks;

5) inspect the vane overhang centrifugal limiters and check if there is no work on the "pawls" and stops. Do not tilt on socks of "dogs," as well as work of inserts of stops of blade overhang limiters, which causes violation of overhang angle;

6) visually and by hand force check attachment of levers of rotor blades turning to bodies of axial hinges. Not allowed

Loosening of bolts tightening and violation of their locking 7) Examine the current collector fairing of anti-icing system and hoses of AMG10 oil supply to hydraulic dampers. Cracks on fairing are not permitted. Hose rubber swelling and hose exit from the tips sealing are not allowed.

Admissible lowering of the level of oil in cavities of hinges of NV sleeves, at installation of nuts of GS with No. C41865 - 60 mm (20 mm are lower than established). At installation of nuts OSH with No. SP38195 - 35 mm (15 mm are lower than established). Measure the oil level in the hinges from the outer end of the filling holes of GSh and VSh of oil meters B1911M02, OR - with oil meter 81330M03 No. 03035-75 DK.

1.06.09 Check air pressure in blade spars by visual annunciators.

Operation content as per Job Instruction No.1.06.07:

Inspect the caps of visual annunciators of blade spars damage. The red belt of the sensor should not be in view. At ambient air temperature - 40 ° С and lower, check air pressure in spars with pressure gauge. The pressure shall not be less than 25 kPa (0.25 atm). In case of faulty annunciator, helicopter flights are allowed until the defect is eliminated by the factory supplier representative, with daily check of air pressure in the spar by the pressure gauge.

In form A2:

1.06.01 Inspect LV bushing, automatic skew, units and units located on them. Make sure that there are no mechanical damages and violations of bolts and nuts locking of parts and units. Make sure that there is no oil leak from the bushing joints and from the hydraulic dampers compensating system.

Operation content as per Job Instruction No.1.06.01:

1) check if there are oil leaks from axial, vertical, horizontal hinges and hydraulic dampers of the rotor bushing; Oil leakage from hinges and hydraulic dampers is not allowed.

Slight injection of lubricant through seals is permitted

hinges without drop formation;

2) clean the rotor bushing and the skew machine from dust, dirt and lubricant traces;

3) check on the parts of the bushing, the skew machine, if there are no centers of corrosion, nicks or cracks. Examine places with suspected cracks using magnifying glass, Corrosion centers, nicks and cracks;

4) inspect the earrings connecting the hydraulic damper with the horizontal hinge, make sure that there are no cracks;

5) inspect centrifugal limiters of blade overhang and make sure that there is no work on "pawls" and stops. Do not tilt on socks of "dogs," as well as work of inserts of stops of blade overhang limiters, which causes violation of overhang angle;

6) visually and by hand force check attachment of levers of rotor blades turning to bodies of axial hinges. Loosening of bolts tightening and their locking are not permitted;

7) inspect the current collector fairing of anti-icing system and hoses for supply of AMG10 oil to hydraulic dampers. Cracks on fairing are not permitted. Hose rubber swelling and hose exit from the tips sealing are not allowed.

Admissible lowering of the level of oil in cavities of hinges of NV sleeves, at installation of nuts of GS with No. C41865 - 60 mm (20 mm are lower than established). At installation of nuts OSH with No. SP38195 - 35 mm (15 mm are lower than established). Oil level in hinges to measure from an external face of jellied openings of GS and VS of oil meters of B1911M02, OSH - an oil meter 81330M03 No. 03035-75

DC.

1.06.02, 1.06.04, 1.06.05 Make sure that hoses are compressed by clamps

supply operating fluid AMG10, FH-51 to hydraulic dampers and make sure that

that there is no violation of external braid of hoses in places of their compression

clamps. Check absence of skew and deformation of clamp halves

attachment of skew automatic drive.

Note: Do not perform any work on helicopters with installed limiters of clamp displacement.

Check condition and attachment of clamp displacement limiter of skew machine carrier and make sure that the plates are fixed with screws and cover areas of semi-ring surface painted orange.

