SDR NACA2025020200002

Service difficulty report · Keelbeam · Boeing 737301

Difficulty date: February 2, 2025
Submitted: February 7, 2025
Operation: Air carrier
Aircraft: N360WA
Make and model: Boeing 737301
Aircraft serial: 23553
Aircraft time: 65,274 hours, 55,408 cycles
System (JASC): 5314 · Fuselage Main, Keel
Part: Keelbeam
Condition: Corroded
Location: Zone 100
Stage of operation: IN
How discovered: V
Nature of condition: O
Precautionary procedure: K

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

What was found

WHILE PERFORMING N360WA SERVICE CHECK, CORROSION WAS FOUND ON THE KEEL BEAM LOWER CHORD AT BS 540, LBBL 6.50. FOLLOWING CORROSION REMOVAL, IT WAS DETERMINED THAT THE BLENDOUT EXCEEDED THE 737-300 BOEING SRM 53-60-12 ALLOWABLE LIMITS. AAC ENGINEERING CONTACTED ASAP INC. TO REQUEST A REPAIR PLAN. AN ALTERNATE REPAIR WAS PROVIDED FROM THAT OF BOEING SRM 53-60-12, REPAIR 3 - KEEL BEAM SPLICE. CORROSION REMOVED AND REPAIRED IAW NAC EO 737-53-0369.