VISCOSITY :

THE RESISTANCE OF THE OIL TO FLOW SO , OIL FLOWING SLOWLY IS VISCOUSIT IS THE MEASURE OF POURABILITY

FLASH POINT OF OIL : THE TEMP AT WHICH THE OIL WILL BEGIN TO GIVE OFF IGNITABLE VAPORS ( FLASH)

FIRE POINT OF OIL : THE TEMP AT WHICH THERE IS SUFFICIENT VAPORS TO SUPPORT FLAME ( FIRE)

CLOUD POINT OF OIL : THE TEMP AT WHICH ITS WAX CONTENT BEGINS TO SOLIDIFY AND SEPARTE INTO TINY CRYSTALS , CAUSING OIL TO BE CLOUDY OR HAZZY.POUR POINT OF OIL : THE LOWEST TEMP AT WHICH IT STILL CAN BE POURED OR FLOWED

OIL SYSTEM

INTRODUCTION

- LUBRICANT TENDS TO ADHERE TO BOTHE METALS IN CONTACT AND TENDS TO PREVENT THE ACTUAL KETALLIC CONTACT.THE VISCOSITY TENDS TO KEEP THE LUBRICANT FROM BENG SQUEEZED OUT BY THE PRESSURE ON THE BEARING SURFACES.

- THE MOVEMENT OF SURFACES CAUSE SHAERING ACTION ON THE OIL FILM .

- THE INTERNAL FRICTION OF THE OIL FILM ( FLUID FRICTION ) REPLACES THE METALLIC FRICTION.

MOVING SURFACE

FIXED SURFCAE

OIL SYSTEM FUNCTIONS

1- LIBRICATING ( REDUCING FRICTION )

OIL FILM

- EVEN SURFACES THAT LOOK SMOOTH , THEY HAVE MICROSCOPICALY ROUGH SURFACES WHCH LOCK OTHER SURFACES TO CAUSE FRICTION AND WEAR

-- ANY SURFACE IS NOT SMOOTH BUT IT CONTAINS PEAKS AND

VALLEYS.- THE OIL FILLS IN THE VALLEYS , WETS THE SURFACES AND PREVENT MEAL – TO - METAL CONTACT .

- THE MOVEMENT IS NOW BETWEEN THE LAYERS OF THE OIL AND THE OIL SLIDES OVER ITSELF WITH VERY LITTLE FRICTION. ( SHEAR RESISTANCE FORMED BETWEEN THE LAYERS )

- THE VISCOSITY OF AN OIL IS A MEASURE OF THE OIL FRICTION ( HIGH VISCOSITY------ HIGH OIL FRICTION HIGH LOAD CARRYING HIGH REDUCTION OF FRICTION BETWEEN THE TWO SURFCAES )

- THE CLEARENCE BETWEEN MOVING PARTS DETERMINE THE VISCOSITY NEEDED TO PREVENT OIL BRAKING AWAY

2- COOLING :

WHERE FRICTION HEAT is MINIMIZED

3- FUEL HEATING ( TO MELT ANY ICE FORMATION AND RAISE THE TEMP OF FUEL WHERE AT HI ALT. ICE MAY BE FORMED)

4- CLEANING ( THE CONTAMINATION WILL STICK WITH THE OIL WHILE FLOWING AND TRAPPED IN THE RETURN FILTER

OIL SERVICING

AFTER S.D BY 5 MIN OR BEFORE 2 HRS

One) SERVICING < 5 MIN

BREATHER AIR IS STILL INSIDE THE TANK AND NOT VENTED YET. DANGER TO PERSONNEL

Two) SERVICING > 2 HRS

SINCE THE TANK IS LOCATED IN HIGHER LEVEL THAN THE USERS SO THE OIL MAY FLOW BY GRAVITY INSIDE THE TUBES.DRY MOTORING SHOULD BE DONE 1ST TO PREVENT OVERSERVICING , OVERTEMP , CARBON SEAL PROBLEMS

CHIP DETECTOR TEST

A) IT CAN CARRY A STEEL BALL OF DIAMETER 3 / 4 “

ORThree) IT CAN HANG ON A FLAT METAL SURFACE BY ITSELF

OILS

A) CATEGORY I : MINERAL (PETROLIUM OIL)

USED IN PISTON ENGINES

AT HIGHT TEMP . , SPEEDS, THESES MINERAL OIL ARE OXIDIZED AND PRODUCE MANY PRODUCTS ( CARBON AND GUM ) THAT BLOCK THE FILTERS AND OIL PASSAGES AND LUBRICATIING C/C ARE DETERIORATED.