Operation content as per Job Instruction No.1.06.08 *, 1.06.02a, 1.06.02b

1) inspect the external condition of the clamp mixing limiter of the skew machine ledge, having received special attention to the tides. Cracks, dents and other mechanical damages are not permitted;

2) inspect the attachment of the plates of the displacement limiter, make sure that the plates are fixed with mats and completely cover the areas of the surface of the semi-rings painted orange in color. Cutting of attachment screws of one of the plates and appearance of orange-colored sections on the surface of the semi-ring is not allowed. Deformation of the clamp bracket of the skew machine carrier is not more than 1 mm;

3) inspect the attachment of the limiter for mixing of the ledge clamp and check the following: reliability of attachment of the half-rings of the mixer limiter; clearance in accessible places along perimeter between ends of semi-rings of limiter of carrier clamp mixing to skew machine. The semi-rings with their ends must come close to the end of the rotor bushing without a gap. Local clearance is not more than 0.2 mm. Loosening of attachment and violation of locks is not allowed.

1.06.03 Check oil condition in axial joints of LC bushing by inspection cups.

Content of work according to checklist No. 1.06.01a:

Visually check oil condition in axial hinges of the rotor bushing by inspection cups. The oil must be transparent without noticeable darkening (the opposite wall of the cup is visible). Metal particles are not allowed.

Oil turbidity is allowed if MC20 oil replacement with VNIINP25 oil is made. 2.

Drain oil from axial hinge when magnetic plug and inspection cup are turned away.

1.06.06 Check oil level in compensating barrel.

Operation content as per Job Instruction No.1.06.03:

Check filling of compensating tank of hydraulic dampers with AMGU oil. The oil level of the tank shall not be higher than the hairline applied on the transparent cap and not lower than the lower edge of the cap.

1.06.07 Inspect the surface of spar, tail sections and anti-abrasive strap, LV blades. Check for swelling, blade skin lag and mechanical damages.

Operation content as per Job Instruction No.1.06.04:

1) examine the blades and make sure that there is no ice, snow, dust, dirt and oil stains on their surface. Remove snow with a hairbrush, ice and frost - by blowing the blades with warm air from the ground heater (the temperature of air supplied to the blade should not exceed. 60 ° С). Blow down until the blade surface is completely dry. Remove dust, dirt and oil stains in summer with H% water solution of technical soap, then wipe with clean napkin wetted with water. In winter, remove dust and contaminants with a dry napkin, and oil stains with a napkin wetted with kerosene and squeezed out, then wipe the surface with a dry clean napkin;

2) inspect blade spars and make sure that there are no damages on their surface. Damage to the paint coating without metal bare, swelling, local deflections of anti-icing rubber are allowed, if they do not disturb the normal operation of the rotor (vibrations, cotton), abrasive wear, cracks and Other damage to the rubber without bare glass fabric, but only in glued places. Through damages of rubber at places of swelling or deflection are not allowed. Minor abrasive wear and dents up to 1 mm deep are allowed without breaking the metal of anti-abrasive shackles;

3) inspect the tail compartments of the blades, make sure that there are no damages of their skin and violation of glue connections of the skin with the spar. Pay special attention to compartments 18 - 21.

1.06.08 Check the condition of stringers and attachment of end fairings of the blade, as well as make sure that there is no corrosion and damage of the LCP on the spars, cracking and painting of the sealant in the joints above the spar. Inspect lap parts of blades for absence of sealing compound cracks in joints above the spar. Inspect the comb parts for no cracks. Use 7x magnification magnifying glass to inspect suspicious areas.

Operation content as per Job Instruction No.1.06.05:

Check visually if:

- curvatures and touches of rear stringers of adjacent compartments. Small curvatures of the tail stringer (with deflection boom up to 5 mm) are allowed, if they do not cause abnormalities in the operation of the rotor;

- loosening of screws of end fairings of rotor blades. Loosening of screws tightening is detected by the absence of paint at the screw heads and by the dark gray deposit formed around the head

loosened screw.

visually check condition and presence of sealant in joints of tail compartments. Do not crack and paint the sealing compound in the joints of the tail compartments under the spar until the spar is bare;

examine the spars if there is no mechanical damage and

corrosion centers. Examine places with suspected corrosion using magnifying glass. If necessary, remove paint coating. Corrosion centers have the form of small dark spots with uneven, broken outlines and with branches. Places with suspected corrosion should be additionally wiped intensively with ink rubber: if the dark spot after that remains, then this indicates the presence of corrosion foci. The usual mechanical damage (dent) of the spar when treated with rubber (cleaned of dirt) has a light bottom. Operation of blades with mechanical damages or corrosion points on spars is prohibited.

