What was found
TRAILING EDGE FLAP SYSTEM EICAS MESSAGE, FLAP/SLAT ELEC DISPLAYED. EMERGENCY DECLARED, DURING DESCENT EXTENDING THE FLAPS FROM 20 TO 25 AT APPROXIMATELY 180 KTS. BITE CHECKED ALL 3 FSEU AND ONLY NOTED FAULT ON FSEU NR 1 WHICH SHOWED FLA FAIL. BITE. ACCOMPLISHED IAW FIM AND FOUND TO OPERATE NORMALLY AT ALL FLAP SETTING INCLUDING FLAP LOAD RELIEF FUNCTIONS. FIM 27-51-00-815-810 FIG .107. REPLACED FSEU NR 1 AS A PRECAUTION IAW MM 27-51-01. BITE TEST FUNCTIONS CHECKED GOOD AND FLAP OPERATIONS CHECKED GOOD.