B) CATEGORY II: SYNTHITIC ( MIXTURE OF SOME OILS)

SYNTHITIC = MAN MADE

IT IS A BLEND OF CERTAIN DIESTERS WHICH MADE FROM SYNTHIZED FROM MINERAL , ANIMAL , VEGETABLE OILS.USED IN TURBOJET

NOT MANFCTURED FROM THE PETROLIUM OIL

COMMERCIAL BRANDS :

1- MOBIL JET II2- SHELL V3- ESSO TURBO OIL 2380 ( WAS USED IN EGYPTAIR)4- EXXON TURBO OIL 2380 ( NOW USED IN EGYPTAIR)

CAUTION : OILS MIXINGOne) MIXING OF DIFFERENT OILS MAY CAUSE GELATIN AND

CAUSES ENGINE S.D Two) TO USE NEW OIL , FLUSHING IS NECESSARY 1ST

Three) WHEN THERE IS TWO COMPATIBLE OILS : FLUSHING IS NOT NEEDED

SPECIFICATION STANDARDS:

MIL-L-7808 : Ex. : AN AKLYL DIESTER OIL ( KNOWN AS TYPE I ) MIL-L-23699 : Ex. : POLYESTER LUBRICANT ( KNOWN AS TYPE II )

VISCOSITY

COEFFICIENT OF ABSOLUTE VISCOSITY : POISETHE VISCOSITY OF TURBINE OIL NORMALLY < 1 POISE SO THE CENTIPOISE ( 1 Cp = 0.01 p ) is used.

HANDLING WITH SYNETHTIC OILS

1- WARNING :

- IT HAS HIGH SOLVANT C/C : IT MAY PENETRATE AND DISSOLVE PAINTS AND PHYSICAL INJURIES MAY OCCUR IF IT TOUCES THE SKIN.

- SYNTHITIC OIL CONTAIN ADDITIVES WHICH ARE ABSORBED BY THE SKIN AND BE TOXIC

2- IF IT TOUCHES THE SKIN : IT SHOULD BE CLEANED BY WIPING UP AND WASHING WITH SUTIABLE CLEANING AGENT.

.

OIL CHARACTERISTICS

BEARING PRESSURE INCREASE OR OIL TEMP INCRESES WILL LEAD TO DECREASING THE VISOSITY- THE DESIRED CHARACTERISTICS OF SYNTHTIC OILS:1- LOW VLATILITY : TO PREVENT EVAPORIZATION AT HIGH ALTITUDE.2- ANTI-FOAMING QUALITY : FOR MORE +VE LUBRICATION3- HIGH FLASH POINT4- LOW POUR POINT ( TO ENSURE MAXIMUM FLUIDITY AT LOW TEMP.

TO BE FRAEDY TO FOLW DURING LOW TEMP STARTING ) 5- PROPPER VISCOSITY AT THE OPERATING TEMPERATURES AND

MUST RESIST THE PRESSURE BETWEEN THE MOVING SURFACES AND CAN DISTRBUTE EASILY TO THE REQUIRED PARTS

6- HIGH ANTI-FRICTION CHARACTERISTICS : TO PREVENT THE METALLIC FRICTION AND OIL FRICTION ( OIL DRAG)

7- MIN. CHANGE OF VISCOSITY WITH TEMP CHANGE : AT HIGH TEMP , THE OIL FILM BECOMES LOW AND MAY ALLOW METALLIC CONTACT

8- MAX COOLING ABILITY : TO ABSORM AS MUCH HEAT AS POSSIBLE AND DISSIPATE THROUGH OIL COOLERS.

9- MAX RESISTANCE TO OXIDATION : TO PREVENT HARMFUL DEPOSITES ON THE METAL PARTS. WHERE AT HIGHT TEMP THE OIL MAY OXIDE AND PRODUCES SLUDGE , CARBON RESIDUE, ASPHALTINES, INORGANICE ACIDS.

10- NON-CORROSIVE TO MEATLS

OIL DISADVANTAGES

IT REMOVES PAINT IF SPILLED ON IT, SO PAINTED SUTFACES SHOULD BE WIPED WELL WITH PETROLIUM SOLVENT AFTER SPILLAGE

FAA REQUIREMENTS1- “OIL” WORD MUST BE STENCILED IN THE AREA OF FILLER OPENING2- A MEANS TO PREVENT INADVERTANT FILLING OF EXPANSION

SPACE3- EXPANSION SPACE MUST BE PROVIDED WITH 10 %4- OIL TANK SCUPPER DRAIN

5- OIL FILTER MUST ALLOW ALL THE OILTO FLOW WITHIN IT

OIL PRESSURE SYSTEM

FUNCTION :

TO PROVIDE OIL WITH SUFFICIENT ( PRESSURE & QUANTITY ) TO BEARINGS , GEARS , DRIVE SHAFTS

MAIN COMPONENTS :

1- TANK ( RESVOIR)2- PRESSURE PUMP ( BOOSTER PUPMS & +VE DISP. PUMP)3- PRESSURE FILTER4- OIL COOLER ( IF HOT TANK SYS )5- SENSORS ( QUANTITY TRANSMITTER, PRESSURE TRANSMITTER,

TEMP. TRANSMITTER , DIFF. PRESS. S/W)6- PRESSURE REGULATING RELIEF VALVE

NOTE : S/W ------------------------- LIGHT OR BULB TRANSMITTER-------- INDICATOR OR COMPUTER

OIL TANK

TYPES

1- INTEGRAL ( WHERE G.B IS USED FOR STORAGE THE OIL AS IN APU )2- SEPARATE : LOCATED ON THE COLD SECION OF ENGINE)

FUNCTION

1- OIL SORAGE FOR ENGINE USE

LOCATION :

1- ON THE ENG ( ON COLD SECTION AS FAN CASE OR COMPRESSOR CASE OR ON G.B ). IT IS PLACED HIGH ENOUGH ABOVE THE OIL PUMP INLET TO ENSURE GRAVITY FEED.