1.06.09 Check pressure in blade spars by visual annunciators.

Operation content as per Job Instruction No.1.06.07:

Inspect the caps of visual annunciators of blade spars damage. The red belt of the sensor should not be in view. At ambient air temperature - 40 ° С and lower, check air pressure in spars with pressure gauge. The pressure shall not be less than 25 kPa. In case of faulty annunciator, helicopter flights are allowed until the defect is eliminated by the factory supplier representative, with daily check of air pressure in the spar by the pressure gauge.

1.06.10 Inspect the pendulum vibration damper. Make sure that locking is serviceable. Examine hub, fairings and make sure that

that there are no damages and cracks on them.

Operation content as per Job Instruction No.2.06.14:

In the form of OB1:

1.06.03 Check oil condition in axial joints of LC bushing

by viewing glasses.

Content of work according to checklist No. 1.06.01a:

Visually check oil condition in axial hinges of the rotor bushing by inspection cups. Oil must be clear

without noticeable darkening (the opposite wall of the cup is visible). Metal particles are not allowed. Note: 1. Oil turbidity is allowed if MC20 oil replacement with VNIINP25 oil is made. 2. Drain oil from axial hinge when magnetic plug and inspection cup are turned away.

1.06.06 Check oil level in compensating barrel.

Operation content as per Job Instruction No.1.06.03:

Check filling of compensating tank of hydraulic dampers with AMGU oil. The oil level in the tank shall not be higher than the hairline applied on the transparent cap and not lower than the lower edge of the cap.

1.06.09 Check pressure in blade spars by visual annunciators.

Operation content as per Job Instruction No.1.06.07:

Inspect the caps of visual annunciators of blade spars damage. The red belt of the sensor should not be in view. At ambient air temperature - 40 ° С and lower, check air pressure in spars with pressure gauge. The pressure shall not be less than 25 kPa (0.25 atm). In case of faulty annunciator, helicopter flights are allowed until the defect is eliminated by the factory supplier representative, with daily check of air pressure in

spar.

3.2 Transient Services

After 75 hours of flight:

2.06.02 Inspect the hydraulic dampener shackle. Make sure that there are no cracks on eyes and that there is no turn of pin for attachment of shackle to

hydrodampphere.

Operation content as per Job Instruction No.2.06.11:

1) inspect the earrings of hydraulic dampers using magnifying glass of 7 times increase and make sure that there are no cracks on the eyes (cracks are not permitted);

2) inspect the pins that attach the earrings to the hydraulic damper. Make sure that there is no turning. The turn is determined by the shift of the print from the bracket on the earring. Do not turn the finger.

2.06.07 Remove and inspect magnetic plugs of axial joints of LV bushing.

Operation content as per Job Instruction No. 2.06.13:

1) install the rotor blade, from the axial hinge of which the magnetic plug is removed, in the direction of the tail beam;

2) unlock and remove the filling plug in the axial hinge housing;

H) to raskontrit, turn off a magnetic plug and to establish the stopper 81910312 enclosed to the ZIP of the sleeve of the bearing screw to the place of the removed stopper;

4) inspect the magnetic plug. On a magnetic plug, flake and needle metal particles larger than 0.5 mm are not allowed.

After 150 hours of flight.

2.06.04 Examine rotor blades and make sure that there are no

swelling and deflection of tail compartment skin from spar,

tail stringers from ribs. Make sure that there is no swelling and local destruction of rubber, lag of anti-abrasive shackles, as well as mechanical damages of shackles and tail compartments.

