Aircraft Engine Parts And Accessories Spare Parts

About Aero Technologies BC Inc.

2010-02-17T05:41:00.006+02:00

About Aero Technologies BC Inc.

Aero Technologies BC Inc is located in Langley, British Columbia, Canada.
Our purpose is to supply an ever growing market with Overhaul and Repair
solutions related to our customers' needs. With great care we strive to
establish professional valued relationships with our customers and
suppliers. We believe in continuous improvement, proactive thinking and a
positive outlook.

The combined management experience at Aero Technologies BC
Inc spans over 45 years in the Aerospace Industry.

Aero Technologies BC, Providing Repair and Overhaul Solutions!

The ATBC Philosophy

2010-02-17T05:37:00.001+02:00

The ATBC Philosophy

The company's philosophy is to get closer to its clients and partners in order to better understand their needs and provide the best possible solutions. It has long been the aim of Aero Technologies BC to stand out by a personalised approach, "stepping into the shoes" of the customer to obtain a clearer picture of their requirements.

Thanks to the diversity of services it provides, Aero Technologies BC will meet your expectations. Import, export, inspection, repair, or overhaul formalities: Aero Technollogies BC is here to help you achieve your goals and solutions!

Aero Technologies BC, Providing Repair and Overhaul Solutions!

services

2010-02-17T05:33:00.008+02:00

ATBC Services

Aero Technologies BC facilitates Overhaul and Repair solutions for Gas Turbine Engines and Accessories. We also facilitate reworks for engine components such as, Air and Oil Seals, Nozzles, and also Blade reworks and Coatings.

Aero Technologies BC, Providing Repair and Overhaul Solutions!

contact us

2010-02-17T05:27:00.002+02:00

Contact ATBC

Aero Technologies BC welcomes your questions, comments and suggestions. You can contact us by e-mail, and we will address your concerns/comments as quickly as possible.

E mail : aerotechnologiesbc@gmail.com

Address: PO BOX 32008 Langley BC V1M 2M3 Canada.

two fuel systems for starting the ATAR 09 C turbojet engine

2009-06-30T23:23:00.005+03:00

There are two fuel systems for starting the ATAR 09 C turbojet engine which are both independent:

- the self-contained kerosene starter fuel system,
- the engine fuel system.
A. Self contained kerosene starter fuel system
When the engine is started the fuel used by the self-contained kerosene starter is take from the inlet connection fixed on the fuel pump. It is then a pressure between 1 and 2.5 bar.
The fuel passes through a pipe to the electric pump unit from where it flows at a pressure of 4.5 bar.

Up on operation of the three way solenoid valve the fuel flows through it to the fuel control unit.
The fuel is metered according to the "P2 starting pressure".

When the engine is operating, the centrifugal starting speed detector interrupts the electrical supply to the self-contained kerosene starter. The electric pump unit and three way solenoid valve are no longer supplied with current. The valve allows fuel in the fuel control unit to flow to the drain connection.
Note that a pipe is connected between the starter and the purge valve. The valve is designed to allow the unburned fuel to leave the gas generator combustion chamber as soon as the starter stops. During operation the pressure in the combustion chamber retains the valve on its seat thus preventing any gas from escaping.
B. Engine starting fuel system
Under impulse from the self-contained kerosene starter, the engine begins to rotate. The fuel pump secured to the accessory support supplies the main fuel control unit.

The starting block pressure reducer valve supplies the starting injectors at a constant pressure of 2.6 bar. This supply is continued as long as the starter solenoid valve is energized. Fuel sprayedinside the ignition antechamber, is, alighted by the igniter plugs, thus the combustion of the fuel sprayed by the two-flow injectors begins.

Note that, to flow to the starter injectors, the fuel must pass through the double check-valve.
This prevents the combustion gases from escaping into the starter fuel system during dry engine operation. Note also that the fuel remaining in the starter injectors after thy have operated is drawn in through a drain piping. The piping is fitted on the junction section.