MATERIAL :1- STAINLESS STEEL2- ALUMINUM ALLOY

DEAERATOR

FIRE RESISTANCE

1- HEAT SHIELD BLANKET ( PAPER SHEET)2- SILICON RUBBER ( A PAINT )

COMPONENTS :

1- SCUPPER DRAIN ( IN THE FILLER CAP TO TO CATCH OVERFLOW OIL DURING SERVICING AND DIRECT IT INTO A DRAIN LINE TO BE OVERBOARD )

2- FILLER CAP WITH “ OIL “ WORD3- OIL VENT LINE4- SUPPLY LINE5- DRAIN VALVE6- SIGHT GLASS

NOTE : OIL TANK DESIGNED TO HAVE EXPANSION SPACE OF ABOUT 10 % OF TANK CAPACITY

DEAERATOR

SCAVENGE OIL AIR

OIL (DRAINED IN THE TANK)

FUNCTION : TO SEPARATE THE AIR L FROM THE SCAVENGE OIL WHERE :

1) PREVENTING THE FOAMING INTO THE TANK 2) AIR IS USED IN PRESSURIZING THE OIL TANK

OIL SYSTEM CLASSIFICATION

1- HOT TANK SYSTEM ( OIL COOLER IN THE PRESSURE LINE)

2- COLD TANK SYSTEM ( OIL COOLER IN THE RETURN LINE)

PRESSURE PUMP

GEAR TYPE PUMP ( +VE DISP. PUMP) : GIVES UNLIMITED PRESURE , SO IT MAY CAUSE DAMGE TO LINES IF HI PRESSURE

SO GEAR TYPE PUMP HAS A PRV AT ITS OUTLET ( TO LIMIT THE OUTPUT PRESSURE)………..

- THE CAPACITY OF PRESSURE PUMP IS ALWAYS GREATER THAN THE NEED OF THE ENGINE AND EXCESS OIL IS RETURNED TO THE INLET OF OIL PUMP BY PRV. THIS MAKES IT POSSIBLE FOR THE PUMP TO INCREASE ITS OILDELIVERY TO THE ENGINE AS THE ENGINE WEARS AND CLEARENCES BECOME GREATER

- + VE DISPL. PUMP-CONSISTS OF DRIVER GEAR ( DRIVEN BY THE MGB ) AND IDLER GEAR ( DRIVEN BY THE DRIVER )- THEY ARE TWO MESHED CLOSE FITING GEARS INSIDE A CASE WHERE THE THERE IS MINIMUM SPACE BETWEEN THE GEAR AND THE CASE.

PRESSURE REGULATOR VALVE

IT HAS ITS ADJUSTABLE SCREW WHICH ADJUSTS THE SPRING

STIFFNESS TO DETERMINE THE VALUE AT WHICH THE VALVE OPENS

- SCREW TURN CLOCKWISE : PRESSURE INCREASE : 1 TURN : + PSI

- SCREW TURN ANTI-CLOCKWISE : PRESSURE INCREASE : 1 TURN : - PSI

MAIN OIL FILTER ( MOF)

CONTAMINATION SOURCES

1- ( BLACK OIL )PRODUCTS OF OIL DECOMPOSITION OF THE OIL ITSELF, USUALLY SEEN AS SMALL BLACK SPECKS OF CARBON

2-METALLIC PARTICLES : FROM ENGINE WEAR AND COROSION IN OIL WETTED AREAS

3- DIART AND FOREIGN MATTER ENTERED WITH OIL DURING SERVICING

CLASSIFICATION ACCORDING TO SIZE ??????????????????

1- 100 MESH ( RECTANGULAR HOLES WITH LENGTH OF ANY SIDE IS 1/100 “ )2- MICRON ( CIRCULAR HOLES) : 15 – 40 MICRON

CLASSIFICATION ACCORDING TO MATERIAL

1- METALLIC ( CLEANABLE SCREEN ) IT IS CALLED “STRAINER “2- PAPER ( DISPOSABLE)

ASSEMBLY

1- HEAD SECTION2- BOWL 3- FILTER ELEMENT

One- CLEANABLE : METAL TYPETwo- DISPOSABLE : PAPER TYPE

FILTER RATING :THE RATING OF THE FILTER MESH IS MEASURED IN MICRON ,i.e IT IS DESIGNED TO PREVENT THE PASAGE OF MICRONIC-SIZE PARTICLES

WHERE :

RED BLOOD CELL = 8 MICRONSWHITE BLOOD CELL = 25 MICRONS HUMAN HAIR = 50 MICRON

Ex . FILTER RATING IS 20 micron IT FILTERS OUT PARTICLES LARGER THAN 20 micron IN DIAMETER

NOTE: IF FILTER CLOGGED WHILE FLIGHT :

THE PILOT SHOULD DECREASE THE POWER OR S.D THE ENGINE TO PREVENT FLOWING DIRTY OIL TO THE BEARINGS WHICH MAY LEAD TO COMPLETE DISASSEMBLY OF ENGINE

NOTE : PRESSURE DROP ACROSS THE MAIN OIL FILTER (MOF )

AT OIL TEMP = 65 C :

CLEAN FILTER PRESS DROP = 6 psiCLOGGED FILTER PRESS DROP = 23 psi ( BY PASS VALVE IS BYPASSED )

NOTE : RATING OF FILTER

MOF SIZE IS NORMALLY = 46 MICRONS ( LARGE PARTICLES FILTER)

MOF BY-PASS VALVE :

TO ALLOW OIL TO FLOW WHEN THA MOF IS CLOGGED WHERE DIRTY OIL IN THE ENGINE IS BETTER THAN NO OIL AT ALL.

