Fan Vibration less than 4 Units with Noise / Rumble

TASK 77-00-00-810-862-A
Fan Vibration less than 4 Units with Noise / Rumble

1. Possible Causes

fan blades
LPT Stage 4 blades
fan blades mid-span shrouds

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
AMM 71-00-00-750-001	Fan Trim Balance - 1 Sensor 3 Speed
AMM 72-21-00-210-004	Detailed Inspection and Relubrication of Fan Blade Dovetails, Midspan Shrouds, Retainers, Spacers, Dampers and Fan Disk Dovetail Slots
AMM 72-21-00-210-009	Inspection of Fan Rotor Blades Installed on the Fan Disk
AMM 72-21-00-210-025	Inspect Fan Rotor Blades Installed on the Fan Disk
AMM 72-54-00-210-001	Optional Visual Inspection of the Stage 4 Blades from the Rear of the Engine
AMM 72-54-00-210-004	Optional Visual Inspection of the Stage 4 Blades from the Rear of the Engine
AMM 72-54-00-290-002	Inspection of the Stage 4 Blades
AMM 72-54-00-290-006	Inspection of the Stage 4 Blades

3. Fault Confirmation
Subtask 77-00-00-710-149-A ** ON A/C NOT FOR ALL

A. Test
(1) Not applicable, the fault is evident.

4. Fault Isolation
Subtask 77-00-00-810-119-A ** ON A/C NOT FOR ALL

A. If the fault symptom is identified on the lower ECAM display unit by the crew observation: ENG 1(2)-FAN VIBRATION less than 4 units along with noise/rumble

NOTE: Trouble Shooting is recommended at next maintenance opportunity not interfering with Revenue Service Operation.

(1) Do a check of the fan blades AMM 72-21-00-210-025.

NOTE: A black light inspection of the fan blades can help find soft body impact. Refer to CFMI SPM 70-00-06-800-007.

(a) If the check is not correct:

If fan blade indication or mid-span shroud shingling, repair as necessary.

(2) Do a check of the LPT Stage 4 blades for shingling or indication. Do one of the steps that follow:
(a) Do an inspection of the LPT Stage 4 blades from the rear of the engine AMM 72-54-00-210-001. And then, if the blades are shingled or have indications, do a borescope inspection of the LPT Stage 4 blades AMM 72-54-00-290-002, or
(b) Do a borescope inspection of the LPT Stage 4 blades AMM 72-54-00-290-002.
(3) If checks are correct:

Do a Cold Trim Balance per specific procedure "Fan Trim Balance" AMM 71-00-00-750-001.

(4) If the same crew observation is still reported during following flight(s):

Do a relubrication of the fan blades mid-span shrouds and dovetails AMM 72-21-00-210-004.

Subtask 77-00-00-810-119-B ** ON A/C NOT FOR ALL

A. If the fault symptom is identified on the lower ECAM display unit by the crew observation: ENG 1(2)-FAN VIBRATION less than 4 units along with noise/rumble

NOTE: Trouble Shooting is recommended at next maintenance opportunity not interfering with Revenue Service Operation.

(1) Do a check of the fan blades AMM 72-21-00-210-009.

NOTE: A black light inspection of the fan blades can help find soft body impact. Refer to CFMI SPM 70-00-06-800-007.

(a) If the check is not correct:

If fan blade indication or mid-span shroud shingling, repair as necessary.

(2) Do a check of the LPT Stage 4 blades for shingling or indication. Do one of the steps that follow:
(a) Do an inspection of the LPT Stage 4 blades from the rear of the engine AMM 72-54-00-210-004. And then, if the blades are shingled or have indications, do a borescope inspection of the LPT Stage 4 blades AMM 72-54-00-290-006, or
(b) Do a borescope inspection of the LPT Stage 4 blades AMM 72-54-00-290-006.
(3) If checks are correct:

Do a Cold Trim Balance per specific procedure "Fan Trim Balance" AMM 71-00-00-750-001.

(4) If the same crew observation is still reported during following flight(s):

Do a relubrication of the fan blades mid-span shrouds and dovetails AMM 72-21-00-210-004.

[Rev.8 from Aug 2018] 2026.04.04 04:37:33 UTC