ENGINES


Stall During Acceleration • The compressor bleed valve(s) are stuck shut – Replace bleed valve(s)


• The compressor bleed valve(s) are out of calibration – Have the unit(s) bench checked and calibrated


• A defective fuel control unit is overfueling – Replace the fuel control unit


• Compressor FOD – Check first-stage compressor blades for FOD


Failure to Accelerate Properly • The P3 sense line is restricted or leaking – Check the line for any obstruction(s)


• Corrosion or ice in the fuel control unit bellows section – Remove the fuel control unit for cleaning; check the P3 line for water


• Defective fuel control unit – Replace the fuel control unit


• Dirt in pneumatic section of fuel control unit – Clean the fuel control unit


• Contaminated P3 filter – Check and change filter; this will also cause a slow start


• Defective temperature compensator – Replace the unit


Failure to Decelerate • Disconnected or improperly-rigged fuel control unit – Repair or re-rig as necessary


• Fuel control unit bypass valve is stuck – Replace the fuel control unit


• Binding control linkage – Check the control linkage and repair as necessary


Flameout • Interrupted fuel supply – Aircraft fuel valve shut off inadvertently


• Fuel pump drive failure preceded by slight increase in N1 rpm


– Check fuel pump cranking pressure


• Air in fuel system – Flameout at idle after a start; bleed fuel system and check reason for air entering the fuel system


• Contaminated fuel control unit – Check all fuel filters; clean the fuel system and replace filters as necessary


• Incorrectly-rigged fuel control unit linkage, not contacting maximum stop at full throttle – Re-rig fuel control unit


• Fuel nozzle restriction, partially plugged – Clean and flow check fuel nozzles; this will cause hot section distress


TRAINING IN: • ENGINEERING • MANUFACTURING • REPAIR


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