MAGNETIC CHIP DETECTORS :

LOCATED IN :

SCAVENGE LINES , MGB , OIL TANK.FN : IT INDICATES THE PRESENCE OF METAL CONTAMINATION WHERE IT PICKS UP FERROUS METAL PARTICLES.

OPERATION : IT HAS A PERMENANT MAGNET CENTER PLUG.

OIL JETS

IT DELIVERS ATOMIZED SPRAY OF OIL INTO HE BEARINGS.THEY ARE EASILY CLOGGED DUE THEIR SMALL ORIFICE IN THEIR TIPS. SO THEY ARE PROTECED BY FINE-MESH SCREENS CALLED “ LAST CHANCE FILTERS’.

IF LAST FILTERS ARE CLOGGED , BEARING FAILURE RESULTS SINCE OIL NOZZLES ARE NOT ACCESIBLE FOR CLEANING. TO PREVENT OIL JETS CLOGGING , MOF USUALLY INSPECTED

OIL SYSTEM CLASSIFICATION

1- FLOW REGULATING SYSTEM ( TRIM ORIFICE USED TO TRIM THE FLOW AND THUS TRIM THE PRESSURE…..EX.: PW4000 )

2- PRESURE REGULATING SYSTEM ( PRESSURE REGULATIING VALVE USED TO REGULATE THE PRESSURE GOING TO THE USERS)

IN BOTH CASES THE TARGET IS TO KEEP THE SUPPLY PRESSURE TO USERS CONSTANT EITHER BY CONTROLLING THE FLOW OR PRESSURE DIRECTLY)

FUEL OIL COOLER

- HEAT MAY CAUSE OIL DECOPMOSITION SO OIL TEMP IS CONTROLED AND MONITORED.

- INTERNAL LEAKAGE IS NOT ALLOWED TO PREVENT OIL MIXING WITH FUEL.

INDICATIONS OF FUEL IS MIXING WITH OIL :

One) FUEL SMELL INSIDE OIL TANKTwo) OIL QUANTITY IS INCREASED AFTER FLIGHT OR IS THE SAME ( NO

CONSUMPTION)

OPERATION :

- METERED FUEL : PASSES THROUGH THE TUBESHOT OIL : PASSES AROUNDTHE TUBES AND IS BAFFELED TO GIVE MAX EXCHANGE OF HEAT.

- IF COOLED IS BLOCKED : ITHAS BY-PASS VALVE

OIL COOLER

FUNCTION : TO COOL OIL BY METERED FUEL OR BY FAN AIR

One) FUEL/OIL COOLER

OPERATION :

THERE IS FUEL/OIL H.E TO COOL THE OIL.FUEL FLOWED INSIDE THE TUBES AND THE OIL AROUND THE TUBES .THE COOLER HAS INTERNAL PLATES ( BAFFLES) TO LET THE OIL TAKES LONG PATHS

- FAILURES:

1- CRACKING : FUEL I SFLOWED WITH OIL TO THE USERS AND IT MAY BURN. OIL CONSUMPTION MAY BE ZERO .

2- BLOCING DUE TO CONTAMINATION : IT MAY HAVE PRESSURE . S/W OR BY PASS VALVE FOR PROTECTION

Two) AIR/OIL COOLER

OPERATION :

THERE IS AIR / OIL H.E TO COOL THE OIL . FAN AIR IS THE COOLING AIR

OIL USERS

- BEARINGS- MGB- AGB

NOTE : OIL DAMPED BEARING ( SQUEEZE FILM BEARING)

THIS OIL FILM DAMPS THE RADIAL MOTION OF THE ROTATING ASSEMBLY AND THE DYNAMIC LOADS TRANSMITTED TO THE BEARING HOUSING, THUS REDUCING THE VIBRATION LEVEL OF THE ENGINE AND POSSIBILTY OF DAMAFE BY FATIGUE.SEAL RING S AROUND THE BEARING ‘s OUTER RACE HELP CONTAIN OIL IN CAVITY.

OIL BEARNGS AND SEALS:

1- OIL SEALS TYPE : CARBON OR LABYRNTH2- OIL SEALS TYPE : TO KEEP THE OIL IN THE BEARING CAVITY3- LABYRNTH SEAL ADGANTEAGE : WEAR ALMOST SO RARE4- PRESSURIZED CHAMBRE PRESURIZED BY THE AIR SUPLIED FROM

ENGINE COMPRESSOR. THAT AIR MAY GO INWARD TO THE SUMP ( THR OIL SEAL ) OR OUTWARD AS AIR LEAKING ( THR AIR SEALS)SO THE TOTAL AIR VOLUME SUPPLIED SHOULD BE ENOUGH FOR THESE TOW FLOWS ( INWARD AND OUTWARD )

5- THE BEARING CHAMBRE HAS VENT LINE AT THE TOP OF THE SUMPTO INSURE INWARD AIRFLOW TO THE SUMP BECAUSE IF AIR FLOWING INWARD SO OIL CAN NOT FLOW OUTWARD.

