As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING FLAP EXTENSION NR 4 KRUEGER FLAP FAILED TO EXTEND. COMPLETED ABNORMAL PROCEDURE AND LANDED. AFTER LANDING NR 4 KRUEGER FLAP SHOWED EXTENDED. PERFORMED OPERATIONAL AND LEAK CHECK ON KRUEGER FLAP SYSTEM, OPS CHECK GOOD. NO LEAKS DETECTED IAW B727 27-81-00.