The 80 bar starting by-pass solenoid valve limits the fuel flow admitted to the two-flow injectors.
The flow increases as rapidly permitted by the double-stop control device of the main fuel control unit.
The engine continues to accelerate and when the speed reaches 1900 rpm, the centrifugal starting speed detector cuts-off the supply to the starter solenoid valve(6 bar) and the starting by-pass solenoid valve (80 bar).
Dry engine operation then begins.

The compressor

2009-06-13T22:24:00.006+03:00

The compressor is an axial flow type comprises:

* A rotor comprising a series of discs fitted with blades

* A stator comprising two half-shells fitted with rows of vanes which fit between the blades on each rotor disc.

Note

A row of vanes or blades constitutes a cascade.

The grouping of a cascade of blades with a cascade of vanes constitutes a complete compressor stage.

The compressor of the ATAR 09 C engine comprises 9 stages whom the compression ratios varying from 1.2 to 1.3. The total compression ratio is about 5.5.

Since the volume of the air mass diminishes during compression, the section of the airflow will decrease progressively despite a simultaneous reduction of the axial speed.

The increase of the total energy of air is caused by the rotational of the blades which are driven by the turbine wheel.

Each blade assembly imparts a certain speed to the air flow which is transformed into pressure party in blade assembly and party in the vane assembly.

The operation of the compressor can be described thus; each blade or vane can be compared to a wing and follows aero-dynamic laws. Allowing for the effect of the neighboring blades or vanes (cascade effect)

The phenomenon of loss of lift or "stalling" encountered on an aircraft wing occurs in the compressor in the form of malfunctioning (in particular "compressors stall") if abnormal operating conditions are accidentally imposed on the engine.

Axial thrusts act to compressor and turbine. Their intensity varies following operation requirements but:

A part is compensated by pressures (controlled by the clearance in the labyrinth seals) on the front and rear flanges of the compressor.

The other part is beared by the front bearing compressor constituted by a ball bearing with three contact points and deep groove.

Central casing

Attached to rear of compressor it works like diffuser decreasing substantially the flow speed of P2 air. Speed decreasing, static pressures increases before to supply burners. The latter located in the primary flow, are secured to the rear part of the central casing.

Burners are made in such way to create turbulences to stabilize the flame. They allows a correct mixing of air and fuel sprayed by two-flow injectors.

The combustion chamber

The combustion chamber is of the annular type.

Part of the air flowing from the compressor ensures the complete combustion of the fuel, which is injected and sprayed by the injectors: it is the primary air.

Combustion which is behind burners, requires an "air/fuel" ratio closely to these of stoichiometric value, consequently primary air is heated to a temperature between 1500°Cmass and 1800 °C.

Gases at this high temperature must no enter the turbine. So, the reminder of the air or secondary air, first cools the chamber and then through the dilution apertures, mix with and cool the burned gases.

Some of these secondary approximately 2.5 to 3 percent of the total flow cools the bearings N° 2 and 3, the turbine 1 st-stage guide vane assembly and turbine discs.

For complete combustion the "air/fuel" mass ratio should be 15/1. The practical ratio is 60/1. The excess air, mixed with gases can be used in the afterburner after a second injection of fuel down-stream from the turbine. An "afterburner ignition" injector in the combustion chamber gives aflame which passes through the turbine and ignites the fuel distributed by the afterburner injection manifolds.

Detailed operation of the engine

2009-06-13T15:27:00.009+03:00

The air intake duct (on the airframe)

The air intake duct is before the turbojet engine and pipes air required to thermodynamics operation of the later. It must ensure an axial flow supply giving highly efficient operation with the minimum loss and disturbance.

Above a given air speed, dynamic compression takes place in the air intake duct ( increasing as the speed increases ). This duct is adapted to a predetermined range of air speeds outside which a greater loss results; in particular during ground running the losses are considerable and thrust of the engine on aircraft is often less than that obtained on the test bench this is due to efficient difference between the two duct.

The air intake duct is a part of the airframe. At higher flight speed the duct has a great effect on the operation of the engine and plays an important part in obtaining performance.

The intake casing

The intake casing which is located between the duct and compressor, determines the cross sectional area of the compressor intake. The ring of vanes upstream from the first group of blades is secured to the casing.

This part is positioned at the front end of the engine and a hot air supply is required to prevent icing.