Operation content as per Job Instruction No.2.06.01:

make sure that there is no ice, snow, dust and dirt on the blades ;

inspect rotor blades and make sure that there are no

expansion and lag of tail compartment skin in gluing points to

cellular filler, to spar, tail stringers and ribs. Pay special attention to compartments 18 - 21. Expansion of tail compartment skin is not permitted. Blades with the following defects on the tail compartments are allowed for operation;

- scratches on the skin without metal exposure;

- small dents without material rupture and paint coating violation;

- smooth dents without metal rupture up to 2 mm deep and with an area of up to 100 cm not more than two on each side of the compartment.

Tail compartments with cracks, holes, skins, violation of glue connections of the compartment with spar along the skin boundary (gap formation) are not allowed for further operation.

Warning. It is strictly forbidden to determine gluing violations by introducing metal probes under the skin.

Compartments with 20X20 mm holes located no closer than 20 mm from the spar wall and 10 mm from the ribs and rear stringer are allowed for repair, at that the number of specified holes must not be more than

two on compartments 2 - 10 and not more than one on other compartments.

inspect rubber linings for anti-abrasive protection of blade spar and make sure that there are no cracks, abrasive wear, mechanical damages, bloating, painting and partial

rubber peeling. Operation of blades with cracks is permitted,

abrasive wear and mechanical damage to rubber without bare heating element belts and spar metal, if they do not disturb the normal operation of the rotor;

4) inspect and make sure that steel anti-abrasive shackles are not damaged. Further operation is allowed

blades in the presence of the following defects;

- violation of gluing on one lobe of shrouding up to 8 cm2, which does not go to the edge of the lobe, with a total area of ​ ​ one shroud up to 50 cm2;

- slight abrasive wear of the shackles and the formation of a corrugated surface on them from a corrugation height of not more than 0.5 mm without disturbing the gluing of the shackles;

- dents without through breakdown of shackles up to 1 mm deep.

on blades, where anti-abrasive shackles are coated with polyurethane, check if there are local damages of the polyurethane film in the form of breaks and delays from shackling. Uniform abrasive wear of the polyurethane coating and operation of the blades without restoration of this coating are allowed.

Note: Sticky tape is not applied to the area with polyurethane protection of shackles.

2.06.05 Examine lugs of lugs and their plates in places of bolts installation, check locking of nuts of bolts that attach blades to LV bushing.

Operation content as per Job Instruction No. 2.06.02:

examine lugs of lugs and their plates and make sure that there are no lugs;

- cracks at the points of connection of the eyes and in the area of connection of the tip plates with the spar at the places of installation of bolts (especially at the places of transition of the conical neck of the tip to the plates at the ends and surfaces of the plates). Examine places with possible formation of cracks using magnifying glass (cracks are not permitted);

- mechanical and corrosive damages of the pile tips. Further operation of the blades after removal of damages up to 0.2 mm deep is allowed. Measure and eliminate defects similar to that specified in Job Instruction No. 2 06 07 for the surface of the spar - corrosion cutting at the points of joints of the left tips with the rotor bushing. Corrosion fringing is characterized by a brown deposit in the joint zone and is the result of friction of the articulated parts. Corrosion fringing is not allowed.

2) check locking of nuts and bolts of blades attachment to LH tips, make sure that locking is serviceable. Failure of locking is not permitted;

3) check if there is no loosening and turning of bolts attaching the lap tips to the spar. It is determined by the violation of the paint coating at the point of contact of the head (nut) with the spar. Loosening and turning of bolts is not allowed;

4) check locking of nuts of blades attachment bolts to the rotor bushing, make sure that locking is serviceable. Failure of locking is not permitted.

2.06.06 Inspect rear edges of blade compartments and make sure that there are no damages of end fairing and TE flaps, as well as coarse curvatures or contacts of rear stringers of adjacent compartments. Check if end fairings attachment screws are loosened.

Operation content as per Job Instruction No.2.06.03:

inspect rear edges of tail compartments of blades and make sure that adjacent compartments are not curved and in contact with rear stringers. The maximum permissible curvature of the tail stringer with a deflection boom is up to 5 mm. Do not touch adjacent compartments with stringers;

inspect end fairings of blades, make sure that there are no:

- cracks of contour fire glass. Cracks are not allowed;

- cracks, holes and dents of fairing Cracks are most likely around holes of attachment screws. Cracks and holes are not allowed.

Point dents are allowed without limitation.

