DOC AIRBUS | AMM A320FVisual Inspection of NF Speed Probe [PW11]
TASK 77-11-22-210-801-A
Visual Inspection of NF Speed Probe
Use this procedure to do a visual inspection of the NF speed probe after a bird ingestion, surge with a Pb more than 350 psi (2413 kPa), or a bird ingestion that occurs with an engine surge or stall identified by AMM TASK 72-00-00-210-807 or AMM TASK 72-00-00-200-809.
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment
B. Work Zones and Access Panels
C. Referenced Information
3. Job Set-up
Subtask 77-11-22-941-052-A ** ON A/C NOT FOR ALL
Subtask 77-11-22-210-050-A ** ON A/C NOT FOR ALL
[Rev.10 from 2021]
2026.04.01 03:18:45 UTC
Visual Inspection of NF Speed Probe
WARNING:
BE CAREFUL WHEN YOU DO WORK ON THE ENGINE AFTER SHUTDOWN. THE ENGINE CAN STAY HOT FOR A LONG TIME. IF YOU DO NOT OBEY THIS INSTRUCTION, INJURY CAN OCCUR.
1. Reason for the JobUse this procedure to do a visual inspection of the NF speed probe after a bird ingestion, surge with a Pb more than 350 psi (2413 kPa), or a bird ingestion that occurs with an engine surge or stall identified by AMM TASK 72-00-00-210-807 or AMM TASK 72-00-00-200-809.
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment
| REFERENCE | QTY | DESIGNATION |
|---|---|---|
| No specific | 1 | ACCESS PLATFORM 1M(3 FT) |
| No specific | 1 | GLOVES - PROTECTIVE |
| No specific | 1 | MAT - PROTECTIVE |
| 636-1100-3GSE | 1 | INLET COWL PROTECT COVER |
| ZONE/ACCESS | ZONE DESCRIPTION |
|---|---|
| FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENG 1) | |
| 437AL, 438AR, 452AR | |
| FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENG 2) | |
| 447AL, 448AR, 462AR | |
| REFERENCE | DESIGNATION |
|---|---|
| TASK 71-00-00-860-832-A | Procedure to Prevent Engine Motoring and to Stop the Electrical Supply to the EEC |
| TASK 71-13-00-010-802-A | Opening of the Fan Cowl Doors |
| TASK 72-00-00-200-809-A | Inspection of the Engine (After Surge or Stall) |
| TASK 72-00-00-210-807-A | Visual Examination (After Bird Strike (Foreign Object Damage)) |
| TASK 77-11-22-000-801-A | Removal of the NF Speed Probe |
| TASK 77-11-22-290-801-A | Borescope Inspection of NF Speed Probe |
| TASK 77-11-22-400-801-A | Installation of the NF Speed Probe |
| TASK 78-30-00-040-805-A | Deactivation of the Thrust Reverser System for Ground Maintenance |
| TASK 78-36-00-010-802-A | Opening of the Thrust Reverser Cowl-Doors |
Visual Inspection of NF Speed ProbeSubtask 77-11-22-941-052-A ** ON A/C NOT FOR ALL
A. Safety Precautions
(1) Do the procedure to prevent engine motoring and to stop the electrical supply to the Electronic Engine Control (EEC)
(Ref. AMM TASK 71-00-00-860-832).
Subtask 77-11-22-010-054-A ** ON A/C NOT FOR ALL (1) Do the procedure to prevent engine motoring and to stop the electrical supply to the Electronic Engine Control (EEC)
(Ref. AMM TASK 71-00-00-860-832).
B. Get Access
(1) Open the fan cowl doors (Ref. AMM TASK 71-13-00-010-802):
(a) FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENG 1)
437AL 438AR
(b) FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENG 2)
447AL 448AR
(2) Put an ACCESS PLATFORM 1M(3 FT) in position.
Subtask 77-11-22-040-052-A ** ON A/C NOT FOR ALL (1) Open the fan cowl doors (Ref. AMM TASK 71-13-00-010-802):
(a) FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENG 1)
437AL 438AR
(b) FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENG 2)
447AL 448AR
(2) Put an ACCESS PLATFORM 1M(3 FT) in position.
C. Deactivation of the Thrust Reverser for Maintenance
Subtask 77-11-22-010-055-A ** ON A/C NOT FOR ALL WARNING:
YOU MUST DEACTIVATE THE THRUST REVERSER BEFORE YOU DO WORK ON OR AROUND IT. IF YOU DO NOT, THE THRUST REVERSER CAN OPERATE ACCIDENTALLY AND CAUSE AN INJURY AND/OR DAMAGE.
