Engine Malfunctions

Question 1

Engine Failure Immediately After Takeoff

Answer 1

Total loss of power

Fairly rapid reduction in airspeed

Question 2

Engine Failure During Flight

Answer 2

Initial indications:
-Loss of power/airspeed

• Rapid decay in N1, torque, and ITT
• Propeller moves towards feather due to loss of oil pressure

Question 3

Uncommanded Power Changes / Loss of Power / Uncommanded Propeller Feather Causes

Answer 3

• Engine rollback due to PMU scheduling (based on actual or faulty input to the PMU)
• Oil/engine/fuel system contamination
• A propeller dump solenoid failure
• Loss of oil pressure to the propeller pitch control mechanism from momentary contact between the oil transfer sleeve and the propeller shaft (a “prop-sleeve touchdown”)

Question 4

Uncommanded Power Changes / Loss of Power Indications

Answer 4

Uncommanded reduction in power/thrust

If the PMU remains ONLINE:

• Lower than expected fuel flow
• Uncommanded decrease in N1
• Oil/Engine/Fuel Contamination
• errant electrical signal to the feather dump solenoid, causing reduction in oil pressure to the propeller pitch control mechanism

Question 5

Uncommanded Propeller Feather Indications

Answer 5

• rapid reduction in propeller RPM (Np) accompanied by high torque
• increase in propeller noise
• noticeable loss of thrust
• engine/airframe vibrations
• PMU FAIL/PMU STATUS warning/caution could illuminate if the PMU drops off line (otherwise will remain on and continue to provide protection against over-torque)

Question 6

What is a prop-sleeve touchdown

Answer 6

When the propeller moves toward feather due to a temporary loss of oil pressure to the propeller pitch control mechanism

Question 7

Indications of a prop-sleeve touchdown

Answer 7

• Fluctuations in Np
• Torque increasing
• Thrust decreasing
• Engine vibrations (all of the above should be less than 20 seconds)
• CHIP detector warning

Question 8

Compressor Stalls Indications

Answer 8

 Abnormal engine noise

 Increasing ITT

 Decreasing N1 and torque

 Possibly followed by fluctuations of ITT, N1, and torque

 Loud bangs, backfires, or engine sputtering (different from uncommanded power loss)

 Flames and/or smoke from the engine

Question 9

Compressor Stalls Causes

Answer 9

 Damaged or degraded compressor/turbine blades

 Disrupted airflow to the engine

 Compressor bleed valve malfunctions and therefore may occur during engine acceleration/deceleration

Question 10

Oil System Malfunction

Answer 10

Use this procedure for any of the following:
 Red OIL PX warning

 Amber OIL PX caution

 Oil pressure fluctuations

 Oil temperature out of limits

 Visibly confirmed leaking oil from the aircraft

 If OIL PX warning illuminates and oil pressure indicates <5 psi, check OIL TRX circuit breaker on the battery bus circuit breaker panel (left front console). If the circuit breaker is open, it may be reset.

 Due to the sensitivity of the signal conditioning unit (SCU), a single, momentary

Question 11

Fire in Flight

Answer 11

Illumination of the fire warning light accompanied by one or more of the following indications is confirmation of an engine fire:
 Smoke
 Flames
 Engine vibration
 Unusual sounds
 High ITT
 Fluctuating oil pressure, oil temperature, or hydraulic pressure

Question 12

Fire on the Ground

Answer 12

 Illumination of the FIRE annunciators

 Visual smoke or fire

 Engine indications (high ITT, fluctuating or high fuel flow)

 Notification from exterior sources such as ground crew, tower, or another aircrew