A B767-300 crew reported a le slat asym EICAS alert on final as flaps 20 were selected. A go-around ...

Narrative:

During descent for runway 31; the captain called for flaps 20 and landing gear down. At flaps 20; we received a le slat asym amber alert and associated EICAS message. We performed a missed approach; raised the landing gear and were transferred to approach. The captain was flying and the first officer accomplished the appropriate checklist. Once the checklist was complete; we returned for approach. An emergency was declared. We landed uneventfully with flaps 20 and vref 30+30 as per QRH. Landing was soft; rollout normal. The captain then taxied the aircraft to the gate with the flaps/slats in the 20 position. The aircraft had experienced the same problem the previous day.

Original NASA ASRS Text

Title: A B767-300 crew reported a LE SLAT ASYM EICAS alert on final as flaps 20 were selected. A go-around was initiated; an emergency declared and after the checklist was completed; a normal landing accomplished. This same anomaly occurred during the previous night's landing.

Narrative: During descent for Runway 31; the Captain called for flaps 20 and landing gear down. At flaps 20; we received a LE SLAT ASYM amber alert and associated EICAS message. We performed a missed approach; raised the landing gear and were transferred to Approach. The Captain was flying and the First Officer accomplished the appropriate checklist. Once the checklist was complete; we returned for approach. An emergency was declared. We landed uneventfully with flaps 20 and Vref 30+30 as per QRH. Landing was soft; rollout normal. The Captain then taxied the aircraft to the gate with the flaps/slats in the 20 position. The aircraft had experienced the same problem the previous day.

Data retrieved from NASA's ASRS site as of April 2012 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.

Attributes
ACN	874924
Time
Date	201002
Local Time Of Day	1201-1800
Place
Locale Reference	ZZZ.ARTCC
State Reference	US
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	B767-300 and 300 ER
Operating Under FAR Part	Part 121
Flight Phase	Final Approach
Route In Use	Visual Approach
Flight Plan	IFR
Component
Aircraft Component	Leading Edge Slat
Person 1
Function	Pilot Not Flying First Officer
Person 2
Function	Captain Pilot Flying
Events
Anomaly	Aircraft Equipment Problem Critical

A B767-300 crew reported a le slat asym EICAS alert on final as flaps 20 were selected. A go-around was initiated; an emergency declared and after the checklist was completed; a normal landing accomplished. This same anomaly occurred during the previous night's landing.