inspections followings major maintenance activities and major components changed 1

FOR TRAINING PURPOSE ONLY Malaysian Institute of Aviation Technology

AJD21603 ROTORCRAFT SERVICING, MAINTENANCE AND ROLE EQUIPMENT

WEEK 12

INSPECTIONS FOLLOWING MAJOR MAINTENANCE ACTIVITIES AND MAJOR COMPONENTS CHANGED


LESSON OBJECTIVE AND OUTCOMEOBJECTIVE:

GAIN KNOWLEDGE ON INSPECTION REQUIREMENT AFTER MAJOR INSPECTION & MAINTENANCE ACTIVITIES.

OUTCOME:

EXPLAIN THE SUBSEQUENT ACTIONS AFTER A PARTICULAR MAINTENANCE OR COMPONENT REPLACEMENT.


DEFINITION OF HELICOPTER MAJOR COMPONENTS

ON HELICOPTER, MAJOR COMPONENTS CAN BE DESCRIBED AS COMPONENTS THAT ARE VITAL FOR OPERATION OF HELICOPTERS.

NORMALLY MAJOR COMPONENTS WILL HAVE OTHER SUB-COMPONENTS.

MAINTENANCE REQUIREMENTS ON THESE COMPONENTS CAN BE EITHER HARD TIME OR ON CONDITION.

EXAMPLES OF COMPONENTS: MAIN ROTOR BLADES, MAIN ROTOR HEAD, MAIN GEARBOX, FLIGHT CONTROL COMPONENTS, TAIL ROTOR BLADES & TGB AND ENGINE(S).


INSPECTION ON MAJOR COMPONENTS

INSPECTION ON MAJOR COMPONENTS CAN BE EITHER SCHEDULED OR UNSCHEDULED.

SCHEDULED INSPECTIONS ARE CARRIED OUT AS A RESULT OF MAINTENANCE SCHEDULE REQUIREMENTS.

UNSCHEDULED INSPECTIONS ARE CARRIED OUT AS A RESULT OF INCIDENTS FOR EXAMPLE MAIN GEARBOX CHIPS OR AS A RESULT OF SERVICE BULLETIN’S REQUIREMENT.


REPLACEMENT OF MAJOR COMPONENTS

REPLACEMENT OF MAJOR COMPONENTS ARE NORMALLY RESULTED FROM HARD TIME REQUIREMENTS I.E COMPONENTS HAVE TO BE REPLACED AT SPECIFIC TIME SCHEDULED.

IT CAN ALSO BE RESULTED FROM INCIDENTS AS MENTIONED EARLIER. EXAMPLE WHEN THE CHIPS EXCEEDING THE LIMITS.

NORMALLY THE PROCEDURES FOR CHANGING THE COMPONETS ARE NORMALLY DESCRIBED IN DETAILS IN THE M.M.


EXAMPLES OF PROCEDURES TO BE FOLLOWED AFTER MAJOR COMPONENTS REPLACEMENT

ENGINES: REFER TO M.M. OBSERVED THE SAFETY PRECAUTIONS. ENSURE ALL DOCUMENTATIONS ARE COMPLETED

AND SIGNED BEFORE COMMENCING GROUND RUN. ENSURE YOU FULLY BRIEF THE PILOTS BEFORE THE

ENGINES ARE STARTED.


FOR INITIAL RUN IT MAY BE NECESSARY TO START THE ENGINES AND ALLOWS ITS TO IDLE AT LOW SPEED. REASON: TO CHECK FOR LEAKS, ENSURE NONE OF THE PARAMETERS ARE EXCEEDED, TO ALLOWS THE PILOT TO SHUT DOWN ENGINE QUICKLY SHOULD THERE BE ANY ABNORMALITIES SUCH AS FIRE, COMPONENTS LOOSED, ABNORMAL NOISE AND SO FORTH.

AFTER SATISFACTORY INITIAL START-UP ONLY THEN YOU ALLOWS THE PILOT TO MOVE THE THROTTLE TO FLIGHT IDLE OR FLIGHT GATE.


EXAMPLE OF HELICOPTER COCKPIT


GLASS COCKPIT


ROTOR & ENGINE RPM GAUGES


ONCE THE ENGINES HAS RUN AT FLIGHT IDLE, CHECK THE N1, N2 AND NR, ENSURE THAT THEY ARE NORMAL. OTHER PARAMETER SUCH AS ENGINE OIL PX. ,TEMP. AND TORQUE MUST BE OBSERVED DURING THE GROUND RUN.

CHECK THE ENGINES FOR RESPONSE AND ENGINE ACCLERATION/DECELERATION.

MAY REQUIRED TO DO OTHER THINGS SUCH AS VIBRATION LEVEL, GENERATOR BALANCING AND OTHERS.

ONCE SATISFACTORY, SHUT DOWN THE ENGINE, CHECK THE SURROUNDINGS, ENSURE NO LEAKS AND FIRE UPON SHUTTING DOWN.

MAY REQUIRE FLIGHT TEST TO CHECK ENGINE BEHAVIOUR SUCH AS PERFORMANCE CHECK & FOR NORMAL PARAMETERS.

ONCE SATISFACTORY, ENSURE ALL DETAILS IN LOG BOOK AND RAISED THE CRS.


EXAMPLES OF PROCEDURES TO BE FOLLOWED AFTER MAJOR COMPONENTS REPLACEMENT

THESE GENERALLY REFERS TO COMPONENTS LIKE MGB, MRH, MRB, TGB, TRB & TRDS, FLIGHT CONTROL SERVOS, HYDRAULIC COMPONENTS.