3) check visually if attachment screws are loosened

end fairings of rotor blades.

Loosening of screws is not allowed. Loosening of screws is detected by the absence of paint at the screw heads and by the gray deposit formed around the head of the loosened screw.

2.06.18 Inspect 35 pins of vibration damper. Before that remove umbrella.

Operation content as per Job Instruction No.2.06.19 *

2.06.20 On bushings NV 81930000 ser.02 of the release from the 3rd quarter of 1991. to the 3rd quarter of 1993 inspect external surfaces of blade turning levers visually and by method of colour inspection for detection of cracks. (Ism. 10 Osn.: Uk. FSVT No. 25.1.555 dated 15.03.00.)

Operation content as per Job Instruction No.2.06.19 *

After 300 hours of flight:

2.06.08 Check the plays in the hinges of the drive of the skew machine.

Operation content as per Job Instruction No.2.06.10:

brake the bearing screw. To fix the case of the axial hinge, next to a lead, on a front emphasis by means of T63586225 wedge, having inserted it between a back emphasis and to fix it by screw 3164A1044 .

Twist the blades;

2) to measure the total play of the lead in the vertical plane, attach the tool string on the link lever, and install the indicator leg on "O." Apply P = ± 20kG force to the lead shackle through the dynamometer, measure the indicator reading difference;

3) to measure the total play of the lead in the plane of rotation

attach the accessory string on the rotor bushing damper, and rest the indicator leg on the machine plate by providing 2 mm tension, arrow

set the indicator to "O." Use rod T6358- to install

6223. Apply the force in the plane of rotation of the tray P = ± 20kG through the dynamometer to the shaft of the end hinge of the tray, measure the difference in indicator readings.

Note: During measurements, the indicator leg should be installed on the surface perpendicular to the indicator leg. Plays in the connections of the skew automatic leash are not more than:

- in the vertical plane 0.7 mm;

- in the plane of rotation 1, 2 mm.

2.06.09 Check serviceability of the blade spar damage alarm system by making a record in the blade certificate.

Operation content as per Job Instruction No. 2.06.04:

wipe with napkin, unlock and remove the cap-wrench and measure the value of air pressure in the cavity of blade spar using pressure gauge, at that red belt of annunciator must not be in the field of view;

2) press the slide valve rod to release air pressure from the spar until red belt appears in the field of view. Zamert this pressure (the beginnings of operation - Rman) the manometer;

3) determine the value of absolute pressure of the works of the beginning of actuation by the formula ras = rotm + rman, where ratm is atmospheric pressure at the moment of detector check;

according to the diagram of the pressure of the start of operation of the annunciator against the ambient air temperature (Fig. 27), determine the pressure of the start of operation and compare it with the measured one. The measured pressure of the start of operation must be within the limits of permissible deviations on the diagram;

5) by hand pump create pressure in the spar, pa 15 (0.15 atm);

Kpa exceeding the actuation start pressure.

Notes:

- do not inflate air into the spar to a pressure of more than 80 Kpa (0.8 atm) by pressure gauge and inflate air into the spar using compressors and compressed air cylinders;

- in case of helicopter operation at temperature below - 40 ° С, pressure in blade spars shall be maintained not less than 25 Kpa (0.25 atm);

- if air is pumped into the spar by manual pump, check pressure periodically. 60-70 pitches increase the pressure by 10 Kpa (0.1 atm).

6) check tightness of the slide valve with soap solution, then install and lock the cap-wrench.

2.06.12, 2.06.14 Inspect eyes of axial hinges when blades are removed.

On removed blades examine eyes, connection holes, neck of tip, as well as cheeks of tip in places of attachment bolts installation. Examine the spar. Make sure that there are no cracks, hairlines, nicks, corrosion. Check sealing condition of tail compartments joints.

Operation content as per Job Instruction No. 2.06.07:

ATTENTION. Operations on disconnection (docking) of plug connectors, disconnection (connection) of wire bundles, inspection of electrical equipment components condition are performed by an aircraft equipment specialist, guided by the materials specified in the procedure for scheduled maintenance of electrical equipment, Section 1.

remove the rotor blades from the helicopter;

make sure that there is no snow, ice, dirt, oil on the blades;

inspect the blade spar and make sure that there are no cracks, nicks, hairlines, scratches and corrosion on its surface. Pay special attention to

section from compartment 10 to the end of the blade, at the joints of the tail compartments, as well as to the place where the paint coating is violated. Cracks of spar are not allowed.