6- OVERBOARD OIL DRAIN : ON THE BOTTOM OF THE PRESSURIZED CHAMBRE TO EVACUATE ANY LEAKED OIL FROM OIL SEALS TO PREVENT THAT OIL PASS THR. AIR SEAL AND GET BACK TO THE COMPRESSOR, MIXED WITH PNEUMATIC SYS. AND MAY CAUSE OILSMELL IN THE AIRCONDITIONG SYS.

OIL SCAVENGE SYSTEM

FUNCTION :

TO COLLECT OL FROM SUMPS & G.B. AND RETURN OIL TO TANK

MAIN COMPONENTS :

1- SCAVENGE PUMPS2- OIL COOLER ( IF COLD TANK SYS )3- SCAVENGE FILTER

SCAVENGE PUMP

- THEY ARE PUMPS FOR A DRY-SUMP LUBRICATION SYSTEM.

TO RETURN THE OIL FROM THE SUMPS ( ENG BEARING CAVITIES ) TO THE TANK OR MGB SUMP.- SCAVENGE PUMP HAS HIGHER CAPACITY THAN THE PRESSURE

PUMP BECAUSE THE OIL INJECTED INTO THE SUM IS FOAMY ( DUE TO THE AIR THAT MIXES WITH THE OIL ) SO THE VOLUME OF OIL ICREASED SO TO KEEP THE SUMP DRAINED , THE SCAVENGE PUMP MUST HANDLE GREATER VOLUME OF OIL THAN THE PRESSUR EPUMP

- SCAVENGE PUMP NORMALLY DRIVEN BY HE SAME SHAFT OF PRESSURE PUMP BUT ITS TEETH DEPTH IS TWICE THAT OF PRESSURE PUMP.

FILTERS

1- MAGNETIC CHIP DETECTORS 2- MAIN SCAVENGE FILTER3- MASTER CHIP DETECTOR

NOTE 1: MAIN FILTER ( OIL MAIN FILTER AND MAIN SCAVENGE FILTER ) HAS : a) BY- PASS b) CLOG DELTA-P SWITCH

NOTE 2:

MAIN OIL FILTER IS LOCATED DOWNSTREAM OF PRESSURE PUMP

WHILE FUEL FILTER IS LOCATED BETWEEN LP & HP FUEL PUMPS

BREATHER SYSTEMFUNCTION :

2- TO PREVENT OIL LEAKAGE FROM THE BEARING CAVITY3- TO CONNECT (VENT ) THE BEARING CAVITIES , MGB AND THE OIL

TANK.4- TO ASSIST OIL TO RETURN TO TANK ( SINCE IT PROVIDE A

PRESSURE HEAD )

NOTE1 : FOR OLD ENGINES , ITS BREATHER PRESSURE IS HIGH SINCE THE CLEARENCE IS INCREASED

NOTE 2 : THE SEALS TEMP WILL INCREASE DURING OPERATION , SO OIL NOZZLES WILL COOL NOTE 3 : ANY PROBLEMS WITH OIL SYSTEM MAY LEAD TO ENGINE REMOVAL

NOTE 4: OIL VAPOURS INSIDETHE BREATHER ARE REMOVED INSIDE THE MGB THROUGH DEAERATOR ( CENTRIFUGAL SEPARATOR UNIT ).

WHERE :

- OIL-FREE BREATHER IS DISCHARGED OVERBOARD THR. VENT PIPE

- OIL IS DRAINED INTO THE TANK.

REMARKS:

1- THE PRESURE INSIDE THE CAVITY IS CONTROLLED BY THE BREATHER SYSTEM TO ENSURE PROPER OIL FLOW ( IF PRESSURE INSIDETHE CAVITY IS INCREASED SO OIL FLOW WILL BE INTERRPUTED)

2- AIR LEAKAGE TO THE CAVITY WILL INCREASE THE CAVITY PRESSURE

3- IF THE SUPPLIED OIL PRESSURE IS LOW : AIR LEAKAGE IS INCREASD INSIDE THE CAVITY AND CAVITY PRESSURE INCREASES SO THE OIL FLOW WILL DECREASE AND LUBRICATION IS REDUCED

4- IF THE SUPPLIED OIL PRESSURE IS HIGH :

THE OIL FLOW WILL INCCREASE AND OIL MAY LEAKE FROM OIL SEALS TO THE OUTER CHAMBER SO HIGH OIL CONSUMPTION RESULTS IN

5- AIR PRESSURE COMES FROM DIFFERENT STAGES OG THE COMPRESSOR AND ITS PRESSURE IS FUNCTION OF RPM

SOAP ( OIL ANALYSIS)

TO ANALYZE THE OIL CONDITION TO IDENTIFY SOME ENGINE PROBLEMS BEFORE MAJOR DAMAGE .MANY OIL ANALYSIS PROGRAMS AVAILABLE.