(1) Do the deactivation of the thrust reverser system for maintenance (Ref. AMM TASK 78-30-00-040-805). D. Get Access
(1) Open the right thrust-reverser cowl-doors (Ref. AMM TASK 78-36-00-010-802):
(a) FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENG 1)
452AR
(b) FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENG 2)
462AR
4. Procedure(1) Open the right thrust-reverser cowl-doors (Ref. AMM TASK 78-36-00-010-802):
(a) FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENG 1)
452AR
(b) FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENG 2)
462AR
Subtask 77-11-22-210-050-A ** ON A/C NOT FOR ALL
A. Visual Inspection of NF Speed Probe
(1) Find the NF speed probe located approximately at the one o'clock position on the No. 1 and 1.5 bearing support assembly.
(2) Refer to (Ref. AMM TASK 72-00-00-210-807) and/or (Ref. AMM TASK 72-00-00-200-809) to identify if it is necessary to examine the NF speed probe.
(3) Put a MAT - PROTECTIVE or 636-1100-3GSE INLET COWL PROTECT COVER in the air intake cowl.
(5) Remove the MAT - PROTECTIVE from the air intake cowl.
(6) If fan blade damage is found, and is in serviceable limits, identify if the NF speed probe operates correctly and examine it as follows:
(a) If the NF speed probe operates correctly, remove the NF speed probe and examine it after fan blade removal, or by a maximum of 750 hours if the fan blades are not removed. Refer to (Ref. AMM TASK 77-11-22-000-801).
(b) If the NF speed probe does not operate correctly, remove the NF speed probe and examine it within the time specified in the Master Minimum Equipment List (MMEL).
(c) Examine the NF speed probe for damage. Refer to Table 601 for inspection areas and limits.
(7) If fan blade damage is found that is not in serviceable limits, remove the NF speed probe immediately and examine it for damage (Ref. AMM TASK 77-11-22-000-801). Refer to Table 601
(8) If damage is found on the NF speed probe, a visual inspection of the fan shaft and fasteners is necessary (Ref. AMM TASK 77-11-22-290-801).
(9) Install the NF speed probe (Ref. AMM TASK 77-11-22-400-801).
(10) Examine the assembly for foreign objects, damage and correct assembly.
(1) Find the NF speed probe located approximately at the one o'clock position on the No. 1 and 1.5 bearing support assembly.
(2) Refer to (Ref. AMM TASK 72-00-00-210-807) and/or (Ref. AMM TASK 72-00-00-200-809) to identify if it is necessary to examine the NF speed probe.
(3) Put a MAT - PROTECTIVE or 636-1100-3GSE INLET COWL PROTECT COVER in the air intake cowl.
WARNING:
USE PROTECTIVE GLOVES TO PREVENT POSSIBLE INJURY TO THE HANDS WHEN YOU TOUCH OR HOLD THE FAN BLADES. THE BLADE EDGES ARE SHARP AND CAN CUT THE HANDS.
(4) Do a visual inspection of the fan blades for damage with GLOVES - PROTECTIVE. Refer to section 72-11-00 of the applicable Clean, Inspect, and Repair Manual for serviceable limits. (5) Remove the MAT - PROTECTIVE from the air intake cowl.
(6) If fan blade damage is found, and is in serviceable limits, identify if the NF speed probe operates correctly and examine it as follows:
(a) If the NF speed probe operates correctly, remove the NF speed probe and examine it after fan blade removal, or by a maximum of 750 hours if the fan blades are not removed. Refer to (Ref. AMM TASK 77-11-22-000-801).
(b) If the NF speed probe does not operate correctly, remove the NF speed probe and examine it within the time specified in the Master Minimum Equipment List (MMEL).
(c) Examine the NF speed probe for damage. Refer to Table 601 for inspection areas and limits.
(7) If fan blade damage is found that is not in serviceable limits, remove the NF speed probe immediately and examine it for damage (Ref. AMM TASK 77-11-22-000-801). Refer to Table 601
(8) If damage is found on the NF speed probe, a visual inspection of the fan shaft and fasteners is necessary (Ref. AMM TASK 77-11-22-290-801).
(9) Install the NF speed probe (Ref. AMM TASK 77-11-22-400-801).
| Table 601 - NF Speed Probe Inspection Limits |
| EXAMINE | DAMAGE | DISPOSITION |
|---|---|---|
| Sensor tip | | |
| | Damage not more than 0.003 in. (0.076 mm) depth | Permitted. |
| | Damage more than 0.003 in. (0.076 mm) depth | Replace sensor |
| Sensor housing | Contact marks | Replace sensor |