To determine the nature of mechanical damage to the spar, remove the paint coating according to Annex 1 and inspect the damaged area using a magnifying glass. Determine the defect depth by the indicator. Before measuring the defect depth, bring out the detected nicks, scratches and hairlines with a blade and skin, with subsequent polishing of these surfaces with GOI paste. Perform grinding and polishing by tool movement only along spar axis. Traces of hairlines after polishing are not allowed. After removal of the defect by the accessory (support and indicator), determine the depth of the defect. If the risk or face is across the spar, measure several times by moving the indicator along the spar axis to determine the maximum depth. Before removal of defect inspect adjacent section of spar. In the 50 mm area on both sides of the defect on the same surface of the spar and 100 mm on both sides on the opposite surface of the spar, there shall be no traces of elimination of defects occurring earlier. If this condition is not met, replace the blade.

Inspect places with suspected corrosion using magnifying glass, if necessary, remove paint coating. Corrosion centers appear in the form of small dark spots, which have not even, broken outlines with branches.

Wipe places with suspected corrosion intensively with ink rubber. Dark spot after grinding indicates corrosion. The usual mechanical damage to the spar when treated with rubber (cleaned of dirt) has a bright bottom.

Operation of blades with mechanical damage or corrosion on the spar is prohibited.

examine lugs of lugs and their plates.

Perform inspection, refer to Job Instruction No. 2 06 02 of this inlet;

check condition and presence of sealing compound in joints between compartments on spar. Do not crack and paint the sealant in the joints of the tail compartments until the spar is bare;

seal joints between the blade compartments in the following sequence:

- degrease the cladding of compartments in places of sealant application with tampon wetted with gasoline and dry for not less than 15 min;

- mark the boundaries of sealant application;

- Mark the area to be sealed with adhesive tape;

- degrease the compartment skin in places of sealant application with tampon wetted with gasoline and dry for not less than 15 min;

- apply UZOMES5 sealing compound to joints between compartments with a spatula, the time of use of the spatula sealing compound is not more than 2 hours from the moment of preparation.

At restoration of sealing compound in joints of tail compartments skin

the sealing roller must protrude forward from the edge of the tail compartments by 8-10 mm (to the nose) and cover the skin of the compartments by 2-3 mm. The roller thickness shall be within 0.8-I mm;

- tear off the adhesive tape sequentially at each joint after application of sealant;

- hold the applied sealant for not less than 24 hours at temperature of 15-30 ° С and relative air humidity of 33-75%.

2.06.13 On removed blades check using IAD2 device

or by piercing the quality of the skin of the tail compartments to the honeycomb and spar, as well as check by piercing

quality of anti-icing glue. Note: When replacing blades on newly installed blades, perform work in the amount of 300 hours maintenance.

Operation content as per Job Instruction No.2.06.08:

remove rotor blades, refer to Job Instruction (33) for Process Instructions for Replacement of Units, remove 16;

make sure that there is no snow, ice, stump or dirt on the blades;

by IAD1 device (IAD2) or by puncturing with a hammer, check the condition of gluing of the tail compartment skin to the spar and cellular filler.

Make sure that:

- violations of the shell of the tail compartments with a spar. Check along the whole blade for width 33 mm. In case of violation of gluing of tail compartments skin with spar, further operation of blades is permitted without elimination of the following defects;

a) up to 18 cm2 from each edge of the compartment on both surfaces;

b) inside zone A with total area not exceeding 40 cm2 on each surface of the compartment. Do not combine the gluing violations specified in para "a" and "b";

- violations of the tail compartment with honeycomb filler. At

failure to glue the skin of the tail compartments with cellular filler with an area not exceeding 350 cm2 on each side of the compartment, and an area of ​ ​ 100 cm2 on the side of each rib (with the skin lagging from the rib shelves by a length of not more than 50 mm);

- further operation of blades without elimination of the above mentioned data defects is permitted.

