1-1 FAILURE SYMPTOM LIST
The following list contains the titles of all Failure Symptoms in this manual. The titles are alphabetically
arranged beneath the system and chapter where they are found.
S Y M P T OM
TASK
CHAPTER 2
VIBRATION ANALYSIS
ROTOR BLADE SHOCK ABSORBER ISOLATION
PROCEDURE
2-1.1
VIBRATION FREQUENCY IDENTIFIED AS 375
CYCLES PER SECOND (1/REV)
2-1.1
VIBRATION FREQUENCY TOO RAPID TO
COUNT BUT A FREQUENCY BEAT NOTICEABLE
PRIMARILY BY PILOT AND/OR COPILOT
2-1.1
VIBRATION FREQUENCY TOO RAPID TO
COUNT, VIBRATION FELT IN PEDALS OR
STRUCTURE, VIBRATION SENSED BY HEARING
HIGH PITCHED TONE, OR PILOTS
COMPLAINED OF DOUBLE VISION
2-1.1
DYNAMIC ABSORBER
CTR VIB ABSORB CIRCUIT BREAKER WILL
NOT STAY CLOSE D
2-2.4
LH VIB ABSORB CIRCUIT BREAKER WILL
NOT STAY CLOSED
2-2.4
NO INDICATION ON TEST BOX METER WHEN
TEST SWITCH IS SET TO EXTEND OR RE-
TRACT, SWITCH AT CENTER
2-2.4
NO INDICATION ON TEST BOX METER WHEN
TEST SWITCH IS SET TO EXTEND OR RE-
TRACT, SWITCH AT LEFT
2-2.4
NO INDICATION ON TEST BOX WHEN TEST
SWITCH IS SET TO EXTEND OR RETRACT,
SWITCH AT RIGHT
2-2.4
RH VIB ABSORB CIRCUIT BREAKER WILL
NOT STAY CLOSED
2-2.4
TEST BOX METER INDICATES ONE DIREC-
TION BUT NOT EXTEND AND RETRACT
WHEN TEST SWITCH IS SET TO EXTEND AND
RETRACT, SWITCH AT CENTER
2-2.4
S Y M P T OM
TASK
TEST BOX METER INDICATES ONE DIREC-
TION BUT NOT EXTEND AND RETRACT
WHEN TEST SWITCH IS SET TO EXTEND AND
RETRACT, SWITCH AT LEFT
TEST BOX METER INDICATES ONE DIREC-
TION BUT NOT EXTEND AND RETRACT
WHEN TEST SWITCH IS SET TO EXTEND AND
RETRACT, SWITCH AT RIGHT
CHAPTER 4
ENGINE PERFORMANCE CHECK
DUAL ENGINE BEEP TRIM IS LOW, ROTOR
RPM IS LESS THAN 96 PERCENT WITH
ECL AT FLIGHT
NO. 1 ENG HIGH PTIT READING DURING
START OR HOT START
NO. 1 ENGINE GROUND IDLE SPEED
BELOW 60 TO 63 PERCENT RPM
NO. 1 OR NO. 2 ENGINE HIGH PTIT
NO. 1 OR NO. 2 ENGINE N2 OVERSPEED OC-
CURS WHEN ECL IS MOVED FROM GROUND
IDLE TO FLIGHT
NO. 1 OR NO. 2 ENGINE OIL TEMP HIGH
NO. 1 OR NO. 2 ENGINE ROUGH OR SURGING
ACCELERATION FROM GROUND IDLE TO
FLIGHT
NO. 2 ENGINE GROUND IDLE SPEED BELOW
60 TO 63 PERCENT RPM
NO. 2 ENGINE HIGH PTIT READING DURING
START OR HOT START
ROTOR RPM CHANGES MORE THAN +0 OR -2
PERCENT OR ENGINE TORQUE SPLIT EXCEEDS
6 PERCENT DURING HOVER
2-2.4
2-2.4
4-1.1
4-1.1
4-1.1
4-1.1
4-1.1
4-1.1
4-1.1
4-1.1
4-1.1
4-1.1
TM 55-1520-240-T
1-1
S Y M P T OM
TASK
ENGINE ANTI-ICE SYSTEM
ENG NO. 1 OR NO. 2 ANTI-ICE CIRCUIT
BREAKER WILL NOT STAY CLOSED
NO. 1 ENGINE ANTI-ICING VALVE DOES
NOT OPERATE (CLICK NOT HEARD)
NO. 2 ENGINE ANTI-ICING VALVE DOES
NOT OPERATE (CLICK NOT HEARD)
ENGINE LOW OIL LEVEL WARNING
NO. 1 OR NO. 2, ENGINE OIL LOW CAUTION
LIGHTS DO NOT COME ON
ENGINE START AND IGNITION
ENGINE NO. 1 IGN CIRCUIT BREAKER
DOES NOT STAY CLOSED
ENGINE NO. 1 START & TEMP CIRCUIT
BREAKER DOES NOT STAY CLOSED
ENGINE NO. 2 IGN CIRCUIT BREAKER
DOES NOT STAY CLOSED
ENGINE NO. 2 START & TEMP CIRCUIT
BREAKER DOES NOT STAY CLOSED
ENGINE 1 STARTER ON LIGHT DOES
NOT COME ON
ENGINE 2 STARTER ON LIGHT DOES
NOT COME ON
NO. 1 ENGINE DOES NOT MOTOR (GAS
PRODUCER TACHOMETER DOES NOT
INDICATE 10 TO 15% N1)
NO. 1 ENGINE DOES NOT START (ENGINE
FUEL SYSTEM FAILURE)
NO. 1 ENGINE DOES NOT START (ENGINE
IGNITION SYSTEM FAILURE)
NO. 1 ENGINE MOTORS NORMALLY BUT
DOES NOT START
4-2.4
4-2.4
4-3.3
4-4.4
4-4.4
4-4.4
4-4.4
4-4.4
4--4.4
4-4.4
4-4.4
4-4.4
4-4.4
GO TO NEXT PAGE
Change 1
1-2.1