Engine Monitoring: Safety & Ground Operations

• This document is about engine monitoring and ground operation, from the School of Mechanical & Aeronautical Engineering.

Safety & Walk-Around

• Focuses on safety precautions and exterior walk-around procedures.

Safety Precautions (Air Intake)

• A high suction force is created around the inlet area during engine operation.
• Avoid the inlet during engine operation.
• Observe the AMM intake hazard areas for safety.
• Regularly clean and examine the engine compartment, air inlets, and work area to prevent Foreign Object Damage (FOD).

Safety Precautions (Exhaust)

• Exhaust gases exit the engine at high temperature, pressure, and velocity and observing AMM exhaust hazard areas is crucial.
• In reverse thrust position, fan air exits in the forward direction.
• Exhaust gases are dangerous, potentially causing injury to eyes and breathing difficulties.
• Jet engines produce noise levels harmful to ears, requiring ear protection, and adhering to AMM time/distance restrictions is recommended.

Safety Precautions (Fuel and Oil, Hot Engine Parts)

• Engine parts become extremely hot, including pneumatic/fuel/oil tubes and the engine hot section/exhaust section.
• Fuel and oil pose a fire hazard and are toxic, requiring precautions to avoid skin contact.
• Spills can make surfaces slippery.

Safety Precautions (Ignition & Compressor Bleed Valve)

• Ensure the ignition system is off before maintenance and ground runs.
• Open compressor bleed valves require keeping personnel away from surge bleed ducts during engine operation.

Exterior Walk-Around

• Exterior walk-around procedures illustrated on Airbus A320 by Captain Joe.
• Checks include L forward fuselage, nose, landing gear, R forward fuselage, R/L center fuselage/wing, R engine, R wing leading edge/tip/trailing edge.
• Also, rear landing gear, R/L aft fuselage, tail & APU, L wing trailing edge/tip/leading edge, and L engine.
• Parking brake must be on before inspection.
• Minimum fuel quantity in main tanks, external electrical power, pneumatic as necessary.
• Assuring no fuel, oil, dirt, parts, or tools in engine inlets.
• Ensuring ramp and gear areas are clean and free of contamination or FOD.
• Proper engine cowling position, ground observer communication to flight deck crew.
• Wheel chocks in place.

Exterior Walk-Around Warnings and Cautions

• Engine-operating areas should be clean and clear.
• Engine run-up with thrust reverser cowls open is prohibited.
• Engine run-up with fan cowls open and secured by hold open rods above idle power is prohibited.
• Ensure wheel chocks are in position and an authorized person with fire extinguisher is present.
• Nose wheel steering bypass pin should be removed and all operating limits/procedures known.
• Engine start shouldn't be performed if tail wind exceeds 35 knots.
• Restrict operation to 70% NI or below if tail wind exceeds 25 knots.

Maintenance: Engine Borescopic Inspection

• Engine Borescopic Inspection is a visual method for quality control of areas inaccessible to human eyes.
• Special areas include compressor blades, combustion chamber, and compressor-turbine blades/vanes.
• It is done to check for critical damage due to foreign object damage or fuel corrosion, and burnt/cracked parts.

Compressor Clean/Wash

• Compressor washing removes contaminants from the engine compressor via hot water or specialized solutions.
• Contaminants include fine dirt, oil vapors, soot, exhaust fumes, and environmental salt.
• Compressor washing improves thermal efficiency, affecting turbine/compressor inlet temperature, burner efficiency, compression ratio, and compressor/turbine efficiency.

Checks for Engine Starting and Ground-Run

• Perform leak checks on pneumatic, fuel, and oil systems post component change or suspected leakage.
• Vibration tests data is obtained to calculate trim balance mass and location.
• Check availability of power at different power settings of the engine, also known as the 'Power Assurance Test'.
• Check availability of Integrated Drive Generator (IDG) power on electrical buses.
• Determine whether the engine can accelerate between two power settings within a given time frame called the 'Engine Acceleration Test'.

Engine Operation Limits: N1 and N2 Overspeed

• Following steps in the event of NI or N2 exceeding limits are critical.
• Use the Stop the Engine (Normal) procedure for rapid engine shutdown.
• Conduct an overspeed inspection before restarting.
• Maintain all overspeed records with the engine's permanent records.

Engine Operation Limits: Exhaust Gas Temperature (EGT)

• Actions are required if EGT surpasses redline limits defined in tables or EGT GUIDELINES.
• Recording temperature level reached, duration, and engine operating condition at the time is critical. Perform applicable inspection as given in the Engine Manual.
• Over-temperature can occur when fuel flow, N2, or EGT increases rapidly.

Motoring Procedures

• Turning on the engine with the starter, minus the supply of ignition is defined as motoring the engine.
• The Dry-Motor supplies fuel to the fuel pump as a lubricant, but does not supply fuel to the engine combustion chamber.
• The Wet-Motor provides fuel to the fuel pump and lets fuel go into the combustion chamber without ignition and to the fuel servo pressure actuated components and should be used only when necessary.

Certification & Accessories Gearbox: Engine Certification Test

• Aircraft/Engine manufacturers undergo rigorous and complex testing including:
• Fan blade out.
• Bird ingestion.
• Water ingestion.
• Triple redline (EGT, NI. N2 & Oil Temp).
• High altitude start - Skt.
• Cold start ground.
• After passing tests and being certified, the aircraft is cleared for production.

Engine Data Plate

• Regulatory requirements for aircraft data plates are found in 14 CFR Part 45, Identification and Registration Marking.
• Included on the data plate is required by § 45.11(a) and (b) is:
• Builder's name.
• Model designation.
• Builder's serial number.
• Type certificate number, if any.
• Production certificate number, if any.

Accessories Gearbox

• Drives various components including:
• LP/HP Fuel pump.
• Oil Pump.
• Starter motor.
• Hydraulic pump.
• Engine electrical generator.
• Centrifugal breather.

Overview of engine monitoring and ground operations with a focus on safety. Includes safety precautions regarding air intake, emphasizing the dangers of high suction force and the importance of FOD prevention. Also covers exhaust hazards such as high-temperature gases and noise levels.