Note: In case of failure of gluing of tail compartments skin with

cellular filler with area of more than 280 cm2 (on each side of the compartment) or violation of gluing of the skin facing the ends of the compartments with area of

more than 80 cm2 at the same time on more than three compartments on each blade it is necessary to check after each flight day the condition of adhesive connection in these places by piercing or instrument.

using a hammer to check if there are no swells and lags in the places of gluing of the heating patch of the anti-icing system to the spar;

Failure to close and break the glue between the electric heating patch package and the spar with a total area of ​ ​ 100 cm2 on each stack is allowed. At that, single gluing disturbances must be not more than 180 cm2 and a total area of 500 cm2 at a length of 1 m along the blade radius (but not more than 50 mm along the label perimeter)

install rotor blades, refer to Process Instructions for Replacement of Units, ext. 16.

After 600 hours of flight:

2.06.03 Check tightening torque of nut for attachment of pin of hydraulic damper shackle.

Operation content as per Job Instruction No.2.06.12:

unlock the nut of pin attachment bolt of hydraulic damper shackle

bending of bracket antennae.

loosen the nut of the earring pin attachment bolt on half turn and tighten it with torque of 60-80 Nm (6-8 kgf m).

lock the bolt nut with unused antennae of bracket B

if the nut does not match the slot or if there are no spare antennae on the bracket, remove the nut and screw that attach the hoses of the hydraulic damper and replace the bracket. Dispose the removed bracket.

Note: If 81910605A bracket is replaced with bracket

To make 8 1910605B fastening of hoses of a hydrodamper details a bolt 3500a412kd; nut 3373A4KD, washer 4Kd, OST 111532 - 74. Use the attachment parts of hydraulic dampener hoses at the following

possible replacement of brackets.

After 750 hours of flight:

2.06.10 Check tightening torque of attachment bolts of hydraulic dampers brackets of bushing.

Operation content as per Job Instruction No. 2.06.06:

Check torque of attachment bolts of hydraulic dampers brackets in the following sequence:

- unlock the crown nuts of bolts;

- check the torque of the bolts with a calibrated wrench, while holding the bolt head with a wrench without turning. Perform tightening check diagonally (cross-cross) similar to that given in para 12 of general part. Tightening torque must be 45 - 60 Nm (4.5 - 6.0 kgf m);

- lock the bolts after tightening check.

2.06.11 Check tightening torque of attachment bolts of blade turning levers.

Operation content as per Job Instruction No.2.06.05:

Check tightening of attachment bolts of blade turning levers, for

then unlock the bolt heads; check torque of bolts using calibrated wrench. Check tightening diagonally (cross-cross) similar to that given in para 12 of general part. Tightening torque must be 100 - 110 Nm (10 - 11 kgf m); lock the bolts with wire.

2.06.15 Check tightening torque of nuts of pins that attach the vibration damper hub to the bracket.

Operation content as per Job Instruction No.2.06.14

2.06.16 Inspect the hoses of vibration damper hub. Make sure that there are no cracks on them.

Operation content as per Job Instruction No.2.06.15

2.06.17 Check tightening torque of the nut for attachment of the rotor bushing on the shaft of the main reduction gear box.

Operation content as per Job Instruction No. 2.06.09:

ATTENTION: Operations on disconnection (docking) of plug connectors, disconnection (connection) of wire bundles, inspection of electrical equipment components condition are performed by an aircraft equipment specialist, guided by the materials specified in the procedure for scheduled maintenance of electrical equipment, Section 1. Perform tightening check of attachment nut of the rotor bushing in the following order.

unlock and remove the screws that attach the current collector protective casing and remove the casing;

move the SR rubber caps onto the wires going from the current collector to the blades;

unlock and remove the connectors SR nuts and disconnect the bundles of wires going from current collector to blades;

slide rubber caps from wire tips

current collector;

unlock and remove nuts that attach wire tips to current collector contact bolts and remove tips from current collector terminals;

unlock and remove the nuts that attach the current collector housing to the compensating tank and carefully remove the current collector, bringing it out of the splined connection of the Work, specified in para 5 - 6 is performed by the specialist on AiREO;

clean from dust and dirt of connectors and tips of flexible hoses of oil supply to hydraulic dampers with napkin wetted with kerosene and squeezed out;

unlock and remove swivel nut of flexible attachment

hose to hydraulic damper connector and disconnect the hose, drain oil from

compensating tank, before that install the pan under the hydraulic damper connector. Plug the flexible hose and connector of hydraulic damper with threaded blankings of the same process sequence

disconnect flexible hoses of other connectors of hydraulic dampers;

unlock and remove screws of compensating tank attachment and remove the tank.

