SDR AALA202508056094

Service difficulty report · Tube · Boeing 737823

Difficulty date: August 4, 2025
Submitted: August 5, 2025
Operation: Air carrier
Aircraft: N867NN
Make and model: Boeing 737823
Aircraft serial: 40762
Aircraft time: 42,152 hours, 17,974 cycles
System (JASC): 4990 · APU Oil System
Part: Tube
Condition: Leaking
Location: Zone 200
Stage of operation: DE
How discovered: V
Nature of condition: B
Precautionary procedure: K

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

What was found

AIRCRAFT WAS GROUNDED: FUME EVENT STRONG CHEMICAL SMELL (SMELLS LIKE FERTILIZER) ON DESCENT AND THEN AGAIN ON THE GROUND WITH THE HIGH PRESSURE CART ATTACHED AND THE PACKS SELECTED ON. VERIFIED ENGINE OIL LEAKING OUT OF APU DRAIN MAST. VERIFIED ENGINE OIL LEAKING OUT OF APU DRAIN MAST. REMOVE AND REPLACED AFT BEARING OIL RETURN TUBE. OPERATIONAL LEAK CHECK GOOD. REF CMM 49-26-95.