THE ANALYSIS TYPES :

1- TO DETERMINE THE WEAR METALS IN THE SAMPLE WEHRE WEAR METALS ARE VERY SMALL PARTICLES ( < 1 MICRON )

THE LABORATORY CAN DETERMINE IF THESE WEAR IS EXCCESIVE OR NOT AND FROM WHAT PART OF ENGINE. THESE WEAR METALS ARE MUCH SMALLER THAN THE FILTER HOLES SO IT REMAINS SUSPENDED IN THE OIL

2- TO IDENTIFY THE LARGER CONTAMINANTS WHICH ARE TRAPPED BY TH EFILTERS AND ANALYZED TOO. THE WEIGHT , SIZE , TYPE AND SHAPE CAN LEAD TO THE DAMAGED AREA.

GENERA L :

One) OIL ANALYSIS IS A PREVENTIVE MAINTENANCE AND CAN PREDICT WITH ANY IMPENDING FAILURE.

Two) THE LABORATORY WILL ISSUE “OIL SAMPLE ANALLYSIS REPORT “

FAILURES

1- “Eng. FILTER CLOG”

CREW ACTION : THROTTLES : IDLE ( POWER DECCRAESE)One) IF CLOG LIGHT : OFF ( ADVANCE TO POSITION BELOW WARNING LEVEL)

Two) b) IF CLOG LIGHT : STILL ON ( KEEP IDLE )

2- “EnG OIL LO PR”

CREW ACTION : ENGINE SHUTDOWN ( FUEL LEVER :OFF)

( OIL PRESSURE INCREASES WITH N2 AND THERE IS OIL PRESSURE ENVELOPE WHICH SHOWS THE Min & Max PRESSURE ALLOWED DURING OPERATION ) SYSTEM OIL PRESSURE MAY NEED TO BE TRIMMED

3- “Eng. OIL HI TEMP”

CASE ( 1) : HIGH OIL TEMP + LOSS OF OIL QUANTITY

CAUSES

AT HI THRUST

REDUCE THRUST TO REDUCE HEAT GENERATION

AT LOW THRUST

THRUST INCREASE MAY INCREASE OIL COOLING

EXTERNAL LEAKAGE OR HI OIL CONSUMPTION OR SCAVENGE PUMP FAIURECASE ( 2) : HIGH OIL TEMP + OIL QUANTITY NORMAL

CAUSES

FUEL OIL COOLERBY-PASS FAILURE ( SUCH THAT IT IS OPEN ALL THE TIME AND BY PASSES HOT OIL )

CREW ACTION FOR CASE (1) & ( 2) :

4 - Eng OIL QUANTITY LOSS

NOTE : GUPLING EFFECT

INDICATED OIL QTY WILL DROP NORMALLY BY 3 OR 4 QUATS AFTER ENGIN START.

CASE (1) : IF OIL PRESSURE AND OIL TEMP ARE NORMAL

CREW ACTION CONTINUE OPERATION EVEN QTY INDICATES ZERO

CASE (2) : IF OIL PRESSURE : DROP OR FLUCTUATES

CREW ACTION

ENGINE S.D

5-ENGINE INTERNAL FIRE

INDICATIONS :

a) EGT RAPIDLY INCREASES WHEN FUEL LEVER : ONb) INTERNAL TAIL PIPE FIRE REPORTED BY THE GROUND CREW

CAUTION : DO NOT USE EXTERNAL FIRE AGENTCREW ACTION:FUEL LEVER : OFF -- FIRE HANDLE : PULL - DRY MOTOR UNTILL NO EVIDENCE OF BURNING

6- HOT START

INDICATIONS :

RAPID EGT RISEN2 RISE IS BELOW NORMALF.F NORMAL OR HIGHTAIL PIPE BURNING MAY EXIST

CREW ACTION :

FUEL LEVER:OFF -- DRY MOTOR ( CRANK FOR 3O sec)

7 – NO LIGHT UP DURING START

INDICATIONS :

EGT NO RISEN1 , N2 , FF : NORMAL

CREW ACTION :

FUEL LEVER: OFF -- DRY MOTOR ( CRANK FOR 3O sec)

8- HUNG START

INDICATIONS :

N2 STAGNATES BELOW IDLE ( 55 % TO IDLE )

N1 STAGNATES BELOW IDLE

EGT , FF : FAIL TO DROP TO NORMAL IDLE VALUES

CREW ACTION :

9- ENGINE FAILS TO ACCELERATE FROM GND. IDLE

INDICATIONS :

N1 , N2 : NO RESPONSE WITH THROTTLE ADVANCEFF, EGT : INCREASE

FACTS ABOUT AVIATION OIL

FACTS ABOUT AVIATION OILBy Bill Coleman The following facts about aviation oil were developed by Harold Tucker, Lubricants Technical Director for the Phillips 66 Company; Dr. Alex Schuettenberg, Senior Research Chemist, Lubricants Technical Support for Phillips 66; and by Richard Fowler, President of America’s Aircraft Engines, Inc.

