Service difficulty report · Proximity Sensor · Boeing 737824

Difficulty date
February 7, 2024
Submitted
February 12, 2024
Operation
Air carrier
Aircraft
N34222
Make and model
Boeing 737824
Aircraft serial
28931
Aircraft time
77,265 hours, 28,323 cycles
Part
Proximity Sensor
Part number
189929
Condition
Failed
Location
Le Flap,#4
Stage of operation
TX
How discovered
O
Nature of condition
F, J
Precautionary procedure
D, O

As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.

What was found

E FLAPS TRANSIT LIGHT ILLUMINATED WITH FLAPS POSITION FOR TO *DM* PLEASE UPDATE WITH DETAIL WHICH LEADING EDGE FLAP 1-4 OR ALL. THANKS DM. SUSPECT ISSUE TO BE INTERMITTENT. REQ MEL. COMPLIED WITH MEL. REMOVED BULBS FROM LE TRANSIT ANNUNCIATOR. PLACARDS INSTALLED. LEADING EDGE FLAP AMBER LIGHT SYSTEM INOPERATIVE. MEL 2704B APPLIED. PERFORMED FSEU BITE TEST FOUND F4 PROXY RETRACT FAULT, MSG #27-81222, IPER FIM 27-88 TASK 805. CHECKED THE GAPS VALUES ARE NORMAL. INSPECTED PROXIMITY SENSORS UNIT AND ITS WIRING CONNECTION, ALL LOOKS IN NORMAL STATE/ CONDITION. NEXT STEP CHECK THE WIRING ON THE PROXIMITY SENSOR TO THE FSEU USING THE BREAK OUT BOX. TOOL NOT IN STOCK IN SAN. RE-ACTIVATED L/E FLAP IND SYSTEM, SEE LP FOR 7033175 FOR #4 LE FLAP RETRACT SNSR S174 REPLACEMENT AND OPS CHK. REFERENCE 7017027 , SUSPECT FAILED SENSOR COULD CAUSE TAKEOFF WARNING WHEN THROTTLES ARE ADVANCED. PLEASE REPLACE PRIOR TO DISPATCH UPDATE- RPLCD #4 L/E FLAP RETRACT SENSOR S174 AS REF''D IN ABOVE AMM REMOVED AND REPLACED LEADING EDGE FLAP PROX SENSOR #4 REF AMM 27-88-11-400-802 . ALL OPS TEST GOOD