B757-200
Flight Crew Air Transport Pilot (ATP)
Aircraft Equipment Problem Critical
General Declared Emergency
Aircraft
When selecting Flaps 1 on approach to ZZZ the LE SLAT DISAGREE message appeared. The flap indicator showed less than Flaps 1. We asked Approach Control for delaying vectors or a hold; so that we could do the checklists. We followed the QRH procedures which led us to a Flap 20 landing with a VREF of VREF 30 + 30 KTS. Due to this high speed landing I declared an emergency. We finished the LE SLAR ASYM checklist and the non-normal landing procedures and continued the approach. Landing was normal and passengers were debriefed as to the delay and the emergency vehicles. There had been two previous write-ups in the logbook for this aircraft for the same issue. The aircraft had been flown about 8 flights since the last repair for this issue; with no problems.
Upon approach into ZZZ; at 3;000 FT; and 210 KTS; [I] called for Flaps 1. Flap position indicator stopped prior to Flaps 1 and EICAS message 'LE Slat Disagree' annunciated. We went into a holding pattern; accomplished QRH procedures; declared an emergency and landed with Flaps 20 VREF 30 + 52030. Uneventful landing.
The pilots of a B757 experienced a Lead Edge Slat Disagree problem on approach. After performing the associated checklist; they completed a successful landing.