1. OIL ADDITIVES WEAR OUT . Technically, oil does not wear out. However, extended use causes an oil’s additives to wear out or become depleted. For example, an ashless dispersant aviation oil is designed to suspend dirt and metal particles picked up from an aircraft engine. Eventually the oil will become "over-suspended." The principal reason oil is changed at regular intervals is to rid the engine of these suspended impurities. Old oil, with a high degree of contaminants, can cause bearing corrosion and deposit buildup. It can also get to the point where it will not suspend the additional particles created during engine operation. This produces particle buildup or sludge. Overworked oil will also result in the depletion of its other additives. The result is that it will be unable to perform with the benefits the additives were designed to provide.

2. OIL REMOVED DURING AN OIL CHANGE SHOULD APPEAR DIRTY.If an oil is doing its job properly, it should suspend dirt, metallic wear materials, and unburned carbon. Therefore, when you change your oil it should look much dirtier than it did when first added to the engine.

An excellent method for monitoring an oil’s condition is through oil analysis, which can be key to any preventive maintenance program. Oil analysis must be conducted regularly to establish trends of operation. It provides information on wear metals, viscosity integrity, fuel dilution, and air intake system leaks, among other things. As a long-term preventive maintenance tool, it will build a history of the engine’s performance and aid in the detection of possible problems before they become severe.

3. AIRCRAFT ENGINE OIL SHOULD BE CHANGED EVERY 25 OPERATING HOURS WHEN NOT USING AN OIL FILTER. Phillips 66, like other aviation oil manufacturers, recommends changing aviation oil every 25 hours if an oil filter is not being used. If an oil filter is being used, it should be changed every 50 hours.

4. OFF-THE-SHELF OIL ADDITIVES DO NOT IMPROVE AIRCRAFT ENGINE PERFORMANCE.Except in extremely rare instances, original engine manufacturers (OEMs) do not recommend using additives with aviation oil. Changing oil regularly is much more beneficial. Little is to be expected from the inclusion of aftermarket additives to an approved oil, and no OEM recommends their use. These include additives that claim to fortify or enhance the oil’s lubrication properties.

5. MULTIVISCOSITY OILS OFFER OPERATING TEMPERATURE BENEFITS.Multiviscosity oils such as Phillips 66 X/C 20W-50 oil offer high and low temperature protection for your engine. A 20W-50 oil acts like a 20W (winter) oil in cold engines and a 50-weight oil in hot engines. The 20W provides instant lubrication and makes cold starting easier. The 50-weight protects against potential metal-to-metal wear during hot operation. Once an aircraft engine is started, it forgets how cold it is outside. It is only concerned with its high-heat operating environment. For this reason, engines require high-temperature lubrication even on cold days.

6. FUEL-INJECTED ENGINES CAN BENEFIT FROM MULTIVISCOSITY OIL.Proponents of fuel-injected engines claim they start better in cold weather than a carbureted engine. For this reason, a multiviscosity oil can be of great benefit to a fuel-injected engine because it can provide instant lubrication at cold start-up. Single-grade oil may not flow quickly enough to provide adequate lubrication at those low temperatures because it is too

sluggish, creating excessive viscous drag. Approximately 85 percent of harmful engine wear occurs during the start-up phase.

7. AUTOMOTIVE OIL SHOULD NEVER BE USED IN AN AIRPLANE ENGINE.The most important reason not to use automotive oil in an aircraft engine is the number of additives in it that are designed for use in water-cooled engines operating within a certain range of temperatures and pressures and at constantly changing levels of power. Aircraft engines are air-cooled and operate under an entirely different set of parameters.

8. AN OIL’S VISCOSITY IS KEY TO ITS PERFORMANCE.Viscosity plays a key role in preventing aircraft engine wear and is also important at low temperatures for pumpability. Viscosity determines how easy it is for oil to pump and move through lines and passages. The oil must be thick enough to keep moving parts from contacting each other, and thin enough to permit adequate flow and minimize viscous drag.

9. USING A MULTIVISCOSITY OIL CAN DECREASE OIL CONSUMPTION.Phillips 66 has found that multiviscosity oils will reduce oil consumption rates. The three ways oil leaves an engine are base oil evaporation at high temperatures, leaks, and blow-by past the piston rings during operation. Because base oils for aviation lubricants are not formed from light base stocks, the evaporation factor is negligible. Multiviscosity oils do not thin out as much at high temperatures, helping to prevent excessive blow-by and/or leakage.

10. NO DETERGENTS ARE EVER ADDED TO AVIATION OILS.There is no such thing as an aviation oil that contains detergents. Aviation oils have not contained detergent packages since the mid-1950s. Single and multiviscosity grade mineral-based oils instead contain ashless dispersant (AD) additive packages. ADs are very different than detergents:• ASHLESS refers to non-metallic additives. Detergents, on the other hand, are metallic by nature. Detergents may scrub existing ash deposits from an engine’s interior surfaces, which will contribute to the ash content, and possible clogging, of the oil. • DISPERSANT refers to the oil’s ability to suspend combustion by-products, keeping them dispersed until the oil is drained. Because they suspend engine by-products, AD oils darken faster than non-AD oils. This is a sign that the oil is preventing by-products from solidifying on interior engine surfaces. All AD aviation oils contain

oxidation inhibitors as part of their standard additive chemistry. AD oils will not dislodge quantities of sludge from interior engine surfaces that lead to restricted oil screens. AD oils do not add deposit build-up. Instead, they help dissipate existing by-products over time. For example, if an operator uses a non-AD oil for 500 hours, then switches to an oil with an AD package for 500 hours, the AD oil will not "clean out" the first 500 hours worth of engine deposits.