Self-contained kerosene starter and dry engine starting systems

2009-06-04T00:54:00.003+03:00

Summary of the fuel system accessories
Self-contained kerosene starter
Allows engine starting and drives it during clearing operations
Electric pump unit
Supplies fuel to the self-contained kerosene starter>
Fuel control unit
Controls the fuel flow for the self-contained kerosene starter
Starting speed detector
Stops the self-contained kerosene starter when the engine reaches 1800
Starting block comprising:
- pressure reducer valve
Limits the pressure of the fuel supply to the starter injectors to 2.6 bar
- Master control valve
Shuts off the fuel supply to the two flow injectors when throttle control is turned to "stop"
- Starting solenoid valve (6 bar)
Allows fuel to flow to the starter injectors when starting or re-lighting in flight.
- Starting by-pass solenoid valve (80 bar)
Limit the pressure of fuel supplying the two-flow injectors while starting on the ground.
- Double check valve
To prevent combustion gases flowing back to the starter system (through the starting injectors)
- Starting injectors
To spray the fuel in the ignition antechambers while starting on the ground or relighting in flight.

Afterburner ignition system

2009-05-29T22:28:00.005+03:00

Afterburner ignition system

Summary of the fuel system accessories

Afterburner ignition solenoid valve

To control the fuel supply to the afterburner ignition injector.

Afterburner ignition check valve

To prevent the gases from the combustion chamber flowing back to the afterburner.

Afterburner ignition injector

To inject the afterburner ignition fuel upstream from the turbine 1 st-stage nozzle guide vane assembly to produce a flame which reaches the burner rings.

Ionization probe

To detect the afterburner ignition and send an electric signal to the flame detector amplifier.

Electronic amplifier for flame detection

To amplify the signal transmitted by the ionization probe and thus control the afterburner ignition system.

Afterburner ignition pressure switch

To supply the afterburner ignition warning light on the aircraft panel.

Dry engine fuel system and fuel control

2009-05-29T20:45:00.006+03:00

Summary of the fuel system accessories

Fuel pump

Supplies fuel to the main fuel control unit.

Which is then distributed to the two-flow injectors.

Main fuel control unit

For each position of the throttle lever, it gives a corresponding engine rotational speed and maintains upstream turbine gas temperature constant for maximal speed.

Pressurizing and dump valve

Pressurizing : divides the fuel into two

Streams : pilot and main flows.

Dump valve : when the engine stops this allows the fuel in the manifolds to flow to the drain.

Tow – flow injectors

Spray the fuel flowing to the combustion chamber from the main fuel control unit

Two of them Spray the fuel, metered by the main fuel control unit, in the combustion chamber and allows measurement of the Pib pressure.

P2 air – filter ( twin body )

Prevents from clogging of the accessories operated by the P2 air pressure.

Flyweight stop corrector with altitude compensation

Allows the engine rotational speed to control the operation of the main fuel control unit double stop to protect engine security against stall.

Pressure reducer

Adjusts the "P2 red" pressure to the nozzle control of the main F.C.U.

Relief solenoid valve.

Provides a bleed for the"P2 red" system which is acting on the temperature control when the engine is running on "Emergency fuel control" system.

Fuel dipper (weapons) solenoid valve

Reduce the fuel flow supplying to the pressurizing and dump valve when guns or missiles are fired.

Flyweight speed detector for the fuel control system

Controls the fuel dipper time-delay switch according to the rotational speed of the engine.

Time-delay switch

Controls the energizing of the fuel dipper solenoid valve according to the signals sent out by:

The switch for the firing control.

The flyweight speed detector for the fuel control system.

Approach control unit solenoid valve

Allows the "P2 red app" air to the flow to the nozzle control bellows.

Air coolers

Reduce the temperature of the P2 air for the cooling of bearing No 2 and No 3 .

fuel system

2009-05-28T21:50:00.007+03:00

fuel system

Most modern aircraft are equipped with 2 or more fuel tanks (or cells). In high wing aircraft, the cells are housed in the wings. Since they are higher than the engine, the fuel flows down to the engine by the force of gravity.

