SDR AALA202003019001

Service difficulty report · Sensor · Boeing 737823

Difficulty date: February 28, 2020
Submitted: March 1, 2020
Operation: Air carrier
Aircraft: N957AN
Make and model: Boeing 737823
Aircraft serial: 29541
Aircraft time: 55,885 hours, 23,332 cycles
System (JASC): 2781 · Leading Edge Slat Position Indicating System
Part: Sensor
Condition: Intermittent
Location: Le Slat
Stage of operation: AP
How discovered: O
Nature of condition: F, N
Precautionary procedure: O

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

What was found

AIRCRAFT WAS GROUNDED: DURING APP WITH FLAPS SELECTED TO 1. LEADING EDGE FLAP TRANSIT LIGHT ILLUMINATED. NO.3 L.E. FLAP DID NOT DEPLOY. SAME WHEN SELECTED TO 5. DEPLOYED ON ITS OWN A SHORT TIME LATER. DEBRIEF WITH CREW STATED THAT IT MAY HAVE BEEN NO.4 L.E. FLAP AND NOT NO. 3. FSEU FAULT CODE OF 27-81223 AND PRIOR HISTORY BOTH POINT AT NO. 4 L.E. FLAP EXTEND SENSOR S175. REPLACED NO. 4 SENSOR. OPER TEST OF NO. 4 AND 3 L.E. FLAP EXTEND SENSORS NORMAL IAW MM 27-88-11.