11. ENGINES USING A STRAIGHT MINERAL OIL CAN EASILY BE SWITCHED TO AN ASHLESS DISPERSANT (AD) OIL.If the changeover is completed properly, there are no negative effects to switching from a straight mineral to an AD oil, regardless of the number of operating hours accumulated. All AD aviation oils use the same base stock and additives. For instance, Phillips 66 Type A 100 Single Grade AD Oil uses the same base oil and additives as Phillips 66 multiviscosity 20W-50 X/C AD oil. AD oils will not remove past accumulations of lacquer and varnish or hardened sludge. Therefore, AD oils will not cause sludge to move, blocking oil galleys. When switching from mineral to AD oils, a darkening of the oil as the dispersant suspends surface deposits can be expected at the first two oil changes. This poses no danger to the engine and means the oil is properly suspending engine-wear particles.

12. AVIATION OIL BRANDS VARY WIDELY IN PERFORMANCE.All aviation oils provide some form of lubrication, but that’s where the similarities end. Each manufacturer blends proprietary additives to enhance the oil and provide predictable performance characteristics for the end-user. Each oil’s viscosity grade is designed to satisfy specific engine requirements. Using the right aviation oil for a specific aircraft engine can help improve engine efficiency.

13. MULTIVISCOSITY MINERAL AD OILS CAN BE USED TO SEAT NEW PISTON RINGS IN A NEWLY REPLACED CYLINDER.

Just as it is true that a multiviscosity mineral AD oil, such as Phillips 66 20W-50 aviation oil can be used during engine break-in, it can also be used to seat piston rings in a new cylinder. In fact, it is a good practice for the operator to continue using a multiviscosity AD oil after the cylinder has been replaced because the cylinder will run hotter until the piston rings have seated. Engines run hotter during a replacement cylinder’s ring seating process just as they do during the initial engine break-in period. This is due to increased friction between the cylinder bore and the piston rings and less heat transfers to the cooling fins. The metal-to-metal contact necessary for ring seating causes temperatures to rise within the cylinders.

14. SYNTHETIC OILS DO NOT SHOW SUPERIOR PERFORMANCE WHEN USED IN PISTON-POWERED AIRCRAFT.The decision to use synthetic oils should be based on the expected use of the oil. Since synthetics cost at least twice as much as mineral oil-based products, there is a tendency on the part of the operator to expect them to outperform in all circumstances. In a piston engine aircraft environment, however, the favorable properties of synthetic oils are marginal. Supporters of synthetic oils have basically two main claims: one, they increase time between oil changes and second, they improve startability at extreme low temperatures. Synthetic oils will become contaminated just as quickly as mineral oil in a piston aircraft engine and synthetics do not show any appreciable difference in wear levels. OEMs do not distinguish between synthetics and mineral-based products for oil change recommendations. Also, for piston-powered aircraft, any possible low temperature benefit to a synthetic oil is irrelevant because piston aircraft started in temperatures of 20F or below must be pre-heated. With regard to extremely high-temperature operation, very few, if any, piston-powered aircraft are operated at temperatures that highlight the benefits of synthetic oils.

15. USING A MULTIVISCOSITY AD MINERAL OIL TO BREAK IN A FACTORY-NEW OR ZERO-TIME OVERHAULED AIRCRAFT ENGINE WILL NOT DAMAGE THE CYLINDERS. It is not true, as some believe, that multiviscosity mineral AD oils do not properly break in aircraft engines will damage the cylinders. The break-in phase (the engine’s first 10 to 12 operating hours) is, simply, the dirtiest time for an engine. During break-in, the engine’s oil will be exposed to contaminants and break-in wear metals, as well as excess fuel. Over the past 10 years, America’s Aircraft Engines, Inc. (Tulsa, Okla.), has researched and overseen extensive tests on the break-in of engines using multiviscosity mineral AD oils. Using Phillips 66 X/C 20W-50 multiviscosity oil as its research and testing base, America’s Aircraft Engines has determined several key advantages to breaking in an engine with a multiviscosity mineral AD oil:• Multiviscosity mineral AD oils "seat" piston rings in approximately half the time of a straight grade oil. Synthetics are unable to break-in an engine. • Multiviscosity mineral AD oils reduce the chance of break-in cylinder glazing, a risk pilots take when breaking in an engine with a straight-grade mineral oil. A straight- grade will often deposit varnish and lacquer in the high engine temperatures reached during break-in. As a result, these materials may collect in the cylinder wall crosshatching and magnify glazing of a marginal cylinder.• Multiviscosity mineral AD oils, when used during break-in and beyond, provide quicker start-up than straight grade mineral oils. The lubrication provided by multigrade mineral AD oils is more immediate than that provided by straight grade mineral oils.• A good single or multigrade AD mineral oil will suspend debris that is created during the "dirty" time of break-in, keeping it from being deposited inside the engine. An initial 10-hour drain will rid the system of the contamination introduced during break in.