On low wing aircraft fuel pumps are required. To initially get fuel to the engine for starting, an electrical “boost pump” is turned on to pump fuel to the engine. After the engine is started, a mechanical fuel pump driven by the engine feeds fuel to the engine. The electric boost pump can now be turned off.

Each fuel tank is equipped with a drain valve located at the lowest point in the tank. This drain allows the pilot during preflight walk-around to check for and drain off any water which may have accumulated in the fuel tank. There is usually another drain located at the lowest part of the fuel piping system. This valve must also be drained during pre-flight to eliminate any water which may have accumulated in the fuel lines. Associated with this drain is a fuel strainer which filters out foreign matter which may be in the fuel system.

A vent line allows air to enter the tank as fuel is used. During hot weather, fuel may expand and overflow through the vent when tanks are full.

A fuel selector valve located inside the cockpit allows the pilot to select which tank(s) are to be in use during flight. Most small aircraft operate with the selector set on Both, such that both the left and right fuel tanks are simultaneous feeding fuel to the engine. The pilot may set the selector on Left or Right tank as a means of equalizing the loading of the aircraft. Usually, the selector should be set to both for take-off and landing. Pilots of low wing aircraft should exercise caution in their fuel management if tank selection is other than both. Running a tank dry can cause the engine to quit and vapour lock to occur in the fuel lines. It may be impossible to restart the engine under these conditions.

There is a fuel gauge in the cockpit for each fuel tank. The lower 1/4 of the fuel gauge indication is marked with a red line as a caution to the pilot of a low fuel condition. The pilot should never rely on the fuel gauge as the sole measure of fuel remaining. The gauges on aircraft are subject to a variety of indicator errors. The pilot should therefore double check the fuel remaining based on the power setting of the engine in flight and time in flight.

Inside the cockpit a fuel mixture control and a fuel primer pump are located on the instrument panel. The mixture control is used to adjust the air/fuel mixture for the altitude being flown. It allows the pilot to adjust the fuel/air ratio entering the engine. As altitude is gained, the intake air becomes less dense. Less fuel must be fed through the carburettor to permit the fuel/air mixture to remain correct proportion. If leaning is not accomplished by the pilot, a rich mixture (too much fuel) results. This is not only wasteful of fuel, but can result in fouled spark plugs due to carbon and soot buildup on the spark plugs. A rough running engine results. An additional gauge called an Exhaust Gas Temperature Gauge can be installed in the aircraft as an aid in achieving the proper “leaning” of the engine.

The fuel primer is a plunger that can be used in cold weather to inject fuel directly into the carburettor as an assist in starting the engine in cold conditions.

Three different grades of fuel are used in reciprocating engine aircraft. These grades are designated by octane rating and are colour coded so the pilot can insure the proper grade of fuel is being pumped into the tanks.

These grades are:

OCTANE RATING..........FUEL COLOUR

..... 80/87........ ..... ..... .........Red

.......100LL (low lead). ..... .......Blue

...... 100/130.... ..... ...............Green

When refuelling, if the appropriate grade of fuel is not available, USE THE NEXT HIGHER GRADE. Using a lower grade can cause overheating and damage to the engine. Sparks during refuelling can be an extreme fire hazard. The following precautions should be taken when refuelling is in progress.

1. Attach a ground wire between the fuel pump or truck to a metal part of the aircraft. This will neutralize any static charge which may exist between the pump and the aircraft.

2. The fuel nozzle should be grounded to the side of the fuel filler hole during refuelling.

3. The fuel truck should be grounded to both the aircraft and the ground.

Do not use automotive fuel unless the engine has been specially modified for automotive fuel use.

