What was found
CREW REPORTS THE FLAPS WOULD NOT EXTEND PAST 5 DEGREES. ON APPROACH, WHEN FLAPS WERE EXTENDED TO 25, FLAP INDICATOR NEVER MOVED PAST 10. CREW RECYCLED FLAPS AND THEY INDICATED NORMAL. FLIGHT LANDED WITHOUT FURTHER INCIDENT. MX INSPECTED TRAILING EDGE FLAPS AND FOUND EROSION DAMAGE FROM SEAL CONTACT ON NR 4 MIDFLAP L/E, I/B SIDE, RT SIDE. RIGHT OUTBOARD MIDFLAP, I/B SIDE LOWER TRAILING EDGE SKIN HAS A GOUGE 2 3/8' LENGTH X 1/2" WIDE X .062" DEEP. REMOVED DAMAGE AND INSTALLED DOUBLER PER SRM 57-53-01-2R-8 AND SRM 51-40-02. ACCOMPLISHED SATISFACTORY TEST FLIGHT. AIRCRAFT OK FOR SERVICE.