BASICALLY THE PROCEDURES ARE SIMILAR TO THE ONE MENTIONED BEFORE WITH FEW EXCEPTIONS.

TYPICAL PROCEDURES: REFER TO M.M. OBSERVED THE SAFETY PRECAUTIONS. ENSURE ALL DOCUMENTATIONS ARE COMPLETED AND

SIGNED BEFORE COMMENCING GROUND RUN. ENSURE YOU FULLY BRIEF THE PILOTS BEFORE THE

ENGINES ARE STARTED.


FOR INITIAL RUN IT MAY BE NECESSARY TO START THE ENGINES AND ALLOWS ITS TO IDLE AT LOW SPEED. REASON: TO CHECK FOR LEAKS ON MGB, MRH ETC, ENSURE NONE OF THE PARAMETERS ARE EXCEEDED E.G MGB OIL TEMP & PX, TO ALLOWS THE PILOT TO SHUT DOWN ENGINE QUICKLY SHOULD THERE BE ANY ABNORMALITIES SUCH AS COMPONENTS LOOSED, ABNORMAL NOISE, EXCESSIVE VIBRATION AND SO FORTH.

AFTER SATISFACTORY INITIAL START-UP ONLY THEN YOU ALLOWS THE PILOT TO MOVE THE THROTTLE TO FLIGHT IDLE OR FLIGHT GATE.


HELICOPTERTHROTTLE


ONCE THE ENGINES HAS RUN AT FLIGHT IDLE, CHECK THE NR, ENSURE THAT THEY ARE NORMAL. OTHER PARAMETER SUCH AS MGB OIL PX. ,TEMP. AND TORQUE MUST BE OBSERVED DURING THE GROUND RUN. IF MRB & TGB HAS BEEN CHANGED, MEASURE THE VIBRATION LEVEL BOTH LATERALLY AND VERTICALLY. CHECK THE CONTROL FOR ANY ABNORMALITIES

FOR VIBRATION INSPECTION, YOU MIGHT HAVE TO DO FEW RUNS TO BRING THE LEVEL DOWN.

ONCE SATISFACTORY, SHUT DOWN THE ENGINE, CHECK THE SURROUNDINGS, ENSURE NO LEAKS AND FIRE UPON SHUTTING DOWN.

MAY REQUIRED TO DO THE FLIGHT TEST TO CHECK THE VIBRATION LEVEL AND AIRCRAFT BEHAVIOUR FOR EXAMPLE AUTO-ROTATION RPM, AIRCRAFT MANUEVERING ETC.


INSPECTION REQUIREMENTS AFTER MAJOR MAINTENANCE ACTIVITIES.

WHAT IS MAJOR MAINTENACE?- MAJOR INSPECTIONS IS CLASSIFIED AS MAINTENANCE THAT

REQUIRE REMOVAL COMPONENTS FROM AIRCRAFT, TAKING CONSIDERABLE HOURS TO COMPLETE RANGING FROM 1 WEEK TO FEW MONTHS, REQUIRE STRIPPING DOWN OF AIRCRAFT COMPONENTS SUCH AS TAIL BOOM, VERTICAL & HORIZONTAL STABILIZERS, REMOVING THE PAINTS FOR DETAILS INSPECTION STRUCTURE FOR CORROSION, CRACKS AND ALIGNMENTS.


- ITS NORMALLY CARRIED OUT AT PERIOD PRECRIBED IN THE MAINTENANCE SCHEDULE, FOR EXAMPLE AS 355 REQUIRE MAJOR INSPECTION EVERY 500HRS/24 MONTHS, AND 6000HRS/12 YEARS.

- AS MAJOR COMPONENTS ARE REMOVED DURING THE MAJOR INSPECTION, CHECKS AFTER COMPONENTS HAS BEEN INSTALLED ARE VERY SIMILAR TO THE ONES MENTIONED PREVIOUSLY WITH THE ADDITION THAT THE CHECKS ARE IN BIGGER SCALE.


CHECKS TO BE DONE AFTER MAJOR INSPECTIONIN ADDITION TO THE CHECKS THAT WERE MENTIONED

PREVIOUSLY (ENGINES & TRANSMISSION COMPONENTS) YOU MIGHT NEED TO CHECK THE FOLLOWING AIRCRAFT SYSTEMS: AIRCRAFT ELECTRICAL SYSTEM – CORRECT VOLTAGES,

LOADING & BALANCING. AIRCRAFT INSTRUMENTS – ALL ARE WORKING NORMALLY. AUTO-PILOT SYSTEM – CHECK FOR SERVICEABILITY. AIRCRAFT COMMUNICATION & NAVIGATION SYSTEM –

CHECK FOR SERVICEABILITY. THE ABOVE CHECKS MIGHT ALSO NEED TO BE PERFORMED

DURING FLIGHT TEST. REMEMBER: ENSURE ALL THE REQUIRED

DOCUMENTATIONS ARE COMPLETED PRIOR TO RELEASING THE AIRCRAFT.


QUESTIONS?

WHAT SHOULD YOU DO IF DURING THE GROUND RUN, YOU FOUND DEFECTS WHICH YOU’RE ARE UNABLE TO RECTIFY? THIS IS DESPITE AFTER YOU CHANGED THE SUSPECTED COMPONENTS.

CAN YOU DO THE ENGINE GROUND RUN WITH COWLINGS OFF/BEING REMOVED?

inspections followings major maintenance activities and major components changed 1

Engineering