Thermodynamic operation and air systems

2009-05-26T20:04:00.007+03:00

Engine operation
The turbojet engine belongs to the heat-engine group. Its energy source is fuel which ,mixed with a combustive (air oxygen) and by means of combustion gives under thermal form the energy which is contained in it under chemical form.
In piston engines ,thermal energy given to certain air amount is taken on mechanical form to a shaft. In a turbojet engine, this energy serves to increase the speed of the air passing through it .
The air leaves the engine at a grater velocity than that at the intake and develops a thrust which moves the aircraft forward.
So that the engine may operate efficiently, combustion must take place under a given compression ratio. Compression is provided by a compressor which can operate under varying relative engine conditions (different altitudes and airspeed) and is driven by a turbine absorbing the necessary energy from the gases leaving the combustion chamber.
The remaining energy is transformed into kinetic energy in the nozzle.
Operationally the propulsion unit of a turbojet engine comprises:
- an air intake duct
an turbojet engine.-
technically the components of the engine are :
1) intake casing
2) compressor
3) central casing
4)combustion chamber
5) turbine
6) afterburner jet pipe
7) nozzle
the first six components constitute a compressed-air generator.
The nozzle accelerates the flow of compressed and heated gases at the velocity of which determines the thrust of the turbojet engine.

A Turbojet Engine technology

2009-05-24T16:21:00.007+03:00

How Does A Turbojet Engine Work?

A turbojet engine is a type of internal combustion engine often used to propel aircraft. Air is drawn into the rotating compressor via the intake and is compressed to a higher pressure before entering the combustion chamber. Fuel is mixed with the compressed air and ignited by a small flame in the eddy of a flame holder.

This combustion technique significantly raises the temperature of the gas. Hot combustion chemicals leaving the combustion expand through the turbine, where power is drawn to employ the compressor. Although this expansion process reduces both the gas temperature and pressure at exit from the turbine, both variables are for the most part still well above ambient conditions. The gas stream exiting the turbine expands to ambient pressure through the propelling nozzle, causing a high velocity jet in the exhaust plume. So if the jet velocity surpasses the aircraft flight speed it amazingly creates a forward thrust

Under normal circumstances, the pumping action of the compressor prevents any back flow, this kindly helps the flow of the jet engine. You can compare the whole method with a four stroke cycle, but with induction, compression, ignition, expansion and exhaust taking place simultaneously. The efficiency of a jet engine is strongly dependent upon the pressure ratio (Combustion Entry Pressure/Intake Delivery Pressure) and the Turbine Inlet Temperature of the cycle.

It is also perhaps instructive to compare turbojet engines with propeller engines. Turbojet engines take a rather small mass of air and accelerate it by a large amount, whereas a propeller takes a large mass of air and accelerates it by a small amount.

At great speed the exhaust of a jet engine makes it efficient at high speeds (particularly supersonic speeds) and high altitudes.

On planes that go slower and fly a shorter range, a gas turbine-powered propeller engine, commonly known as a turboprop, is far more common and also more efficient. Especially small aircraft primarily use conventional piston engines to drive a propeller but small turboprops are getting smaller as technology improves each day.

The turbojet mentioned above is a single spool design, where a single shaft connects the compressor to the turbine Higher Overall Pressure Ratio designs often have two concentric shafts, this is to in essence improve the stability of the compressor during engine throttle movements.

Basically it''s the outer shaft that connects the turbine engine to the high pressure compressor. The combustion together with the high pressure compressor spool forms the core or gas generator of the engine. We must not forget that the inner shaft connects the low pressure compressor to the LP Turbine to create the LP Spool. Either spools are free to operate at their optimum shaft speed.

Aircraft Engine Parts Considerations

2009-05-17T14:52:00.006+03:00

Aircraft Engine Parts Considerations
The process of developing an engine is one of compromises. Engineers design specific attributes into engines to achieve specific goals. Aircraft are one of the most demanding applications for an engine, presenting multiple design requirements, many of which conflict with each other. An aircraft engine must be:

* reliable, as losing power in an airplane is a substantially greater problem than an automobile engine seizing. Aircraft engines operate at temperature, pressure, and speed extremes, and therefore need to operate reliably and safely under all these conditions.
* lightweight, as a heavy engine increases the empty weight of the aircraft & reduces its payload.
* powerful, to overcome the weight and drag of the aircraft.
* small and easily streamlined; large engines with substantial surface area, when installed, create too much drag, wasting fuel and reducing power output.
* repairable, to keep the cost of replacement down. Minor repairs should be relatively inexpensive.
* fuel efficient to give the aircraft the range the design requires.
* capable of operating at sufficient altitude for the aircraft.