Turbine Trouble-Shooting Test

If the data concerning an engine problem is conflicting or incomplete, what action could be done to rectify the problem?

run the engine yourself

What consideration should be taken when deciding whether or not to run the engine to get the missing parameters?

if any other damage will occur

What publication can be used to determine if there is an actual problem with the engine?

Maintenance Manual or Operations Manual

When troubleshooting a problem, what is the first thing that should be accomplished?

Make sure the discrepancy data is complete and accurate

When trouble shooting a problem, isolation of the fault is accomplished by first listing the what?

possible causes

Define - No Start?

Fuel/Air mixture fails to ignite

Define - Hot Start?

EGT goes beyond limits

Define - Hung Start?

Fails to reach idle RPM

How can an indication problem be identified?

Deviation in one of the gauges

The flight log reads: Engine shut down in flight due to very low oil pressure. Oil temp increased as pressure dropped. Vibration normal. No evidence of oil leak?

Internal Oil leak and low quantity of oil

The flight log reads: Oil pressure follows throttle movement. Pressure higher than normal at take off. Oil temperature and quantity normal?

Pressure regulator

The flight log reads: Engine start aborted due to no evidence of engine rotation. Ground crew did not observe engine RPM. Bleed duct pressure did not change?

Air valve failed

The flight log reads: During start engine had a hot start on the first start of the day. Bleed duct pressure normal?

Not at proper RPM before introducing fuel

The flight log reads: The engine lights off but fails to reach idle. Electrical load draw normal during start?

Insufficient start fuel flow

The flight log reads: Engine slow to light off. Fuel flow and RPM normal. Ignition circuit breaker closed. Popping of igniters heard by ground crew?

Improper ignitor emersion depth

The flight log reads: Engine would not start. No fuel flow on gauge and evidence of fuel in hot section?

Fuel control

The flight log reads: Engine would not start. Normal RPM and fuel flow. Evidence of fuel in turbine section and tailpipe?

Ignition component failure

The flight log reads: No engine rotation evident on RPM gauge during start. Did not hear normal engine spooling noise. Current draw did not increase on AMP gauge during start?

Starter Solenoid

The flight log reads: Engine acceleration slow compared to throttle movement. Take off power normal with good N1 and N2 RPM. Fuel flow and EGT good. Throttle levers are matched with no split?

Variable Bleed valves and stator vanes improperly adjusted

The flight log reads: Take off EPR low with throttle levers aligned. All other parameters normal?

damaged Pt7 lines or probes

The flight log reads: Unable to make take off EPR or RPM before EGT limit reached on engine #2. Engine seems slower to spool up compared to engine #1?

Turbine Damage

The flight log reads: Unable to make take off EPR without N2 overspeed. W/F normal?

Improper rigging of variable stator vanes or bleed valves

The flight log reads: Throttle lever hits its forward stop before take off EPR reached. All other parameters low but within limits?

improper rigging of the throttle controls

The flight log reads: On 3rd flight of the day, engine experienced a hot start?

Failure to spool hot engine to acceptable EGT prior to turning on fuel

The flight log reads: Engine oil consumption exceeds allowable tolerances. evidence of oil in compressor?

Internal oil leak

The flight log reads: Engine oil consumption excessively high. Oil found coming from accessory drain in bottom of cowling?

accessory gearbox drive seal

The flight log reads: #2 engine throttle lever ahead of #1 engine in excess of "1 1/2" with engines at takeoff power. Both engines within normal tolerances with no indication of overspeed or over temp?

Improperly rigged throttle system

The flight log reads: Engine surged while taxiing aircraft to runway. Engine produces full power with all parameters normal?

High cross wind at the inlet

The flight log reads: Engine surged while accelerating to take off power. Take off parameters normal with no split between throttle levers?

Faulty variable stator vanes or bleed valves

The flight log reads: Engine surged at takeoff power?

FOD in the Compressor

The flight log reads: Oil filter bypass warning light illuminated in flight. Neither chip detector nor Delta P lights came on but both tested good. All other oil and engine parameters normal?

Faulty warning light switch and bypass valve

The flight log reads: Oil temperature excessively high. Oil pressure low but within limits. All other parameters normal?

Thermostatic valve on the oil cooler

The flight log reads: Engine oil Delta P, chip detector, and oil filter bypass warning light came on, shut down engine. Oil temperature and engine vibration higher than normal?

Internal engine failure

The flight log reads: Oil pressure below acceptable valve in flight and shut down engine. Delta P and filter bypass light did not illuminate out tested good?

Regulator out of adjustment