unlock and remove the screws that attach the locking plates, remove the plates and knock out the locking pins of the nut that attach the rotor bushing on the shaft of the main reduction gear box.

check tightening of the nut for attachment of the rotor bushing with a calibrated wrench, as specified in para 12 of the common part. Tightening torque must be 2400 - 2800 Nm (240 - 280 kgf m) When tightening the nut, observe safety rules.

install pins, locking plates and screws that attach the plates on the shaft of the main reduction gear box, tighten the screws and lock them with wire.

install the compensation tank on the main rotor bushing, align the hole in the tank flange with the hole on the main rotor bushing and tighten the tank attachment bolts. Lock the bolts with wire.

fill the compensating tank with oil in the following order:

- open the cover of the filling hole;

- install the funnel in the filling hole and pour fresh AMG10 oil into the compensation tank. The level should not be higher than the hairline on the transparent cap of the tank;

- after filling of compensating tank remove the funnel and lock the cover of filling hole;

15) set the rotor blade with handle ≪ShAG - GAZ≫ to the position in which the hydraulic dampener to be connected to the compensation tank is arranged horizontally;

16) unlock and remove plugs on the hydraulic damper cylinder;

17) refill the hydraulic damper with oil with syringe through socket of connector, before that remove it. After filling, tighten and lock the connector. Refill until a full jet of pure oil appears without air bubbles from the holes;

18) tighten the plugs in holes, lock them with wire;

19) remove the threaded blanking from the hose end and drain the oil from it until there is a full jet without air bubbles, then connect the hose to the hydraulic damper connector. Lock swivel sleeve for hose attachment with wire. In the same process sequence, refill the exiled hydrodampers by performing the works specified in pi 15 - 19 separately for each hydrodamper;

20) refuel the compensating tank with oil, refer to para 14. During the first 10 hours of flight time after 2-3 hours of operating time, open and remove plugs of hydraulic dampers cylinder and make sure that there is no air in

in cylinders of hydraulic dampers, then tighten and lock plugs;

21) flap oil supply hoses from compensating tank to connectors of hydraulic dampers. For that install flanging clamps of hoses on studs, then tighten nuts and lock nuts;

22) install the current collector in place. Installation of current collector is performed by AiREO technician.

2.06.19 Inspect parts of bifilar suspension of vibration dampers pendulum. Note: After operating time with vibration damper 4500 h

works as per no.2.06.15; 2.06.16; 2.06.19 perform flight time after 300 hours.

Operation content as per Job Instruction No. 2.06.19.

Special maintenance

Maintenance performed after flight in turbulent atmosphere, sharp turns, helicopter lightning damage, flight in icing zone, rough landing, at increased level of vibration, after resonance events, getting into storm conditions on ground.

When ground rotor blades or other obstacles are touched:

Item RO 5.01.06 Quality check of blade skin gluing

carrying and steering screws by means of textolite hammer.

Maintenance after replacement of the rotor bushing:

Item RO 5.02.22 - 5.02.25

replace oil in axial joints of the bearing and steering screws bushing. Replace oil with new or out-of-service bushing;

check tightening torque of attachment nuts of LV bushing on the shaft of the main reduction gear box. Perform check also after repair of faults related to removal of bushing;

check tightening torque of attachment bolts of LV blades turning levers. Perform operations on new or out-of-service bushing

HV;

check tightening torque of attachment bolts of hydraulic dampers of LV bushing. Perform operations on new or out-of-service HV bushing.

Conclusion

Effective maintenance and high-quality maintenance, of course, always depends on the level of theoretical knowledge, preparedness, practical skills and technician skills. This project discusses the maintenance process.